A Metal-Free Oxidative Amination of Benzoxazoles with Primary Amines and Ammonia

Abstract

An efficient synthesis of 2-aminobenzoxazoles is described by a direct oxidative amination of unfunctionalized benzoxazoles with primary amines. The reaction could be performed in the absence of transition metals by using catalytic amounts of a quaternary ammonium iodide and tert-butylhydroperoxide as a cheap and easy-to-handle co-oxidant. In addition to primary amines, aqueous solutions of NH3 were used to introduce a primary amine group into the heterocyclic core.