Cobalt-Catalyzed Electroreductive Cross-Coupling for the Synthesis of Atropisomeric 3-Arylindoles

The synthesis of atropisomeric 3-arylindoles via transition metal-catalyzed reductive cross-coupling remains challenging due to their intrinsically low rotational barriers and the comparable electronic characteristics of the two coupling partners. Herein, we present a cobalt-catalyzed enantioselective electroreductive cross-coupling between indole bromides and aryl iodides. This method enables efficient access to atropisomeric 3-arylindoles with high chemo- and enantioselectivities. Notably, it successfully addresses the challenges posed by indole substrates lacking electron-withdrawing groups at the 2-position.