CaRLa Winter School 2011 Heidelbergcarla-hd.de/wp-content/uploads/2018/02/Abstract... · Homogeneous Gold Catalysis A. Stephen K. Hashmi 10:30 Coffee Break 11:00 Training Session

CaRLa Winter School 2011 Heidelberg

March 5-11, 2011

Final Program

Welcome to the 4th CaRLa Winter School

Welcome to the picturesque town of Heidelberg, welcome to CaRLa, the joint Catalysis Research Laboratory of BASF and the University of Heidelberg and welcome to our fourth CaRLa Winter School on Homogeneous Catalysis!

With our Winter School, we aim to foster intense scientific exchange between established and young researchers in the field of homogeneous catalysis.

The conference takes place from March 5-11, 2011 at the German-American-Institute downtown Heidelberg, within walking distance to the old town.

Our scientific program consists of 1 Keynote Lecture, 10 lectures, 10 problem set sessions and poster presentations.

The days are organized as a morning and afternoon session. Each session is divided into two parts; the first part consists of a scientific lecture while the second part has a more educational focus. Between the two sessions of the day, we have scheduled a prolonged lunch break for individual use. In the evening, we have planned short poster presentations of selected poster contributions, after which a light dinner is served in parallel with the poster sessions.

All presentations are scheduled to leave enough room for discussion and we encourage every participant to use this time to make our Winter School an exciting event for science.

The conference is fully sponsored by BASF and we are happy to announce, that we will have the opportunity for making an excursion to BASF on Thursday afternoon.

We hope that all participants will have a pleasant and scientifically stimulating stay in Heidelberg during our Winter School.

If we can assist you in any way to make your stay in Heidelberg more pleasant, please do not hesitate to contact us.

Michael Limbach Peter Hofmann

1

2

Prog

ram

m o

f the

CaR

La W

inte

r Sch

ool -

Ove

rvie

w

All S

essi

ons

take

pla

ce in

the

Ger

man

-Am

eric

an-In

stitu

te H

eide

lber

g

Satu

rday

, 05.

03.2

011

Sund

ay, 0

6.03

.201

1M

onda

y, 0

7.03

.201

1Tu

esda

y, 0

8.03

.201

1W

edne

sday

, 09.

03.2

011

Thur

sday

, 10.

03.2

011

Frid

ay, 1

1.03

.201

109

:00

- 10:

30D

unca

n W

ass

(Lec

ture

), C

hrom

ium

-cat

alys

ed

Ole

fin T

rimer

isat

ion

– Br

eaki

ng th

e R

ules

in

Ole

fin O

ligom

eris

atio

n

Bern

hard

Hau

er

(Lec

ture

), Fr

om

Bio

cata

lysi

s to

Syn

thet

ic

Bio

logy

Karo

l Gre

la (L

ectu

re),

Mot

ivat

iona

l Too

ls in

C

halle

ngin

g O

lefin

M

etat

hesi

s R

eact

ions

Her

bert

Plen

io (L

ectu

re),

N-H

eter

ocyc

lic C

arbe

ne

Liga

nds

and

Ole

fin

Met

athe

sis

Ret

o D

orta

(Lec

ture

), N

ew C

arbo

n- a

nd

Sulfu

r-Ba

sed

Liga

nds

in L

ate-

Tran

sitio

n M

etal

C

atal

ysis

A. S

teph

en K

. Has

hmi

(Lec

ture

), H

omog

eneo

us G

old

Cat

alys

is

10:3

0 - 1

1:00

Cof

fee

Brea

kC

offe

e Br

eak

Cof

fee

Brea

kC

offe

e Br

eak

Cof

fee

Brea

kC

offe

e Br

eak

11:0

0 - 1

2:00

12:0

0 - 1

4:30

Free

Tim

e (L

unch

)Fr

ee T

ime

(Lun

ch)

Free

Tim

e (L

unch

)Fr

ee T

ime

(Lun

ch)

Free

Tim

e (L

unch

)Po

ster

Priz

e C

erem

ony

Clo

sing

Rem

arks

14:3

0 - 1

6:00

Cla

rk L

andi

s (L

ectu

re),

Cat

alys

ts fo

r En

antio

sele

ctiv

e H

ydro

form

ylat

ion:

Sy

nthe

sis,

App

licat

ion,

an

d M

echa

nism

John

M. B

row

n (L

ectu

re),

H-H

and

C-H

Act

ivat

ion;

A

ppro

achi

ng C

atal

ysis

vi

a M

echa

nism

Sieg

fried

Ble

cher

t (L

ectu

re),

Ster

eoco

ntro

lled

Met

athe

sis

Rea

ctio

ns

Luka

s G

ooße

n (L

ectu

re),

New

Con

cept

s fo

r C

atal

ytic

C-C

-Bon

d Fo

rmat

ion

Excu

rsio

n BA

SFD

epar

ture

16:0

0 - 1

6:30

until

16:

00 A

rriv

alC

offe

e Br

eak

Cof

fee

Brea

kC

offe

e Br

eak

Cof

fee

Brea

k

16:3

0 - 1

7:30

16:3

0 Be

rnha

rd E

itel ,

Rec

tor o

f R

upre

cht K

arls

Uni

vers

ity H

eide

lber

g,

Wel

com

e Ad

dres

s

17:0

0 - 1

8:30

Frie

dhel

m B

alke

nhoh

l (K

ey N

ote

Lect

ure)

, Raw

Mat

eria

l C

hang

e in

the

Che

mic

al In

dust

ry

17:3

0 - 2

2:00

Post

er S

essi

onPo

ster

Ses

sion

Post

er S

essi

onPo

ster

Ses

sion

Lig

ht D

inne

r L

ight

Din

ner

Lig

ht D

inne

r L

ight

Din

ner

from

18:

30 L

ight

Din

ner/G

et T

oget

her

Sym

posi

um D

inne

r

Ret

o D

orta

(Tra

inin

g-Se

ssio

n), N

ew C

arbo

n-

and

Sul

fur-

Base

d Li

gand

s in

Lat

e-Tr

ansi

tion

Met

al

Cat

alys

is

John

M. B

row

n (T

rain

ing-

Ses

sion

), H

-H a

nd C

-H

Act

ivat

ion;

App

roac

hing

C

atal

ysis

via

Mec

hani

sm

Sieg

fried

Ble

cher

t (T

rain

ing

Sess

ion)

, R

uthe

nium

-Cat

alyz

ed

Tand

em R

eact

ions

In

clud

ing

Ole

fin

Met

athe

sis

Dun

can

Was

s (T

rain

ing-

Sess

ion)

, Fro

m

Dis

cove

ry to

Pro

duct

ion

– A

Cas

e S

tudy

of

Poly

olef

in C

atal

yst

Com

mer

cial

isat

ion

Bern

hard

Hau

er (T

rain

ing-

Ses

sion

), S

ynth

etic

B

iolo

gy

Karo

l Gre

la (T

rain

ing

Sess

ion)

, Mak

ing

Met

athe

sis

Wor

ks

Cla

rk L

andi

s (T

rain

ing-

Sess

ion)

, Dire

ct

Obs

erva

tion

of

Prop

agat

ing

Spec

ies

in

Cat

alys

is: M

etal

loce

ne-

Cat

alyz

ed A

lken

e Po

lym

eriz

atio

n

A St

ephe

n K.

Has

hmi

(Tra

inin

g-Se

ssio

n), G

old

Cat

alys

is: M

echa

nism

ve

rsus

Ret

rosy

nthe

sis

Her

bert

Plen

io (T

rain

ing-

Sess

ion)

, The

Cra

dle

and

the

Gra

ve -

befo

re a

nd

afte

r Ole

fin M

etat

hesi

s

Luka

s G

ooße

n (T

rain

ing-

Sess

ion)

, New

Con

cept

s fo

r Cat

alyt

ic C

-C-B

ond

Form

atio

n

3

Saturday, 5th March

until 16:00 Arrival 16:30 Welcome Address Prof. Dr. Bernhard Eitel

Rector of Ruprecht Karls University in Heidelberg

17:00 Key Note Lecture “Raw Material Change in the Chemical Industry” Friedhelm Balkenhohl, BASF SE

18:30 Snacks and “Get-together”

4

Sunday, 6th March 9:00 Lecture

Chromium-catalysed Olefin Trimerisation –

Breaking the Rules in Olefin Oligomerisation Duncan Wass

10:30 Coffee Break

11:00 Training Session

From Discovery to Production – A Case Study

of Polyolefin Catalyst Commercialisation Duncan Wass

12:00 Lunch Break

14:30 Lecture

Catalysts for Enantioselective Hydroformylation:

Synthesis, Application, and Mechanism Clark Landis

16:00 Coffee Break


Direct Observation of Propagating Species in Catalysis:

Metallocene-Catalyzed Alkene Polymerization Clark Landis

17:30 Poster Presentation

18:00 Poster Session including light dinner All

5

Monday, 7th March 9:00 Lecture

From Biocatalysis to Synthetic Biology Bernhard Hauer

10:30 Coffee Break


Synthetic Biology Bernhard Hauer

12:00 Lunch Break

14:30 Lecture

H-H and C-H Activation;

Approaching Catalysis via Mechanism John M. Brown

16:00 Coffee Break


H-H and C-H Activation;

Approaching Catalysis via Mechanism John M. Brown



6

Tuesday, 8th March 9:00 Lecture

Motivational Tools in Challenging

Olefin Metathesis Reactions Karol Grela

10:30 Coffee Break


Making Metathesis Works Karol Grela

12:00 Lunch Break

14:30 Lecture

Stereocontrolled Metathesis Reactions Siegfried Blechert

16:00 Coffee Break


Ruthenium-Catalyzed Tandem Reactions

Including Olefin Metathesis Siegfried Blechert



7

Wednesday, 9th March 9:00 Lecture

N-Heterocyclic Carbene Ligands and

Olefin Metathesis Herbert Plenio

10:30 Coffee Break


The Cradle and the Grave -

before and after Olefin Metathesis Herbert Plenio

12:00 Lunch Break

14:30 Lecture

New Concepts for Catalytic

C-C-Bond Formation Lukas Gooßen

16:00 Coffee Break


New Concepts for Catalytic

C-C-Bond Formation Lukas Gooßen



8

Thursday, 10th March 9:00 Lecture

New Carbon- and Sulfur-Based Ligands in

Late-Transition Metal Catalysis Reto Dorta

10:30 Coffee Break


New Carbon- and Sulfur-Based Ligands in

Late-Transition Metal Catalysis Reto Dorta

12:00 Lunch Break

13:15 Transfer to Ludwigshafen All

14:00 Excursion of BASF’s Main Site in Ludwigshafen All

19:00 Winter School Dinner in “Kulturbrauerei” All

9

Friday, 11th March 9:30 Lecture

Homogeneous Gold Catalysis A. Stephen K. Hashmi

10:30 Coffee Break


Gold Catalysis: Mechanism versus Retrosynthesis A. Stephen K. Hashmi

12:00 Poster Prize Ceremony

12:15 Closing Remarks

14:00 Departure

10

Lectures & Training Sessions

11

Raw Material Change in the Chemical Industry Friedhelm Balkenhohl*

BASF SE, GCB – M313, 67056 Ludwigshafen, Germany e-mail: [email protected]

At each time availability and price structure of the fossil raw materials coal,

petroleum and natural gas have significantly influenced the technological basis and consequently the buildup and development of the chemical industry. In the energy industry a consistent raw material change from coal to oil and gas has occurred since the middle of the 20th Century. The reason for this change lies mainly in the simpler logistics as well as the versatile usefulness of oil and gas. Parallel to the change in the energy industry the raw material base of the chemical industry has been changed from coal to oil and gas. Olefins, which are produced mainly by steam cracking of naphtha, and aromatic hydrocarbons, are still the crucial raw materials for the majority of the value added chains of the chemical industry. Price volatility, regional distribution and the finite reserves of crude oil are the main drivers for the development of conversion technologies to utilize alternative raw materials, e.g. natural gas, coal, renewables and carbon dioxide as feedstocks for the chemical industry.

12

Stereocontrolled Metathesis Reactions Siegfried Blechert*

TU Berlin – Berlin Institute of Technology, Institute of Chemistry, Str. d. 17. Juni 115, 10623 Berlin, Germany

e-mail: [email protected]

Alkene metathesis is one of the most valuable tools in organic synthesis. These days many different catalysts with high tolerance of functional groups are available. However there are still remaining problems and further developments are eligible.

Stereocontrol is an important feature. Stereocontrolled olefin metathesis reactions include the E/Z-problem as well as the creation of new stereocentres.

The lecture is focusing on the second aspect. Stereocontrol is possible by two different concepts, diastereoselective reactions or enantioselective metathesis.

Among the different types of metathesis reactions ring-rearrangement metathesis (RRM) has proven to be powerful concept. It has used in many natural product synthesis. We have extended the principle by a diastereoselective RRM using the ring opening metathesis of pro-chiral cycloolefins.

I will present recent results of d-RRM and its application in natural product synthesis as well as new chiral Ru-catalyst for enantioselective metathesis.

13

Ruthenium-Catalyzed Tandem Reactions including Olefin Metathesis Siegfried Blechert*

TU Berlin – Berlin Institute of Technology, Institute of Chemistry, Str. d. 17. Juni 115, 10623 Berlin, Germany


The different olefin metathesis reactions like CM, ROM, RCM or RRM have been intensively used in organic synthesis.

Besides, non metathetic reactions promoted by ruthenium complexes have been observed. Side reactions due to special reaction conditions could be optimized to a second or third useful catalytic transformation, thus allowing tandem reactions.

In the seminar we will discuss in situ modifications of Ru-metathesis catalysts and their use in tandem processes.

14

H-H and C-H Activation; Approaching Catalysis via Mechanism John M. Brown*

Chemistry Research Laboratory, University of Oxford, 12 Mansfield Rd., Oxford OX1 3TA, UK


Progress in the development of multistep catalytic reactions is greatly facilitated

by an understanding of the mechanism. This includes identification of the turnover-limiting step(s) so that reactivity and selectivity can be managed as desired. The lectures will first assess and exemplify the general principles that underpin mechanistic studies of catalysis, and then apply these in real situations, with specific case analyses. The first session will cover formal hydrogenations (and the reverse reaction, dehydrogenations). The ability to intercept key intermediates and divert the catalytic process has important synthetic consequences.

