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Andy BrusoeAlexanian Lab
2
Nucleophilicityp y
Acidity and basicity
3Brotzel, F.; Chu, Y.C.; Mayr, H. J. Org. Chem., 2007, 72 3679
L t t iti t lLate transition metalsGreater functional group tolerance
Enantioinduction must occur concurrent with C-N bond formationNo imine reductions
Focus heavily on most recent chemistry
Most widely studied examples
4
H d i tiHydroaminationAlkenes, Alkynes, Allenes
Allylic AminationAllylic Amination
Carbene and Nitrene InsertionsCarbene and Nitrene Insertions
5
ChallengesPoisoning of catalyst with aminesProducts reacting as nucleophilesRegioselectivityRegioselectivitySmall thermodynamic driving forceProduct racemization
6
7Zhou, J; Hartwig, J. J. Am. Chem. Soc., 2008, 130, 12220
PNH2ArH Ir NHAr
P
NH2ArHArHN
IrP
NHArP
H
IrP
P
H
NNHArArHN H
Ar
H
8
IrP NHAr
PNHArZhou, J; Hartwig, J. J. Am. Chem. Soc., 2008, 130, 12220
9Zhou, J; Hartwig, J. J. Am. Chem. Soc., 2008, 130, 12220
Au(I)Ln*Cl
AgOTf
Au(I)Ln*
R2N H
R2N Au(I)Ln*
H
Au(I)Ln*
2 n
10Zhang, Z; Lee, S.D.; Widenhoefer, R. A. J. Am. Chem. Soc. 2009, 131, 5372NHR2
N o-tolyl
80%63% ee
H
Ph
11Shen, X.; Buchwald, S.L.; Angew. Chem. Int. Ed. 2010, 49, 564Liu, Z.; Hartwig, J. J. Am. Chem. Soc. 2008, 130, 1570
O PhPCy2
Cy-Mop =
NfNNf
MeO
93%98% ee
H
Narsireddy, M; Yamamoto, Y. J. Org. Chem. 2008, 73, 9705 12
NPh HX
Ph
Pd0Ln
XPd(II)HLn
N
NNf
Nf
Pd(0)Ln
NHNf
PhXPd HLn
H PhNf
PhPd Ln
HX
H
XLnPd(II)
Ph
HNH
Nf
Nf
NHNf
XLnPd(II) Ph
13
Yamamoto et al.J. Am. Chem. Soc., 2004, 126, 1622J. Org. Chem. 2006, 71, 4270J. Org. Chem. 2008, 73, 9705
HNNf
Ph
HPd(II)LnX
HTos n pentylCbz H
N
80%98% ee
TosN n-pentyl
PhPh
86%98% ee 86%6% ee
14LaLonde, R. L.; Sherry, B.D.; Kang, E. J.; Toste, F.D. J. Am. Chem. Soc. 2007, 129, 2452Zhang, Z.; Bender, F. B.; Widenhoefer, R. A. Org. Lett. 2007, 9, 2887
N
2
R1N
R12.5% BiarylAu2Cl2
5% AgClO4N
R2
Ph Ph Ph
HCbz
H HCbz Cbz
NCbz H
NCbz H
R2R2m-Xylene
rt, 24 hR1
PhPh
PhPh
PhPh
N
i-Pr
PhPh
(Z)63%
(E)31%
N
C6H13
PhPh
(Z)90%
(E)9% 63%
95% ee31%
67% ee90%91% ee
9%9% ee
N
HCbzN Et
Cbz H
N t-BuCbz H
i-Bu
PhPh
(Z)72%
(E)27%
C6H13
(Z)70%
PhPh
(E)16%
PhPh
(E)50%
(Z)2%
15Zhang, Z.; Bender, F. B.; Widenhoefer, R. A. J. Am. Chem. Soc., 2007, 129, 14148
87% ee 54% ee 84% ee 47% ee rac 2% ee
N
2
R1N
R12.5% BiarylAu2Cl2
5% AgClO4N
R2
Ph Ph Ph
HCbz
H HCbz Cbz
NHCbz NHCbz A LH Cbz Cb
R2R2m-Xylene
rt, 24 hR1
PhPh
PhPh
PhPh
NHCbz
PhPh
•
Et
BiarylAu2Cl2
