离子液体中CO_2与炔醇在温和条件下高效合成-亚甲基环状碳酸酯

Efficient synthesis of α-alkylidene cyclic carbonate from CO_2 and propargylic alcohols in ionic liquids under mild conditions

本文研究了离子液体1-乙基-3-甲基咪唑二乙基磷酸酯([EMIM][(EtO)2PO2])中醋酸银(AgOAc)对CO2与炔醇反应生成-亚甲基环状碳酸酯的催化性能,发现该反应可以在温和的条件下进行.在AgOAc/[EMIM][(EtO)2PO2]催化体系中,30℃、4 MPa CO2压力下,反应6h时-亚甲基环状碳酸酯的产率为97%;当压力降到0.5 MPa时,反应24 h产物产率为65.8%.[EMIM][(EtO)2PO2]在反应中起到了溶剂和碱的双重作用.AgOAc/[EMIM][(EtO)2PO2]体系重复利用3次活性仅略有下降.另外,该体系也可用于催化CO2与其他炔醇(3-甲基-1-戊炔-3-醇、3,5-二甲基-1-己炔-3-醇和2-苯基-3-丁炔-2-醇)的反应.

The reaction between CO2 and 2-methyl-3-butyn-2-ol catalyzed by AgOAc in 1-ethyl-3-methylimidazolium diethylphosphate （[EMIM] [（EtO）2PO2]） was conducted under mild conditions. It was found that the reaction could be completed within 6 h at 30 ℃ under 4 MPa CO2. The reaction even could proceed at 30 ℃ under 0.5 MPa CO2 and the yield of α-alkylid-ene cyclic carbonate reached 65.8% within 24 h. [EMIM][（EtO）2PO2] acted as both base and solvent in the reaction. Moreover, the AgOAc/[EMIM][（EtO）2PO2] catalytic system could be reused three times without considerable loss of the activity. The catalytic system was also active for other propargylic alcohols, such as 3-methyl-1-pentyn-3-ol, 3,5-dimethyl-l-hexyn-3-ol and 2-phenyl-3-butyn-2-ol.