The second session will cover C-H activation, a relative newcomer insofar as synthetic utility is concerned, but now assimilated into the general framework of basic catalytic transformations.

15

New Carbon- and Sulfur-Based Ligands in Late-Transition Metal Catalysis Ronaldo Mariz,a Xinjun Luan,a Michele Gatti,a Emma Drinkel,a Justus J. Bürgi,a Linglin

Wu,a Fiona Gaggia,a Sascha Blumentritt,a Anthony Linden,a Chiara Costabile,b Luigi Cavallo,b Albert Poater,c Reto Dortaa*

aOrganisch-chemisches Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland; bDipartimento di Chimica, Università degli Studi di Salerno, Via Ponte don Melillo,

Fisciano (SA), I-84084, Italy; cCatalan Institute for Water Research (ICRA), H2O Building, University of Girona, Emili Grahit 101, E-17003 Girona, Spain


New alternatives to known, monodentate N-Heterocyclic carbene ligands are presented that rely on N-naphthyl substituted side chains. These ligands are then used in both ruthenium-catalyzed ring-closing metathesis reactions and various palladium-catalyzed transformations. First results on chiral NHC ligand derivatives based on the same design will be discussed.

In a second part, we present a family of chiral C2-symmetric disulfoxide ligands. Results in the asymmetric, rhodium-catalyzed 1,4-addition reaction are presented in detail and newer results on other transformations might be presented.

16

New Concepts for Catalytic C-C-Bond Formation L. J. Gooßen,* N. Rodríguez, P. P. Lange, B. Song, F. Manjolinho, T. Knauber

Institut für Organische Chemie, TU Kaiserslautern, Erwin-Schrödinger-Straße, 67663 Kaiserslautern, Germany

e-mail: [email protected] In the presence of a Cu/Pd catalyst system, a broad range of aromatic

carboxylates, �-oxo-carboxylates, and �-imino-carboxylates were coupled under extrusion of CO2 with various carbon electrophiles such as aryl and heteroaryl halides, triflates, and tosylates.[1] Over the last years, decarboxylative cross-couplings have proven to be an efficient and broadly applicable concept for catalytic C-C bond formation.

X

CO2K Y

R

R CO2K

YR2

R1R2

R1

R1

-CO2Pd/Cu cat.� or �W

NMP/quinoline� or �W

NMP/quinoline

-CO2Pd/Cu cat.

X = Br, Cl, OTf, OTs Y = O, NR2

Not only do the newly found Cu-catalysts facilitate the extrusion of CO2, but also its insertion. This was exploited in a catalytic carboxylation of terminal alkynes under C-H activation.[2] Moreover, they were found to effectively mediate the trifluoromethylation of aryl iodides under mild, base-free conditions. In this context, potassium (trifluoromethyl)trimethoxyborate was introduced as a crystalline, shelf-stable and easy-to-handle trifluoromethylation reagent.[3]

OH

O

R

N

N

Ph

Ph

R

I: R1= C6H5X: R1= p-F-C6H4

CO2, Cs2CO3, 35-50 °C, DMF

NO3Cu(PR13)2

R= alkyl, aryl, heteroaryl

CF3 BOMe

OMeOMe

K+

I

Cu cat.DMSO, 60 °C

FG

CF3FG

R1 R2

O

R1 R2

OH

CF3THF, 60 °C

[1] L. J. Gooßen, G. Deng, L. M. Levy, Science 2006, 313, 662; L. J. Gooßen, B. Zimmermann, T.

Knauber, Angew. Chem. 2008, 120, 7211; L. J Gooßen, N. Rodriguez, C. Linder, J. Am. Chem. Soc. 2008, 130, 15248; L. J. Gooßen, N. Rodríguez, P. P. Lange, C. Linder, Angew. Chem. 2010, 122, 1129; F. Rudolphi, B. Song, L. J. Gooßen, Adv. Synth. Catal. 2011, in print.

[2] L J. Gooßen, N. Rodríguez, F. Manjolinho, P. P. Lange, Adv. Synth. Catal. 2010, 352, 2913. [3] L. J. Gooßen, T. Knauber, F. Arikan, G.-V. Röschenthaler, Chem. Eur. J. 2011, DOI:

10.1002/chem.201002749.

17

Motivational Tools in Challenging Olefin Metathesis Reactions Karol Grelaa,b*

aInstitute of Organic Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224, Warsaw, Poland; bOrganometallic Synhesis Laboratory, Faculty of Chemistry, University of Warsaw, Pasteura

1, 02-093, Warsaw, Poland e-mail: [email protected]

Ruthenium-catalyzed olefin metathesis reactions represent an attractive and

powerful transformation for the formation of new carbon-carbon double bonds.[1] This area is now quite familiar to most chemists as numerous catalysts are available that enable a plethora of olefin metathesis reactions.[2] However, some transformations, such as formations of substituted double bonds, formations of strained rings, low-temperature metathesis, etc. still remain challenging.[3] This limitation can be solved by designing new more active catalysts[4] or searching for new reaction conditions.[5]

O

ClRu

Cl

N N

NO2

O O

NH NSO

N S

NH

O

C6H13 S

O

O O

NH NSO

N S

NH

O

S

O

4 equiv

cat. (15 mol%)1,2-dichloroethane

90 oCLargazole [Ref. 3]

75%

catalyst:

yield:

O

ClRu

Cl

N N

13%

O

ClRu

Cl

N N

44% During the lecture examples representative for both of the above mentioned

strategies will be given.[4],[5],[6]

[1] A. H. Hoveyda, A. R. Zhugralin, Nature, 2007, 450, 243. [2] A. Thayer, Chemical & Engineering News 2007, 85 (07), 37. [3] T. Seiser, F. Kamena, N. Cramer, Angew. Chem. Int. Ed. 2008, 47, 6483. [4] K. Grela, S. Harutyunyan, A. Michrowska, Angew. Chem. Int. Ed. 2002, 41, 4038. [5] R. Kadyrov, M. Bieniek, K. Grela, DE Patent Application 102007018148.7, April 11, 2007. [6] C. Samoj�owicz, M. Bieniek, A. Zarecki, R. Kadyrov, K. Grela, Chem. Commun. 2008, 6282.

18

Making Metathesis Works Karol Grelaa,b*

aInstitute of Organic Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224, Warsaw,

Poland; bOrganometallic Synhesis Laboratory, Faculty of Chemistry, University of Warsaw, Pasteura

1, 02-093, Warsaw, Poland


Currently, olefin metathesis is one of the most intensively studied transformations

in synthetic organic chemistry. During the Training Session a number of representative examples will be analyzed. It’s quite surprising that while this transformation has been use in laboratory scale syntheses of thousands of natural and biologically active compounds, it is not entering commercial pharmaceutical manufacturing. This could be caused by a variety of reasons, during the Session we will try to list some of them.

19

Homogeneous Gold Catalysis A. Stephen K. Hashmi*

Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer

Feld 270, 69120 Heidelberg, Germany


Homogeneous gold catalysis has emerged to a powerful synthetic tool

and now represents a hot spot of catalysis research.[1] The presentation will cover subjects like ligand and catalyst preparation, methodology and mechanistic studies.

Examples are show below.

P

R

R

R = Me or OMe

P

R

RAu

Tf2N

1. (tht)AuCl, CH2Cl230 min, r.t.

2. AgNTf2, CH2Cl230 min, r.t.

NH

Ph

O

X

Ph NO

X(IPr)AuOTs

DCM, rt, 16 h

[1] A. S. K. Hashmi, M. Bührle, Aldrichimica Acta 2010, 43, 27-33. A. S. K. Hashmi,

Angew. Chem. 2010, 122, 5360-5369; Angew. Chem. Int. Ed. 2010, 49, 5232-5241.

20

Gold Catalysis: Mechanism versus Retrosynthesis A. Stephen K. Hashmi*

Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270,

69120 Heidelberg, Germany


The complex transformations, often forming several new bonds and breaking

several bonds, have made homogeneous gold catalysis a challenge for retrosynthetic analysis. Not always the mechanistic insights, which were gained in troublesome work, are helpful in this context. An example for non-trivial retrosynthetic disconnection is the compound shown below.

O

OH

H

Examples of different targets and possible mechanisms as well as retrosynthetic disconnections will be discussed and links to synthetic targets be shown.[1]

[1] A. S. K. Hashmi, M. Rudolph, Chem. Soc. Rev. 2008, 37, 1766-1775.

21

From Biocatalysis to Synthetic Biology Bernhard Hauer*

Institute of Technical Biochemistry, Allmandring 31, 70569 Stuttgart, Germany e-mail: [email protected]

Biocatalysis is an established technology to manufacture speciality chemicals like

enantiomerically pure building blocks for pharmaceutical active compounds. Enzymes like lipases, nitrilases, oxynitrilases or oxidoreductases are efficient biocatalysts used in numerous processes. However the potential of enzymes for synthetic applications is by far not exploited. To expand the scope of technical enzymes for organic synthesis we study enzymes like monooxagenases and develop enzymes with novel functions to catalyze C-C ligation reactions. In my lecture I will discuss selected examples.

Selectively hydroxylated hydrocarbons are of great interest in the chemical industry, due to their role as intermediates for the synthesis of bulk and fine chemicals. The selective terminal hydroxylation of alkanes is still problematic and there is to date no efficient chemical strategy to direct the introduction of hydroxyl groups on primary non-activated C-H bonds. Cytochrome P450 monooxygenases CYP153 enzymes are such enzymes catalyzing the terminal hydroxylation of aliphatic, alicyclic and alkyl-substituted compounds with high regio- and stereoselectivity under mild reaction conditions. Two CYP153A enzymes were cloned and expressed in Escherichia coli. The activity of each P450 was reconstituted with artificial electron transfer partners. The CYP153A enzymes were assayed in vitro with purified proteins using C5-C12 n-alkanes and C6-C12 primary alcohols as substrates.

C-C ligation reactions are another important reaction for organic syntheses. We characterized a novel cyclase from the gram-negative, alcohol producing bacterium Zymomonas mobilis (ZmSHC1) and compared its activity and substrate spectrum with another, previously described squalene-hopene cyclase (ZmSHC2) from the same organism. In order to do this, we optimized a protocol for the expression of these enzymes in Escherichia coli and the conditions for the enzymatic reaction. Subsequently, we determined the enzymatic activity of ZmSHC1 with a variety of substrates including citronellal, homofarnesol and squalene.

Despite the differences in chain length (C10-C30) and the presence of C=C double bounds or functional groups like aldehydes at the position where protonation needs to occur for the initiation of the reaction, conversion could be found for all of these substrates. Beside the conversion of squalene to hopene, the cyclization of

22

homofarnesol to ambroxan and citronellal to isopulegol is of particular interest, as these compounds are commonly used in the manufacturing of fragrance and flavour concentrates or could provide a bio-catalytic access for the production of menthol, respectively. From these results, we conclude that the squalene-hopene cyclase ZmSHC1 from Z. mobilis has a high bio-catalytic potential for a large variety of industrial applications.

Our goal is to move towards a synthetic biology. We will combine several enzymes in cascade like reactions or by establishing novel pathways to synthesize chemicals in one technical step.

23

Catalysts for Enantioselective Hydroformylation: Synthesis, Application, and Mechanism

Clark Landis* Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison 53706 WI,

USA e-mail: [email protected]

Critical attributes of green chemical processes include high atom economy, catalytic

use of expensive reagents, selectivity, building complexity from simplicity, and simple separations. Enantioselective hydroformylation - by which enantiopure transition metal complexes selectively catalyze the conversion of simple alkenes, dihydrogen, and carbon monoxide into chiral aldehydes - possesses many of these attributes. Our construction of practical catalysts for enantioselective hydroformylation incorporates computer modeling, development of new organophosphorous chemistry, and strategies for making diverse collections in order to produce a new class of ligand, 3,4-diazaphospholanes. Catalysts based on rhodium complexes of 3,4-diazaphospholanes are highly active and selective for the hydroformylation of simple alkenes such as allyl ethers, vinyl acetates, vinyl enamides, aryl alkenes, and 1,3 dienes. The resulting products constitute powerful chiral building blocks, especially for the pharmaceutical industry. What is the origin of selectivity in the multistep catalytic cycle of hydroformylation? Insights arise from careful studies of gas pressure effects on rate and selectivity, the application of isotopic labels, and reaction kinetics.

OAc

Ph

CN

OAc

O

H

O

H

Ph

O

H

CN96% e.e.

87% e.e.

89% e.e.

Rh(acac)(CO)20.003 mol %

PP NNN

N

O

O

O

O

R

R R

R

L=

24

Direct Observation of Propagating Species in Catalysis: Metallocene-Catalyzed Alkene Polymerization

Clark Landis* Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison 53706

WI, USA e-mail: [email protected]

Despite enormous progress in the development and application of single-site

metallocene catalysts for alkene polymerization, several longstanding problems remain unresolved. Such problems include (1) the origin of strong co-catalyst effects on activity, stereoselectivity, and molecular weights (2) determination of the fraction of sites that are actively producing polymer and (3) the affect of monomer concentration on chain termination events. NMR exhibits high information density and simple concentration-intensity relationships that are ideal for in situ monitoring of catalyst speciation during catalysis. However, the time scale of many catalytic transformations is too fast for common NMR techniques. Stopped-flow methods enable the direct determination of critical alkene polymerization events – initiation, propagation, and termination – on the time scale of tens of milliseconds while simultaneously reporting quantitative distributions of catalyst species.

