Efficient and sustainable fixation of CO₂ into 2-oxazolidinones utilizing ionic liquid functionalized SiO₂...

Chemical fixation of CO₂ into 2-oxazolidinones is of significance because of the important application in the chemical synthesis. In this study, a series of ionic liquid functionalized SiO₂ nanocomposites were synthesized and developed as heterogeneous catalysts for the CO₂ cyclization reaction. The resulting SiO₂-MILZrCl₅ behaved as high-efficiency heterogeneous catalyst for solvent-additive-free CO₂ cyclization at 70 °C and 0.1 MPa CO₂. A high yield of 93% with selectivity of 99.4% over 5-methyl-3-phenyloxazolidin-2-one was attained. Furthermore, a wide range of epoxides were transformed with high yields and excellent selectivities under atmospheric pressure. Additionally, SiO₂-MILZrCl₅ could serve as a durable and recoverable heterogeneous catalyst for the reaction, which could be used for five cycles without significant loss of catalytic activity. This study offers novel insights for the development of green catalysts for the efficient CO₂ fixation.