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以苯乙烯、环己烯和反式二苯乙烯为烯烃底物,以双氧水、叔丁基过氧化氢和异丙苯过氧化氢为氧化剂,以苯环上对位和邻位氯取代的四苯基金属卟啉为仿生催化剂,对烯烃的催化环氧化反应进行了对比研究.讨论了不同氯取代位的四苯基金属卟啉对烯烃环氧化性能的影响.实验结果表明,在没有助催化剂存在下,邻位氯代的四(2,6-二氯苯基)铁(锰)卟啉对烯烃的环氧化具有优异的催化性能,烯烃底物的转化率和环氧选择性都比对位氯代的四苯基铁(锰)卟啉高,且反应条件温和.其中FeⅢ(TDCPP)Cl的催化性能最好,环氧化选择性最高,催化氧化苯乙烯时,环氧苯乙烷的选择性达到了90.4%.相同金属离子不同配体的金属卟啉传递氧原子的能力为TDCPP>T(p-Cl)PP>TPP.氧化剂的结构对环氧化物的选择性有较大影响.过氧键连有吸电子基团的异丙苯过氧化氢对环氧化物的选择性最高.根据实验结果,对金属卟啉催化环氧化机理进行了分析.
With styrene, cyclohexene and trans stilbene as olefin substrate, with hydrogen peroxide, t-butyl hydroperoxide and cumene hydroperoxide as oxidant, the benzene ring para and ortho chloro four Phenylmetalloporphyrins as biomimetic catalysts for the catalytic epoxidation of olefins were contrastively studied.Furthermore, the effects of different P-substituted tetraphenylporphyrins on the epoxidation of olefins were discussed.The experimental results show that in the absence of Ortho-chlorinated tetrakis (2,6-dichlorophenyl) iron (manganese) porphyrin has excellent catalytic performance for the epoxidation of olefins in the presence of a co-catalyst, the conversion of olefinic substrates and epoxy selectivity Which is higher than that of the ortho-chloro-substituted tetraphenylniron (porphyrin) porphyrin and the reaction conditions are mild. Among them, FeⅢ (TDCPP) Cl has the best catalytic performance and the highest epoxidation selectivity. When catalytically oxidizing styrene, epoxy The selectivity of ethylbenzene reached 90.4%. The ability of metalloporphyrins of different ligands with the same metal ion to transfer oxygen atoms was TDCPP> T (p-Cl) PP> TPP. The structure of the oxidant was selective to epoxides. A greater impact.Operoxide bond with electron-withdrawing cumene hydroperoxide has the highest selectivity to epoxide As a result, the mechanism for the catalytic epoxidation metalloporphyrin analyzed.