gold catalysis

1

Gold CatalysisGold Catalysis

Federica Stazi Ph.D.

Literature Meeting

Montréal, 11th April 2006

2

OutlineOutline

• General properties of gold:General properties of gold: - - The element - - Facts and myths

• Heterogeneous catalysis (briefly):Heterogeneous catalysis (briefly): - - Main characteristics

- - Examples: ethyne hydrochlorination, oxidations, hydrogenation, …

• Homogeneous catalysisHomogeneous catalysis - - Overview - - Gold as an oxidant - - Gold as an Lewis Acid

- - C-H activation

- - Alkyne activation

- - Allene activation

- - Asymmetric reaction

- - Recent literature

• ConclusionConclusion

• Questions?Questions?

3

Gold: The ElementGold: The Element

11

4


• Name: from the Sanskrit word Jval and the Anglo-Saxon gold.

Gold’s chemical symbol comes from the Latin word Aurum. Known

for at least 5500 years.

• Sources: generally in conjunction with silver, quartz (SiO2), calcite (CaCO3), lead,

tellurium, zinc or copper. 2/3 of the world’s gold comes from South Africa. It is

present in sea water: about 0.1 to 2 mg/ton, but no isolation method has been

developed.

• Characteristic: most malleable and ductile metal, good conductor of heat and

electricity, not attacked by oxygen or sulfur. Reacts with halogens (e.g. aqua regia

dissolved gold). Soft metal, so it is alloyed with others metals like Ag, Cu, Pt and Pd

to increase the strength (e.g. application in jewelry).

• Applications: the isotope Au-198 (half-life 2.7 days) used for treating cancer.

AuNa3O6S4 (gold sodium thiosulfate) used for arthritis. HAuCl4 (chlorauric acid)

used to preserve photographs by replacing the silver atoms.

5


• Electron configuration: [Xe] 6s1 4f14 5d10

• Oxidation States: from –I to III and +V

• Most common Gold (I) and Gold (III) complex, both used in homogeneous catalysis.

• Prices for 1g (STREM catalog 2004-06):

AuAu Pd Pd

PtPt RhRh RuRu

AuCl

86$

AuBr3

55$

HAuCl440$

PtCl 70$

PtO2

76$

Pt

110$

PdCl238$

Pd(OAc)2

52$

Pd2(dba)3

66$

RhCl(PPh3)

42$

RhCl3

136$

Rh(acac)2

134$

very

expensive

c.f. Christopher’s

presentation

PPh3AuCl 125$ (Alfa Aesar)

6

Gold: Facts and MythsGold: Facts and Myths

FALSE: • Gold is chemically inert and uninteresting

• Gold is expensive (cheaper than Platinum)

TRUE: • Gold is stable in the presence of oxygen and water

• Gold can be used for heterogeneous and homogeneous catalysis

“The use of gold as a catalyst is desirable when it shows similar activity as for a more

expensive catalyst or higher selectivity than a less expensive catalyst and when a new

transformation is possible”.

When is it convenient to use gold as a catalyst? (A. S.K. Hashmi Gold Bull. 2004, 51-65)

7

OutlineOutline





- - C-H activation





• ConclusionConclusion


8

HeterogeneousHeterogeneous Catalysis

Key Features: Key Features: • Particle size (1 and 10 nm in diameter)

• Nature of the support (transition metal oxide, carbon, zeolite)

Active Catalyst: supported small metallic gold particles

Advantages:Advantages: • High catalytic activity (small amounts are necessary)

• Mild conditions (low temperature, low pressure)

