Organophotoredox Pd-Catalyzed C–H Arylation at Room Temperature using Diaryliodonium Salts

Direct functionalization of C–H bonds is the most expeditious strategy to build complexity into organic molecules. Unfortunately, most Pd-catalyzed C–H arylation strategies require high temperatures or stoichiometric oxidants. The creation of metallaphotoredox C–H arylation in 2011 forged a new pathway to achieve arylation at room temperature. Since this discovery, most reports still use explosive diazonium salts as aryl radical precursors. Alternatively, a single report uses bench-stable diaryliodonium salts, albeit with an Ir-based pho-tocatalyst. Herein, we develop an organophotoredox manifold that enables Pd-catalyzed C–H arylation of numerous N-aryl amide sub-strates including the preparation of unsymmetrical m-terphenyl products. The results we present are expected to revitalize the use of dia-ryliodonium salts to achieve room temperature arylations of wide-ranging C–H bond classes.