Enantioselective and diastereoselective Michael addition of ketone/aldehyde to trans-nitroolefins catalyzed by a novel chiral pyrrolidine-thiourea.

The direct Michael addition reaction of cyclohexanone/aliphatic aldehydes with nitroolefins, catalyzed by a novel chiral pyrrolidine-thiourea catalyst 1a, is described. The desired 1,4-adducts were obtained in moderate yields with enantioselectivities up to 99% ee and dr up to 99:1 of the syn product. (c) 2007 Wiley-Liss, Inc.