AuCl3 catalyzed [3 + 2 + 1] cycloaddition: first use of aldehyde as a carbon monoxide-like one carbon synthon for triple C–C coupling

Abstract

A new [3 + 2 + 1] cycloaddition strategy is demonstrated using an aldehyde, an aldimine of a glycine ester and a terminal triple bond with AuCl₃ catalyst. Aldehyde is exploited as the first alternative to the crucial partner CO for triple C–C coupled annulation for the synthesis of novel fused-tricyclic heterocycles.