Facile approach to multifunctionalized 5-alkylidene-3-pyrrolin-2-ones via regioselective oxidative cyclization of 2,4-pentanediones with primary amines and sodium sulfinates

Abstract

A multi-component cascade cyclization reaction of readily available 2,4-pentanediones, primary amines and sodium sulfinates is reported. Highly functionalized 5-alkylidene-3-pyrrolin-2-ones were efficiently synthesized in moderate to excellent yields under mild conditions. This cascade cyclization was achieved by direct regioselective transformation of C(sp³)–H bonds at two weakly nucleophilic sites in the enaminone intermediate while two strongly nucleophilic sites of the structure were not involved.