Bio Fuels, Chemicals and Materials A Walk on the Green ...biorefinery.utk.edu/posters/PT chemistry 21c.pdf• Efficient, Copper-Catalyzed, Aerobic Oxidation of Primary Alcohols by

Bio Fuels, Chemicals and MaterialsA Walk on the Green Side of

Sustainability

Art J. RagauskasSchool of Chemistry and Biochemistry

Georgia Institute of Technology

Top Global Challenges

• ENERGY• WATER• FOOD• CHEM 2312• ENVIRONMENT • TERRORISM & WAR

GT Chem 2312 Students

Global Challenges Energy/Sustainability

Production

Research Opportunities: New Industrial EconomyDavid Morris - early 1980s • Coined the term "carbohydrate economy"• Envisaged shifting society's engine toward renewable, environmentally benign

materials from agro/forestry-based materials

- Agricultural Risk Protection Act of 2000 Title III: Biomass R&D Act of 2000, established the Biomass Research & Development Board.

Dr. Arden L. Bement, Jr.Director, National Science Foundation

Defining a Biobased EconomyAn economy based on renewable raw materials to produce products and energy in a sustainable manner

Biofuels – Biomaterial FutureBiomass Resources

OO

O OAcO

O

HOOAc

O

HOO

OO

AcOOH

O-XylanO

O

HOOAc

OO

AcOOAc

O

O

HO

HO

OHO

OHO

HO OH

HO

O

O

HO

OH

O

O

O

H3CO

OH

OH

OH

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O

OH

OH

O

OH

OH

OCH3HO

OCH3

O

HO

HO

H3COO

HO

HO OCH3

O

HOOCH3

OHO OH

OOH3CO

HO

HO

O

OH

OH

OCH3

OCH3

OH

OH

OOCH3

OO

OCH3

O

OCH3

HO

HO

OCH3

O

O

OCH3

HOO

HO

HO

OCH3

Lignin

PolymerDerived from

Coniferyl, Coumaryl,Sinapyl, Alcohol

Major Global Biopolymers Hemi

Cellulose

Short chainbranched,substitutedpolymer of sugarsDP: ~ 70 - 200

Cellulose

Polymer of β-(1,4)-glucan

DP: ~300 – 15,000

Content: ~ 35 – 50%

Cont

ent:

~ 20

-30

%Content: ~ 15 –

30%

Lignin

PolymerDerived from

Coniferyl, Coumaryl,Sinapyl, Alcohol

Major Global Biopolymers Hemi

Cellulose

Short chainbranched,substitutedpolymer of sugarsDP: ~ 70 - 200

Cellulose

Polymer of β-(1,4)-glucan

DP: ~300 – 15,000

Content: ~ 35 – 50%

Cont

ent:

~ 20

-30

%Content: ~ 15 –

30%

Lower Cost Higher AvailabilityNo Competition with Food Demand

BioResource Lignin : Hemicellulose : CelluloseSoftwood 0.66 0.68 1.00Hardwood 0.53 0.64 1.00Corn Stover 0.47 0.58 1.00Wheat Straw 0.60 0.55 1.00Fine Paper - 0.25 1.00Switch Grass 0.58 0.64 1.00

Biofuels – Biomaterials FutureIntegrated Biorefinery

The Path Forward for Biofuels and Biomaterials. Ragauskas, A.J.; Williams, C.K.; Davison, B.H.; Britovsek, G.; Cairney, J.; Eckert, C.A.; Frederick, W.J., Jr.; Hallett, J.P.; Leak, D.J.;

Liotta, C. L.; Mielenz, J.R.; Murphy, R.; Templer, R.; Tschaplinski, T. Science (2006), 311(5760), 484-489

The biorefinery is facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. It fully

utilizes all components of biomass to make a range of foods, fuels, chemicals, feeds, materials, heat and power in proportions

that maximizes sustainability.

Biofuels: Novel Oxidative Chemistry In Ionic Liquids

OH

OH

OCH3HO

OCH3

O

HO

HO

H3COO

HO

HO OCH3

O

HOOCH3

OHO OH

OOH3CO

HO

HO

O

OH

OH

OCH3

OCH3

OH

OH

OOCH3

OO

OCH3

O

OCH3

HO

HO

OCH3

O

O

OCH3

HOO

HO

HO

OCH3

C8 – C22

Need New Fundamental Green Chemistry StudiesCatalytic Oxidative System (s) Preferably in Ionic Liquid

• Inert solvent • Tailor solubility of lignin• Almost no vapor pressure• Facilitate isolation of oxidized fragments

OH

HO

O OCH3

O

OCH3

O

HO

O OCH3

O

OCH3

Oxid.

