Synthesis of styrene carbonate from styrene oxide and carbon dioxide in the presence of zinc bromide and ionic liquid under mild conditions

The synthesis of styrene carbonate (SC) from styrene oxide (SO) and CO2 has been studied with various catalyst systems including metal halides and ionic liquids. The total conversion of SO and the selectivity for SC strongly depend on the catalyst systems used. The highest SC yield of 93% can be achieved at a low temperature of 80 °C for 1 h with a catalyst system of ZnBr2 and [C4-mim]Cl at a molar ratio of 1 ∶ 2. A CO2 pressure of 4 MPa is optimal but elevated pressures have no positive effects on this SC synthesis.