Regioselective Synthesis of 5‑Aminooxazoles via Cp*Co(III)-Catalyzed Formal [3 + 2] Cycloaddition of N‑(Pivaloyloxy)amides with Ynamides

A simple and efficient protocol for the regioselective synthesis of 5-aminooxazoles is disclosed. The reaction, catalyzed by a cheap Cp*Co­(III) catalyst, starts from easily accessible N-(pivaloyloxy)­amides and ynamides. Mild reaction conditions, a broad substrate scope, good functional group tolerance, and good to excellent yields were observed.