环辛烯双氧水相界催化环氧化反应研究

以氯甲基化大孔聚苯乙烯-二乙烯苯交联树脂接枝N-苄基-N,N-二甲基-N-十二烷基季铵磷钨杂多酸盐为相界催化剂,进行了无搅拌条件下的环辛烯双氧水催化环氧化反应研究。对影响反应的因素如催化剂用量、反应温度、双氧水与环辛烯摩尔比、双氧水质量分数、溶剂、催化剂颗粒直径、催化剂重复使用性等进行了讨论。结果表明,催化剂可以处于环辛烯双氧水界面处,在完全没有搅拌的条件下催化环辛烯的环氧化反应。在无溶剂、无搅拌、催化剂0.3g,n(双氧水):n(环辛烯)=1.5:1,反应温度72℃,静止反应8h的条件下,环氧环辛烷的产率可达99%以上。催化剂重复使用5次未见活性明显降低。

Phase Boundary Catalysis of Cyclooctene Epoxidation with Aqueous Hydrogen Peroxide

PS grafted N-benzyl-N,N-dimethyl-N-dodecyl quaternary ammonium phosphor tungsten heterpolyacid salts were used in the phase boundary catalysis epoxidation of cyclooctene(COE) with aqueous hydrogen peroxide(HP) under stirred-free conditions.The factors to affect the reaction investigated,such as amount of catalysts,reaction temperature,molar ratio of HP to COE,mass fraction of HP,solvent,particle size of catalysts,reusability of catalysts and so on.The results show that the catalysts can be laid at the phase boundary between COE and HP resulting in catalyzing epoxidation of COE with HP in stirred-free conditions.The yield of 1,2-epoxycyclooctane can reach 99% under the following conditions:stirred-free,solvent-free,catalysts 0.3 g,n(HP)∶n(COE)=1.5∶1,reaction temperature 72 ℃ and reaction time 8 h.Moreover,the catalyst did not obviously decrease its activity even after reusing for five times.