25

N-Heterocyclic Carbene Ligands and Olefin Metathesis Herbert Plenio*

Organometallic Chemistry, Inorganic Chemistry, TU Darmstadt, Petersenstr. 18, 64287 Darmstadt,

Germany


The catalytic activity of ruthenium-based catalysts for olefin metathesis reactions

is massively influenced by the nature of the NHC ligands (N-heterocyclic carbenes). Apart from the conventional �-donor/�-acceptor interactions, the NHC ligands typically employed in Grubbs type complexes seem to have additional, special donating properties, which are revealed by systematically modifying the electron donation of NHC ligands. This tuning also has an influence on the catalytic activity of the respective ruthenium complexes in olefin metathesis in a multitude of ways and enables new and efficient transformations of organic molecules, some of which will be reported.[1]

[1] M. Süßner, H. Plenio, Angew. Chem. Int. Ed. 2005, 44, 6885-6888; S. Leuthäußer, D. Schwarz, H.

Plenio, Chem. Eur. J. 2007, 13, 7195-7203; S. Leuthäußer, V. Schmidts, C. M. Thiele, H. Plenio,

Chem. Eur. J. 2008, 14, 5465-5481; H. Weychardt, H. Plenio, Organometallics 2008, 27,

1479-1485; T. Vorfalt, S. Leuthäußer, H. Plenio, Angew. Chem. Int. Ed. 2009, 48, 5191-5194; L.

H. Peeck, S. Leuthäußer, H. Plenio, Organometallics 2010, 29, 4339-4345; V. Sashuk, L. H.

Peeck, H. Plenio, Chem. Eur. J. 2010, 16, 3983-3993; L. H. Peeck, H. Plenio, Organometallics 2010, 29, 2761-2768; S. Wolf, H. Plenio, submitted for publication 2011.

26

The Cradle and the Grave - before and after Olefin Metathesis Herbert Plenio*,

Organometallic Chemistry, Inorganic Chemistry, TU Darmstadt, Petersenstr. 18, 64287 Darmstadt,

Germany


Catalyst initiation and catalyst decomposition are essential stages in the life of

catalysts. The first step leads to the formation of catalytically active species for the catalytic cycle, which enables the generation of the desired organic products. The last step characterizes the departure of the catalytically active species from the catalytic cycle and the end of the organic transformation. This talk will focus on recent observations concerning the beginning and the end of ruthenium-based olefin metathesis catalysts of the Grubbs type.

27

Chromium-Catalysed Olefin Trimerisation – Breaking the Rules in Olefin Oligomerisation Duncan Wass*

School of Chemistry, University of Bristol, Bristol BS8 1TS, UK e-mail: [email protected]

Current industrial methods for olefin oligomerisation largely rely on non-

selective catalysed processes which yield a distribution of 1-alkene products. More recently, catalysts have emerged which operate by a different mechanism and give high selectivity to only trimer products. In 2002, we reported that chromium complexes supported N,N-bis(diarylphosphino)amine (“PNP”) ligands are extremely productive and selective catalysts for ethylene trimerisation; subsequent developments have shown that careful ligand modification can also lead to unprecedented selective olefin tetramerisation. This lecture will discuss our recent results in this area, including: the development of new catalyst activation methods which avoid the need for typical activators such as methyl aluminoxane; new reactions based on this methodology, including co-trimerisation and selective isoprene trimerisation to terpenoid compounds; and an exploration of new diphosphine ligands, to both understand the key features of the PNP catalyst and discover even more active and selective systems.

28

From Discovery to Production – a Case Study of Polyolefin Catalyst Commercialisation

Duncan Wass* School of Chemistry, University of Bristol, Bristol BS8 1TS, UK

e-mail: [email protected] What does it take to discover a new polyolefin catalyst? And what is needed to

take this discovery to commercial reality? This lecture will answer these questions using the example of BP’s development of iron-based catalysts for the production of high density polyethylene. It will discuss the fundamental science of the catalysts, in terms of synthesis, performance and mechanism. However, the focus of the lecture will be how industrial needed an understanding of this chemistry to be combined with materials science, knowledge of the commercial polymers market, chemical engineering, health and safety considerations, patent law and economics. It will follow the story of these catalysts from laboratory discovery to commercial trial, examining the important factors at each stage. It will also follow this story to its conclusion and the reasons why ultimately the catalysts are not operated today.

29

30

Poster Abstracts

31

Enantioselective Organocatalytic One-pot Strategies in Target Oriented Synthesis

�ukasz Albrecht, Karl Anker Jørgensen*

Center for Catalysis, Deptartment of Chemistry, Aarhus University, Langelandsgade 140, DK-8000

Aarhus C, Denmark


Target oriented synthesis of optically active compounds occupies prominent

position in a modern organic chemistry. Asymmetric organocatalytic one-pot strategies offer a possibility to access various important molecules with a minimal number of isolation and purification protocols. Herein, we present the application of organocatalytic one-pot strategies for enantioselective dihydroxylation and aminohydroxylation of �,�-unsaturated aldehydes[1] as well as in the synthesis of aminoalkyl- and hydroxyalkyl-substituted heteroaromatic compounds relevant for the life-science industry.[2],[3]

[1] �. Albrecht, H. Jiang, G. Dickmeiss, B. Gschwend, S. G. Hansen, K. A. Jørgensen, J. Am. Chem.

Soc. 2010, 132, 9188-9196.

[2] �. Albrecht, L. K. Ransborg, B. Gschwend, K. A. Jørgensen, J. Am. Chem. Soc. 2010, 132, 17886-17893.

[3] �. Albrecht, A. Albrecht, L. K. Ransborg, K. A. Jørgensen, submitted.

32

Poster 1

Pd-catalyzed Asymmetric Fluorination Using SpanPhos Ligands Carolina Blanco,a Olivier Jacquet,a Carmen Claver,b Piet W. N. M van Leeuwena*

aInstitut Català d'Investigació Química, Avgda. Paisos Catalans 16, 43007 Tarragona, Spain bUniversitat Rovira i Virgili, Departament de Química Física i Inorgànica, C/Marcel.lí Domingo s/n

43007 Tarragona, Spain


Chiral organofluorine compounds have been widely studied because of their

importance in both pharmaceutical chemistry and materials science.[ 1 ] Chiral �-fluoro �-cyano acetate derivates have useful applications such as chiral synthetic intermediates for organic synthesis and derivatization reagents.[ 2 ] The use of C2-symmetrical bidentate systems having a SPAN backbone containing a spiro carbon as the stereogenic centre has attracted a great deal of attention over the last few years as an interesting trans-type ligand.[3] We present here a preliminary study of the catalytic activity of the SpanPhos ligands in the Pd-catalyzed fluorination reaction. High conversions and enantioselectivities up to 93% were obtained.

[1] P. Kirsch, Modern Fluoroorganic Chemistry, Wiley-VCH, Weinheim, 2004.

[2] H. R. Kim, D. Y. Kim, Tetrahedron Lett. 2005, 46, 3115-3117.

[3] Z. Freixa, P. W. N. M. van Leeuwen, Coord. Chem. Rev. 2008, 252, 1755; X. Sala, P. W. N. M.

van Leeuwen, Eur. J. Org. Chem 2008, 6197.

33

Poster 2

Synthesis of Sodium Acrylate from CO2 and Ethylene: New Insights in a Key Step of the Catalytic Cycle

Gabriella Bodizs,a Stephan A. Schunk,b Michael Limbachc* aCatalysis Research Laboratory, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany, bhte

Aktiengesellschaft, Kurpfalzring 104, 69123 Heidelberg, Germany, cBASF SE, Basic Chemicals Research, GCB/C – M313, Carl-Bosch-Strasse 38, 67056 Ludwigshafen, Germany


Sodium acrylate is the main component of superabsorbent polymers. Its direct synthesis via the oxidative coupling of CO2 and ethylene is of large industrial interest. Since the revolutionary work of Hoberg,[1] nickelalactones (1) are discussed as intermediates in a hypothetic catalytic cycle. Although the full cycle has experimentally not yet been realized, first results of Fischer[ 2 ] and DFT calculations[ 3 ] hint to the point that the most challenging step is the �-hydride elimination from 1. Recently, Rieger[4] found that methyl acrylate is readily liberated from 1 with various Lewis acids, which could be a first entry into the cycle.

Despite of extensive studies on the oxidative coupling of CO2 with various unsaturated substrates, the reaction is not well exploit with ethylene. Formation and stability of the thus derived nickelalactones are strongly dependent on the ligand at the metal center. Its influence on the oxidative coupling of CO2 and ethylene is critically discussed.

ONa

O

LnNi0

LnNiO

O

LnNiO

O

H

oxidativecoupling

ligandexchange

-hydrideelimination

reductiveelimination

CO2 +

NaOH

ONa

O

LnNi0 1

[1] H. Hoberg, Y. Peres, C. Krüger, Y. H. Tsay, Angew. Chem. Int. Ed. Engl. 1987, 26, 771-773. [2] R. Fischer, J. Langer, A. Malassa, D. Walther, H. Görls, G. Vaughan, Chem. Commun. 2006,

2510-2512. [3] D. C. Graham, C. Mitchell, M. I. Bruce, G. F. Metha, J. H. Bowie, M. A. Buntine,

Organometallics 2007, 26, 6784-6792. [4] C. Bruckmeier, M. W. Lehenmeier, R. Reichardt, S. Vagin, B. Rieger, Organometallics 2010, 29,

2199-2202.

34

Poster 3

A Set of Active Olefin Metathesis Catalysts with Extraordinary Stickiness to Silica

José Cabrera,a Jörg A. Schachner,a Robin Padilla,a Michael Limbach*a,b

aCaRLa - Catalysis Research Laboratory, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bBASF SE, Basic Chemicals Research, GCB/C - M313, 67056 Ludwigshafen, Germany


Grubbs type ruthenium complexes have found wide application in metathesis

reactions.[1] However, the development of new and especially latent catalysts for industrial applications remains a challenge. We targeted on longevity and latency, properties, which are e.g. observed for the first and second generation catalysts of former CIBA company, which is now BASF.

This goal has been achieved by replacing one phosphine with a chelating pyridinyl alcoholate ligand. We present an improved synthetic protocol to these complexes, which to a certain extent have also been described by others,[2] and compare their activity and longevity to commercially available state of the art catalyst systems in ROMP, CM, and RCM reactions. In all of the mentioned reactions there is at least one of our catalysts as potent as the state of the art catalyst.

Furthermore, the new pre-catalysts show an extraordinarily high stickiness to commercially available silica, which significantly enhances their adsorptive separation from unprocessed reaction mixtures.

[1] G. C. Vougioukalakis, R. H. Grubbs, Chem. Rev. 2010, 110, 1746.

[2] M. Jordaan, H. C. M. Vosloo, Adv. Synth. Catal. 2007, 349, 184; K. Denk, J. Fridgen, W. A.

Herrmann, Adv. Synth. Catal. 2002, 344, 666.

35

Poster 4

Hydroamination of Ethylene Catalyzed by Novel Platinum(II) N-heterocyclic Carbene Complexes

Peng Cao,a Michael Limbacha,b* aCaRLa � Catalysis Research Laboratory, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bBAFS SE,

GCB/C - M313, 67056 Ludwigshafen, Germany e-mail: [email protected]

Catalytic hydroamination of alkenes is a subject of current interest, both for fundamental

research and for the chemical industry.[1],[2],[3] Although significant progress has been made in the hydroamination with functionalized alkenes (e.g. styrene, 1,3-dienes, bridged aminoalkenes),[3] the intermolecular hydroamination with non-activated olefins is still a great challenge. The direct reaction of ethylene with N-nucleophiles (e.g. amines, amides) is of particular interest for the large-scale synthesis of ethylamine derivatives.

Only recently, we synthesized and characterized the new platinum (II) complexes with

CNC pincer ligands 1-4 and found them to be promising catalyst precursors for the direct hydroamination of ethylene. These complexes are remarkably air- and moisture-stable, and are potentially useful for the large-scale synthesis of ethylamine derivatives.

[1] T. E. Müller, M. Beller, Chem. Rev. 1998, 98, 675. [2] J.-J. Brunet, D. Neibecker, in “Catalytic Heterofunctionalization” (A. Togni and H. Grützmacher, Ed.)

Weinheim, 2001. [3] T. E. Müller, K. C. Hultzsch, M. Yus, F. Foubelo, M. Tada, Chem. Rev. 2008, 108, 3795.

36

Poster 5

Cross-Coupling with Palladium and Gold René Döpp, A. Stephen K. Hashmi*

Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 271,



Gold catalysis has become a versatile tool for efficient and atom-economic

transformations and its use is still growing exponentially. Vinylgold species have recently been isolated and characterized as intermediates of several gold catalyzed cyclization reactions.[ 1 ] From these intermediates, the gold catalyst is usually liberated by an electrophile E (in most cases a proton) generating a C-E bond. C-C bond formation can be accomplished when a second transition metal is used and both catalytic cycles are connected by a transmetallation step. Our studies on a new type of palladium-catalyzed cross-coupling reaction using organogold compounds will be presented.[2]

[1] L.-P. Liu, B. Xu, M. S. Mashuta, G. B. Hammond, J. Am. Chem. Soc. 2008, 130, 17642-17643. [2] A. S. K. Hashmi, C. Lothschütz, R. Döpp, M. Rudolph, T. D. Ramamurthi, F. Rominger, Angew.

Chem. Int. Ed. 2009, 48, 8243-8246; A. S. K. Hashmi, R. Döpp, C. Lothschütz, M. Rudolph, D.

Riedel, F. Rominger, Adv. Synth. Catal. 2010, 352, 1307-1314.

37

Poster 6

Supramolecular Control of Catalyst Selectivity in the Hydroformylation P. Dydio, W. I. Dzik, M. Lutz, B. de Bruin, J. N. H. Reek*

Van’t Hoff Institute for Molecular Sciences University of Amsterdam, Science Park 904, 1098 XH,

Amsterdam, The Netherlands

e-mail: [email protected], [email protected]

A new approach in homogeneous catalysis involves the pre-organisation of a

substrate by specific recognition, affording unusually high selectivities.[1],[2] Here we present DIMPhos (1), a new bidentate phosphorus ligand with an

integral anion recognition site.[ 3 ] The supramolecular interactions between the binding pocket of the Rh(1)-catalyst and alkenes containing anionic functionalities provide an excellent design-concept to achieve remote control of the regioselectivity in hydroformylation.

