Studies On The Synthesis Of Cyclic Carbonates Heterogeneously Catalyzed By Ionic Liquids

As a thermal stable and widely tunable novel green media, ionic liquids (ILs) have been applied to many fields such as catalysis, organic synthesis, separation, electrochemistry, and so on. Synthesizing new kinds of ILs and exploiting ILs'new applications are always the main task of ILs'studies. For homogeneous catalysts being used in industrial production of cyclic carbonate resulted in many key problems such as complicated purification process, decomposition of catalyst and formation of by-products, we developed heterogeneous ionic liquids catalysts for the coupling reaction of epoxides and CO2. The major work and innovative results for this dissertation are summarized as follows.1. we have developed the CS-[EMIM]Br used as catalyst for coupling reaction of epoxides and CO2. In the result, under mild conditions(120℃, 2.0 MPa, 4 h), cyclic carbonates can be obtained in very high yield (95%) and high selectivity (>99%) from the reaction of the epxoide with CO2 catalyzed by CS-[EMIM]Br, which was higher than those with other similar reported catalysts.2. We also developed the CS-[EMIM]2ZnBr2Cl2 catalytic system to study the preparation of the cyclic carbonates. under mild conditions(120℃, 1.5 MPa, 1.5 h), cyclic carbonates can be obtained in very high yield (96%) and high selectivity (>99%) from the reaction of the epxoide with CO2 catalyzed by CS-[EMIM]2ZnBr2Cl2 . The result prove that the synergetic action of Lewis acid (ZnCl2) and Lewis base (Br-) is benefit to the coupling reaction of the epoxides and CO2.