Enantioselective 1,4-addition of kojic acid derivatives to β-nitroolefins catalyzed by a cinchonine derived sugar thiourea

Abstract

A highly enantioselective Michael addition reaction of kojic acid derivatives to β-nitroolefins has been accomplished using a cinchonine derived sugar thiourea. The reaction provides the corresponding Michael adducts in excellent yields with a high degree of enantioselectivity (up to 99% ee) in short reaction time with low catalyst loading. The Michael adducts are found to exhibit promising cytotoxicity against various cancer cell lines.