Nickel-Catalyzed Chain-Walking Cross-Electrophile Coupling of Alkyl and Aryl Halides and Olefin Hydroarylation Enabled by Electrochemical Reduction

Abstract

The first electrochemical approach for nickel-catalyzed cross-electrophile coupling was developed. This method provides a novel route to 1,1-diarylalkane derivatives from simple and readily available alkyl and aryl halides in good yields and excellent regioselectivity under mild conditions. The procedure shows good tolerance for a broad variety of functional groups and both primary and secondary alkyl halides can be used. Furthermore, the reaction was successfully scaled up to the multigram scale, thus indicating potential for industrial application. Mechanistic investigation suggested the formation of a nickel hydride in the electroreductive chain-walking arylation, which led to the development of a new nickel-catalyzed hydroarylation of styrenes to provide a series of 1,1-diaryl alkanes in good yields under mild reaction conditions.

Keywords: 1,1-diarylalkanes; electrosynthesis; migratory cross-coupling; nickel; β-hydride elimination.