Visible light-induced Ni-catalyzed C–heteroatom cross-coupling of aryl halides via LMCT with DBU to access a Ni(i)/Ni(iii) cycle†
Abstract
Cross-coupling of aryl halides with nucleophiles is a synthetically attractive strategy to construct C–heteroatom bonds. Here we report a highly efficient photoinduced Ni-catalyzed method for the C–heteroatom cross-coupling of aryl halides. The reaction proceeds smoothly in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under visible light irradiation and is distinct from that mediated by photoredox/nickel dual catalysis, requiring no external photosensitizers. A diverse range of nucleophiles, including amines, amides, sulfonamides, carboxylic acids, alcohols, thiophenols, phosphite and sodium sulfinate, are successfully coupled with electronically diverse aryl halides, presenting a universal approach for different C–heteroatom coupling reactions. Mechanistic studies suggest that a catalytically active Ni(I) species is generated via photoinduced ligand-to-metal charge transfer (LMCT) with DBU to access a Ni(I)/Ni(III) catalytic cycle.