Green Conversion of Carbon Dioxide to Cyclic Carbonates: Epoxide Activation using Hydroxyl-functionalized Ionic Liquids.

INTRODUCTION

Carbon dioxide (CO2) is a significant contributor to global climate change, and its conversion into valuable chemicals, such as cyclic carbonates, is a vital area of research.

METHODS

The present study involves the synthesis of cyclic carbonates by cycloaddition of carbon dioxide to epoxides in the presence of hydroxy-functionalized ammonium-based ionic liquids.

RESULTS

The effect of different alkyl chains in ionic liquids on the formation of cyclic carbonate product was examined, and the ionic liquid with a butyl chain, N-(2-hydroxyethyl)-N, N-dimethyl1-butanaminium bromide, afforded the highest yield and selectivity for cyclic carbonate formation.

DISCUSSION: The hydroxy group of ionic liquids and the bromide counter ion play a significant role in activating the epoxide ring for CO2 cycloaddition. The developed catalytic system worked well for the gram-scale production of cyclic carbonate with high selectivity.

CONCLUSION

The present method demonstrated excellent catalytic activity for transforming epoxides into cyclic carbonates under ambient CO2 pressure, achieving high yields and selectivity without a co-catalyst or solvent. This catalyst offers a green and efficient method for CO2 conversion to value-added products under mild conditions.