First example of the coupling of α-diazoketones with thiourea: a novel route for the synthesis of 2-aminothiazoles

α-Diazoketones undergo smooth coupling with thiourea in the presence of 10 mol % of copper(II) triflate to produce the corresponding 2-aminothiazoles in excellent yields with high selectivity. The use of copper(II) triflate makes this method simple, convenient and practical. This method works well with both aryl and alkyl diazoketones to furnish a wide range of 2-aminothiazoles.