We describe an Ir-catalyzed intramolecular reaction of 2-alkynyl diaryl sulfides, which gives 9-arylidene-9H-thioxanthene derivatives via 6-exodig cyclization. When 2-alkynylphenyl naphthyl sulfides are used, divergent synthesis of triarylfused thiepines and diaryl-substituted benzothiophenes can be achieved by simply choosing the reaction temperature.