Direct Cross-Coupling Reaction of Simple Alkenes with Acrylates Catalyzed by Palladium Catalyst

12 Pages·2009·1.19 MB·English

Direct Cross-Coupling Reaction of Simple
Alkenes
with Acrylates Catalyzed by Palladium Catalyst
Yun-He Xu, Jun Lu, and Teck-Peng Loh
J. Am. Chem. Soc., Article ASAP
Current Literature
Chenbo Wang @ Wipf Group
Jan 17, 2009
Chenbo Wang @ Wipf Group Page 1 of 12 1/18/2009
Preparation of Diene Units with Cross-coupling
Reactions: Classical Cross-coupling Reactions vs.
Direct Cross-Coupling Reaction of Simple Alkenes
The challenge:
•Chemoselectivity: dimerization
•Stereoselectivity: cis/trans
•Difficulty in activating alkene C-H without a directing group
•Product stability
Chenbo Wang @ Wipf Group Page 2 of 12 1/18/2009
Construction of Diene Units in Natural Product Synthesis:
Suzuki Reaction
O O O
OMOM PPh3,CBr4; OMOM 8B8u%3SnH,Pd(PPh3)4; OMOM
Ph O Ph O Ph O
Br
O
Br Br
OBn
OBn
1.2,5-dimethylhexa-2,4-diene,BH DMS,THF,
3.
OH O 2.H O,thenaq.CH O,
2 2 OH O
3.KHF ,acetone,MeCN,H O;99%
OMOM 2 2
OMOM
O
O
Br Br
BF K
3
H
N
BnO
Pd(PPh ) ,
3 4
O
Cs CO
TH2F/H3O OH O OMOM OH O OH N
2
OMe
42%
O O
OximidineII
Molander, G. A. et al J. Am. Chem. Soc., 2004, 126, 10313
Chenbo Wang @ Wipf Group Page 3 of 12 1/18/2009
Construction of Diene Units in Natural Product Synthesis:
Negishi Reaction
Panek, S. J. et al J. Am. Chem. Soc. 2002, 124, 11368
Chenbo Wang @ Wipf Group Page 4 of 12 1/18/2009
Construction of Diene Units in Natural Product Synthesis:
Stille and Heck Reaction
OMe OMe Bu3Sn SnBu O
3
1.Pd(MeCN) Cl ,DMF/THF
2 2
2.CAN,THF/H O
2
NH C70rC%l2,CHI3; NH 3.5H4F%,CoHv3eCrN3;steps NH
TBSO OMe O TBSO OMe O HO O O
O
TIPSO O OMe TIPSO I I OMe HO OMe
(+)-mycotrienol
MeO OMe C8H17 C8H17 C8H17
1.KHMDS,PhNTf ;90%
2
2.TsOH,actone/H O;80% OTf Pd(PPh ) ,K CO ,MeCN;50%
O 2 3 4 2 3
3.Ph PCH Br,KOtBu;95%
3 3
H H H H H H
O O O O O O
O O O
Intermediateinthetotalsynthesisof taxol
Panek, J. S. et al J. Am. Chem. Soc. 1998, 120, 4123
Danishefsky, S. J. et al J. Am. Chem. Soc., 1996, 118, 2843
Chenbo Wang @ Wipf Group Page 5 of 12 1/18/2009
Alkene Dimerization Reaction: Previous Work
Ishii, Y. et al Org. Lett. 2004, 6, 4623 and references therein
Kohll, C. F. and Van Helden, R. Recl. Trav. Chim. Pays-Bas 1967, 86, 1930
Chenbo Wang @ Wipf Group Page 6 of 12 1/18/2009
The First Practical Example of Oxidative Alkene-alkene
Oxidative Coupling
Ishii, Y. et al Org. Lett. 2004, 6, 4623
Chenbo Wang @ Wipf Group Page 7 of 12 1/18/2009
Proposed Mechanism for Oxidative Alkene-alkene
Oxidative Coupling
Chenbo Wang @ Wipf Group Page 8 of 12 1/18/2009
Direct Cross-Coupling Reaction of Simple Alkenes
:
with Acrylates Optimization of Reaction Conditions
Chenbo Wang @ Wipf Group Page 9 of 12 1/18/2009
Direct Cross-Coupling Reaction of Simple Alkenes
with Acrylates: Substrate Scope
Suitable substrate
for this methodology:
Chenbo Wang @ Wipf Group Page 10 of 12 1/18/2009