Photochemically Enabled, Ni-Catalyzed Cyanation of Aryl Halides

A light-promoted Ni-catalyzed cyanation of aryl halides employing 1,4-dicyanobenzene as a cyanating agent is reported. A broad array of aryl bromides, chlorides, and druglike molecules could be converted into their corresponding nitriles (65 examples). Mechanistic studies suggest that upon irradiation, the oxidative addition product Ni(II)(dtbbpy)( p -C 6 H 4 CN)(CN) undergoes homolytic cleavage of the Ni–aryl bond to generate an aryl radical and a Ni(I)–CN species, the latter of which initiates subsequent cyanation reactions.