研究了CO2与环氧化合物在含羟基的羟乙基三乙烯二铵溴盐离子液体催化下的反应情况,反应过程中不添加有机溶剂及其它添加剂.通过优化反应参数得到了最佳的反应条件为n(催化剂)∶n(环氧化舍物)=1∶100,压力2.0 MPa,时间4h,温度120℃,反应条件相对温和.考察了催化剂的适用范围,不同的环氧化合物与CO2反应都能够得到相应的环状碳酸酯,说明此种催化剂具有广泛的适用性.探讨了该反应的反应机理,催化剂中的羟基能够与环氧化合物反应形成氢键,促进三元环的打开,降低反应的活化能,加速反应酌进行.%Studied on the rea tion of CO2 and epoxide catalyzed by hydroxyl ionic liquid 1-(2-hydroxyethyl)-1,4-diazabicyclo[2,2,2]octan-1-ium bromide ([DABCO-HE]Br).The reaction was carried out in an autoclave with no organic solvent or other additive.The optimized reaction parameter was about n (catalyst) ∶ n (epoxide)=1 ∶ 100,2.0 MPa,4 h,120 ℃,which is relatively mild.This protocol was also used to the other epoxides and CO2 and was found to be applicable to a variety of epoxides producing the corresponding cyclic carbonates in high yields and selectivity.A possible catalytic cycle for the hydrogen bond-assisted ring-opening of epoxide and then reducing the reaction activation energy was also proposed.
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