One‐Pot Copper‐Catalyzed Aerobic Decarboxylative Coupling of Phenylacetic Acids with o‐Aminobenzenes and Dioxygen as the Oxidant Leading to Benzoxazoles and Benzothiazoles

A simple and practical copper‐catalyzed one‐pot method for the synthesis of benzoxazole and benzothiazole derivatives has been developed. The protocol uses inexpensive CuSO 4 as the catalyst, readily available substituted phenylacetic acids and o ‐aminobenzenes as the starting materials, and dioxygen as the sole oxidant. The corresponding benzoxazoles and benzothiazoles were obtained in moderate to good yields. The procedure is based on sequential copper‐catalyzed decarboxylation and aerobic cyclization reactions. This method should provide a useful strategy for the construction of heterocycles.