Asymmetric Catalysis with C02: Direct Synthesis of Optically Active Propylene Carbonate from Racemic Epoxides.

A convenient route to optically active cyclic carbonates by a catalytic kinetic resolution process resulting from the coupling reaction of carbon dioxide and racemic epoxides has been discovered by using simple and highly efficient chiral SalenCo(III)/quaternary ammonium halide catalyst systems. The reaction was carried out with perfect atom economy under solvent-free and extremely mild conditions. Further optimization of such bifunctional nucleophile-electrophile catalyst systems and exploration into the mechanism are now underway in laboratory.