Direct and Selective Electrocarboxylation of Styrene Oxides with CO2 for Accessing β‐Hydroxy Acids

Abstract Highly selective and direct electroreductive ring‐opening carboxylation of epoxides with CO 2 in an undivided cell is reported. This reaction shows broad substrate scopes within styrene oxides under mild conditions, providing practical and scalable access to important synthetic intermediate β ‐hydroxy acids. Mechanistic studies show that CO 2 functions not only as a carboxylative reagent in this reaction but also as a promoter to enable efficient and chemoselective transformation of epoxides under additive‐free electrochemical conditions. Cathodically generated α ‐radical and α ‐carbanion intermediates lead to the regioselective formation of α ‐carboxylation products.