Synthesis of 2-Vinylindole-3-Acetic Acid Derivatives via Cyanide-Catalyzed Imino-Stetter Reaction

Abstract

A new method for the synthesis of 2-vinyl-indole-3-acetic acid derivatives from aldimines, which are derived from 2-aminocinnamic acid derivatives and alpha,beta-unsaturated aldehydes, via a cyanide-catalyzed imino-Stetter reaction is described. Various types of 2-aminocinnamic acid derivatives and alpha,beta-unsaturated aldehydes could be used in this protocol, and the desired 2-vinyl substituted indole-3-acetic acid derivatives were obtained in high yields. This cyanide-catalyzed imino-Stetter reaction was further extended to the preparation of indole-3-acetic acid derivatives bearing a carboxylic acid functionality at the 2-position, using aldimines obtained from glyoxylates and 2-aminocinnamic acid derivatives.