A Metallaphotoredox Strategy for the Cross-Electrophile Coupling of α-Chloro Carbonyls with Aryl Halides

Here, we demonstrate that a metallaphotoredox-catalyzed cross-electrophile coupling mechanism provides a unified method for the alpha-arylation of diverse activated alkyl chlorides, including alpha-chloroketones, alpha-chloroesters, alpha-chloroamides, alpha-chlorocarboxylic acids, and benzylic chlorides. This strategy, which is effective for a wide variety of aryl bromide coupling partners, is predicated upon a halogen atom abstraction/nickel radical-capture mechanism that is generically successful across an extensive range of carbonyl substrates. The construction and use of arylacetic acid products have further enabled two-step protocols for the delivery of valuable building blocks for medicinal chemistry, such as aryldifluoromethyl and diarylmethane motifs.