二苯并-18-冠-6助催化CO2一步酯交换法合成碳酸二甲酯的研究

摘要

首次采用二苯并-18-冠-6(DBC)为助催化剂,以提高卤化钾对环氧化物、甲醇和CO2一步酯交换法合成碳酸二甲酯(DMC)的催化性能.在一个相对温和的条件(CO2初始压力2MPa,反应温度为130℃)下反应8h,KCl和DBC催化体系合成DMC的收率最高可达31.9％,比单纯使用KCl催化剂的收率提高了一倍,表明DBC对该反应明显具有助催化剂作用.从实验结果推测,环氧化物与亲核试剂发生亲核反应而开环是该催化反应的关键步骤.%Dibenzo-18-crown-6(DBC) was firstly used as prormater to improve catalytic performance of potassium halides for one-step transesterification synthesis of dimethyl carbonate( DMC)from epoxide, methanol and CO2. Under a mild reaction condition(initial pressure of CO2 ;2MPa,reaction temperature: 130°C,time;8 h) ,the yield of DMC over KC1 and DBC reached 31. 9% , which has double yield of DMC over KC1 catalyst, indicating that DBC has obvious cocatlysis effect on this reaction. It was proposed that the ring opening of epoxide by nucleophilic reagent was the key step for this reaction.