Electrochemically Driven Radical Reactions: From Direct Electrolysis to Molecular Catalysis

Organic radicals are versatile synthetic intermediates that provide reactivities and selectivities complementary to ionic species. Despite its long history, electrochemically driven radical reactions remain limited in scope. In the past few years, there have been dramatic increase in research activity in organic electrochemistry. We have been developing electrochemical and electrophotocatalytic methods for the generation and synthetic utilization of organic radicals. In our studies, various radical species such as alkene and arene radical cations and carbon‐ and heteroatom‐centered radicals are generated from readily available precursors through direct electrolysis, molecular electrocatalysis or molecular electrophotocatalysis. These radical species undergo various inter‐ and intramolecular oxidative transformations to rapidly increase molecular complexity. The simultaneous occurrence of anodic oxidation and cathodic proton reduction allows the oxidative reactions to proceed through H2 evolution without external chemical oxidants. Organic radicals are versatile intermediates that provide reactivities and selectivities complementary to ionic species. Herein, we summarize some of our efforts in developing electrochemically driven radical reactions. The organic radical intermediates are generated via direct electrolysis, indirect electrolysis employing a homogeneous molecular catalyst or molecular electrophotocatalysis.