DFT calculations show that the substrate anchoring highly restricts movement of

the reactive double bond, and hence favours one reaction pathway. This gives rise to the observed highly selective hydroformylation of a variety of unsaturated carboxylic and phosphonic acids.[4] This provides the first example of wide-ranging remote control of catalyst selectivity by secondary substrate-ligand interactions. In this contribution we discuss the mechanism and the substrate range of this multifunctional catylitic system.

[1] P.-A. R. Breuil, F. W. Patureau, J. N. H. Reek, Angew. Chem. Int. Ed. 2009, 2162.

[2] T. Smejkal, B. Breit, Angew. Chem. Int. Ed. 2008, 311; Chem. Eur. J. 2010, 2470.

[3] P. Dydio, T. Zieli�ski, J. Jurczak, Chem. Commun. 2009, 4560; Org. Lett. 2010, 1076.

[4] P. Dydio, W. I. Dzik, M. Lutz, B. de Bruin, J. N. H. Reek, Angew. Chem. Int. Ed. 2011, 396.

38

Poster 7

Modular Phosphine-Phosphite Ligands in enantioselective, Rh-Catalyzed [4+2]-Cycloadditions

Anna Falk, Hans-Günther Schmalz* Department für Chemie, Cologne, Germany


Phosphine-phosphite ligands of type 1, recently developed in our group, have

proven their potential in asymmetric metal catalysis.[1] We have now investigated the use of such ligands in intramolecular, Rh-catalyzed [4+2]-cycloadditions.[2]

R1

R2

R3

R4PAr2

O PO

O* O

[Rh]L*O

H

H

3 (up to 90% ee)

21

Ligand:

Using a TADDOL-derived ligand of type 1 (R1 = Ph, R2, R3, R4 = H, Ar = Ph), high enantioselectivities were obtained under microwave conditions.

[1] J. Velder, T. Robert, I. Weidner, J.-M. Neudörfl, J. Lex, H.-G. Schmalz, Adv. Synth. Catal. 2008,

350, 1309-1315; T. Robert, J. Velder, H.-G. Schmalz, Angew. Chem. Int. Ed. 2008, 47, 7718-7721; T. Robert, Z. Abiri, J. Wassenaar, A. J. Sandee, S. Romanski, J.-M. Neudörfl, H.-G.

Schmalz, J. N. H. Reek, Organometallics 2010, 29, 478-483; W. Lölsberg, S.Ye, H.-G. Schmalz,

Adv. Synth. Catal. 2010, 352, 2020-2031.

[2] S. R. Gilbertson, G. S. Hoge, D. G. Genov, J. Org. Chem. 1998, 63, 10077-10080.

39

Poster 8

Palladium-Catalyzed Direct Arylations of (Hetero)Arenes with Moisture-Stable Sulfonates as Arylating Reagents

Sabine Fenner, Andreas Althammer, Lutz Ackermann*

Institut für Organische und Biomolekulare Chemie, Georg-August-Universität, Tammannstr. 2, 37077 D-Göttingen

email: [email protected]

Palladium-catalyzed cross-coupling reactions between organic halides or triflates and organometallic reagents are among the most important tools for regioselective C(sp2)–C(sp2) bond formations.[1] The corresponding organometallic nucleophilic starting materials are often not commercially available and lead to the formation of undesired side products. Therefore, focus has shifted in recent years to direct arylations of (hetero)arenes by C-H bond cleavages as ecologically and economically friendly alternatives.[2] Aryl tosylates and mesylates are attractive electrophiles, since they are moisture-stable, inexpensive and easily prepared from readily available phenols. Despite remarkable progress, sustainable palladium-catalyzed[3] direct arylations through C-H bond cleavages with tosylates as electrophiles have only recently been reported by us.[4a]

Herein, we disclose a protocol for palladium-catalyzed direct arylations of

electron-rich heteroarenes using tosylates or mesylates as arylating reagents, which proved applicable to C-H bond functionalizations with alkenyl tosylates as well.[4a] Further, the application of electron-deficient and less nucleophilic (hetero)arenes for palladium-catalyzed direct arylations with aryl mesylates will be presented.[4b]

[1] L. Ackermann, Modern Arylation Methods, Wiley-VCH, Weinheim, 2009; A recent example: L.

Ackermann, A. R. Kapdi, S. Fenner, C. Kornhaaß, C. Schulzke, Chem. Eur. J. 2011, DOI: 10.1002/chem.201002386.

[2] Selected reviews: D. Alberico, M. E. Scott, M. Lautens, Chem. Rev. 2007, 107, 174-238; L. Ackermann, Synlett 2007, 507-526; I. V. Seregin, V. Gevorgyan, Chem. Soc. Rev. 2007, 36, 1173-1193.

[3] For ruthenium-catalyzed direct arylations of arenes using tosylates, see: L. Ackermann, A. Althammer, R. Born, Angew. Chem. Int. Ed. 2006, 45, 2619–2622; L. Ackermann, R. Vicente, A. Althammer, Org. Lett. 2008, 10, 2299–2302.

[4] a) L. Ackermann, A. Althammer, S. Fenner, Angew. Chem. Int. Ed. 2009, 48, 201-204; b) L. Ackermann, S. Fenner, Chem. Commun. 2011, 47, 430-432.

40

Poster 9

New Ruthenium-Nitrosyl Pincer-Type Complexes: Synthesis, Reactivity and Catalytic Activity

Eran Fogler,a Jing Zhang,a Yael Diskin-Posner,b Gregory Leitus,b Linda J. W. Shimon,b Yehoshua Ben-David,a David Milsteina*

aDepartment of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel; bDepartment of Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel


Several pyridine-based ruthenium carbonyl pincer type complexes were

developed in our laboratory and have shown catalytic activity toward conversion of alcohols to esters and H2,[1],[2],[3] the hydrogenation of esters to alcohols,[4] and reactions of alcohols with amines to form amides with liberation of H2.[5] Herein we present novel ruthenium-nitrosyl pincer-type complexes with bent and linear NO ligands (such as complexes 1,2). The catalytic activity of the nitrosyl complexes with alcohols and amines is presented. For example, dehydrogentive coupling benzylamine (see equation). The reaction is selective for amines, even in the presence of alcohol.

[1] J. Zhang, M. Gandelman, L. J. W Shimon, H. Rozenberg, D. Milstein, Organometallics 2004, 23,

4026.

[2] J. Zhang, G. Leitus, Y. Ben-David, D. Milstein J. Am. Chem. Soc. 2005, 127, 10840.

[3] J. Zhang, M. Gandelman, L. J. W, Shimon, D. Milstein, Dalton Trans., 2007, 107.

[4] J. Zhang, G. Leitus, Y. Ben-David, D. Milstein, Angew. Chem. 2006, 118, 1131.

[5] C. Gunanathan, Y. Ben-David, D. Milstein, Science 2007, 317, 790.

N Ru

PtBu2

NEt2

N

Cl

O

1

N Ru

PtBu2

PtBu2

N

BF4

O

2OH

NH2

+cat. 1

0.1 mol % (156oC)-H2

RO

O R

R

+

97% benzylamineconversion

> 0.5%

NH

3.8 : 1

N

41

Poster 10

Anion Abstraction in Hydrogen Bond Donor Catalysis: Studies on the Mechanism of �-Chloroether Activation

David D. Ford, Eric N. Jacobsen*

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138


OR

Cl(±)

OR

R1R1

CO2Me

10 mol% thiourea catalyst1.5 equiv silyl ketene acetal

tBME, Š78 ¼C

S

N NH H

Cl

O

S

N NH H

Cl

O

direct activationSN2-like mechanism

anion abstractionSN1-like mechanism

vs.

Limiting mechanisms for electrophile activation

up to 95% ee

While urea- and thiourea-based hydrogen bond donor catalysts were originally

thought to activate electrophiles directly, recent discoveries in our group have suggested that these catalysts may also promote ionization of the electrophile to form a highly reactive ion pair. This proposed mechanism has served as a powerful guiding principle in developing new reactions, but there has not yet been a comprehensive mechanistic investigation to validate it. We chose the thiourea-catalyzed asymmetric alkylation of silyl ketene acetals with �-chloroethers[1] as a model reaction and have used a variety of methods to probe its mechanism. Our results indicate that there are some important subtleties to this mechanism and once we understand them more fully, we hope to be able to take advantage of this knowledge to discover improved catalysts for challenging classes of substrates (e.g. glycosyl donors).

[1] S. E. Reisman, A. G. Doyle, E. N. Jacobsen, J. Am. Chem. Soc. 2008, 130, 7198-7199.�

42

Poster 11

Hydrogenolysis of Pd(II) Hydroxide and Alkoxide Pincer Complexes Gregory R. Fulmer,a Richard A. Kemp,b Karen I. Goldberga*

aUniversity of Washington, bUniversity of New Mexico, Sadia National Laboritories


Hydrogenolysis of metal hydroxides or alkoxides, resulting in release of water or

alcohol and production of a metal hydride, could be a highly valuable combination step of product release and catalyst regeneration within a catalytic cycle. For example, heterogeneous complexes like Pearlman’s and Adams’ catalysts, two reagents often used in industrial-scale hydrogenation and hydrogenolysis processes, are thought to exhibit exceptional catalytic activity due to the formation of highly reactive M-H bonds on their surface after treatment of these solid state hydroxides and “hydrated oxides” with H2. Stryker’s reagent, a copper hydride complex used in the homogeneous catalysis of conjugate reduction reactions, is generated by the hydrogenolysis of Cu-OtBu bonds. Remarkably, there are few model systems to allow direct investigation of this potentially powerful reaction step. Hydrogenolysis reactions of the palladium(II) complexes (PCP)Pd-OR (PCP = 2,6-bis(CH2PtBu2)C6H3, R = H, CH3, CH2CH2F) to form HOR and (PCP)Pd-H were performed. Mechanistic studies revealed that in the presence of water, the palladium(II) hydroxide exists in solution as a water-bridged dimer; however, kinetic studies suggest the reaction of the palladium(II) hydroxide and H2 proceeds exclusively through the hydroxide monomer to form the palladium(II) hydride and water. Additionally, various mononuclear palladium(II) alkoxide complexes are reported, and their reactivity with H2 is described in comparison to the palladium(II) hydroxide complex.

43

Poster 12

Effective Formation of Macrolides Containing a Conjugated 1,3-Diene Moiety through Ring-Closing Metathesis – Formal Total Synthesis of Lactimidomycin

Daniel Gallenkamp, Alois Fürstner*

Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm Platz1, 45470 Mülheim a.d. Ruhr,

Germany


A conjugated diene moiety is a common structural motif in macrolactones of

biologically active natural products. Some prominent examples are the Oximidines I-III, the resorcyclics Radicicol and Monocillin or the glutarimide macrolide Lactimidomycin.[1] Besides methods like macrolactonization or palladium-catalyzed cross-coupling macrocyclisations, Ring-Closing Metathesis (RCM) of an appropriate precursor is a common way to build up the cyclic core structure.[1]

An efficient strategy has been developed for the selective formation of macrolactones containing a

conjugated E,Z-configured 1,3-diene moiety. An acyclic ene-diene was chosen as RCM precursor, where the internal double bond of the diene part is silyl-substituted to achieve a differentiation during RCM process. Utilizing Grela`s phosphine-free precatalyst, macrolactones are obtained in moderate to excellent yields with the newly formed double bond E-configured

[1] For an overview see S.E. Denmark, J. M. Muhuhi, J. Am. Chem. Soc. 2010, 132, 11768-11778

and references cited therein.

RMe2Si O

On m O

O

SiMe2R

n

m

O

O

n

mproto-desilylation

O

O

n

m

ArPd-cat. Hiyamacross-coupling

12- to 18-membered53-92 % yield

78-85%

75-78%R=Ph, Bn, 2-thienyl

Grela`s cat.

OSiMe2Bn

O O

BnMe2Si

OODMBODMB

O O

OOHHN

O

O

Lactimidomycin

1

Cl2Ru

O

PhiPr

NN

Cy

Cy

75%

3

2

34

44

Poster 13

exclusively.[2] The reaction scope was investigated regarding ring size, substituents on silicon as well as the diene-ester gap. The vinylsilane serves as a useful functionality for further transformations after realized ring-closing including simple protodesilylation or Pd-catalyzed Hiyama cross-coupling reactions.[3]

The newly developed methodology has been successfully applied to the formal total synthesis of the potent cell migration inhibitor lactimidomycin.[4] Key steps are a Pt-catalyzed regioselective alkyne syn-hydrosilylation of an 1,3-enyne as well as the RCM of 1 to form the 12-membered macrocycle 2 using the phosphine-free ruthenium precatalyst 3.[5]

[2] K. Grela, S. Harutyunyan, A. Michrowska, Angew. Chem. Int. Ed. 2002, 41, 4038-4040.

[3] K. Hosoi, K. Nozaki, T. Hiyama, Chem. Lett. 2002, 31, 138-140; S. E. Denmark, S. A. Tymonko,

J. Am. Chem. Soc. 2005, 127, 8004-8005.

[4] K. Micoine, A. Fürstner, J. Am. Chem. Soc. 2010, 132, 14064-14066 and references cited therein. [5] M. Gatti, L. Vieille-Petit, X. Luan, R. Mariz, E. Drinkel, A. Linden, R. Dorta, J. Am. Chem. Soc.

2009, 131, 9498-9499.

45

The Selective Aerobic Oxidation of Functionalized Alcohols and Unprotected Diols Using Ambient Air

Jessica M. Hoover, Shannon S. Stahl*

Department of Chemistry, University of Wisconsin, Madison


Catalytic oxidation employing molecular oxygen as the terminal oxidant is an

atom efficient and environmentally benign alternative to commonly employed stoichiometric oxidants. Unfortunately the most common aerobic alcohol oxidation protocols are either too active leading to over oxidation to carboxylic acid products and oxidation of other functional groups present (Pd catalysts and N-hydroxyphthalimide based systems), or are effective only for a limited scope of activated benzylic or allylic alcohols (Cu/phenoxyl V/Schiff base catalysts). We have developed a new Cu/TEMPO/NMI catalyst system for the highly efficient and highly selective oxidation of primary alcohols to aldehydes under mild conditions using ambient air as the oxidant (NMI = N-methylimidazole). The scope of this Cu/TEMPO/NMI system represents a more extensive functional group tolerance than has been shown for aerobic alcohol oxidation catalyst systems. In addition, this system promotes the selective and predictable oxidation of unprotected diols that is inaccessible using other transition metal, periodinane, swern, or chromate-based oxidations. This aerobic Cu/TEMPO/NMI catalyst system offers distinct advantages over traditional alcohol oxidation protocols and should be considered when selecting an alcohol oxidation.

