Visible-light-induced photoredox-catalyzed dearomative dicarboxylation of arenes using formate and CO2

The visible-light-induced photoredox-catalyzed dearomative dicarboxylation of polycyclic arenes and heteroarenes using formate and CO2 was achieved. This reaction was performed under mild conditions to obtain dearomative dicarboxylative products with high selectivity and good yields. Mechanism experiments were performed to demonstrate that formate enabled the reaction to proceed via the carbon dioxide radical anion (CO2(center dot)-), which could be employed as a potent single-electron transfer (SET) reagent for the direct reduction of stable arenes under visible-light conditions.