[Bmim]Cl/FeCl_3离子液体催化α-生育酚与β-D-五乙酰葡萄糖的糖基化反应

Saccharification of α-Tocopherol with β-D-Acylated Glucose Catalyzed by [Bmim]Cl/FeCl_3 Ionic Liquid

以[Bmim]Cl/FeCl3(三氯化铁/氯化丁基甲基咪唑)离子液体作为反应介质和催化剂,考察了离子液体的酸度、反应温度及反应时间对α-生育酚与β-D-五乙酰吡喃型葡萄糖糖基化反应的影响.结果表明,离子液体的催化活性与其酸强度密切相关,离子液体的酸性越强,其对此糖基化反应催化活性越高.在FeCl3与[Bmim]Cl物质的量比为2的[Bmim]Cl/FeCl3离子液中,α-生育酚与β-D-五乙酰吡喃型葡萄糖在45℃下反应3h,可以得到较高的转化率,α-生育酚的转化率最高可达70.2%.同有机溶剂作为反应介质相比,反应条件温和,反应时间短,室温离子液体具有更好的催化活性,所得产物与离子液体不溶,便于分离,催化体系可循环使用,且对环境友好.

Effects of acidity of ionic liquid, the reaction temperature and reaction time on saccharification of α-tocopherol with β-D-acylated glucose were studied using ionic liquid FeCl3-chloro[butylmethylimidazole] as both reaction medium and catalyst. The experiment results indicated that the acivity of ionic liquid correlated well with acidity. The reactive of ionic liquid increased with the increasing of the acidity. The ionic liquid system provided a fast, efficient protocol to α-tocopheryl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside in higher conversion. When the molar ratio of FeCl3 to [Bmim]Cl is 2 in ionic liquid [Bmim]Cl/FeCl3 and the reation was kept at 45 ℃ for 3 h, about 70.2% conversion rate of α-tocopherol could be obtained. Compared with organic solvents, the reaction condition was mild, the reaction time was short and the reactive activity of ionic liquid was higher. The products could be easily separated from the ionic liquid due to their immiscibility. The ionic liquid could be used repeatedly and regarded as an environmentally benign system.