∼ C800 – C900

N NR1 R2

R2

N+R1R3

N

R

Imidazolium Pyridinium

+

R

R2

P+R1R3

R

Cations Salts

Ammonium Phosphonium

Anions

PF6 BF4

CF3SO3

(CF3SO3)2N

MeOSO3

AlCl4

Cl(Br)

+

Classical Ionic Liquids


Solvent TEMPO (R) Conversion/Selectivity (%) Yield (%)1. EtOAc as solvent H 36/97 312. CHCl3 H 38/99 363. [bmim]PF6 H 98/99 90

Yield GrandBut non-recyclable!

NNPF6

H2O2

2 H2O

2 HBr

Br2

Nitrosonium Ion

NOH

RCH2OHH R

NO

H R

2

H

H

NO

H R

NOH

H R

+

+ RCHO

PhCH2OH PhCHO40 °C/2 h

Model Compound StudiesModel Compound Studies

Initial Effort with TEMPO


OH O

40 oC, 2 h

Solvent TEMPO (R) % Conversion - % Selectivity % Yield1. [bmim]PF6 H 98/99 90

2. [bmim]PF6 NH-Ac 98/98 92Extracted - Reused3. [bmim]PF6 NH-Ac 98/98 90Repeated Three Additional Times6. [bmim]PF6 NH-Ac 98/96 91

First example of TEMPO ‘locked’ in an ionic liquid, can not be extracted with Et2O, n-Hexane

Easy and viable alternative to TEMPO-polymer agents

H2O2, HBr

NO

H R

[1-butyl-3-methylimidazolium] hexafluorophosphate


NNPF6

OH

R40 oC

H2O2, HBrNO

HN

O

Strengths• Acetamido TEMPO in 1-butyl-3-methyl

imidazolium hexafluorophosphate is recyclable• High yield for electron poor, slightly electron

rich benzylic alcohols• >96% selectivity for RCHO

Concerns• Need an expensive oxidant• Limited range of benzylic alcohols• HBr

Benzylic alcohols Conditions Products % Yield

CHO

MeO

CHOCH2OH

CHONC

92

83

81

93

72

91

83

_

87

CH2OH

CHO

CH2OH

CH2OH

CH2OH

CHO

Cl

CH2OH

NC CH2OH

Br CH2OH Br CHO

Cl

CHO

O2N

CH2OH

O2N

CHO

MeO CHO

2 eq. H2O2, 2 h

2 eq. H2O2, 3 h

2 eq. H2O2, 3 h

3 eq. H2O2, 4 h

5 eq. H2O2, 4 h

3 eq. H2O2, 4 h

4 eq. H2O2, 4 h

2 eq. H2O2, 2 h

2 eq. H2O2, 2 h

TEMPO-catalyzed oxidation of benzylic alcohols to aldehydes with the H2O2/HBr/ionic liquid [bmim]PF6 system.Tetrahedron Letters (2005), 46(19), 3323-3326.


NO NHO

OH

R ILs

Literature• Efficient, Copper-Catalyzed, Aerobic Oxidation of Primary Alcohols by I. E. Markóet al. Angew. Chem. Int. Ed. 43, 1588 (2004).• TEMPO/Copper Catalyzed Oxidation of Primary Alcohols to Aldehydes Using Oxygen as Stoichiometric Oxidant by D. GeiBlmeir et al. Montashefte fur Chemie136, 1591 (2005)

NNMe Bu

[bmim] [mmim] [bmpy]

NNMe Me

NBu Me N N

DMAP

0.05 equiv. Cu(II), 0.10 equiv. DMAP

0.05 equiv. acetamido-TEMPO ILs, O2 (1 atm), RT, 5 h

Run Copper salt Ionic Liquid Conversion (%) Yield (%)

147

44

52

87

4345

32

2

3

4 81

CuCl2 [bmim]PF6

[bmim]BF4

[mmim]OSO3Me

[bmpy]PF6

CuCl2

CuCl2CuCl2

CH2OHMeO CHOMeO


NNMe Bu

[bmim] [mmim] [ bmpy]

