N-heterocyclic carbene catalyzed trifluoromethylation of carbonyl compounds.
[reaction: see text]. A novel N-heterocyclic carbene (NHC) catalyzed trifluoromethylation reaction of carbonyl compounds was discovered. Both enolizable and nonenolizable aldehydes and alpha-keto esters undergo facile trifluoromethylation with TMSCF3 at room temperature in the presence of only 0.5-1 mol % of the commercially available NHC (1), providing CF3-substituted alcohols in good yields. Selective trifluoromethylation of aldehydes over ketones can be achieved under NHC catalysis. These conditions are mild and simple and tolerate a variety of functional groups.
Song
Jinhua J
JJ
Department of Chemical Development, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Old Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368, USA. jsong@rdg.boehringer-ingelheim.com
Tan
Zhulin
Z
Reeves
Jonathan T
JT
Gallou
Fabrice
F
Yee
Nathan K
NK
Senanayake
Chris H
CH