Asymmetric sulfa-Michael additions

Numerous asymmetric methods have been developed over the past 30 years to effect the Michael reaction of sulfur donors and Michael acceptors. Many of these stoichiometric and catalytic methods are complementary to one another, each having a certain range of substrate tolerance. Organocatalysis has a place at the origin of this field in the discovery of cinchona alkaloid catalyzed sulfa-Michael reactions. At the same time, it is involved in the current state-of-the-art as several elegant tandem processes that employ secondary amine catalysts and involve initial sulfa-Michael additions have been developed.