NNMe Me

NBu Me N N

DMAP

0.05 equiv. Cu(II), 0.10 equiv. DMAP

0.05 equiv. acetamido-TEMPO ILs, O2 (1 atm), RT, 5 h

CH2OHMeO CHOMeO

Exp. Copper Salt Ionic Liquid Conversion(%) Yield (%)4 CuCl2 [bmpy]PF6 87 81 5 Cu(OAc)2 [bmpy]PF6 66 596 CuBr2 [bmpy]PF6 91 887 Cu(ClO4)2 [bmpy]PF6 99 918a Cu(ClO4)2 [bmpy]PF6 4 --9b Cu(ClO4)2 [bmpy]PF6 0 --10c --- [bmpy]PF6 0 --

a No DMAP added; b No Acetamido-TEMPO added; c No CuII salt added


Entry Alcohols Time (h) Product Convn/Yield(%)

1

2

3

5

6

7

8

CHO

MeO

CHOCH2OH

CHOO2N

4

99/92

98/90

100/90

99/91

99/84

CH2OH

CH2OH

Br CH2OH Br CHO

Cl

CH2OH

O2N CH2OH

Cl

CHO

MeO CHO

MeO

MeO

CH2OH MeO

MeO

CHO

CH2OH CHO

5

5

5

5

5

5

5

5

98/92

100/81

96/89

0.05 equiv. Cu(ClO4)2, 0.10 equiv. DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2 (1 atm), RT, 5 h

ArCH2OH ArCHO

Oxidation of:

1. Alkyl substituted

2. Electron withdrawing

3. Electron rich


11

OH

Ph

Ph CHO

OH

Ph Ph CHOOH

OH

( )6 OHCHO

( )6

24(40 C)

O

O

13

14

15

16

.

5

24(40 C)

24 RT 40 C

24 RT 40 C

94/61

100/54

-

-

100/89

OH CHO 100/7712

MeO CH2OH MeO CHO

Ph CHO17 4

97/75

12/-

5

Ph OH24 48/26

NCHO

NCH2OH

S CH2OH S CHO9

10

5

5

99/88

97/79

0.05 equiv. Cu(ClO4)2, 0.10 equiv. DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2 (1 atm), RT, 5 h

RCH2OH RCHO

Entry Alcohols Time (h) Product Convn/Yield (%)

(8:1)


Strength• Acetamido-TEMPO ‘locked’ in

1-butyl-4-methylpyridinium hexafluorophosphate and easily recycled for five runs without significant loss of catalytic activity

• A mild and efficient aerobic oxidation of primary alcohols in [bmpy]PF6• High selectivity to aldehydes and no over-oxidized product observed• Good tolerance toward heteroatom (S and N) containing compounds• Electron rich benzylic alcohols oxidized

Concerns• Will not oxidize secondary alcohols

Copper(II)-Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes in Ionic Liquid[bmpy]PF6. Organic Letters (2005), 7(17), 3689-3692.

CH2OH

OMe

CHO

OMe0.05 equiv. Cu(ClO4)2, 0.1 equiv. DMAP

0.05 equiv. acetamido-TEMPO [bmpy]PF6, O2, RT

1 5 99 912 5 96 913 5 94 924 8 93 855 8 87 81

run time (h) conversion (%) yield (%)

Biofuels: Novel Oxidative Chemistry Ionic Liquids Proposed Rxn Mechanism

CuIIN N

NN

ICuII

N N

NN

ORH H

H

II

NNHAcO

CuIINN

N

NH OR

HH III

N NHAcOH

CuIINN

N

NOR

H

H

IV

CuIN N

NNHN

NHAcO

N NHAcOH

1/4 O2

1/2 H2O

RCH2OH

NNHAcO

RCHO

N NHAcOH

1/4 O2

1/2 H2O

N. Jiang, A. J. Ragauskas Org. Lett. 2005, 7, 3689


ILs, O2

CHOCH2OH

R R

O

O

V

2

Vanadium Oxyacetylacetonate: VO(acac)2

O

Oxovanadium


Entry Ionic Liquid Additive Convn/sel % Yield

1

62/>99

28/>99

31/>9952/>99

37/>99

59/>99

2420

43

17

49

234

7

5

51

64/>99 586

[bmim]BF4

[bmim]PF6

[hmim]OTf[bmpy]PF6

[bmim]PF6

[bm2im]BF4

[bmpyr]NTf2

51/>998 [bmim]PF6

90/459 [bmim]PF6

98/>9910 [bmim]PF6

-DMAP

DABCO

Et3NEt3NEt3NEt3N

Et3N

Et3N

Pyridine

DBU40

91

N

N

DABCO

N

N

DBU (1,8-diazabicyclo[5.4.0]undec-7-ene)

