Recent Advances in Photochemical/Electrochemical Carboxylation of Olefins with CO2

CO2 is an abundant, nontoxic, and renewable C1 feedstock in synthetic chemistry. Direct carboxylation of readily available olefins incorporating CO2 is regarded as a promising strategy to access high value-added carboxylic acids as well as CO2 fixation. However, due to the thermodynamic stability and kinetic inertness of CO2 and the difficulty in controlling the regioselectivity, the carboxylation of olefins with CO2 still remains challenging. Radical-type functionalization with olefins represented a powerful protocol and enabled the development of novel transformations in this realm. More recently, the advance of new technology, such as photoredox catalysis and the renaissance of electrochemistry in organic synthesis, offered access to unique chemical reactivities of radical precursors and provided new solutions to the functionalization of olefins. This review presents the recent advances in the radical-type carboxylation of olefins, which has mainly been achieved through photocatalysis and electrocatalysis in the last decade. In this article, we provide a comprehensive introduction of the progress, summarize the advantages and limitations of current research, and discuss the potential outlook for further development.