Water as an efficient medium for the synthesis of cyclic carbonate

Herein, we report a novel method for the synthesis of cyclic carbonate in water. By tuning the amount of water, cycloaddition of CO₂ to epoxide in aqueous medium leads to cyclic carbonates with moderate to excellent yields and high selectivities. In addition, the presence of water could remarkably improve the activity of ionic liquids by which the turnover frequency of the reaction is about 4-5 times higher in the presence than in the absence of water. The relationship between the higher catalytic reactivity and water was proposed.