Abstract
Catalytic desymmetrization of cyclic anhydrides has been widely investigated in the field of organocatalysis. Using this approach, many stereocenters can be established in a single, symmetry-breaking transformation. Herein, a thiourea organocatalyst was prepared in a single step from a chiral diamine, (R,R)-1,2-diphenylethylenediamine, and used for the desymmetrization of various cyclic anhydrides through double hydrogen-bonding activation. The asymmetric ring-opening reaction of the cyclic anhydride proceeded via the enantioselective addition reaction catalyzed by diamine thiourea. Thiolysis afforded the desired products in the yields of 86-98% and enantioselectivities of 60-94%, while aminolysis afforded the yields of 90-94% and enantioselectivities of 90-95%.