Palladium-catalyzed highly regioselective 6-exo-dig cyclization and alkenylation of ortho-ethynylanilides: the synthesis of polyene-substituted benzo[d][1,3]oxazines

Abstract

A Pd-catalyzed highly regioselective 6-exo-dig cyclization/alkenylation reaction of ortho-ethynylanilides has been developed. This tandem cross-coupling protocol represents a simple, efficient, step- and atom-economic approach for the construction of scarcely known polyene-substituted benzo[d][1,3]oxazines in moderate to excellent yields with a broad substrate scope.