• Good resistance to deactivation

INDUSTRIAL APPLICATIONSINDUSTRIAL APPLICATIONS

G. J. Hutchings Catal. Today 2005, 55-61; C. W. Corti, R. J. Holliday, D. T. Thompson Catal. Today 2005, 253-261.

9

Heterogeneous CatalysisHeterogeneous Catalysis

1.1. Ethyne (acetylene) Hydrochlorination Ethyne (acetylene) Hydrochlorination

Cl+ HClAu/C

180 ºC

G. J. Hutchings J. Catal. 1985, 292-295; G. J. Hutchings Gold Bull. 1996, 123.

PVC market

Advantages: • 3x more reactive than the traditional HgCl2

• catalyst recycling

2. CO Oxidation at Low Temperature

CO CO2

air

CatalystIndustrial, environmental and domestic sectors

M. Haruta, T. Kobayashi, H. Sano, N. Yamada Chem. Lett. 4, 1987, 405.

Catalyst: Hopcalyte (mixed oxide of Mn and Cu)Anhydrous conditions necessary

Not active at ambient temperature

Au/Fe2O3 or Co3O4

More active and stable

Activity at -70 ºC

10


3. Oxidations Mediated by O3. Oxidations Mediated by O22

High temperatures are necessary (270 - 720 ºC) and product mixtures are observed.

OHOH

OHO

O

Na+O2 3 atm, NaOH aq 0.4 M

Catalyst

Catalyst: 1% Au/C (reagent/catalyst= 1000) conversion: 96% selectivity: 98%

1% Au/TiO2 conversion: 95% selectivity: 98%

5% Pd or Pt/C selectivity: 77%

OH

NH2

O

O

NH2

Na+O2 3 atm, NaOH aq 0.4 M

Catalyst

1% Au/C conversion: 22% selectivity: 100%

1% Au/Al2O3 conversion: 100% selectivity: 100%

5% Pd or Pt/C no reaction

S. Biella, G.L. Castiglioni, C. Fumagalli, L. Prati, M. Rossi Catal. Today 2002, 43-49.

11


3. Oxidations Mediated by O3. Oxidations Mediated by O22

S. Carrettin, P. McMorn, C. Fumagalli, P. Johnston, K. Griffin, G. J. Hutchings Chem. Commun. 2002, 696-697.

1% Au/graphite

conversion: 56%selectivity: 100%

O2 3 atm, NaOH aq

60ºC, 3h

5% Pt/C

conversion: 88%

55%

23%

O2 6 atm, NaOH aq

60ºC, 3h

selectivity: 63%

12


4. Selective Hydrogenation (under H4. Selective Hydrogenation (under H22 pressure) pressure)

P. Claus Appl. Catalysis A: General 2005, 222-229.

Extended studies on the size particles, supports and synthesis technique on the selectivity.

13


4. Selective Hydrogenation4. Selective Hydrogenation

S. Schimpf, M. Lucas, C. Mohr, U. Rodemerck, A. Bruckner, J. Radnik, H. Hofmeister, P. Claus Catal. Today 2002, 63-78.

Au/SiO2 Pt, Pd and Rh

14


5. Industrial Application: Commercial Uses (Patent)5. Industrial Application: Commercial Uses (Patent)

C. W. Corti, R. J. Holliday, D. T. Thompson Appl. Catalysis A: General 2005, 253-261.

15

OutlineOutline





- - C-H activation






16

Homogeneous CatalysisHomogeneous Catalysis

Key Features:Key Features:

• Soft transition metal, soft partners such as carbon are preferred.

• Often reactions are faster than other transition metals. In some cases a completely new

product is formed.

• Organogold intermediates undergo fast protodemetallation.

• Cross-coupling chemistry seems difficult due to the easy reduction (difficult oxidation) of

gold.

• It has been shown that often reactions are possible with both Au (I) and Au (III), so the

real catalytic species is not known. On the other hand, in some cases different products

are observed for the different oxidation states.A. S.K. Hashmi Gold Bull. 2003, 3-9; A. S.K. Hashmi Gold Bull. 2004, 51-65; A. S.K. Hashmi Angew. Chem. Int. Ed. 2005, 44, 6990-6993.

