Palladium-Catalyzed Iodine-Mediated Electrophilic Annulation of 2‑(1-Alkynyl)biphenyls with Disulfides

A palladium-catalyzed, iodine-mediated electrophilic annulation between 2-(1-alkynyl)­biphenyl and disulfide has been developed. With the combination of PdCl2 and I2, a variety of 2-(1-alkynyl)­biphenyls underwent electrophilic annulations with various disulfides successfully to afford the corresponding 9-sulfenyl phenanthrenes in moderate to excellent yields.