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制备了一系列通过苯氧基修饰的聚(苯乙烯-异丙烯膦酸)磷酸氢锆(ZPS-IPPA)轴向固载手性MnⅢ(Salen)催化剂,并将其应用于苯乙烯的环氧化反应。催化结果表明:苯氧链接手臂邻位取代基对于环氧化结果有重要影响,相比邻位取代基为-H和-CH3,取代基为t-Bu基团时,催化剂能够提供更高水平的对映选择性。同时,比较了两种长度几乎一致的链接手臂(-NH-C6H4-NH-,-O-C6H4-O-),结果表明:在没有轴向助剂N-甲基玛琳氮氧化物(NMO)参与下,在间氯过氧苯甲酸(m-CPBA)为氧化剂的体系中,链接手臂-O-C6H4-O-比-NH-C6H4-NH-更有利于取得优异的催化效果。制备的非均相催化剂重复使用5次后催化活性与对映选择性没有明显的变化。
A series of catalysts supported by phenoxy-modified poly (styrene-isopropenyl phosphonic acid) zirconium phosphate (ZPS-IPPA) were prepared and immobilized on the styrene The reaction. The catalytic results showed that the ortho-substituent of phenoxy chain has a significant effect on the epoxidation results. Compared with ortho-substituents of -H and -CH3, when the substituent is t-Bu group, the catalyst can provide a higher level of Enantioselective. In the meantime, two kinds of arms (-NH-C6H4-NH-, -O-C6H4-O-) almost identical in length were compared, and the results showed that in the absence of axial promoter N-methylmarine nitrogen oxide ) Is more favorable to obtain excellent catalysis effect than that of -NH-C6H4-NH- in the system of m-CPBA as oxidant. The catalytic activity and enantioselectivity of the prepared heterogeneous catalyst were not changed after repeated use for 5 times.