A. Arcadi, S. Di Giuseppe Curr. Org. Chem. 2004, 8, 795-812; A. Hoffmann-Roder, N. Krause Org. Biol. Chem. 2005, 3, 387-391.

• Low propensity for β-H elimination.

17


1.1. Gold as an oxidantGold as an oxidant

RS

R' RS

R'

O

5% Bu4N[AuCl4]

CH3NO2/ HNO376-97%

R= aryl or alkylR'= alkyl

ON

O

5% Na[AuCl4]

CH3NO2

+

35%

50 ºC

HNO3, NaNO2

F. Gasparrini, M. Giovannoli, D. Misiti, G. Natile, G. Palmieri Tetrahedron 1983, 39, 3181-3184 and 1984, 40, 165-170.

F. Gasparrini, M. Giovannoli, D. Misiti, G. Natile, G. Palmieri, L. Maresca J. Am. Chem. Soc. 1993, 115, 4401-4402.

O

O

O

5% AuCl3[OP(n-C12H25)3]

72%

5% AgSbF6/ [(H3C)3Si]O2

J. Sundermeyer, C. Jost DE 10041510 1999.

1.1 Thioether Oxidation

1.2 Oxidative Alkyne Coupling

1.3 Baeyer-Villiger Oxidation

18


2. Gold as a Lewis Acid2. Gold as a Lewis Acid

R

O O

R

NHCBz

NH2

O

OBz

R

O

R

O NHCBz

CH2Cl2 r.t R= Ph 99%

+5% AuCl3.H2O

Me 65%

R= Ph 78%

S. Kobayashi, K. Kakumoto, M. Sugiura Org. Lett. 2002, 4, 1319-1320.

R R'

O O

R''NH

R''' R R'

N OR'''R''

5% NaAuCl4

EtOH r.t.

+

A. Arcadi, M. Chiarini, S. Di Giuseppe Green Chemistry 2003, 5, 64-67.

2.1 Michael Addition

2.2 Carbonyl-amine condensation

19


2. Gold as a Lewis Acid (continue)2. Gold as a Lewis Acid (continue)

O NH

I

O

Ph

NH2 O

Ph

N

99%

CuI 10%ZnCl2 41%AgNO3 24%Na2PdCl4 60 %

90%

CH3COO- NH4+, Benzene reflux, AcOH 70%

62%

Benzene reflux, p-TsOH 61%

RR'

O

X

NH2

O

R''

R'

RN

R''

X

2.5% NaAuCl4

EtOH, r.t.

+

A. Arcadi, M. Chiarini, S. Di Giuseppe, F. Marinelli Synlett 2003, 203-206.

2.3 Friendländer Quinoline Synthesis

20


2. Gold as a Lewis Acid (continue)2. Gold as a Lewis Acid (continue)

N

COOEt

Ph

N

Ph

COOMe

N

Ph

COOPh

N

Ph O

N

Ph

F

83%

CuI 0%ZnCl2 43%AgNO3 0%Na2PdCl4 0%

87% 62%

150 ºC, 4h 70% H2SO4, AcOH reflux 86%

87%

100-120 ºC, 80%

81%

A. Arcadi, M. Chiarini, S. Di Giuseppe, F. Marinelli Synlett 2003, 203-206.

21


3. C-H Activation3. C-H Activation

NAu

ArCl

Cl

Ph

Ar

PhAuCl3ArH2,6-lutidine THF, 50 ºC

Ar= benzene, toluene, xylene, mesitylene, cumene, methoxybenzene, chlorobenzene

Y. Fuchita, Y. Utsunomiya, M. Yasutake J. Chem. Soc., Dalton Trans. 2001, 2330-2334.

Ar'

Ar

Ar'

Ph Ph

OH

Ph

Br

AuCl3 (1.5%)ArH

CH3NO2, 50 ºC

+AgSbF3 (3%)

16-95%

86% 90% 30%

Hydroarylation of Alkynes

M. T. Reetz, K. Sommer Eur. J. Org. Chem. 2003, 3485-3496.

22



PhAr

Ph

Ar H

[Au]

Ar

Ph

[Au]

COOEt

Ar COOEt

Ar H

L[Au]

Ar COOEt

L[Au]

L[Au]

[Au]

+ H+

+

(Z)+ H+

+

n+ (n-1)+

n+

+ +

+

2Z. Shi, C. He J. Org. Chem. 2004, 69, 3669-3671.

