温控聚乙二醇两相体系中钼配合物催化的环己烯环氧化反应研究

将温控聚乙二醇(PEG)两相体系用于环己烯环氧化,筛选出了由PEG-4000/二氯乙烷/正庚烷组成的温控PEG两相体系。合成了催化剂PEG-4000-MoO_2(acac)(乙酰丙酮)络合物,在此体系中催化环己烯环氧化反应,研究了反应温度、反应时间、催化剂用量、反应物料配比等因素对环氧化过程的影响,优化得到较佳工艺条件(以0.1 mol t-BuOOH计):反应温度80℃,反应时间60 min,催化剂用量1.5 g,n(C_6H_(10)):n(t-BuOOH) =3:1,该条件下环氧环已烷选择性与收率分别达94.6%、90.2%。催化剂循环使用10次,活性无明显下降。

MOLYBDENUM COMPLEX CATALYZED EPOXIDATION OF CYCLOHEXENE IN THERMOREGULATED PEG BIPHASE SYSTEM

Thermoregulated polyethylene glycol(PEG) biphase system,composed of PEG-4000 and the mixture of dichloroethane and heptane,was developed and used in the epoxidation of cyclohexene. PEG-4000-MoO_2(acac) catalyst was synthesized and used in the reaction.The factors influencing the epoxidation,such as reaction time,reaction temperature,amount of catalysts,and molar ratio of C_6H_(10) to r-BuOOH were studied.Under the optimum conditions,i.e.,reaction time 60min,reaction temperature 80℃,n(C_6H_(10)):n(t-BuOOH)=3:1(based on 0.1 mol t-BuOOH),catalyst 1.5 g, the selectivity and yield of cyclohexene oxide were about 94.6%and 90.2%,respectively.The catalyst, after being recycled ten times,showed no appreciable loss of catalytic activity.