Selective oxidation of pseudocumene and 2-methylnaphthalene with aqueous hydrogen peroxide catalyzed by γ-Keggin divanadium-substituted polyoxotungstate
作者:Olga V. Zalomaeva、Vasiliy Yu. Evtushok、Gennadii M. Maksimov、Oxana A. Kholdeeva
DOI:10.1016/j.jorganchem.2015.04.020
日期:2015.9
of a γ-Keggin divanadium-substituted phosphotungstate, (Bu4N)4[γ-PW10O38V2(μ-O)(μ-OH)], has been evaluated in the selective oxidation of 1,2,4-trimethylbenzene (pseudocumene, PC) and 2-methylnaphthalene with the green oxidant, 35% aqueous hydrogen peroxide. Under conditions of H2O2 deficiency ([PC]/[H2O2] = 17–22), PC oxidation proceeded with unusually high chemo- and regioselectivity, producing exclusively
一个γ-的Keggin二钒取代的磷钨酸盐的催化性能,(BU 4 N)4 [γ-PW 10 ö 38 V 2(μ-O)(μ-OH)],已经在1选择氧化评价2,4-三甲基苯(拟枯烯,PC)和2-甲基萘与绿色氧化剂,35%的过氧化氢水溶液。在H 2 O 2缺乏([PC] / [H 2 O 2] = 17–22),PC氧化以异常高的化学选择性和区域选择性进行,仅生成摩尔比为7.3的2,4,5-三甲基苯酚(2,4,5-TMP)和2,3,5-TMP / 1,基于氧化剂的产率为73%。发现了痕量的异美2,3,6-三甲基苯酚。在过量的H 2 O 2([H 2 O 2 ] / [PC] = 8)的条件下,形成2,3,5-三甲基-1,4-苯醌(TMBQ,维生素E关键中间体),在41%的选择性下41%的底物转化率。在2-甲基萘的氧化中也发现非典型区域选择性,该氧化主要产生6-甲基-1,4-萘醌(6-MNQ),而