Direct Asymmetric Mannich-Type Reaction of α-Isocyanoacetates with Ketimines using Cinchona Alkaloid/Copper(II) Catalysts

The enantioselective direct Mannich-type reaction of ketimines with alpha-isocyanoacetates has been developed. Excellent yields and enantioselectivity were observed for the reaction of various ketimines and a-isocyanoacetates using cinchona alkaloid/Cu(OTf)(2) and a base. Both enantiomers of the products could be obtained by using pseudoenantiomeric chiral catalysts. This process offers an efficient route for the synthesis of alpha, beta-diamino acids.