Synthesis of 2,5-disubstituted oxazoles via cobalt(iii)-catalyzed cross-coupling of N-pivaloyloxyamides and alkynes.

An efficient synthesis of 2,5-disubstituted oxazoles via Co(iii) catalysis is described herein. The synthesis is achieved under mild conditions through [3+2] cycloaddition of N-pivaloyloxyamides and alkynes. The reaction operates through an internal oxidation pathway and features a very broad substrate scope. The one-step synthesis of natural products such as texamine and balsoxin has been demonstrated via this protocol.