AgClO4
NHCbz
PhPh
•
Et
AuL N
PhPh
AuL
Et
HH Cbz Cbz
N
PhPh
Et
H
BiarylAu2Cl2AgClO4
H CbzNHCbz
PhPh
•Et
BiarylAu2Cl2
AgClO4
NHCbz
PhPh
•Et
AuLN
PhPh
AuL
EtH
H Cbz CbzN
PhPh
EtH
16Zhang, Z.; Bender, F. B.; Widenhoefer, R. A. J. Am. Chem. Soc., 2007, 129, 14148
H d i tiHydroaminationAlkenes, Alkynes, Allenes
Allylic Amination
Carbene and Nitrene Insertions
17
ChallengesPoisoning of catalyst with aminesProduct reacting as nucleophileProduct racemizationProduct racemizationRegioselectivity▪ Most metals give reaction at less substituted terminus
18
Not cheap, but not rhodium[Ir(COD)Cl]2 1g = $115 [Rh(COD)Cl]2 1g = $255 PdCl2(COD) 1g = $62[Ir(COD)Cl]2 1g $115, [Rh(COD)Cl]2 1g $255, PdCl2(COD) 1g $62
Preferentially gives branched substitution products
Phosphoramidites are most commonly used ligandsReadily available, easily made
OO
P N
Ar
Ar
OO
P Cl HN
Ar
Ar
OHOH
PCl3
19
OP N
Ph
20Ohmura, T.; Hartwig, J. J. Am. Chem. Soc., 2002, 124, 15164
OP N
Ph
Phosphoramidite
21
Weinhofen, R.; Tverskoy, O; Helmchen, G. Angew. Chem. Int Ed., 2006, 45, 5546Pouy, M. J.; Leitner, A.; Weix, L. D.; Weix, D. J.; Hartwig, J. F. Org. Lett., 2007, 9, 3949Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc., 2009, 131, 8971Stanley, L. M.; Hartwig, J. F. Angew. Chem. Int. Ed., 2009, 7841Welter, C.; Dahnz, A.; Brunner, B.; Streiff, S.; Dubon, P.; Helmchen, G. Org. Lett., 2005, 7, 1239
NH3Cl3
73%97%97% ee
NH3Cl
57%99% ee
22Pouy, M. J.; Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc. 2009, 131, 11312
ConsiderationsNature of [Ir]I
RegioselectivityRegioselectivityStereoselectivityRelative rates of amines as nucleophiles
23Kashio, M; Takeuchi, R. J. Am. Chem. Soc., 1998, 120, 8647Bartels, B.; Garcia-Yebra, C.; Rominger, F.; Helmchen, G. Eur. J. Inorg. Chem., 2002, 2569
IrClCl
Ir2 eq L1
IrL1Cl
Catalytically inactive
Catalytically active
24Kiener, C. A.; Shu, C.; Incarvito, C.; Hartwig, J. F. J. Am. Chem. Soc., 2003, 125, 14272
ligand conditions yield ratio A/B
P(OPh)3 RT, 3 h 89 96:4
PPh3 reflux, 16 h 6 24:76PPh3 reflux, 16 h 6 24:76
dppe reflux, 16 h 18 39:61
25Kashio, M; Takeuchi, R. J. Am. Chem. Soc., 1998, 120, 8647
26Madrahimov, S. T.; Markovic, D.; Hartwig, J.F. J. Am. Chem. Soc., 2009, 131, 7228
27Leitner, A.; Shu, C.; Hartwig J. F. Org. Lett., 2005, 7, 1093
28Leitner, A; Shu, C.; Hartwig, J.F. Proc. Natl. Acad. Sci. U. S. A., 2004, 101, 5830
29Yamashita, Y.; Gopalarathnam, A.; Hartwig, J. F. J. Am. Chem. Soc., 2007, 129, 7508
