摘要
使用两种ω-氯代酰氯(氯乙酰氯与氯丁酰氯)对交联聚苯乙烯微球(CPS)进行Friedel-Crafts酰基化反应,使用1,4-二氯甲氧基丁烷对CPS微球进行氯甲基化反应,分别将可交换的氯引入CPS微球表面,制备了化学改性的CPS微球.然后使用三苯基膦对改性微球进行季鏻化反应,制备了间隔臂(spacerarm)长度不同的三种季鏻(QP)盐型三相相转移催化剂QP-CPS.考察了主要反应条件对制备过程的影响,并以氯化苄与乙酸钠合成乙酸苄酯的反应体系作为三相相转移催化的模型体系,初步考察了QP-CPS的相转移催化活性,探索了催化剂结构与相转移催化活性的关系.结果表明,季鏻盐的化学稳定性较差,在制备过程中需控制反应时间与温度,且宜选用极性较高的溶剂.季鏻盐型三相相转移催化剂QP-CPS对乙酸苄酯的合成具有较高的催化活性,在液-固-液之间可有效地实现反应物种乙酸根的转移.与季铵盐(QN)型三相相转移催化剂QN-CPS相比,季鏻盐型三相相转移催化剂QP-CPS具有更高的相转移催化活性.间隔臂越长,QP-CPS的相转移催化活性越高,QP-CPS的亲水和亲油性能对相转移催化活性也有很大的影响.
Friedel-Crafts acylation reaction of crosslinked polystyrene （CPS） microspheres was conducted using two kinds of ω-chloroacyl chloride as reagents, and chloromethylation reaction of CPS microspheres was performed using 1,4-dichloromethyoxybutane without carcinogenic toxicity as reagent. By these reactions, exchangeable chlorine was introduced onto the surface of CPS microspheres and resulted in chemically modified CPS microspheres. Subsequently, the modified microspheres were transferred into quaternary phosphonium-type triphase catalysts via quaternary phosphonium （QP） reaction with triphenylphosphine. Three kinds of quaternary phosphonium-type triphase catalysts QP-CPS with different spacer ann lengths were obtained. The effects of main factors on quaternary phosphonium reaction were examined. The phase-transfer catalytic activity of the prepared triphase catalysts for esterification between benzyl chloride and sodium acetate was investigated. The results indicate that the stability of quaternary phosphonium is poor. The reaction temperature and time need to be controlled, and the solvent with higher polarity is adapted during synthesis. The prepared quaternary phosphonium-type triphase catalysts have higher activity for the synthesis of benzyl acetate, and the reaction species acetate ion can be effectively transferred between the liquid-solid-liquid phases. In comparison with quaternary ammonium-type catalyst QN-CPS, the quaternary phosphonium-type triphase catalyst QP-CPS has higher catalytic activity. The catalyst QP-CPS with a longer spacer arm has higher catalytic activity. The hydrophilic and hydrophobic properties of catalyst QP-CPS also greatly affect the phase-transfer catalytic activity.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2010年第1期112-119,共8页
基金
山西省自然科学基金(2008021013)
关键词
相转移催化
三相相转移催化剂
季鏻盐
聚苯乙烯
乙酸苄酯
间隔臂
phase-transfer catalysis
triphase catalyst
quaternary phosphonium salt
polystyrene
benzyl acetate
spacer arm
