Enantioselective Michael addition of ketones to maleimides catalyzed by bifunctional monosulfonyl DPEN salt.

An unprecedented enantioselective Michael addition of various ketones to maleimides catalyzed by a simple bifunctional primary amine, monosulfonyl DPEN salt, is reported and provides the desired adducts in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 99%).