46

Poster 14

Additives, Mechanisms and Controversy in Organocatalysis Matthew Hughes,a Alan Armstrong,a* Donna Blackmondb*

aDepartment of Chemistry, Imperial College, South Kensington, London, SW7 2AZ, UK; bThe

Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA, 92037, USA.


Organocatalysis: A multitude of reactions catalysed by different small organic molecules have been developed during the last decade,[1] but relatively few mechanistic studies exist and we have focussed on this under-investigated area.

Amination: In the asymmetric proline-catalysed amination of aldehydes[2] we have discovered an extraordinary inversion of enantioselectivity when bases are added.[ 3 ] Prolinate salts also give inverted selectivity and this phenomenon has been probed by further investigations. The collected observations have profound implications for the controversial, mechanistic debate surrounding enamine catalysis.

Aldol: The intramolecular aldol reaction[4] is another case with unresolved mechanistic

questions. A model system has been developed to allow reaction monitoring by sampling and HPLC analysis and the effects of additives have been thoroughly investigated.

[1] P. Melchiorre, M. Marigo, A. Carlone, G. Bartoli, Angew. Chem., Int. Ed. 2008, 47, 6138. [2] A. Bøgevig, K. Juhl, N. Kumaragurubaran, W. Zhuang, K. A. Jørgensen, Angew. Chem. Int. Ed.

2002, 41, 1790; B. List, J. Am. Chem. Soc. 2002, 124, 5656.

[3] D. G. Blackmond, A. Moran, M. Hughes, A. Armstrong, J. Am. Chem. Soc., 2010, 132, 7598.

[4] Z. G. Hajos, D. R. Parrish, J. Org. Chem. 1974, 39, 1612; U. Eder, G. Sauer, R. Wiechert, Angew. Chem. Int. Ed. 1971, 10, 496.

47

Poster 15

Ligand-Controlled Cyclization of 1,5-Enynes: Application to the Synthesis of Anhydrocannabimovone

Núria Huguet, Verónica López-Carrillo, Ángeles Mosquera, Antonio M. Echavarren*

Institute of Chemical Research of Catalonia (ICIQ), Spain


Ligands modulate the nature of the intermediates in gold(I)-catalyzed cyclizations

of 1,5-enynes allowing the for the selective formation of a variety of products.[1] Trapping of the cyclopropyl gold(I) intermediates 2 by intramolecular cyclopropanation is also possible.

PhO2S Me AuL+

LAu

PhO2S H

HMe

PhO2S H

H

O

Me

LAu

PhO2S HMe

PhO2S H

H

O

Me

ZR

AuL+

Z

R

H

AuL +

Z H

R

Z

R

H

1 2

3

4

low donating ligand

highly donating ligand

ZH

n5: n = 1,2

OR

R

R

highly donating ligand

low donating ligand

6

8

7 9

10

O

R

O

R

Application of this methodology to the total synthesis of the natural product

anhydrocannabimovone (13)[2] will be presented.

O

HO

O

13

MeO

OMe

OTBS

AuL+

MeO

OMeTBSO

11 12

[1] E. Jimenez-Núñez, A. M. Echavarren, Chem. Rev. 2008, 108, 3326; C. J. Gorin, B. D Sherry, D.

Toste, Chem. Rev. 2008, 108, 3351. [2] O. Taglialatela-Scafati, A. Pagani, F. Scala, L. de Petrocellis, V. di Marzo, G. Grassi, G.

Appendino, Eur. J. Org. Chem. 2010, 2067.

48

Poster 16

Synthesis of New Gold Phenolate Complexes and Nitrile Activation in Homogeneous Gold Catalysis

Nada Ibrahim,a A. Stephen K. Hashmia,b*�aCaRLa - Catalysis Research Laboratory, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany;

bOrganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany

e-mail: [email protected] �

Nowadays the synthesis of new gold complexes is undoubtedly a central theme for many researchers.[1] These complexes have been explored either with regard to their catalytic properties or as tools for many useful applications as for example in material science or medicine. One very important feature of these complexes is that they may provide a better understanding of the properties of the metal itself, which is quite an important criterion to determine the reactivity of gold and to discover new reactions. In addition, the use of gold complexes in catalysis and especially in homogeneous catalysis is a hot topic as gold now is involved in a large variety of organic transformations. �

With regard to these subjects, the present work is divided into two parts: The first is focused on the synthesis and isolation of unprecedented gold phenolate complexes and further studies to gain insight into the nature or the bonds in these species. The second part is focused on the investigation of the involvement of C-N triple-bonds in homogeneous gold catalysis for the development of a reaction in which a series of nitriles reacted with alcohols to afford various secondary amides.�

�

[1] For recent reviews on gold complexes and gold catalysis see: A. S. K. Hashmi, Chem. Rev. 2007, 107, 3180; F. D. Toste, D. J. Gorin, Nature 2007, 446, 395; Z. Li, C. Brouwer, C. He, Chem. Rev. 2008, 108, 3239; G. Helgard, G. H. Raubenheimer, S. Cronje, Chem. Soc. Rev. 2008, 37, 1998; P. de Frémont, D. E. Stevens, D. M. Eelman, D. E. Fogg, S. P. Nolan, Organometallics 2006, 25, 5824.

49

Poster 17

Exploring the Nature of Catalytic Olefin Dioxygenation with PhI(OAc)2 Yan-Biao Kang,a Lutz H. Gadea,b*

aCatalysis Research Laboratory (CaRLa), Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bAnorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120

Heidelberg, Germany


Evidence for the protiocatalytic nature of the diacetoxylation of alkenes using

PhI(OAc)2 as oxidant is presented. Systematic studies into the catalytic activity in the presence of proton trapping and metal complexing agents indicate that protons act as catalysts in the reaction. Metal cations,[1] such as Pd(II) and Cu(II) may interact with the oxidant in the initiation phase of the catalytic transformation, however, one equivalent of strong acid is produced in the first cycle which then functions as the active catalyst. Based on a kinetic study as well as in situ mass spectrometry, a mechanistic cycle for the proton catalyzed reaction, which is consistent with all experimental data presented in this work, is proposed.

[1] Y. Li, D. Song, V. M. Dong, J. Am. Chem. Soc. 2008, 130, 2962; J. Seayad, A. M. Seayad, C. L. L.

Chai, Org. Lett. 2010, 12, 1412.

50

Poster 18

From enantioconvergent to Stereodivergent Processes in Copper-catalyzed Aymmetric Allylic Alkylation

Jean-Baptiste Langlois, Alexandre Alexakis*

Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva 4,

Switzerland


The copper-catalyzed asymmetric allylic alkylation (AAA) is one of the most powerful methods to introduce a simple alkyl group in allylic position.[1] Copper is particularly known to induce a high �-selectivity stemming from a SN2’ process. This feature has been mainly applied to the alkylation of linear prochiral substrates leading to the formation of stereogenic centers. In sharp contrast, the use of racemic substrates has been scarcely studied. We will present here that this range of substrates could be interesting reaction partners leading to the development of new valuable resolution processes.[2]

R X R

AlkylAlkylMgBr,"chiral Cu catalyst"

XX

ee ?yield ?

AlkylMgBr,"chiral Cu catalyst"

AlkylMgBr,"chiral Cu catalyst"

high eehigh yield

(+/-) (+/-)

[1] A. Alexakis, J. E. Bäckvall, N. Krause, O. Pamies, M. Dieguez, Chem. Rev. 2008, 108, 2796; C.

A. Falciola, A. Alexakis, Eur. J. Org. Chem. 2008, 3765.

[2] J. B. Langlois, A. Alexakis, Chem. Commun. 2009, 3868; J. B. Langlois, A. Alexakis, Adv. Synth. Catal. 2010, 352, 447; J. B. Langlois, A. Alexakis, Angew. Chem. Int. Ed. 2011, 50, 1877.

51

Poster 19

Synthesis of Au(I, III) Complexes and Their Potential in the Reductive Ar-N and Ar-X Bond Formation

Ronald Lindner,a Séverine Lavy,a Marek Pažický,a Frank Rominger,b Daniel Serra,a Michael Limbacha,c*

aCatalysis Research Laboratory (CaRLa), Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bRuprecht-Karls-Universität, Organisch-Chemisches Institut, Im Neuenheimer Feld 270, 69120

Heidelberg, Germany; cBASF SE, GCB/C – M313, 67056 Ludwigshafen, Germany


Within our investigation we strive to develop a catalytic system for the C-H

activation of nonactivated arenes based on the Au(I)/Au(III) redox couple. To facilitate the rational development of such a system, initially stoichiometric activity studies of Fuchita’s well defined arylgold(III) complex[1] were performed. Within these investigation almost quantitative reductive amination and halogenation was achieved.[ 2 ] In further studies we aim to develop a catalytic system for the halogenation of arenes based on this principle.

[1] S. Gaillard, A. M. Z.; Slawin, S. P. Nolan, Chem. Commun. 2010, 46, 2742. [2] S. Lavy, J. J. Miller, M. Pažický, A.-S. Rodrigues, F. Rominger, C. Jäkel, D. Serra, N. Vinokurov,

M. Limbach, Adv. Synth. Catal. 2010, 352, 2993.

52

Poster 20

Evolution of a Catalyst for Secondary C-H Borylation Carl W. Liskey, John F. Hartwig*

aDepartment of Chemistry, University of Illinois at Urbana-Champaign, USA


The development of a catalyst to perform the borylation of secondary C-H bonds

is reported. Previously, rhodium or ruthenium catalysts have been employed in the borylation of primary C-H bonds, but these catalysts are unreactive towards secondary C-H bonds. Iridium-trisboryl complexes, which are the active catalysts in the C-H borylation of arenes, were prepared containing different substituents on boron and different ancillary ligands.[11] The reactivity and electronic properties of these complexes are presented. Complexes containing the more electron-rich pinacol substituents on boron react faster than analogous complexes containing catechol substituents on boron. Also, complexes containing bipyridine ligands react faster and in higher yield than the analogous complexes containing bulky chelating phosphine ligands. Although these complexes are unreactive towards aliphatic C-H bonds, information was gained that led us to develop a catalyst that performs the borylation of secondary C-H bonds. The secondary borylation is shown on a number of cyclic substrates, including cyclic ethers and cyclopropanes.

H[Ir], B2pin2

Bpin

[1] C. W. Liskey, C. S. Wei, D. R. Pahls, J. F. Hartwig, Chem. Commun. 2009, 5603

53

Poster 21

Nickel-catalyzed Cross-Coupling of Aryl Bromides with Tertiary Grignard Reagents Utilizing Donor-functionalized N-Heterocyclic Carbenes

Claudia Lohre, Thomas Dröge, Congyang Wang, Frank Glorius* Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstraße 40,

48149 Münster, Germany


The utilization of sterically hindered alkyl substrates represents a major challenge

of present cross-coupling methodolody.[1] The nickel-catalyzed Kumada[2] cross-coupling of 3° alkyl Grignard reagents with aryl bromides allows this difficult reaction with numerous different substrates by using sterically demanding, “bifunctional” N-heterocyclic carbene ligands. Good yields of the coupled products were obtained and a wide range of functional groups is well tolerated.[3]

[1] J. Terao, Y. Naitoh, H. Kuniyasu, N. Kambe, Chem. Commun. 2007, 825-827; L. Hintermann, L.

Xiao, A. Labonne, Angew. Chem. Int. Ed. 2008, 47 8246-8250.

[2] T. Hayashi, M. Konishi, K. Yokota, M. Kumada, Chem. Lett. 1980, 767-768. [3] C. Lohre, T. Dröge, C. Wang, F. Glorius, submitted.

54

Poster 22

Catalytic Asymmetric Carbon-Carbon Bond Formation with Organolithium Compounds

Martín Fañanás-Mastral, Manuel Pérez, Pieter H. Bos, Alena Rudolph, Syuzanna R. Harutyunyan, Ben L. Feringa*

Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The

Netherlands


Carbon-carbon bond formation is the basis for the biogenesis of nature’s essential

molecules and, consequently, it is at the heart of the chemical sciences. The ability to build, through chemical synthesis, a wide range of carbon-based structures is critical for natural product chemistry and biological studies, as well as for future developments in materials science and medicine. The discovery of novel catalytic C-C bond forming processes for the construction of chiral organic compounds continues to be an especially challenging goal.[1] Chiral catalysts for asymmetric C-C bond formation to yield single enantiomers from several organometallic reagents have been developed. Remarkably in the case of the extremely reactive organolithium compounds, which are among the most broadly used reagents in chemical synthesis a general catalytic methodology for enantioselective C-C formation has proven elusive; until now.[2],[3]

We report a chiral catalytic system that allows carbon-carbon bond formation with alkyllithium reagents with extremely high enantioselectivities.

[1] E. N. Jacobsen, A. Pfaltz, H. Yamamoto, Comprehensive Asymmetric Catalysis: Supplement 2

(Springer-Verlag, 2004).

[2] Z. Rappoport, I. Marek, The Chemistry of Organolithium Compounds (Wiley-VCH, 2004).

[3] D. M. Hodgson, Organolithiums in Enantioselective Synthesis (Springer-Verlag, 2003).

55

Poster 23

Efficient Catalytic Asymmetric Entry to Planar Chiral Complexes Audrey Mercier, E. Peter Kündig*

Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva 4,

Switzerland


Optically pure planar chiral complexes are of interest for both asymmetric

synthesis and catalysis. We here report on an easy access to highly enantioenriched compounds via desymmetrization of prochiral dibromoarene complexes using a bulky chiral palladium catalyst.[1],[2] The potential utility of this reaction is illustrated with the synthesis of a wide range of highly enantioenriched planar chiral complexes.

