Merging photoredox with nickel catalysis: Coupling of α-carboxyl sp³-carbons with aryl halides

Over the past 40 years, transition metal catalysis has enabled bond formation between aryl and olefinic (sp²) carbons in a selective and predictable manner with high functional group tolerance. Couplings involving alkyl (sp³) carbons have proven more challenging. Here, we demonstrate that the synergistic combination of photoredox catalysis and nickel catalysis provides an alternative cross-coupling paradigm, in which simple and readily available organic molecules can be systematically used as coupling partners. By using this photoredox-metal catalysis approach, we have achieved a direct decarboxylative sp³-sp² cross-coupling of amino acids, as well as α-O- or phenyl-substituted carboxylic acids, with aryl halides. Moreover, this mode of catalysis can be applied to direct cross-coupling of C_sp3-H in dimethylaniline with aryl halides via C-H functionalization.