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

Abstract

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 and/or stoichiometric oxidants. The discovery of metallaphotoredox C−H arylation in 2011 forged a new approach to achieve metal catalyzed C−H 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 photocatalyst. In this study, we develop an organophotoredox manifold that enables Pd-catalyzed C−H arylation of numerous N-aryl amide substrates. The results we present are expected to revitalize the use of diaryliodonium salts to achieve room temperature arylations of wide-ranging classes of C−H bonds.