Electrochemical Dicarboxylation of Vinyl Epoxide with CO₂ for the Facile and Selective Synthesis of Diacids

We present a novel electrochemical dicarboxylation of epoxides with CO₂, characterized by the cleavage of two C-O single bonds. Not only are vinyl epoxides viable, but cyclic carbonates also serve as effective substrates, facilitating the synthesis of E-configured adipic and octanedioic acids with high chemo-, regio-, and stereoselectivity. The synthetic practicality is further highlighted by the diverse functionalizations of the resulting multifunctional diacids. Mechanistic studies support the single-electron transfer reduction of CO₂ to its radical anion, which undergoes radical addition to the vinyl moiety of epoxides. The subsequent reductive cleavage of two C-O bonds, coupled with a nucleophilic attack on CO₂, culminates in the formation of the desired diacid products.