Rapid synthesis of cyclic carbonates from CO₂ and epoxides under microwave irradiation with controlled temperature and pressure

The solvent-free synthesis of cyclic carbonates from CO₂ and epoxides were carried out under microwave irradiation with controlled temperature and pressure. In comparison with classical heating of oil bath, microwave was demonstrated to be a more effective energy source, which could offer the highest TOF numbers reported up to now for CO₂ coupling reaction with epoxides in the presence of a novel catalyst consisted of zinc phenosulfonate octahydrate and Bu₄NBr. Pseudo-first order kinetic treatment revealed that the observed reaction acceleration under microwave irradiation mainly derived from the non-thermal effects of microwave that lead to an obvious decrease in activation energy.