Enantioselective organocatalytic Michael Addition of ketones to alkylidene malonates

Organocatalysts bearing sulfide or sulfone functions () were studied for the direct asymmetric Michael addition of ketones and alkylidene malonates. The organocatalyst (S)-2-((naphthalen-2-ylthio)methyl)pyrrolidine, bearing a pyrrolidine and a sulfide moiety, showed a very high catalytic activity in the absence of additives. The reaction condition is mild, and the Michael adducts were obtained in very good enantioselectivities (up to 96%), diastereoselectivities (up to >95:5), and chemical yields (up to 95%). Chirality 24:600-605, 2012. © 2012 Wiley Periodicals, Inc.