N N

DMAP

0.05 equiv. VO(acac)2

ILs, O2, 80 °C, 6hCHO

OMe

CH2OH

OMe

High selectivityvirtually no over-oxidation

for all except DBUNN

Bu Me

[hmim] [bmim] [bm2im] [mmim] [bmpy] [bmpyr]

NNMe Me

NNHex Me

NNBu Me

Me

NBu MeN

Bu Me

Oxovanadium

Biofuels: Novel Oxidative Chemistry InIonic Liquids

0.05 equiv. VO(acac)2,

0.10 equiv. DABCO[bmin]PF6, O2, 80-100 °C

RCH2OH RCHOEntry Alcohols Time (h) Product Convn./Yield (%)

1

2

3

5

6

7

8

9

CHO

MeO

CHOCH2OH

CHOO2N

4

99/96

98/90

100/95

98/91

22/

CH2OH

CH2OH

Cl

CH2OH

O2N CH2OH

Cl

CHO

MeO CHO

OH

Ph CHO

Ph Ph CHOOH

MeO

MeO

CH2OH MeO

MeO

CHO

6

6

12

12

9

24*

6

O

11

12

13

14

12

12

98/86

14/ (100 C)

100/87

-

-

100/87 (100 oC)

10

94/82

6*

Ph OH

NCHO

NCH2OH

S CH2OH S CHO

MeO

HO

CH2OH MeO

HO

CHO

6*12

94/90 (100 oC)35/29

6*

12

99/91 (100 oC)

OH O

Ph24* <5/ (100 oC)PhOH O

6* 96/85 (100 oC)-

96/94

0.05 equiv. VO(acac)2,

0.10 equiv. DABCO[bmim]PF6, O2, 80 °C

Recycling of VO(acac)2 aerobic catalytic system for 4-methoxybenzyl alcohol into aldehyde

CH2OH

OMe

CHO

OMe

1 6 98 912 6 93 873 9 97 92

Run Time (h) % Conversion % Yield

Strengths:• Aerobic catalytic• Tolerant for hetero-atoms• Electron rich/poor benzylic hydroxyl groups• Oxidizes 1o and 2o benzylic hydroxyl groups• First oxovanadium oxidation system in ILConcerns• noneVanadium-catalyzed selective aerobic alcohol oxidation in ionic liquid [bmim]PF6 Submitted Tet. Lett.

Biofuels: Novel Oxidative Chemistry Ionic Liquids Proposed Rxn Mechanism

VOX2

PhCH2OH O2, L

LVO2X

OH

VOHO X

OL

LV(OH)2X

O

0.5 O2

H2O

X = acac and L = DABCO

Oxovanadium Oxidation

(IV)

(V)

Novel Oxidative Green Chemistry

• Better to prevent waste than treat it

• Raw materials should berenewable

• Catalytic reagents aresuperior to stoichiometric reagents


Entry Ligand Additive Conversion (%)c Yield (%)

1

21

90

5345

56

76

414530

84

234

7

5

Optimization of Aerobic Oxidation of 4-Methoxybenzyl Alcohol with Acetamido-TEMPO in DMSO (4 h).a

66

85 706

DMAP

TMDPTMDP

TMDP

nonenonenonenone

BipyPhen

TMDP

K2CO3

KOH

968 Et3N

1009 TMDP DABCO10010e

TMDP

DABCOTMDP9911 Et3N

- (No HNAc-TEMPO)

pyridine

-

9096

aReaction condition, 0.06 mol equiv. acetamido-TEMPO, 0.04 mol equiv. Cu(ClO4)2·6H2O, 0.04 mol equiv. %, 4 h. e Reaction was run for 2h. f Water (0.1 mL) was added. g No acetamido-TEMPO was added. h No TMDP was added.

_

11e, f DABCO

-

TMDP100TMDP

012e,g

13e,h DABCOTMDP

0DABCO

9192 (2h)

94 (H2O)

Question: Can CuII/Acetamido-TEMPO catalyze aerobic oxidations in other solvents/Me2SO?

