Cupreines and cupreidines: an emerging class of bifunctional cinchona organocatalysts

Angew Chem Int Ed Engl. 2006 Nov 20;45(45):7496-504. doi: 10.1002/anie.200602318.

Abstract

In the steadily expanding field of organocatalysis, cinchona alkaloids play a prominent role. Until the late 1990s, bifunctional catalysts based on this scaffold relied exclusively on the C9-hydroxy group as the hydrogen-bond donor. Recently, new cinchona catalysts have been developed that feature a phenolic OH group in the C6' position-a structural feature that allows a diverse set of reactions to be catalyzed in a highly stereoselective fashion. This Minireview describes the scope and modes of action of this new class of asymmetric bifunctional organocatalysts.