LiBH4, DABCO

RB(OH)2, KF

MLnBr

BrMLn

H

Br

MLn

R

R'

MLn

R

Br

up to 99% ee

Metalation/E+ quenchTM-catalyzed couplings

Pd/L*

Pd/L*

R = H, Aryl, Vinyl, AlkylR' = PR2, Pyridine...

MLn

R

R'PdX

X

Catalytic Desymmetrization Synthetic Potential

up to 98% ee

Peri-cyclometalation

MLn = Cr(CO)3, RuCp*+, RuCp

Ph

Ph

OO P N

Ph

Ph

L* :

[1] Cr complexes: X. Urbaneja, A. Mercier, C. Besnard, E. P. Kündig, Chem. Commun. 2011, in

press; A. Mercier, X. Urbaneja, W. C. Yeo, P. D. Chaudhuri, G. R. Cumming, D. House, G.

Bernardinelli, E. P. Kündig, Chem. Eur. J. 2010, 16, 6285. [2] Ru complexes: A. Mercier, W. C. Yeo, J. Y. Chou, P. D. Chaudhuri, G. Bernardinelli, E. P.

Kündig, Chem. Commun. 2009, 5227; A. Mercier, W. C. Yeo, X. Urbaneja, E. P. Kündig,

Chimia 2010, 64, 177.

56

Poster 24

Kinetic Resolution of Homoaldols via Catalytic Asymmetric Transacetalization Steffen Müller, Ilija �ori�, Benjamin List*

Max-Planck-Institut für Kohlenforschung, Kaiser Wilhelm Platz 1, 45470 Mülheim an der Ruhr,

Germany


�-Hydroxycarbonyl compounds, or homoaldols, represent a versatile motif for

organic synthesis which can be easily transformed into a vast array of important chiral compounds. Despite their importance, general catalytic methods to access enantiomerically enriched homoaldols are rare. We have developed a kinetic resolution of racemic �-hydroxyacetals rac-1 by an intramolecular transacetalization reaction, catalyzed by the novel chiral phosphoric acid (S)-STRIP (2). Both, �-hydroxyacetals 1 and cyclic acetals 3 are obtained in high enantiomeric ratios at conversions of around 55%.[1]

Attractive features of our reaction are the easy accessibility of the starting

materials, low catalyst loading, high efficiency for secondary and tertiary homoaldols, operational simplicity and high atom economy without the need for stoichiometric reagents.

[1] I. �ori�, S. Müller, B. List, J. Am. Chem. Soc. 2010, 132, 17370-17373.

57

Poster 25

Intermolecular P/B-Frustrated Lewis Pairs: Activation of H2 and CO2 and the Formation of New Formato-Borate Complexes

Ilona Peuser, Gerald Kehr, Roland Fröhlich, Gerhard Erker*

Institute of Organic Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 40, 48149

Münster, Germany


The concept of “Antagonistische Paare” or “Frustrated Lewis Pairs” (FLPs) is

based on the combination of sterically bulky Lewis acids and bases, preventing the formation of the classical adducts.[1] A diversity of FLPs are known to activate small molecules such as H2, N2O or CO2.[2]

R-B(C6F5)2 + PtBu3CO2 O

BPtBu3

O

R

(C6F5)2

21

H2

[RB(C6F5)H] [tBu3PH]CO2 O

BR

H

O

(C6F5)2B

R

(C6F5)2[tBu3PH]

3 4

R= hexyl, cyclohexyl, norbornyl

-CO2

In this work intermolecular P/B-FLP-systems (1) were tested towards the

activation of CO2 (2) and H2 (3). Subsequent reaction of 3 with CO2 led to the new formato-borate complexes 4.[3]

[1] G. Wittig, E. Benz, Chem. Ber. 1959, 92, 1999-2013; W. Tochtermann, Angew. Chem. Int. Ed.

1966, 5, 351-371; Angew. Chem. 1966, 78, 355-375; D. W. Stephan, Science 2006, 314, 1124-1126.

[2] For a review see: D. W. Stephan, G. Erker, Angew. Chem. Int. Ed. 2010, 49, 46-76. [3] I. Peuser, G. Erker, D. W. Stephan, submitted.

58

Poster 26

Synthesis of Axially Chiral Phosphonite-functionalized N-Heterocyclic Carbenes as Ligands for Asymmetric Catalysis

Manojkumar Poonoth,a Peter Hofmanna,b* aCatalysis Research Laboratory, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bInstitute of

Organic Chemistry, University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany


Transition metal complexes with N-heterocyclic carbene (NHC) ligands have emerged as a hot research area. Recently, research has also been devoted to the synthesis of complexes with polydentate NHC-based ligands. The incorporation of the carbene functionality into ligand systems containing other classical’ donor group offers vast opportunities for ligand design. In particular, the combination of Nitrogen functionality, such as pyridine or a phosphine and an NHC moiety has attracted considerable interest.[11] At this instance, the synthesis of a chiral version of such an N-Heterocyclic Carbene-Phosphine (NHC-P) that are having an axially chiral moiety on the Phosphorous as ligands for asymmetric catalysis seemed to be very interesting.

NC

N

P R'n

n = 0, 1, 2achiral

RR

O

O

NC

N

P R

chiral P substituents

NC

N

P R'RR

n*

n = 1, R = Mesa

n

The synthesis of such an axially chiral phosphonite-functionalized imidazolium precursor from commercially available enantiopure Binol, chloromethyl dichlorophosphane and N-mesitylimidazole will be presented.

[1] C.-C. Lee, W.-C. Ke, K.-T. Chan, C.-L. Lai, C.-H. Hu, H. M. Lee, Chem. Eur. J. 2007, 13, 582-

591; H. M. Lee, P. L. Chiu, J. Y. Zeng, Inorg. Chim. Acta 2004, 4313-4321; S. Gründemann, A. Kovacevic, M. Albrecht, J. W. Faller, R. H. Crabtree, J. Am. Chem. Soc. 2002, 124, 10473-10481; S. Gründemann, A. Kovacevic, M. Albrecht, J. W. Faller, R. H. Crabtree, Chem. Commun. 2001, 2274-2275.

59

Poster 27

Stoichiometric Investigation of C-H activation at PdIV Joy M. Racowski, Melanie S. Sanford*

University of Michigan


Fundamental investigations of reactivity at isolable PdIV complexes have the

potential to accelerate the discovery of new catalytic transformations. Recently, several groups have proposed C-H activation at PdIV in catalytic reactions, involving the oxidative dimerization of 2-arylpyridines,[1] the intramolecular carboamination of olefins in the presence of N-fluorobenzenesulfonimide,[ 2 ] and allylic C-H acetoxylation with PhI(OAc)2.[ 3 ] Understanding the reactivity, selectivity and mechanism of this elementary step might allow for the rational design of other novel catalytic reactions.

Our goal was to design a complex to observe and study intramolecular C-H activation at PdIV. Oxidation of (dtbpy)PdII(o-PhC6H4)(CF3) with 1.0 equivalent of 2,4,6 N-fluorotrimethyl pyridine triflate at room temperature afforded (dtbpy)PdIV(o-PhC6H4)(CF3)(F)(OTf) in 91% yield. A variety of oxidants were proficient for the transformation. Additionally, reactions exploring the site selectivity of C-H activation at PdIV versus PdII were explored.

[1] K. L. Hull, E. L. Lanni, M. S. Sanford, J. Am. Chem. Soc. 2006, 128, 14047-14049.

[2] P. A. Sibbald, C. F. Rosewall, R. D. Swartz, F. E. Michael, J. Am. Chem. Soc. 2009, 131, 15945-15951.

[3] L. T. Pilarski, N. Selander, D. Bose, K. J. Szabo, Org. Lett. 2009, 11, 5518-5521.

60

Poster 28

Water Soluble Metathesis Catalysts Containing Hemi-Labile Ligands Robin Padilla,a Michael Limbacha,b*

aCatalysis Research Laboratory (CaRLa) – Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bBASF SE, GCB/C – M313, Carl Bosch Strasse 38, 67056 Ludwigshafen, Germany


Thermoplastic polymers, such as cyclic olefin copolymer (COC) and polydicyclopentadiene (DCPD), have many applications ranging from packaging materials and coatings to vehicle panels. Current investigations are focusing on preparing these polymers in aqueous media using two new classes of water-soluble metathesis catalysts. Both of these ruthenium-based systems incorporate the H2ITap ligand (H2ITap = 1,3-bis(2’,6’-dimethyl-4’-dimethylaminophenyl)-4,5-dihydroimidazol-2-ylidene), with one class containing a pyridinyl-alcoholate ligand and the second catalyst type containing a coordinating pyridine ring tethered to the carbene moiety. Treatment with acid protonates the amine groups on the H2ITap ligand, making the complexes water soluble. The hemi-labile pyridinyl-alcoholate and the pendant pyridine ligands help enhance the stability and latency of the catalyst while also providing polymers with the desired properties.

61

Poster 29

Ureaphosphines: New P,O Ligands for the Iridium Catalyzed Asymmetric Hydrogenation of Various Olefins

Denise Rageot, Andreas Pfaltz*

University of Basel, Department of Chemistry, St. Johanns-Ring 19, 4056 Basel, Switzerland


Iridium complexes with chiral P,N ligands derived from amino acids are highly

efficient catalysts in the asymmetric hydrogenation of a broad range of substrates, with generally excellent enantioselectivities.[1] However, only a few catalysts based on P,O ligands have been described so far. Taking advantage of the chiral pool, we have synthesized a library of simple P,O ligands derived from L-proline in order to evaluate their efficiency in the asymmetric iridium catalyzed hydrogenation of olefins. X-ray crystallography of the resulting iridium complexes showed these ligands to chelate in a bidentate fashion to iridium (I).

We found these complexes to be selective in the iridium catalyzed hydrogenation of trisubstituted olefins. Depending on the ligand structure, selectivities of up to 99% ee could be achieved. The synthesis of these P,O ligands and their application in hydrogenation studies will be presented.

[1] S. J. Roseblade, A. Pfaltz, Acc. Chem. Res. 2007, 40, 1402-1411.

62

Poster 30

Mixed Hydroxylase/Desaturase Activity with a Biomimetic, Non-Heme Iron Catalyst

Sean A. Reed, Marinus A. Bigi, M. Christina White*

Department of Chemistry, University of Illinois, 600 S. Mathews Ave., Urbana, IL 61801 USA


We recently reported the first example of a small molecule catalyst [Fe(PDP)]

capable of mixed hydroxylase and desaturase activity on unactivated, aliphatic C-H bonds with substrates containing carboxylic acids.[1] Mechanistic studies showed that similar to Nature’s desaturases, the radical intermediate formed after C-H abstraction can rebound to give hydroxylation products that spontaneously lactonize, or alternatively be oxidized again to generate olefins, which undergo further oxidation to hydroxyl lactones. We provide the first direct evidence for this extremely short-lived radical species through the use of a novel taxane-based radical trap, and also demonstrate the utility of this method for diversifying known natural product scaffolds and investigating biosynthetic C-H oxidation pathways.

[1] M. A. Bigi, S. A. Reed, M. C. White, Nat. Chem. 2011, ASAP doi: 10.1038/nchem.967

63

Poster 31

Palladium-Catalysed Intermolecular 1,2-Diamination of Alkenes Caren Röben,a Kilian Muñiza,b*

aInstitute of Chemical Research of Catalonia (ICIQ), Tarragona, Spain; bCatalan Institution for

Research and Advanced Studies (ICREA), Barcelona, Spain.


We have recently been interested in the application of palladium catalysts to

realise unprecedented 1,2-diamination reactions of alkenes.[1] Within this context, the application of suitable high oxidation state palladium catalysis[2] represents a key methodology.

We now report two first protocols for palladium catalysed intermolecular diamination reactions of alkenes, which employ readily available nitrogen sources.[3] The diamination products are formed with complete regioselectivity and chemoselectivity. Subsequent transformation of these products into more elaborate diamine building blocks will also be discussed.

RR

NNTos2

O2S O

Palladium-Catalyst

Iodo(III)Oxidant

NHSO2

O

HNTos2

intermolecular diamination of nonfunctionalised alkenes:

NN(SO2Ph)2

ONH

O

F-N(SO2Ph)2

O

RO

O

RO

Regio-selective

Palladium-Catalysis

1,2-DiaminationProduct

intermolecular diamination of allylic ethers:

[1] K. Muñiz, C. H. Hövelmann, J. Streuff, J. Am. Chem. Soc. 2008, 130, 763; J. Streuff, C. H.

Hövelmann, M. Nieger, K. Muñiz, J. Am. Chem. Soc. 2005, 125, 14586; K. Muñiz, J. Am. Chem. Soc. 2007, 129, 14542.

[2] K. Muñiz, Angew. Chem. Int. Ed. 2009, 48, 9412.

[3] A. Iglesias, E. G. Pérez, K. Muñiz, Angew. Chem. Int. Ed. 2010, 49, 8109; K. Muñiz, J. Kirsch, P.

Chávez, Adv. Synth. Catal. 2011, accepted.

64

Poster 32

Synthesis and Catalytic Properties of a Series of Novel Mono-, Di- and Trinuclear Gold (I) Complexes

Lara-Isabel Rodríguez, Julio Lloret-Fillol, Torsten Roth, Lutz H. Gade*

Anorganisch-Chemisches Institut. Ruprecht-Karls-Universität Heidelberg. Im Neuenheimer Feld 270,



Asymmetric gold catalysis has experienced an explosive growth recent years, as

it can be judged from the ever rising number of manuscripts in this field.[1] However, despite the fact that the use of dinuclear gold catalysts is a general choice in the majority of the studies present in this field, no systematic studies concerning the potential catalytic influence of Au-Au interactions have been elaborated. Furthermore, to the best of our knowledge, no examples of gold complexes of higher nuclearity have been studied in asymmetric homogeneous catalysis up to date.

