Synthesis of 6-Thiocyanatophenanthridines by Visible-Light- and Air-Promoted Radical Thiocyanation of 2-Isocyanobiphenyls

A convenient, efficient, and metal-free synthesis of 6-thiocyanatophenanthridines by visible-light-and air-mediated, eosin Y-catalyzed, sequential radical cyclization and aromatization of 2-isocyanobiphenyls with ammonium thiocyanate is reported. Advantageously, the protocol utilizes inexpensive, clean, and sustainable natural resources such as visible light and atmospheric oxygen at room temperature in a one-pot procedure.