N NN N

N NN

N

2,2'-bipyridine Bipy

1,10-phenanthrolinePhen DABCO

trimethylenedipyridine TMDP

0.04 equiv. Cu(ClO4)2, 0.04 equiv. L

0.06 eqival. acetamido-TEMPO0.1 equiv. additive, DMSO, RT, O2R2

R1

OH

R2

R1

O

Entry R Cycle #

% Conversion % Yield

1 4-MeOPh 100/90 94/89 88/82

0.04 equiv. Cu(ClO4)2, 0.04 equiv. TMDP

0.06 equiv. acetamido-TEMPO, O2 0.1 equiv. DABCO, DMSO, RT

RCH2OH RCHO

2 Ph 100/85 93/92 90/89

3 3-ClPh 99/93 95/85 92/90

4 4-MePh 100/92 96/91 89/83

5 trans-PhCH=CH 99/93 93/84 90/87

Recycling of the Catalytic System for Aerobic Oxidationof Benzylic andAllylic Alcohols

1 2 3


Entry Alcohols Product Time (h) % Conversion % Yield

Aerobic CatalyticOxidation of Alcohols in DMSO with Cu2+/Acetamido-TEMPO

1

2

3

5

6

7

CHO

MeO

CHOCH2OH

4 CH2OH

CH2OH

Cl

CH2OH

Cl

CHO

MeO CHO

Ph CHO

Ph Ph CHOOH

( )6 OHCHO

( )6

CH2OH CHO

2 100 98

2 98 90

2 99 93

2 100 92

24 19 11

2 100 92

9

2 99 93

OH CHO

8

2 100 85

Ph OH24 (40 oC) 71 40

24 (40 oC) 58 33

10

11

NCHO

NCH2OH 2 98 71

S CH2OH S CHO2 99 92

N

N

DABCO

N N

trimethylenedipyridine TMDP


0.06 eqival. acetamido-TEMPO 0.1 equiv. DABCO, DMSO, RT, O2R2

R1

OH

R2

R1

O

For Compounds 1 – 7Turn-over Frequency (TOF) of 12.5/h were achieved, which for a RT reaction is very good


Entry Alcohols Product Time (h) % Conversion % Yield

Aerobic CatalyticOxidation of Alcohols in DMSO with Cu2+/Acetamido-TEMPO

OH

OH

O

O

13

14

15

24 35 27

-

-

MeO CH2OH MeO CHO

18

1.57 -

OH O 24 (40 oC) 87 74

PhOH Ph

O

24 (40 oC) 98 90

16

24 (RT/40 oC)

24 (RT/40 oC)

12

24 (40 oC)

OH O

PhOH Ph

OOH O

-

-

97 75

95 84

- -

Ph Ph CHOOH 98 85

Ph CHOPh OH 4 -1.517

N

N

DABCO

Cu(II)-Catalyzed Selective Aerobic Oxidation of Alcohols under Mild Conditions. Journal of Organic Chemistry 71, 7087 (2006). 4,4'-trimethylenedipyridine (TMDP)

N N


0.06 equiv. acetamido-TEMPO 0.1 equiv. DABCO, DMSO, RT, O2R2

R1

OH

R2

R1

O

Conclusions

• Acetamido-TEMPO is‘locked’ in DMSO

• Highly selective and no over oxidation

• Amendable to hetero atoms

• Recyclable• Novel green chemistry

oxidative system

14:1

24:1

Novel Oxidative Green Chemistry Solvent Re-use* at ‘End-of-Life’

PiperyleneSulfone (PS)

S

O O

+ SO2

Piperylene Sulfone: A “Labile” and Recyclable DMSO SubstituteD. Vinci, M. Donaldson, J.P. Hallett, E.A. John, P. Pollet, C. A. Thomas, P.G. Jessop, Charles L. Liotta. C.A. Eckert

Additional collaborative studies ongoing …Enhanced Green Chemistry Oxidation

*

Retro-cheletropic

ConcertedCheletropic

CH2OH

OMe

CHO

OMe 0.01 equiv. CuBr, 0.02 equiv.DMAP

0.02 equiv. acetamido-TEMPO O2 (1atm), PS, RT, 3 h

1 100 96 33.32 95 88 31.73 85 82 28.3

run conversion (%) yield (%) TOF (h-1)

S CHOCHO

S CH2OHCH2OH

CH2OH

CHO

Cl

98% 92% 91% 94%

CH2OH

Cl

CHO


Laccase

Novel Oxidative Green ChemistryLaccase: Overview

Laccase

Laccase

•• Oxidoreductase enzyme••Reduces OReduces O2 to H2O2

concomitantly oxidizesconcomitantly oxidizes• MW varies 65,000-140,000.• Carbohydrate content ~10-45 (% wt).

