Copper-catalyzed oxidative C‒H, N‒H coupling of azoles and thiophenes

C‒H, N‒H coupling of azole and thiophene derivatives takes place in the presence of a catalytic amount of Cu(OAc)2 and an additive. The reaction of azoles smoothly occurs with several amines and amides catalyzed by 20 mol % of Cu(OAc)2–2PPh3 and 4 equiv of NaOAc under O2 or in the presence of Ag2CO3 under N2. The coupling reaction leads to a facile synthesis of a N-substituted analogue of 2,5-diarylthiazole, which shows photoluminescent properties with extended π-conjugation. Spectroscopic characteristics of the obtained thiazole derivatives are discussed by measurements of UV–vis absorption and photoluminescent spectra. Under the reaction conditions using Ag2CO3 as an additive and Cu(OAc)2–2PPh3 as a catalyst, thiophene derivatives also react with 2-pyrrolidone to undergo C‒H, N‒H amidation.