Microwave-assisted palladium-catalyzed direct arylation of 1,4-disubstituted 1,2,3-triazoles with aryl chlorides.

Treatment of 1,4-disubstituted 1,2,3-triazoles with aryl chlorides in the presence of potassium carbonate under palladium catalysis and microwave irradiation at 250 degrees C for 15 min leads to arylation of the triazole at the 5-position. A variety of functional groups, including ester and hydroxy groups, are compatible. The procedure is suitable for the regioselective preparation of trisubstituted triazoles. Microwave irradiation accelerates the reaction, thus allowing the rapid synthesis of trisubstituted triazoles, which are difficult to synthesize selectively.