•Catalysis occurs due to 4 copper atoms/active site

• Active sites near surface

Active sites on surface

E.I. Solomon et al

Cu1+

HisN

Cu1+

SCys

Cu1+

NHis

1+Cu

Type II

Type III

Type I

HO

H

Fully Reduced

Cu2+

OH

SCys

Cu2+

Cu2+

HisN O NHis

2+Cu

H

Fully Oxidized

O2

Laccase employed as a green oxidation agent for:• Phenols, Allylic alcohols• Carbohydrates

Potential for Novel Laccase Initiated Cascade Chemistry

OH

OH

R

Laccase

O2 - H2O

X

Para

or

OrthoQuinone

O

O

RX

O

O

R

X

Novel Oxidative Green ChemistryLaccase Initiated Cascade Chemistry

OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrsH2O

The Effect of Laccase Dose on the Formation of Compound 3

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

500 U/ 1g subatrate1000 U/ 1g substrate2000 U/ 1g substrate4000 U/ 1g substrate

The Effect of Laccase Dose on the Formation of Compound 4

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25Reaction time (hr)

Yiel

d (%

)

500 U/ 1g subatrate1000 U/ 1g substrate2000 U/ 1g substrate4000 U/ 1g substrate

O

MeO

O


OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrs

The Effect of Temperature on the Formation of Compound 3

0102030405060708090

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

25 °C 50 °C 70 °C

The Effect of Temperature on the Formation of Compound 4

0102030405060708090

100

0 5 10 15 20 25

Reaction time (hr)

Yiel

d (%

)

25 °C 50 °C 70 °C

O

MeO

O

O

O

MeO

NR > 100 oC

H2O


OH

OH

MeOO

MeO

O

O

O

MeO

1 2 3 4

Laccase, O2

50 oC, 24 hrs

OH

OH

MeO

O

O

MeO

Laccase+

Diels-Alder

O

MeO

O

Diels-Alder

O

MeO

O

[O]

O

MeO

OCompound 3

[O]

O

MeO

O

[O]

O

MeO

OCompound 3

O

MeO

O

[O]

Compound 4

O

MeO

O

[O]

O

MeO

O

[O]

Compound 4

[Ox]

[Ox]

H2O

Laccase

One-pot cascade chemistry


OH

OH

R1

R2

R3

R4

R5

O

O

R1

R2

R3

R4

R5

R1

R2

R3

R4

R5

O

O

O

O

R1

p-Hydroquinone Diene Products (% yield)

1a: R1 = OMe 2a: R2 = R5 = H, R3 = R4 = Me 3a (10 %) 4a (60 %)

1a 2b: R2 = R4 = H, R3 = R5 = Me 3b (9 %) 4b (55 %)

1a 2c: R3 = R4 = H, R2 = R5= Me 3c (46 %) no product formed

1a 2d: R2 = R5 = H, R3 = R4 = OMe no product formed 4c (12 %)

1a 2e: R3 = R4 = R5 = H, R2 = OMe no product formed 4d (79 %), R2 = H

1a 2f:

1b: R1 = Me 2a 3d (20 %) 4e (22 %)

1b 2c 3e (19 %) no product formed

1b 2d no product formed 4f (4.28 %)c

1b 2e no product formed 4g (40 %), R2 =H

1c: R1 = Br 2a no product formed 4h (21 %)

1b

1c

2f

2f

3f (64 %)

3g (49 %)

3h (51 %)

1 2 3 4

New green chemistry 1-pot synthesis of 1,4-naphthoquinones and related structures in water!New Application of Laccase in Cascade Chemistry

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New green chemistry synthesis of 1,4-, 1,2-naphthoquinones and related structures employing an environmentally benign oxidizing agent/laccase and solvent/water.