Proposed Mechanism:

COOEt

Ar COOEt2AuCl3 (5%)

ArH

DCE, r.t AgOTf (15%) 74-99%

+(Z)

or

1AuPPh3Cl (1%) BF3.OEt (15%) CH3NO2, r.t

1M. T. Reetz, K. Sommer Eur. J. Org. Chem. 2003, 3485-3496.

M. T. Reetz, K. Sommer Eur. J. Org. Chem. 2003, 3485-3496.

23



Z. Shi, C. He J. Org. Chem. 2004, 69, 3669-3671.

Z. Shi, C. He J. Am. Chem. Soc. 2004, 126, 5964-5965.

Y. Luo, C. -H. Li Chem. Comm. 2004, 1930-1931.

X. Yao, C. -H. Li J. Am. Chem. Soc. 2004, 126, 6884-6885.

Also applied to diene, triene and cyclic enol ethers!

Li and Al. Org. Lett. 2005, 7, 673-675.

24


4. Alkynes Activation 4. Alkynes Activation

4.1 Nucleophilic Addition to Alkynes

1Y. Fukuda, K, Utimoto J. Org. Chem. 1991, 56, 3729-3731.

RRR

R

O

RR

OMeMeO

RR

O

RR

OMe

1Na[AuCl4] (2%)

H2O: MeOH (reflux)

> 90%

1Na[AuCl4] (2%)

MeOH (reflux) > 80%

90%

2[Au(PPh3)CH3] (2%)

MeOH (reflux)

H+

+

10%

2J. H Teles, S. Brode, M. Chabanas Angew. Chem. Int. Ed. 1998, 37, 1415-1418.

O-Nucleophile

N-Nucleophile

3Y. Fukuda, K, Utimoto Synthesis. 1991, 975-978.

TetrahydropyridineR'

NH2

R''

N

R'

R''

3Na[AuCl4] (5%)

CH3CN (reflux)

> 90%

25


4. Alkyne Activation 4. Alkyne Activation


2A. Arcadi, G. Bianchi, F. Marinelli Synthesis 2004, 4, 610-618.

R

O

O

OR'

R

O

N

R''

OR'

N

R''

O

R

OR'

O

OR'

O

Na[AuCl4] (5%)

EtOH

+

50-100%

40 ºC

Na2PdCl2 (5%)EtOH 40 ºC

up to 70%

5-exo-dig

R= Me, Ph R'= Me, Et, Ph

R"NH2

R"= Ph, Bz, Ar, Ts, CH2COOEt

Pyrroles1

1A. Arcadi, S. Di Giuseppe, F. Marinelli, E. Rossi Adv. Syn. Catal. 2001, 5, 343-6346.

Indoles2

26




Pyridines

G. Abbiati, A. Arcadi, G. Bianchi, S. Di Giuseppe, F. Marinelli, E. Rossi J. Org. Chem. 2003, 68, 6959-6966.

O

N N

PhN

N

Ph

N

O N

NH

NH

78% 78% 57%

60%

65%

27




Pyridines

G. Abbiati, A. Arcadi, G. Bianchi, S. Di Giuseppe, F. Marinelli, E. Rossi J. Org. Chem. 2003, 68, 6959-6966.

NaAuCl4 2.5 %

EtOH reflux

46-98%

6-endo-dig

28


4. Alkyne Activation4. Alkyne Activation

A. S. K. Hashmi, T. M. Frost, W. Bats J. Am. Chem. Soc. 2000, 122, 11553-11554.

4.2 Furan Isomerisation

R R

R

3 4

Same conditions!

