Yb(OTf)3-catalyzed allenation/ cycloisomerization reaction with propargylic alcohols and amides : a facile synthetic approach to oxazole and its derivatives.

Abstract

An efficient method for allenation/cycloisomerization reaction of propargylic alcohols with amides in the presence of Yb(OTf)3 (5 mol %) at 100oC to afford oxazoles in moderate to excellent yields is reported herein. The method features ease of starting material preparation, use of a low cost and ecologically benign Lewis acid as catalyst under operationally simplistic conditions.