Light-Promoted Nickel-Catalyzed Aromatic Halogen Exchange

Aryl halides are important chemical components in organic syntheses. Herein, we report visible-light-induced, single nickel-catalyzed halogen exchange of aromatic halides with the corresponding halide salts under mild conditions. Varieties of aryl iodides, bromides, and chlorides can smoothly undergo aromatic Finkelstein or retro-Finkelstein reactions with good functional group tolerance. Experimentally, mechanistic studies showed that excited-state Ni^II complexes for facile reductive elimination to form carbon–halide bonds were involved in the process of Finkelstein and retro-Finkelstein reactions.