席夫碱修饰的MCM-41介孔分子筛与碳酸钾共同催化查尔酮的环氧化反应

Epoxidation of α,β-Unsaturated Ketones Catalyzed by Schiff Base Functionalized MCM-41 and Potassium Carbonate

将介孔分子筛MCM-41依次与3-氯丙基三乙氧基硅烷、二氨基硫脲和水杨醛反应,得到席夫碱修饰的介孔分子筛MCM-41催化剂,以过氧化氢为氧源,研究了其与K2CO3共同催化α,β-不饱和酮的环氧化反应。化合物的结构经1H NMR和IR分析确认。考察了金属盐、溶剂、催化剂用量、反应时间等因素对环氧化反应的影响。结果表明,室温下α,β-不饱和酮的环氧化反应在短时间内均以较高的产率(最高达93%)得到了相应的产物。同时,对催化剂的重复利用进行了研究,发现重复使用4次,仍能以较高产率得到环氧化产物。

Mesoporous molecular sieves MCM-41 supported Schiff base was prepared from MCM-41, 3-chloropropyltriethoxysilane, dis-thiocarbohydrazone and salicylide. Both as-prepared supported catalyst and K2CO3 were used to catalyze the epoxidation of α,β--unsaturated ketones in the presence of H2O2. All products from these oxidations were characterized salts, solvents, reaction temperature, th by ^1H NMR and IR. e loading of catalyst, The effects of reaction conditions such as metal and reaction time on the oxidation reaction were investigated. It was found that the epoxidation products of α,β-unsaturated ketones were easily obtained with excellent yields（up to 93% ） at room temperature in a short time. Especially, the heterogeneous catalyst can be reused four times without significant loss of its catalytic activity