Aurophilic interactions may play an important role in determining the catalytic behavior, considering the fact that they are similar in energy to hydrogen bonding. Here we report the synthesis of a series of novel chiral mono-, di- and trinuclear gold complexes and their systematic study in the asymmetric cyclohydroamination of N-protected �-allenyl amines.

[1] Recent Reviews in Homogeneous Gold Catalysis: R. A. Widenhoefer, Chem. Eur. J. 2008, 14,

5382-5391; N. Bongers, N. Krause, Angew. Chem. Int. Ed. 2008, 47, 2178-2181; N. D. Shapiro, F.

D. Toste, Synlett 2010, 5, 675-691; S. Sengupta, X. Shi, ChemCatChem 2010, 2, 609-619.

65

Poster 33

Preparation of Ruthenium Carbene Complexes Based on a Novel NHCP Ligand for ROMP Reactions

Hiyam Salem,a Martin Schmitt,b Ulrike Blumbach,b Peter Hofmanna,b* aCaRLa - Catalysis Research Laboratory Im Neuenheimer Feld 584, 69120 Heidelberg, Germany;

bInstitute of Organic Chemistry, University of Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany

e-mail: e-mail: [email protected]

Grubbs first generation Ru carbenes have found wide application in olefin metathesis. Since their development attempts to improve their stability and reactivity focused mainly on the development of N-heterocyclic carbene based ruthenium complexes which exhibited a dramatic increase in reactivity with a wide variety of olefin substrates. We present herein the synthesis of a new electron-rich and sterically crowded chelating phosphinomethyl substituted N-heterocyclic carbene ligand, its unsaturated 16e Ru(II) �-chloro bridged dimer and the synthesis of a series of new carbene complexes by treatment with a variety of diazo compounds. Preliminary results on the reactivity of those complexes in ROMP reactions will be presented as well.

66

Poster 34

Mixed N-Heterocyclic Carbene/Phosphite Ruthenium Complexes: Towards a New Generation of Olefin Metathesis Catalysts

Thibault E. Schmid, Xavier Bantreil, Rebecca A. M. Randall, Alexandra M. Z. Slawin, Luigi Cavallo, Catherine S. J. Cazin*

EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK


Since the last decade, olefin metathesis has become one of the most useful tools

in organic chemistry. One of the main breakthroughs in the area was the replacement of a phosphine ligand by a N-heterocyclic carbene (NHC), increasing the reactivity and stability of the resulting complex. We chose to investigate the potential of inexpensive phosphites as ligands in olefin metathesis pre-catalysts, to date unexplored. These studies led to the isolation of complexes having an unexpected behavior and geometry, the ligands NHC and P(OR)3 being cis to each other (cis-Caz-1 shown below). Catalytic studies showed these systems to outperform state-of-the-art catalysts in particular for the ring closing metathesis of challenging olefins.[1] These and the latest findings concerning these systems will be presented.

[1] X. Bantreil, T. E. Schmid, R. A. M. Randall, A. M. Z. Slawin, C. S. J. Cazin, Chem. Commun.

2010, 46, 7115-7117.

67

Poster 35

Asymmetric Diels-Alder and Ficini Reactions of Unsaturated -Ketoesters Catalyzed by Chiral Ruthenium PNNP Complexes

Christoph Schotes, Antonio Mezzetti* Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland


We have recently reported the asymmetric Diels-Alder reaction of

�-methylene�-keto ester 2 with a number of dienes catalyzed by the dicationic complex [Ru(2)(PNNP)]2+ (3), formed in situ by activation of 1 with (Et3O)PF6.[1],[2] As an extension of this chemistry, we accomplished the first stereoselective Ficini reaction.[ 3 ] Complex 3 catalyzes the reaction between ynamides 4 and the unsaturated -keto ester 2 to give the corresponding amidocyclobutenes 5 with excellent yield and enantioselectivity (13 examples, up to 99% ee after recrystallization).

The determination of the absolute configuration of the amidocyclobutene indicates that the ynamide attacks from the top face of the ruthenium-bound enone 2. The X-ray structure of 3 shows that a phenyl ring of the PNNP ligand efficiently shields the lower face of the enone, which accounts for the high enantioselectivity of these reactions.

[1] C. Schotes, A. Mezzetti, J. Am. Chem. Soc. 2010, 132, 3652-3653.

[2] C. Schotes, A. Mezzetti, CHIMIA Laureate Edition 2011, in print.

[3] C. Schotes, A. Mezzetti, Angew. Chem. Int. Ed. 2011, in print.

68

Poster 36

A New, Bulky, Hemilabile P,O - Ligand for Homogeneous Catalysis: dtbpmO Erik Schuster, Kathrin Brandt, Frank Rominger, Peter Hofmann*

Organisch-Chemisches Institut, Ruprecht-Karls-Universität, Im Neuenheimer Feld 270, 69120

Heidelberg, Germany


The chemistry of various transition metal systems employing the chelating, bulky

and small-bite-angle ligand bis(di-tert-butylphosphino)methane (dtbpm) for exceptional stoichiometric and catalytic reactions has been studied in our group.[1] The formal oxidation of one phosphorus atom leads to bis(di-tert-butylphosphino)methane monoxide (dtbpmO). According to DFT-studies, this change, depending on the metal, leads to a hemilabile M-O bond.

Herein we present several platinum and palladium complexes showing the hemilability of dtbpmO and interesting bond activation reactions.

[1] P. Hofmann, H. Heiß, G. Müller, Z. Naturforsch. 1987, 42b, 395-409; P. Hofmann, B. F. Straub,

Inorg. Chem. Commun. 1998, 1, 350-353; P. Hofmann, F. Eisenträger, A. Göthlich, I. Gruber, H. Heiß, C. A. Kiener, C. Krüger, J. U. Notheis, F. Rominger, G. Scherhag, M. Schultz, B. F. Straub,

M. A. O. Volland, New J. Chem. 2003, 27, 540-550; P. Hofmann, M. A. O. Volland, S. M. Hansen,

F. Rominger, Organometallics 2004, 23, 800-816; P. Hofmann, H. Urtel, C. Meier, F. Eisenträger,

F. Rominger, J. P. Joschek, Angew. Chem. 2001, 113, 803-806; Angew. Chem. Int. Ed. 2001, 40,

781-784; P. Hofmann, H. Urtel, G. A. Bikzhanova, D. B. Grotjahn, Organometallics 2001, 20, 3938-3949; P. Hofmann, L. A. Perez Moya, M. E. Krause, O. Kumberger, G. Müller, Z.

Naturforsch. 1990, 45b, 897-908; P. Hofmann, F. Eisenträger, WO 02/02573, 2002, BASF AG.

69

Poster 37

Late Transition Metal-Mediated Benzotrifluoride Synthesis Todd D. Senecal, Andrew T. Parsons, Stephen L. Buchwald*

Department of Chemistry, Massachusetts Institute of Technology, Room 18-490 Cambridge,

Massachusetts 02139, United States


The trifluoromethyl group possesses many desirable characteristics such as high

electron-withdrawing ability, high lipophilicity, and excellent metabolic stability. These properties make benzotrifluorides attractive targets for materials and medicinal chemistry, however until recently their synthesis has been far from routine. Recently, we disclosed a system for the trifluoromethylation of aryl chlorides via palladium catalysis.[1] In an effort to increase functional group compatibility and user-friendliness, we have developed a method for the room temperature copper-mediated oxidative trifluoromethylation of aryl and heteroaryl boronic acids.[2] This mild method is amenable to normal benchtop setup and reactions typically require only 1-4 hours.

[1] E. J. Cho, T. D. Senecal, T. Kinzel, Y. Zhang, D. A. Watson, S. L. Buchwald, Science 2010, 328,

1679-1681.

[2] T. D. Senecal, A. T. Parsons, S. L. Buchwald, J. Org. Chem. 2011, 76, 1174-1176.

70

Poster 38

Gold-Catalyzed Tandem 3,3-Sigmatropic Shift/Cyclization/1,5-Acyl Shift: From Diynyl Esters to Conjugated Bisenones

Antoine Simonneau, David Leboeuf, Vincent Gandon, Corinne Aubert, Louis Fensterbank, Max Malacria*

IPCM UMR 7201, Université Pierre et Marie Curie, 4 place Jussieu 75005 Paris


Gold catalysis, homogeneous as well as heterogeneous, has raised since the

beginning of the 2000s considerable interest from the chemists’ community. Since the work of Teles[1] in 1998 which demonstrated the fantastic ability of this metal to activate carbon-carbon multiple bonds, particularly alkynes, the number of publications dealing with gold catalysis will keep on increasing, and nowadays the synthetic power of this metal is no longer debatable.

In our laboratory, we paid attention to the reactivity of this metal towards allenes for the development of cyclization reactions. More precisely, we were interested in the now well-known 3,3-sigmatropic shift of propargyl acetates, an efficient tool for the in-situ generation of allenes, for the design of tandem processes leading to complex products of synthetic and/or biological interest.[2]

• OAcAcO [Au] [Au]

"3,3"further

reactivity In this field, we designed a new gold-catalyzed cascade starting from readily

available diynyl esters to give conjugated bisenones, a rarely encountered motif among the numerous molecules chemists are now able to synthesize. Besides, the synthetic value of these products is emphasized by the rearrangement they undergo in smooth acidic conditions, leading to complex carbocycles in a total diastereo- and regioselective manner. Scope and limitations of this reaction will be discussed.

[1] J. H. Teles, S. Brode, M. Chabanas, Angew. Chem. Int. Ed. 1998, 37, 1415. [2] N. Cadran, K. Cariou, G. Herve, C. Aubert, L. Fensterbank, M. Malacria, J. Marco-Contelles, J.

Am. Chem. Soc. 2004, 126, 3408; G. Lemiere, V. Gandon, K. Cariou, A. Hours, T. Fukuyama, A.

L. Dhimane, L. Fensterbank, M. Malacria, J. Am. Chem. Soc. 2009, 131, 2993.

71

Poster 39

A Functionalized Graphene-Supported Iron Catalyst for the Hydrogenation of Alkenes and Alkynes

Mario Stein, Bernhard Breit*

Institut für Organische Chemie und Biochemie, Freiburg Institute of Advanced Studies (FRIAS),

Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany


Hydrogenation reactions are considered one of the most valuable synthetic

transformations in organic chemistry. The hydrogenation of olefins and alkynes is typically catalyzed by heterogeneous catalysts based on precious metals such as palladium or platinum.[1] Due to their high costs and toxicity, iron catalysts have been explored as alternative.[2]

We herein report on the preparation of iron nanoparticles on chemically derived graphene and their successful application as a catalyst for the hydrogenation of alkenes and alkynes. Furthermore, several catalyst recovery and recycling methods will be presented.

[1] D. Astruc, F. Lu, J. R. Aranzaes, Angew. Chem. 2005, 117, 8062-8083, Angew. Chem. Int. Ed.

2005, 44, 7852-7872; Á. Molnár, A. Sárkány, M. Varga, Appl. Catal. A 2001, 173, 185-221; M.

Studer, H.-U. Blaser, C. Exner, Adv. Synth. Catal. 2003, 345, 45-65.

[2] S. Gaillard, J.-L. Renaud, ChemSusChem 2008, 1, 505-509.

72

Poster 40

Rhodium-Catalysed Hydroformylation of 1,3-Butadiene to Adipic Aldehyde Eszter Takács,a Peter Hofmanna,b*

aCatalysis Research Laboratory CaRLa, Im Neuenheimer Feld 584, 69120 Heidelberg, Germany; bInstitute of Organic Chemistry, University of Heidelberg, Im Neuenheimer Feld 270, 69120

Heidelberg, Germany


The rhodium-catalysed bis-hydroformylation of 1,3-butadiene has been

investigated both theoretically and experimentally. DFT calculations on the reaction mechanism performed for a novel family of highly n-selective chelating bidentate phosphite ligands predict that in the first hydroformylation step the branched (iso) addition of a rhodium hydride intermediate to 1,3-butadiene is slightly preferred over the normal (n) addition and forms stable rhodium 3-1-methallyl complexes.

The hydroformylation of these intermediates produces (E/Z)-3-pentenals and further products originating from them. Experimental studies have confirmed that for most ligands this is the dominant reaction pathway; however, the formation of 4-pentenal and 1,6-hexandial (adipic aldehyde) were also observed. These products result from the normal (n) addition of a rhodium hydride to 1,3-butadiene.

In this part of the research we focus our attention upon the design, synthesis and catalyst screening of new bisphosphite ligands and investigate their suitability as potential ligands in the double hydroformylation reaction of 1,3-butadiene to adipic aldehyde.

73

Poster 41

Synthetic and Mechanistic Studies of Au(I)-Catalyzed Hydroamination and Hydroalkoxylation of Allenes

Z. Jane Wang,a Diego Benitez,b Rebecca LaLonde,a William A. Goddard III,b Robert G. Bergman,a F. Dean Tostea*

aUniversity of California, Berkeley, bCalifornia Institute of Technology


In recent years, gold(I) complexes have emerged as powerful catalysts for the

activation of carbon-carbon multiple bonds.[ 1 ] In our exploration of these transformations, we have discovered the intramolecular addition of N-O, O-N, and N-N nucleophiles to allenes to form pyrazolidines, isoxazolidines and tetrahydrooxazines in good yield and enantioselectivity.[ 2 ] Additionally, the intermolecular variant of this reaction provided us with an opportunity to study the mechanism of the transformation in detail. Toward this goal, we have been able to determine the resting state of the gold specie in the catalytic reaction, the kinetic order of each component, the effect of ligand electronics on the overall rate, and the reversibility of the last steps of the reaction. Our studies suggest that the rate-limiting transition state for the reaction does not involve the nucleophile and that the active catalyst is monomeric in gold(I). Computational studies support an “outersphere” mechanism and predicts that a two-step, no intermediate mechanism may be operative.[3]

[1] D. J. Gorin, B. D. Sherry, F. D. Toste, Chem. Rev. 2008, 3351-3378. [2] R. L. Lalonde, Z. J. Wang, M. Mba, A. D. Lackner, F. D. Toste, Angew. Chem. Int. Ed. 2010, 49,

598-601.

