A concise approach to polysubstituted oxazoles from N-acyl-2-bromo enamides via a copper(I)/amino acid-catalyzed intramolecular C–O bond formation

A straightforward and efficient copper(I)/amino acid-catalyzed intramolecular Ullmann-type C–O coupling reaction has been developed. This protocol affords a facile methodology for the synthesis of a series of novel 2,4,5-substituted oxazoles from readily accessible N-acyl-2-bromo enamides under mild conditions.