Environmentally Benign Chemical Conversion of CO₂ into Organic Carbonates Catalyzed by Phosphonium Salts

Abstract

Quaternary phosphonium salts were proved efficient homogeneous catalysts for solvent-free synthesis of cyclic carbonates from carbon dioxide and epoxides. Propylene carbonate was produced in quantitative yield and excellent selectivity. Furthermore, a PEG-supported phosphonium salt was solidified by adding ether and cooling after reaction and recovered by a simple filtration. Hence immobilization of a phosphonium salt on PEG provides an alternative pathway for realizing homogeneous catalyst recycling.

Keywords:

• Carbon dioxide
• cyclic carbonate
• homogeneous catalyst
• phosphonium salt

Acknowledgments

The work is supported by National Science Foundation of China (Grant 20472030, 20421202, and 20672054) and the Tianjin Natural Science Foundation and State Key Laboratory of Fine Chemicals, Dalian University of Technology (Grant No. KF 0506) for financial support.

Notes

^a Reaction conditions = propylene oxide, 28.6 mmol (2 ml); cat., 1 mol %;

^b PC = propylene carbonate.