[3] Z. J. Wang, D. Benitez, E. Tkatchouk, W. A. Goddard, F. D. Toste, J. Am. Chem. Soc. 2010, 132, 13064-13071.

74

Poster 42

Development of a Cobaloxime Catalyzed alkyl-Heck type Cyclization Matthias E. Weiss, Lukas Kreis, Alex Lauber, Erick M. Carreira*

Laboratorium für Organische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland


Since the discovery that Vitamin B12 mediated transformations involve discrete

alkyl-cobalt species, the chemistry of these versatile compounds has been the subject of intense investigation. During the course of an ongoing total synthesis project we formed a key C-C bond through a cobaloxime mediated alkyl-Heck type cyclization. Further study of this unusual reaction has allowed for the use of catalytic amounts of the cobalt species. The reaction has proven to be a highly functional group tolerant process and requires only catalytic amounts of an air and water stable cobaloxime. A stoichiometric amount of a weak base and irradiation with visible light is sufficient to convert alkyl iodides to the corresponding alkyl-Heck type cyclization products in good to excellent yields. This method has also enabled a concise synthesis of (±)-samin. A mechanistic working model is presented which involves deprotonation of a cobaloxime hydride to turn over the catalytic cycle.

75

Poster 43

Ethenolysis of Natural Rubber Stefanie Wolf, Herbert Plenio*

Organometallic Chemistry, TU Darmstadt, Petersenstr. 18, 64287 Darmstadt

e-mail: [email protected], [email protected]

The enforced shift from crude oil based chemistry to a chemistry relying on

renewable resources has initiated vigorous efforts to explore alternatives - primarily plant based substitutes. Polyolefins, such as natural rubber have been neglected so far - despite the fact that the annual production of NR in 2007 amounts to 9.7·106 t.[1] The high degree of stereoregularity of NR offers excellent chances for controlled polymer degradation by ethenolysis reaction which should lead to smaller isoprene oligomers with terminal double bonds.

To find the optimum reaction conditions, we used the linear triterpene squalene as

a model substrate for natural rubber.

Using (NHC)(NHCewg)RuCl2(indenylidene)[2] complexes catalyst loading of only

0.01 mol% [Ru] per double bond was found to be sufficient for the 75% conversion of squalene. The best catalysts for squalene ethenolysis were applied to the ethenolysis of natural rubber,[ 3 ] several isoprene oligomers were isolated and characterized by NMR spectroscopy and HR-MS.

[1] A. Corma, S. Iborra, A. Velty, Chem. Rev. 2007, 107, 2411-2502.

[2] L. H. Peeck, H. Plenio, Organometallics 2010, 29, 2761-2768. [3] S. Wolf, H. Plenio, Eur. Patent Application 2010, manuscript submitted for publication.

76

Poster 44

Mechanistic Studies of Allylic C-H Amination Mediated by Pt(II) and Pd(II) Complexes Featuring Small Bite-Angle Diphosphine Ligand dtbpm

(Bis-(di-t-butylphosphino)methane) Maria J. Ferreira,a Vladimir B. Romakh,a Carl Jokisch,b Xuan Ye,a Peter

Hofmanna,b*

aCatalysis Research Laboratory INF 584, 69120, Heidelberg, Germany; bOrganisch-Chemisches

Institut, University of Heidelberg, INF 270, 69120, Heidelberg, Germany


Allylamines are highly useful building blocks for organic synthesis, and are

ubiquitous in various biologically active compounds. Traditional synthetic methods for allylamines commonly rely on prefunctionalized starting materials (e.g. allyl chlorides, allylic alcohols and allyl isothiocyanate, etc.) for both reactivity and selectivity. Direct amination of allylic C-H bonds of unactivated alkenes represents an atom-economic, environmentally benign route for allylamines. We have demonstrated that a series of well-defined, electrophilic (�2-dtbpm)Pt(II)X2 and (�2-dtbpm)Pd(II)X2 complexes (dtbpm= bis(di-t-butylphosphino)methane; X=TFA, OTf) readily promote the stoichiometric C-H activation of a number of unactivated hydrocarbons (e.g. propene, cyclohexene, indene, etc.) to afford the corresponding (dtbpm)Pt(II)(allyl)X and (dtbpm)Pd(II)(allyl)X complexes. Nucleophilic attack of the allyl group of the (dtbpm)Pt(II)(allyl)X complex also proceeds smoothly in the presence of a secondary amine (e.g. piperidine) to yield a (dtbpm)Pt(II)( 2-aminopropyl)X complexes. The regeneration of the (dtbpm)Pt(II)(allyl)X species from the (dtbpm)Pt(II)( 2-aminopropyl)X complexes in the presence of alkenes and oxidants are under investigations.

77

Poster 45

Participants �ukasz Albrecht Aarhus University Center for Catalysis Department of Chemistry, Langelandsgade 140 DK-8000 Aarhus C, Denmark [email protected] Friedhelm Balkenhohl BASF SE GCB – M313 67056 Ludwigshafen, Germany [email protected] Carolina Blanco Institute of Chemical Research of Catalonia (ICIQ) Av. Països Catalans 16 43007 Tarragona, Spain [email protected] Siegfried Blechert Technische Universität Berlin Insitute of Chemistry Straße des 17. Juni 135 10623 Berlin, Germany [email protected] Gabriella Bodizs Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Hans-Herbert Brintzinger University of Konstanz Faculty of Chemistry 78457 Konstanz, Germany [email protected] John M. Brown The Dyson Perrins Laboratory South Parks Rd Oxford OX1 3QY, UK [email protected]

Jose Cabrera Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Peng Cao Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] René Döpp Institute of Organic Chemistry University of Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg, Germany [email protected] Reto Dorta University of Zürich Institute of Organic Chemistry Winterthurerstrasse 190 8057 Zürich, Switzerland [email protected] Pawel Dydio University of Amsterdam Van 't Hoff Institute for Molecular Sciences Science Park 904 1098 XH Amsterdam, The Netherlands [email protected] Anna Falk University of Cologne Institute of Organic Chemistry Greinstrasse 4 50939 Köln, Germany [email protected] Martin Fananas-Mastral University of Groningen Stratingh Institute for Chemistry Nijenborgh 4, 9747 AG Groningen, The Netherlands [email protected]

78

Sabine Fenner University of Göttingen Institute of Organic and Biomolecular Chemistry Tammannstrasse 2 37077 Göttingen, Germany [email protected] Eran Fogler The Weizmann Institute of Science 76100 Rehovot, Israel [email protected] David Ford Harvard University Dept. of Chemistry & Chemical Biology 12 Oxford Street Cambridge, MA 02138, USA [email protected] Greg Fulmer University of Washington Department of Chemistry Box 351700 Seattle, WA 98195-1700, USA [email protected] Lutz H. Gade University of Heidelberg Institute of Inorganic Chemistry Im Neuenheimer Feld 270 69120 Heidelberg, Germany and CaRLa - Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Daniel Gallenkamp Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr, Germany [email protected]

Lukas Gooßen Technische Universität Kaiserslautern Department of Chemistry – Organic Chemistry Erwin-Schrödinger-Straße Geb. 54 67663 Kaiserslautern, Germany [email protected] Karol Grela Polish Academy of Sciences Institute of Organic Chemistry ul. Kasprzaka 44/52 PO Box 58, 01-224 Warsaw, Poland [email protected] A. Stephen K. Hashmi University of Heidelberg Institute of Organic Chemistry Im Neuenheimer Feld 270 69120 Heidelberg, Germany [email protected] Bernhard Hauer University of Stuttgart Institute of Technical Biochemistry Allmandring 31 70569 Stuttgart, Germany [email protected] Peter Hofmann University of Heidelberg Institute of Organic Chemistry Im Neuenheimer Feld 270 69120 Heidelberg, Germany and CaRLa - Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Jessica Hoover University of Wisconsin-Madison Department of Chemistry 1101 University Avenue Madison , Wisconsin 53706-1396, USA [email protected]

79

Matthew Hughes Imperial College Department of Chemical Engineering & Chemical Technology London SW7 2AZ, UK [email protected] Núria Huguet Universidad Autónoma de Madrid Departamento de Química Orgánica, Facultad de Ciencias Cantoblanco 28049-Madrid, Spain [email protected] Nada Ibrahim Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Yanbiao Kang Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Clark Landis University of Wisconsin-Madison Department of Chemistry 1101 University Avenue Madison 53706 WI, USA [email protected] Jean-Baptiste Langlois University of Geneva - Sciences II Department of Organic chemistry 30, quai Ernest-Ansermet 1211 Geneva 4, Switzerland [email protected] Michael Limbach BASF SE GCB/C – M313 67056 Ludwigshafen, Germany and CaRLa - Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected]

Ronald Lindner Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Carl Liskey University of Illinois Department of Chemistry Box 58-6 CLSL A410 600 South Mathews Ave. Urbana, IL 61801, USA [email protected] Claudia Lohre University of Münster Institute of Organic Chemistry Corrensstrasse 40 48149 Münster, Germany [email protected] Audrey Mercier University of Geneva - Sciences II Department of Organic Chemistry 30, quai Ernest-Ansermet CH-1211 Geneva 4, Switzerland [email protected] Steffen Müller Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr, Germany [email protected] Robin Padilla Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Ilona Peuser University of Münster Institute of Organic Chemistry Corrensstr. 40 48149 Münster, Germany [email protected]

80

Herbert Plenio University of Darmstadt Eduard-Zintl-Institute of Inorganic and Physical Chemistry Petersenstrasse 18 64287 Darmstadt, Germany [email protected] Manojkumar Poonoth Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Joy Racowski University of Michigan Department of Chemistry 930 N. University Ann Arbor, MI 48109-1055, USA [email protected] Denise Rageot University of Basel Department of Chemistry - Organic Chemistry St. Johanns-Ring 19 4056 Basel, Switzerland [email protected] Sean Reed University of Illinois Department of Chemistry 270 Roger Adams Laboratory 600 South Mathews Ave. Urbana, IL 61801, USA [email protected] Caren Röben Institute of Chemical Research of Catalonia (ICIQ) Av. Països Catalans 16 E-43007 Tarragona, Spain [email protected] Lara Rodriguez Broncano University of Heidelberg Institute of Inorganic Chemistry Im Neuenheimer Feld 270 69120 Heidelberg, Germany [email protected]

Hiyam Salem Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Thibault Schmid School of Chemistry Purdie Building, North Haugh University of St Andrews St Andrews, KY16 9ST, UK [email protected] Christoph Schotes ETH Zürich Laboratorium für Anorganische Chemie HCI H239 Wolfgang-Pauli-Str. 10 8093 Zürich, Switzerland [email protected] Erik Schuster University of Heidelberg Institute of Organic Chemistry, Im Neuenheimer Feld 270 69120 Heidelberg, Germany [email protected] Todd Senecal Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge, MA 02139, USA [email protected] Antoine Simonneau Université Pierre et Marie Curie Paris 6 4 Place Jussieu 75252 Paris cedex 5, France [email protected] Mario Stein University of Freiburg Institute of Organic Chemistry and Biochemistry Albertstrasse 21a 79104 Freiburg i. Brsg., Germany [email protected]

81

Eszter Takacz Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected] Jane Wang University of California Department of Chemistry 619 Latimer Hall Berkeley, CA, 94720-1460, USA [email protected] Duncan Wass University of Bristol School of Chemistry Bristol BS8 1TS, UK [email protected] Mathias Weiss ETH Zürich Laboratory of Organic Chemistry HCI H335 Wolfgang-Pauli-Strasse 10 8093 Zürich, Switzerland [email protected] Stefanie Wolf University of Darmstadt Eduard-Zintl-Institute of Inorganic and Physical Chemistry Petersenstrasse 18 64287 Darmstadt, Germany [email protected] Xuan Ye Catalysis Research Laboratory Im Neuenheimer Feld 584 69120 Heidelberg, Germany [email protected]

82

Conference Venue: dai Deutsch Amerikanisches Institut Sofienstrasse 12 69115 Heidelberg Tel.06221/60730 Accomodation: Hotel Europäischer Hof Exzellenzhotel Heidelberg Friedrich-Ebert-Anlage 1 Rohrbacherstrasse 29 69117 Heidelberg 69115 Heidelberg Tel. 06221/5150 Tel. 06221/9150

Hotel Europäischer

Hof

ExzellenzhotelHeidelberg

83

Lunch Break O

pportunities R

estaurants / Cafés

1 “B

ismarckplatz”

B

ismarck S

quare, various small restaurants, offering international

cuisine e.g. Sushi, C

hinese, Turkish, Germ

an…

2 Petit Paris C

afé-Bistro

Fahrtgasse 18, daily changing lunch offers from

4,50 € 3

Medocs, C

afé and Restaurant

S

ophienstraße 7b, weekly changing lunch m

enu with 5 dishes from

5,50 €

4 Exotica N

atural Specialties (in Shopping- Arcade “C

arré”)

Rohrbacherstraße 8, salads, tapas, w

raps, vegetarian dishes, freshly squeezed juices and exotic fruits

5 Tiger and D

ragon’s Food Corner (in Shopping- A

rcade “Carré”)

P

oststraße 1, asian cuisine with various dishes, also to take aw

ay 6

Raja R

ani, Indian and Tandoori Restaurant

Friedrichstraße 15, indian and tandoori dishes from

3 to 10 €, also to take aw

ay, approx. 7 min. from

Bism

arck Square

7 C

hili’s, Café and R

estaurant

Plöck 93a, vw

ide choice of turkish dishes from 3 to 6 €, approx. 7

min. from

Bism

arck Square, free W

LAN

8 Essighaus, R

estaurant

Plöck 97, hom

e- style cuisine with lunch m

enu from 6,00 €

9 R

ossi, Café and R

estaurant

Rohrbacherstraße 4, daily special lunch offers in the am

bience of a traditional coffee house

Other points of interest

10 Bus- Stop, for excursion

11 DA

I

1

45

2

3

67

8

9

11

10

84

Documents

CaRLa Winter School 2011 Heidelbergcarla-hd.de/wp-content/uploads/2018/02/Abstract... · Homogeneous Gold Catalysis A. Stephen K. Hashmi 10:30 Coffee Break 11:00 Training Session