On the mechanism of CO2 electro-cycloaddition to propylene oxides

We herein present a systematic study on the mechanism of CO2 electro-cycloaddition to propylene oxide, using both experimental and theoretical procedures. The study considers the analysis of mild and sustainable conditions to obtain cyclic carbonates from CO2 recycling. Within the electrochemical approach, the application of an overpotential in the reaction enhances the reaction yield significantly with respect to the thermal pathway. The quantum-mechanical approach provides relevant information about the reaction mechanism. Specifically, the use of the Lewis acid catalyst Mg2+ in the presence of the [C(4)C(1)Im][Br] ionic liquid provides the best condition for the electro-synthesis. The theoretical predictions were confirmed by a new set of experiments. (C) 2016 Elsevier Ltd. All rights reserved.