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.

Ir‐catalyzed transformations initiated by sulfur‐directed vinylic sp2 and benzylic sp3 C−H activation are disclosed that achieve the construction of sulfur‐containing seven‐ and eight‐membered systems. Allyl 2‐alkynylphenyl sulfides were transformed into dihydrobenzothiepines in 30–95 % yield, and 2‐alkynylaryl 2‐tolyl sulfides were converted into dibenzo[b,f]thiepines in 57–95 % yield along with double bond isomerization. In both reactions, the combination of Ir catalyst and sulfide moiety was a key to the facile cyclization.

The inside cover picture illustrates that starting from 2‐alkynyl diaryl sulfides, intramolecular cyclization realized selective construction of sulfur‐containing five to seven‐membered systems by the choice of reaction temperature and aryl group using the same iridium catalysis. When 2‐alkynylphenyl “naphthyl” sulfides were used, triaryl‐fused thiepines possessing a 7‐membered ring were obtained at 100 °C. The reaction of 2‐alkynyl diaryl sulfides at 120 °C gave 9‐arylidene‐9H‐thioxanthenes with 6‐membered system. The reaction of 2‐alkynylphenyl “naphthyl” sulfides at 160 °C afforded diaryl‐substituted benzothiophene with 5‐membered system. Details can be found in the communication by Takanori Shibata and co‐workers (T. Shibata, T. Iwaki, M. Ito, Adv. Synth. Catal. 2022, 364, 3472–3476; DOI: 10.1002/adsc.202200565).