Epoxidation of allyl chloride to epichlorohydrin by a reversible supported catalyst with H2O2 under solvent-free conditions
Epoxidation of allyl chloride to epichlorohydrin by a reversible supported catalyst with H2O2 under solvent-free conditions
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DOI：
10.1021/op060108k
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发表时间：
2006-09-15
影响因子：
3.4
通讯作者：
Xi, Zuwei
中科院分区：
文献类型：
--
作者：
Li, Jun;Zhao, Gongda;Xi, Zuwei
使用新型可逆负载型催化剂——杂多磷钨酸盐/硅烷化硅胶，在无溶剂条件下，烯丙基氯被 H2O2 环氧化为环氧氯丙烷，选择性为 94%。通过 H2O2 的作用，杂多磷钨酸盐从载体表面溶解并形成活性均相试剂。当所有的 H2O2 被消耗时，还原的催化剂重新沉积在支撑载体上。负载型催化剂在反应过程中保留了均相催化剂的特性，但在后处理时表现出非均相性质。固体负载型催化剂易于分离且可重复使用。因此，用于合成表氯醇的反应系统避免了商业化氯醇方法中已知的严重污染问题。一些其他烯烃也可以在纯净条件下通过该催化体系进行环氧化。
Allyl chloride was epoxidized to epichlorohydrin with H2O2 under solvent-free conditions in 94% selectivity using a new reversible supported catalyst, heteropolyphosphatotungstate/ silanized silica gel. By the action of H2O2 the heteropolyphosphatotungstate dissolves from the carrier surface and forms an active homogeneous reagent. When all H2O2 is consumed, the reduced catalyst redeposits on the support carrier. The supported catalyst retains the character of a homogeneous catalyst during reaction but exhibits heterogeneous properties upon work-up. The solid-supported catalyst is easily isolated and can be reused. The reaction system for synthesis of epichlorohydrin therefore avoids the serious pollution issues known from the commercialized chlorohydrin methods. Some other olefins can also be epoxidized by this catalytic system under neat conditions.