CO2 Radical Anion in Photochemical Dicarboxylation of Alkenes

Abstract CO 2 radical anion (CO 2 ⋅ − ) is a highly reductive species ( E red =−2.2 V vs SCE), which can undergo Giese radical addition to an unsaturated C−C bond and install a carbonyl group to synthesize acids. Normally, it has been generated through the direct reduction of CO 2 gas or from formate salts via HAT (hydrogen atom transfer) as the BDE (bond dissociation energy) of the C−H bond in formate is only around 86 kcal/mol. This concept highlights the recent developments on alkenes dicarboxylation reaction with CO 2 and/or formate as the carbonyl sources. In these reactions, CO 2 radical anion species played significant roles in the carboxylation step.