Denitrative Cyanation of Nitroalkanes by Nucleophilic Substitution through Anion–Radical Coupling

Abstract

Abstract We report a photocatalytic denitrative cyanation to directly convert nitroalkanes into nitriles under mild conditions. The reaction proceeds rapidly under blue LED irradiation and exhibits broad functional-group tolerance. Mechanistic investigations support an anion–radical coupling pathway between an α-nitro radical and a cyanide ion. In this mechanism, a nitronate ion undergoes single-electron oxidation to generate an α-nitro radical, which is intercepted by a cyanide ion to form an α-nitronitrile radical anion. Subsequent extrusion of a nitrite ion affords an α-cyano radical, which undergoes reduction and protonation to deliver a nitrile product. This transformation features a distinctive radical anion intermediate that transiently incorporates both a nucleophile and a leaving group, providing a new conceptual platform for the nucleophilic substitution of nitroalkanes.