Gold-Catalyzed Stereoselective Domino Cyclization/Alkynylation of N-Propargylcarboxamides with Benziodoxole Reagents for the Synthesis of Alkynyloxazolines

Abstract

A concise and highly stereoselective synthesis of alkynyloxazolines via a gold-catalyzed domino cyclization-alkynylation cascade of N-propargylcarboxamides with benziodoxole reagents is reported. This new protocol, which represents an attractive alternative to two step sequences based on Sonagashira couplings, offers a broad substrate scope, excellent functional group tolerance, and perfect stereoselectivity. A comparison of the computed energies of the isomers of the product suggests kinetic control as the cause of the observed selectivity. (Figure presented.).