Highly efficient method for the copper-catalyzed selective synthesis of diaryl chalcogenides from easily available chalcogen sources

An efficient protocol for copper-catalyzed CS or CSe bond formation between aryl iodides and easily available chalcogen sources leading to diaryl chalcogenides is reported. A variety of symmetrical diaryl sulfides and diaryl selenides were synthesized in good to excellent yields. Unsymmetrical diaryl sulfides were also obtained in moderate yields from two different aryl iodides by a one-pot tandem process. This strategy was further successfully utilized for the synthesis of 2-phenylbenzo[b]thiophene and of [1]benzothieno[3,2-b]benzothiophene