Electrosynthesis of enantiomerically pure cyclic carbonates from CO ₂ and chiral epoxides

In this paper, the one-step synthesis of enantiomerically pure cyclic carbonates has been developed by electrolyzing the chiral epoxides and CO ₂ (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.