Visible-Light-Driven Alkene Dicarboxylation with Formate and CO2 Under Mild Conditions

The low-cost formate salt was used as the reductant and part of the carboxyl source in a visible-light-driven dicarboxylation of diverse alkenes, including simple styrenes. The highly competing hydrocarboxylation side reaction was successfully overridden. Good yields of products were obtained under mild reactions at ambient temperature and pressure of CO2. The dual role of formate salt may stimu-late the discovery of a range of new transformations under mild and friendly conditions.