Chao Liu,Yifei Ye,Zimin Jiang,Ping Xu,Jiaxu Zhang,Jianmin Sun
The combination from hyperbranched polyethylenimine and Lewis acid ZnI2 (PEI/ZnI2) was facilely obtained, and they showed an efficient activity to the reaction of epoxides and CO2 because of these abundant primary, secondary, and tertiary amines of PEI; additionally, ZnI2 made contribution to the activation of epoxide. With 0.15 g PEI-4 (MW 70 000) and the molar percentage of 2.0 mmol % ZnI2 to propylene oxide (PO), 95% yield was achieved at 100 °C, 3.0 h, and 1.0 MPa, and the selectivity was 96%. Moreover, the PEI-4 catalyst preparation avoided toxic solvents and the harsh preparation conditions. Furthermore, PEI-4/ZnI2 was easily recycled from the entire system. The catalytic system maintained excellent recyclability up to eight times with satisfactory activity, and thus, the facile and efficient PEI-4/ZnI2 catalysts were considered as an industrial candidate for the reaction of epoxides and CO2 to cyclic carbonates.
Chaokun Yang,Mengshuai Liu,Jiaxu Zhang,Xin Wang,Yichen Jiang,Jianmin Sun
The cycloaddition of CO 2 to epoxides is an important reaction and has got increasing attention. In this work, a series of DBU-based ionic liquids (DILs) were synthesized via facile neutralization of superbase 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) with corresponding hydrogen bond donor acids, such as D(−)-tartaric acid (TA), malic acid (MA) and succinic acid (SA). The DILs cooperated with ZnI 2 were first evaluated in detail for catalyzing the coupling reaction of CO 2 with propylene oxide (PO), and DIL-1 exhibited obviously enhanced catalytic activity under 80 °C, 3 MPa and solvent-free conditions. The effects of reaction parameters on the activity for propylene carbonate (PC) synthesis were thoroughly investigated, and a possible synergistic catalytic mechanism was proposed. The catalytic system reported here could be separated by simple centrifugation from the products after reaction and then reused efficiently. Moreover, the catalytic system showed the advantages of simple synthesis, high catalytic activity, low cost, and substrate versatility for CO 2 conversion to cyclic carbonates.
危险品化学品经营许可证（带存储）