A highly efficient and ligand-free copper(I) sulfide catalyzed cross-coupling reaction of aryl iodides with diaryl disulfides was developed. With only 1 mol-% of Cu₂S as the catalyst, iron powder as the reductant, and K₂CO₃ as the base, aryl iodides reacted with disulfides in DMSO at 90–110 °C for 18–24 h under an atmosphere of argon to give the corresponding aryl sulfides in good to excellent yields. In addition, the catalyst is recyclable and reusable with some loss of activity.

Utilizing the dramatic accelerating effect of 2-aminophenols, we developed a copper-catalyzed system for the selective synthesis of di- and triphenylamines. In addition, N- and O-arylation could be achieved in coupling reactions between 2-aminophenol and nitroaryl halides.