R R

29



A. S. K. Hashmi, T. L. Ding, W. Bats, P. Fischer, W. Frey Chem. Eur. J. 2003, 9, 4339-4345.

4.2 Furan Isomerisation: Synthesis of Jungianol

75% 0% 0%

68% 21%7% Jungianol

30



N. Asao, T. Nogami, S. Lee, Y. Yamamoto J. Am. Chem. Soc. 2003, 125, 10921-10925.

4.3 Benzoannulation

AuX3

Cu(OTf)2

AuX3

1 3

11

31



4.4 5-exo-dig and 5-endo-dig Carbocyclisation

Conditions: 1% Au(PPh3)Cl, 1% AgOTf

CH2Cl2, r.t 5 min to 24 h

J. J. Kennedy-Smith, A. T. Staben, F. D. Toste J. Am. Chem. Soc. 2004, 126, 4526-4527.

1

2 34

5

5-exo-dig

93%5-exo-dig

32



4.4 5-exo-dig and 5-endo-dig Carbocyclisation

A. T. Staben, J. J. Kennedy-Smith, F. D. Toste Angew. Chem. Int. Ed. 2004, 43, 5350-5352.

1

2 3

45

5-endo-dig

33



4.5 Cycloisomerisation

C. Nieto-Oberhumber, M. Paz Munoz, E. Bunuel, C. Nevado, D. J. Cardenas, A. M. Echavarren Angew. Chem. Int. Ed. 2004, 43, 2402-2406.

34



4.5 Cycloisomerisation (continue)

2C. Nieto-Oberhumber, M. Paz Munoz, E. Bunuel, C. Nevado, D. J. Cardenas, A. M. Echavarren Angew. Chem. Int. Ed. 2004, 43, 2402-2406.

MeOOC

MeOOC

MeOOC

MeOOC OMe

MeOOC

MeOOC

MeOH (reflux)

AuCl3 (5%)1

16h

98%

[Au(PPh3)Me] (3%)2

MeOH, rt

97%

[Au(PPh3)Cl] (2%)2

25 min

4h

AgSbF6 (2%)

HBF4 (6%),

91%

1M. Mendez, M. Paz Munoz, E. Bunuel, C. Nevado, D. J. Cardenas, A. M. Echavarren J. Am. Chem. Soc. 2001, 123, 10510-10520.

97%

Au(I) Au(I) vs.vs. Au(III) Au(III)

PtClPtCl22 shows broader scope shows broader scope

35


4. Alkynes Activation4. Alkynes Activation

4.5 Cycloisomerisation (Nolan)

97%

1P. De Frémont, N. M. Scott, E. D. Stevens, S. P. Nolan Orgaometallics. 2005, 24, 2411-2418. 2S. P. Nolan and al. Chem. Commun. (ASAP).

3 S. P. Nolan and al. Angew. Chem. Int. Ed. (on press).

N N

Au

Cl

[Au(IPr)Cl]

N-Heterocyclic Carbene Gold(I) Complex [Au(NHC)Cl]

36


55. . Allene ActivationAllene Activation

5.1 Cycloisomerisation of α-hydroxyallenes1,2

1A. Hoffmann-Roder, N. Krause Org. Lett. 2001, 3, 2537-2538.

97%

2N. Krause, A. Hoffmann-Roder, J. Canisius Synthesis 2002, 12, 1759-1774.

Classical conditions: HCl(g) in CHCl3

or stoichiometric AgNO3

37



5.2 Cycloisomerisation of α-amino-1 and α-thioallenes 2

1N. Morita, N. Krause Org. Lett. 2004, 6, 4121-2123.

97%

3-pyrrolines

2,5-dihydrothiophenes

2N. Morita, N. Krause Anew. Chem. Int. Ed. 2006, 45, 1897-1899.

