The electrochemical carboxylation of Morita–Baylis–Hillman (MBH) acetates with CO2 is presented. The process proceeds in the absence of transition-metal catalysts and relies on the cathodic reduction of MBH acetates to generate nucleophilic anions that are able to trap low-pressure CO2. Valuable succinate derivatives are obtained (20 examples) in high yields (up to 90%) and with excellent functional group tolerance. A remarkable substrate-controlled (electronic nature) regioselectivity of the transformation is documented along with a mechanistic rationale based on control experiments.
Key words
electrosynthesis - carbon dioxide - MBH acetates - cathodic reduction - catalyst-free