N NH 4 mol% [Ir]N
MeO2CO PhN NH
2 eq
BnNH22 eq
MeI4 mol% [Ir]K3PO4 1eq
THF, 50 °C Ph
N
Ph
NHBn
99%26 : 74
N N BnNHMe
5 : 95 26 : 7418 : 82
5 : 95(no K3PO4)
BnNH2 is 20x more nucleophilic BnNH2 is ~3x more nucleophilic
30Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc., 2009, 131, 8971
31
H d i tiHydroaminationAlkynes, Allenes, Alkenes
Allylic AminationAllylic Amination
Carbene and Nitrene Insertions
32
Factors that govern site of insertionStrength of bond being brokenSteric environment at center of reactivitySteric environment at center of reactivityStatistics
88 88 98 92 113
33
R R2
M N - H InsertionHN
R4R3 R R2
NR3 R4
HR R RR R R
RC
R2
H C - H InsertionMN
R3 RC
R2
NR3 H
H H
ChallengesStoichiometric oxidant present with reactive transition metalsOxidation of heteroatoms and ligandOxidation of heteroatoms and ligandLimiting cyclopropanation and aziridination
34
NHNs
86%
NHNs
82%86%74% ee
82%73% ee
35Reddy, R. P.; Davies, H. Org. Lett., 2006, 8, 5013
OO
BocN
OS
HN
98%92% ee
SOO
OOO
SHN
51%
OS
HN
OO
48%
36Zalatan, D. N.; Du Bois, J. J. Am. Chem. Soc., 2008, 130, 9220
51%54% ee
48%82% ee
OORh
O
37Fiori, K.W.; Du Bois, J. J. Am. Chem. Soc., 2007, 129, 562
O Rh
Rh2(esp)2
NORh Rh
PhthN
Rh2(PTPI)422%, 54% ee
120 mV
38Zalatan, D. N.; Du Bois, J. J. Am. Chem. Soc., 2008, 130, 9220
N
O
NPh
Ph
39Liu, B.; Zhu, S.; Zhang, W.; Chen, C.; Zhou, Q. J. Am. Chem. Soc., 2007, 129, 5834
O
Ph
Ligand
ArO
Ot BuNH2Boc
7% CuBr6% AgSbF68% ( ) bpy* Ar
O
Ot BuN2
Ot-Bu 8% (-)-bpy
DCE, rt
Ot-BuNHBoc
O
Ot-BuNHBoc
71%71%81% ee
OBr
Fe
O
Ot-BuNHBoc
86%
40Lee, E. C.; Fu, G. C. J. Am. Chem. Soc., 2007, 129, 12066(-)-bpy*
NFe
N86%85% ee
Highly enantio-enriched amines can be synthesized from alkenes, alkynes, allenes, activated allylic alcohols and activated C-H bonds.
F t d l t d d i lk h d i ti d C H b d i tiFuture developments are needed in alkene hydroamination and C-H bond insertions.
41
E ik Al iErik Alexanian
Alexanian GrouppKayla BloomeLiz ClineBen GiglioBen GiglioJustin GoodwinVal Schmidt
42
43
44
22
45
46
OCO Me
2% [Ir(COD)Cl]24% Phosphoramidite
8% TBDTHF rt
HN
N
OCO2Me THF, rt
69%, 99% eeH2N
N
CbzCl, K2CO3CH2Cl2, rt66 - 82%
CbzN CbzN1) HCl, Et2O2) Grubbs II
N
1) TsNHNH2NaOAc96 °C
2) LAH, THFrt
OO
P N
o-anisyl
N N92%N 85%
36% overall99% ee
47Welter, C.; Moreno, R. M.; Streiff, S.; Helmchen, G. Org. Biomol. Chem., 2005, 3, 3266
O
o-anisyl
Phosphoramidite