Peroxotantalate-Based Ionic Liquid Catalyzed Epoxidation of Allylic Alcohols with Hydrogen Peroxide
作者:Wenbao Ma、Chen Chen、Kang Kong、Qifeng Dong、Kun Li、Mingming Yuan、Difan Li、Zhenshan Hou
DOI:10.1002/chem.201605661
日期:2017.5.29
in the epoxidation of various allylic alcohols under very mild conditions by using only one equivalent of hydrogen peroxide as an oxidant. NMR studies showed the reaction was facilitated through a hydrogen‐bonding mechanism, in which the peroxo group (O–O) of the peroxotantalate anion served as the hydrogen‐bond acceptor and hydroxyl group in the allylic alcohols served as the hydrogen‐bond donor. This
烯丙基醇的有效和对环境无害的环氧化已经实现通过使用单体peroxotantalate的新种阴离子官能的离子液体(离子液体= [P 4,4,4,Ñ ] 3 [TA(O)3(η-O 2) ],P 4,4,4,n =季phospho阳离子,n = 4、8和14),它们已经被开发并相应地确定了它们的结构。这项工作揭示了IL的母体阴离子在H 2 O 2存在下经历了结构转变。形成的活性物质表现出优异的催化活性,[P 4,4,4,4 ] 3 [Ta(O)的转换频率3(η-O 2)高达285 H的] -1通过仅使用一当量的过氧化氢作为氧化剂的,和满意的可回收各种烯丙基醇的非常温和的条件下环氧化。NMR研究表明,该反应是通过氢键机制促进的,其中过氧钽酸根阴离子的过氧基团(O-O)充当氢键受体,而烯丙基醇中的羟基充当氢键供体。这项工作表明简单的单体过氧钽酸酯可以有效地催化烯丙基醇的环氧化。