Organocatalytic asymmetric Henry reaction of isatins: Highly enantioselective synthesis of 3-hydroxy-2-oxindoles

Abstract

Organocatalytic asymmetric Henry reaction of isatins with nitromethane has been achieved with the use of C₆′-OH cinchona alkaloid catalyst, affording 3-substituted 3-hydroxy-oxindoles in excellent yields and high enantioselectivities, and this method was successfully applied to the total synthesis of (R)-(+)-dioxibrassinin.