AuCl (5%)88%

38



Proposed Mechanism:

97%

In the case of α-thioallenes more investigation are necessary to established the catalytic species!

39


6. Asymmetric Reactions6. Asymmetric Reactions

R

O

CN

COOMe

NO

R COOMe

NO

R COOMe

N

PPh2

NMe2

PPh2

Fe

CH2Cl2 r.t

1% [Au(c-HexNC)2]BF4-

83-100%

+1% chiral ligand

dr 9:1, ee 96%chiral ligand =

I. Yoshihiko, M. Sawamura, T. Hayashi J. Am. Chem. Soc. 1986, 108, 6405-6406.

6.1 Asymmetric Aldol Condensation

Proposed transition state:

40



P. F. Hughes, S. H. Smith, J. T. Olson J. Org. Chem. 1994, 58, 5799-5802.

6.1 Asymmetric Aldol Condensation

threo-3-hydroxylysine

balanol

90%

dr 19:1%

ee > 99%

41



M.P. Munoz, J. Adrio, J.C. Carrettero, A.M. Echavarren Organometallics 2005, 24, 1293-1300.

6.2 Asymmetric Cycloisomerisation

5% PtCl2, MeOH, (S)-TolBINAP, 80ºC94%, 48% ee (-)

42



C. Gonzalez-Arellano, A. Corma, M. Iglesias, F. Sanchez Chem. Commun. 2005, 3451-3153.

6.3 Asymmetric Hydrogenation

43


Recent Literature: Nucleophilic Attack to Unactivated Alkenes Recent Literature: Nucleophilic Attack to Unactivated Alkenes

1C.-G. Yang, C. He J. Am. Chem. Soc. 2005, 127, 6966-6967.

1 2

3

2J. Zhang, C.-G. Yang, C. He J. Am. Chem. Soc. 2006, 128, 1798-1799.

3C. Brouver, C. He Angew. Chem. Int. Ed. 2006, 45, 1744-1747.

44

ConclusionConclusion

Au (I) or Au (III)? Au (I) or Au (III)?

A. W. Someck, M. Rubina, V. Gevorgyan J. Am. Chem. Soc. 2005, 127, 10500-10501.

R R R

1 2 3AuCl3

Au(PEt3)Cl

Toluene, 5 min to 3 days

X X

XX= Cl, Br, I

45

[[[(Dimethylammino)methylene]amino]-methylene]dimethylammonium Chloride[[[(Dimethylammino)methylene]amino]-methylene]dimethylammonium Chloride11

Br

O

Br

O

N

NH2

O

Br

N

O

N

N+

N

NMe2Cl N

N

NMe2

NH

R

N

N

R

N

NMe2

GR, MeONa

MeOH, reflux

GR, i-PrONa

i-PrOH, reflux

74%

91%

RNH2 + +

It is a brown solid and it is a β-dimethylaminomethylenating agent for ketones and amines2

N+

N NCl

2J. T. Gupton, C. Colon, C. R. Harrison, M. J. Lizzi, D. E. Polk J. Org. Chem. 1980, 45, 4522-4524.

1Encyclopedia of Reagents for Organic Synthesis (Ed L.A. Paquette) Vol3, 1995, 2014.

Questions?Questions?

What is the What is the GoldGold’s reagent?’s reagent?

46

Questions?Questions?

What is the What is the difference between pink, yellow and white golddifference between pink, yellow and white gold??

Pink: Pink: alloy ofalloy of gold and coppergold and copper

White: White: alloy of gold, silver and palladium, coated with rhodiumalloy of gold, silver and palladium, coated with rhodium

Yellow: Yellow: alloy of gold with other metalsalloy of gold with other metals (Karat: measure of gold purity, 24K is pure (Karat: measure of gold purity, 24K is pure gold)gold)

gold catalysis

Documents

oxidant gold

water gold

uninteresting gold

anglosaxon gold

common gold

worlds gold

hashmi gold bull

aqua regia dissolved