L-Prolinol as a highly enantioselective catalyst for Michael addition of cyclohexanone to nitroolefins

Though many chiral amines such as L-proline and its derivatives have proven to be versatile catalysts in many reactions, L-prolinol was seldom used as organocatalyst for reactions. Herein, we report the first L-prolinol catalyzed asymmetric Michael addition of cyclohexanone to nitroolefins in the presence of benzoic acid to afford Michael adducts with high diastereoselectivities (87:13->99:1) and enantioselectivities (82-96%). (C) 2009 Elsevier Ltd. All rights reserved.