Studies ongoing…

OH

OHLaccase - O2

R

O

O R

O

O

O

O

O

O

H3CO

34%

77%

57%

H2O

Green Chemistry: Laccase Initiated Cascade Chemistry via Ortho Quinones Rxn Mechanism

O

O

O CH3 O

O

O CH3

H

B

HH+

O

O

H

B

B

O

HO

HH B

OH

HOLaccase

O

O

O2

Green Chemistry: Laccase Initiated Cascade Chemistry via Para Quinones Rxn Mechanism

O

O

H3COH

OH

O

H3CO

OH

O

H3CO

B

OH

OH

H3CO

H B

Laccase

O2O

O

H3CO

H HB

O

O

H3CO

H HB

O

O

H3CO

H HB

OH

O

H3CO

H H B

OH

OH

H3COLaccase

O2

O

O

H3CO

Biofuel - Bioethanol

BiofuelResearch Challenges

Biofuel

Enzymatic Hydrolysis of Cellulosics

Biofuels: Enzymatic Hydrolysis of CellulosicsBackground

NativeCellulose Iα and Iβ

• I – IV Polymorphs• Amorphous• Paracrystalline

Cellulose II:

anti-parallel

Elementary fibril

Microfibril

Cellulose: Iα is more abundant in lower plants/bacteriaIβ is more abundant in higher plants

Analysis of Cellulose Crystallinity: X-ray, NMR, FT-IR

O

OO

CH2OH

OHO

OH

HOOH

CH2OH1

2

3

45

6

4

1

C-1

C-4

C-2, 3, 5

C-6

Biofuels: Enzymatic Hydrolysis of Cellulosics

Question: What role, if any, does cellulose ultra structure have on enzymatic hydrolysis?

Cellulase from Trichoderma reesei

0 5 10 15 20 253

4

5

6

7

8

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙβCellulose: Iβ

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Glu

cose

yie

ld, %

Pulpavicel

Cellulose: Iα

0 5 10 15 20 252.5

3.0

3.5

4.0

4.5

5.0

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

ΙαCellulose: Iα


• Cellulolytic filamentous fungus

cellobiohyrolasesendoglucanasesβ-glucosidasesNREL

0

20

40

60

80

100

0 10 20 30 40 50

Hydrolysis Time, h

Post

-hyd

roly

sis p

erce

ntag

e, %

avicelpulp

• First study quantifying changein para-crystalline phase

• First to quantify changes in ultrastructure of kraft celluloseafter cellulase treatment

• Complements recent study byHayashi on cellulase changes toIα:Iβ from Cladophora microcryst.cellulose

CP/MAS 13C NMR analysis of cellulase treated bleached softwood kraft pulp. Carb. Res. (2006), 341(5), 591-597.


0 5 10 15 20 25

33

34

35

36

37

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

Para-crystallinePara-crystalline

0 5 10 15 20 25

46

48

50

Rel

ativ

e in

tens

ity, %

Hydrolysis time, hr

AmorphousAmorphous

NanoligninNanocellulose

Nanohemicellulose

Structures – Materials - Composites

Defining the Opportunities, Challenges, and Research Needs for NanoBiomaterials Derived from Lignocellulosics

Nanocellulosem

10 nm

1 nm

µmmm

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

OO

HOOH

OO

HOOH

OH

OH

O

HOOH

OO

HOOH

O-Cellulose

OH

OH

O

Surface AreaFully Exfoliated Clay ∼ Cellulose Nanocrystals > Fumed Silica > Graphite >> Paper Fiber > E-glass Fibers

TensileCarbon Fibers > Cellulose Nanocrystals > > S-Glass > Aramid

100 nm100 nm

Nanocellulose

1. Mechanical Milling40 mesh

2. H+, 45 oC

Pine Cellulosic Fiber

2.7 x 0.07 mm

1. Mechanical Milling2. Pre-swell NaOH – DMSO3. Acidic Ultrasonification(s) 0

50100150200250300350400450500

0 2 4 6 8 10

Time (hour)

Siz

e (n

m)

020406080

100120140160180200

0 1 2 3 4

Size

(nm

)

0.7050 – 100 nm Nanocellulose Balls -Cellulose II


0.61Original Fibers – Cellulose 1

Crystallinity indexSample



0.61Original Fibers – Cellulose 1

Crystallinity indexSample

Cellulose Whiskers100-250 nm length5-15 nm width.

