Electrosynthesis of enantiomerically pure cyclic carbonates from CO2 and chiral epoxides

•Enantiomerically pure cyclic carbonates were electrosynthesized under mild condition.•High conversion, selectivity and excellent ee value were obtained.•The regioselectivity has been firstly studied by the DFT calculation.•Electroreduced CO2 and Mg2 + played an important role in the synthesis process.

In this paper, the one-step synthesis of enantiomerically pure cyclic carbonates has been developed by electrolyzing the chiral epoxides and CO2 (0.1 MPa, rt) in an undivided cell with a 316 stainless steel (SS) cathode and a Mg sacrificial anode containing TEAI–MeCN as supporting electrolyte and solvent with a constant current. To deeply understand this reaction, the effects of various synthesis conditions were investigated using R-styrene oxide as the model compound. Under the optimized conditions, the maximum conversion is 67% with 96% selectivity and 98.8% ee value for R-styrene carbonate. Finally, the reaction mechanism has been proposed by comparative electrolysis and DFT calculation.