N-heterocyclic carbene-catalyzed Mukaiyama aldol reactions.
N-Heterocyclic carbenes were shown to be highly effective catalysts to promote Mukaiyama aldol reactions. In the presence of only 0.5 mol % of N-heterocyclic carbene (5), various aldehydes and 2,2,2-trifluoroacetophenone underwent Mukaiyama aldol reactions in THF with trimethylsilyl ketene acetal (2) at 23 degrees C as well as with trimethylsilyl enol ether (7) at 0 degrees C to afford aldol adducts in good yields. These conditions are extremely mild and operationally simple and tolerate various functional groups. [reaction: see text]
Song
Jinhua J
JJ
Department of Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Old Ridgebury Road/P.O. Box 368, Ridgefield, CT 06877-0368, USA. jsong@rdg.boehringer-ingelheim.com
Tan
Zhulin
Z
Reeves
Jonathan T
JT
Yee
Nathan K
NK
Senanayake
Chris H
CH
D000098:Acetophenones / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D004987:Ethers / Q000737:chemistry; D006838:Hydrocarbons / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008956:Models, Chemical; D013237:Stereoisomerism; D013696:Temperature; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
D000098:Acetophenones; D000447:Aldehydes; D004987:Ethers; D006838:Hydrocarbons; D014297:Trimethylsilyl Compounds; C030011:carbene; C116609:3-hydroxybutanal; D008697:Methane