Cu2O-Catalyzed Ullmann-type C N cross-coupling reaction of carbazole and aryl chlorides

A copper-catalyzed Ullmann-type C N cross-coupling reaction of carbazole with aryl chlorides has been developed employing N , N′ -bis(thiophene-2-ylmethyl)oxalamide as ligand. The reaction proceeds at 140 °C with Cs 2 CO 3 as the base in DMSO/MeCN to afford N -arylcarbazole in good to excellent yields. Both the heteroaromatic ring and amide structures in ligands are important for their efficiency.