InCl₃-catalyzed 5-<i>exo-dig</i> cyclization/1,6-conjugate addition of <i>N</i>-propargylamides with <i>p</i>-QMs to construct oxazole derivatives

Abstract

An InCl3-catalyzed atom-economic intramolecular 5-exo-dig cyclization/1,6-conjugate addition/aromatization of N-propargylamides with p-QMs to produce oxazoles tethering diarylmethane has been successfully developed. InCl3 not only served as Lewis acid to catalyze the cyclization of propargylic amides but also activated the carbonyl of p-QMs to achieve the 1,6-addition process in a one-pot manner. The reaction has attractive features, including mild reaction conditions, broad scope of substrates, good yields, and scalability.