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.

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.