Double Direct C-H Bond Arylation of Thiophenes with Aryl Chlorides Catalyzed by the N -Heterocyclic Carbene-PdCl 2 -1-methylimidazole Complex.

With the combination of the N -heterocyclic carbene-PdCl 2 -1-methylimidazole complex and Cu 2 O, we succeeded in the first example of double direct C-H bond arylation reactions between thiophenes and aryl chlorides, giving the desired 2,5-diarylated thiophenes in moderate to high yields under suitable conditions, consistent with the density functional theory calculations.