Light-Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a Ni(II)-Aryl Complex.

A highly effective C-O coupling reaction of (hetero)aryl electrophiles with primary and secondary alcohols is reported. Catalyzed by a Ni(II)-aryl complex under long-wave UV (390-395 nm) irradiation in the presence of a soluble amine base without any additional photosensitizer, the reaction allows for the etherification of aryl bromides, aryl chlorides as well as sulfonates with a wide range of primary and secondary aliphatic alcohols, affording synthetically important ethers. The intramolecular C-O coupling is also possible. The catalysis appears to proceed via a Ni(I)-Ni(III) cycle.