NanocelluloseBalls

0

500

1000

1500

2000

2500

3000

3500

4000

0 1 2 5 10 20

% Cellulose

Tens

ile E

nerg

y A

bsor

ptio

n

Whiskers

Acacia Fibers

Nanocellulose - Composites

0200400600800

100012001400

TEA

Latex nanoball whisker acacia

Cellulose Whiskers

Cellulose 80 nm Nanoball

Acacia Fibers (0.66 mm)

PolystyrenePLA

Acrylic Latex

Acrylic Films + 5% Nanoballs + 5% Whiskers

Same benefits observed for Tensile and Strain Properties

Investigation into Nanocellulosics versus Acacia Reinforced Acrylic Films - Accepted in Composites Part B (Biocomposites - Invited)

Nanocellulose - Composites• Cellulose Whiskers

– Composites• Biodegradable, Conventional

Polymers• Crosslinked Whiskers for

Film/Barrier Properties– Oxidized

• Hydrophilic Materials– Surface Functionalized

Whiskers• Cellulose Balls

– Drug delivery– Templating– Oxidized/Sulfonated

• Viscosity modifiers

• Self Assembly on Paper – ‘Lotus Effect’ hydrophobic

coatings

New Biocomposites/Biomaterials with Physical Properties not readily AccomplishedWithout Fundamental Design of Molecular Properties

Exploring The Fundamental Chemistry of Bio-Renewable Polymers

2003 – Current

Research Vision

Leader in SustainablePolysaccharide/Lignin

Chemistry

Polysaccharide/Lignin Modification

New Materials

Oligo - Polysaccharide Synthesis

New Biological Tools

Polysaccharide/Lignin Depolymerization

New Resources forBiofuels and Biopolymer

Exploring The Fundamental Chemistry of Bio-Renewable Polymers - Future

Leader in SustainableGreen Chemistry

Polysaccharide/Lignin Modification**

Partial Review

Oligo - Polysaccharide Synthesis

Biological Tools **

Polysaccharide/Lignin Depolymerization

Today’s Presentation

29 Additional Publications** since 2003, including• Beilstein Journal of Organic Chemistry (2006), 2(12) (27Jun 2006)• Tetrahedron Letters (2006), 197• Carbohydrate Research (2005), 340, 2812• Carbohydrate Polymers (2006), 65, 179• Industrial & Engineering Chemistry Research (2006), 45(13), 4509• Journal of Applied Polymer Science (2006), 99, 1346 • Chemical Engineering Communications (2006), 193(6), 683• Canadian J. Chemistry. (2005), 83(12), 2132 • Biotechnology Letters (2005), 27(11), 753 • Biotechnology Progress (2005), 21(4), 1302 • Cellulose (2005), 12(2), 185 • European Polymer J. (2004), 40(3), 477

Acknowledgements

Acknowledgments

• GA Tech– J. Cairney, Y. Deng, – C. Eckert, J. Frederick– L. Gelbaum, J. Hsieh, – C. Liotta, S. May, – J. Muzzy, ZL Wang

• ORNL– B. Davison

• ICL– G. Britovsek, R.

Murphy, C. Williams

• ARS USDA– C. Ziemier

• Forest Services USDA– T. Elder

• Chalmers University of Technology– P. Gatenholm

• North Carolina State University– H. Jameel

AcknowledgmentsProgram Sponsors

• National Science Foundation• NRI USDA Cooperative State

Research, Education and Extension Service

• DARPA – ARO• Department of Energy• Georgia Research Alliance• Georgia TIP3• GA Tech CEO• AtlanTICC Alliance• Gunnar Nicholson Foundation• Chevron• Diversa Corp.• Abitibi-Consolidated Inc.

• Hercules Incorporated• International Paper Company• Asia Pacific Resources• International Holdings Ltd.• Longview Fibre Paper and

Packaging• MeadWestvaco Corp.• Bowater, Inc.• Mitsubishi Heavy Industries• Buckman Laboratories International• Stora Enso North America• Eka Chemicals Inc.• Temple-Inland Corp.• Georgia-Pacific Corp.• Weyerhaeuser Company

Thank You!

AcknowledgementsKay Gilstrap; Gregory Abrams; Shirley Tomes; Jean Gunter; Lloyd Williams; Pat Johnson, Lavon Hunter; Teri Hansen, Marian Pena

David Bell, Suzy Briggs

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