A General Catalyzed Cyanation of Aryl Bromides and Hydrocyanation of Olefins Using Acetonitrile as Cyanide Surrogate

Traditional methods for nitrile synthesis often rely on toxic cyanide reagents, raising serious safety and environmental concerns. Under mild conditions, acetonitrile, a bench-stable and cyano-containing solvent, has emerged as a promising cyanide source for nitrile construction. Herein, we report a highly efficient photoredox nickel dual catalytic system for the cyanation of aryl bromides and the hydrocyanation of olefins, employing acetonitrile as a cyanide surrogate under visible-light irradiation. The mechanism was elucidated through the synthesis and characterization of key nickel intermediates. These studies support a transmetalation process between Ni-CN and Ni-Ar species to generate a mixed Ar-Ni-CN complex, which undergoes reductive elimination to form the aryl nitrile. Furthermore, the protocol enables the synthesis of both linear and branched aliphatic nitriles from a wide range of olefins, including terminal and internal alkenes.