乙酸苄酯合成中接枝型三相相转移催化剂的活性及催化反应动力学

采用"接出(grafting from)"方式,将苯乙烯(St)接枝聚合在微米级硅胶表面,然后对接枝的聚苯乙烯进行了氯甲基化(CM)反应,制得了氯甲基聚苯乙烯/硅胶微粒(CMPS/SiO2);使三丁胺与三苯基膦分别与CMPS大分子链上的苄氯基团发生季铵化与季鏻化反应,分别制得了固载有季铵盐与季鏻盐的接枝微粒QN-PSt/SiO2与QP-PSt/SiO2,即制得了两种接枝型三相相转移催化剂.将该催化剂用于苄氯与乙酸钠合成乙酸苄酯的相转移催化反应,并重点考察了催化剂的活性与催化动力学.实验结果表明,两种接枝型三相相转移催化剂QN-PSt/SiO2与QP-PSt/SiO2对乙酸苄酯的合成都具有明显的催化活性,在液-固-液之间可有效地实现反应物种乙酸根的转移;两者相比,季鏻盐型的催化剂QP-PSt/SiO2的催化活性更高;当水相中乙酸钠用量大大过量时,在有机相中苄氯与乙酸根的反应属准一级反应;两个相转移反应体系相比,以QP-PSt/SiO2为催化剂时反应的表观活化能更低.     

采用季鏻盐型三相催化剂制备N-正丁基邻苯二甲酰亚胺

在新型的季鏻盐型三相相转移催化剂作用下,使用邻苯二甲酰亚胺为亲核取代试剂,与溴代正丁烷发生N-烷基化取代反应,生成N-正丁基邻苯二甲酰亚胺.考察了三种间隔臂不同的季鏻盐型三相相转移催化剂(QP-CPS)的催化效果,结果表明,这三种相转移催化剂对N-正丁基邻苯二甲酰亚胺的合成有明显的催化作用,且间隔臂越长的QP-CB-CPS催化活性越强,当催化剂用量为4 mmol,反应温度为90℃,反应12 h时溴代正丁烷的转化率可达到87%.另外,以催化剂QP-CA-CPS为例,考察了各种因素对三相相转移催化反应的影响规律.结果表明,有机溶剂的极性越强,催化剂的活性越高,且有机相与水相的体积比例以及搅拌速度均对相转移催化效果有较大的影响     

接枝型三相相转移催化剂的制备及其催化作用

将苯乙烯（St）接枝聚合在微米级硅胶表面,制备了接枝微粒PSt／SiO2;使用新型氯甲基化试剂1,4-二氯甲氧基丁烷,对接枝在硅胶表面的聚苯乙烯进行了氯甲基化（CM）反应,制得了氯甲基聚苯乙烯／硅胶（CMPS／SiO2）接枝微粒;使三乙胺与CMPS分子链上的苄氯基团发生季铵化反应,制得了固载有季铵盐（Quaternary salt）的接枝微粒QPSt／SiO2,即制得了接枝型三相相转移催化剂．将此相转移催化剂用于氯化苄与乙酸钠合成乙酸苄酯的相转移催化反应,考察了催化活性、各种因素对相转移催化反应的影响及催化剂的重复使用性能．实验结果表明,接枝型三相相转移催化剂QPSt／SiO2对乙酸苄酯的合成具有较高的催化活性,在液-固-液之间即可有效地实现反应物种乙酸根的转移,在60℃的较低温度下反应7h,氯化苄的转化率可达66．1％;研究发现,固体催化剂QPSt／SiO2表面接枝聚合物PSt的季铵化程度对其催化活性有很大的影响,季铵化程度过大与过小催化活性都较低,当季铵化程度为20％左右时,催化剂的活性最高．     

接枝型三相转移催化剂的制备及其催化作用

将苯乙烯(St)接枝聚合在微米级硅胶表面,制备了接枝微粒PSt/SiO2;使用新型氯甲基化试剂1,4-二氯甲氧基丁烷,对接枝在硅胶表面的聚苯乙烯进行了氯甲基化(CM)反应,制得了氯甲基聚苯乙烯/硅胶(CMPS/SiO2)接枝微粒;使三乙胺与CMPS分子链上的苄氯基团发生季铵化反应,制得了固载有季铵盐(Quaternary salt)的接枝微粒QPSt/SiO2,即制得了接枝型三相相转移催化剂.将此相转移催化剂用于氯化苄与乙酸钠合成乙酸苄酯的相转移催化反应,考察了催化活性、各种因素对相转移催化反应的影响及催化剂的重复使用性能.实验结果表明,接枝型三相相转移催化剂QPSt/SiO2对乙酸苄酯的合成具有较高的催化活性,在液-固-液之间即可有效地实现反应物种乙酸根的转移,在60℃的较低温度下反应7 h,氯化苄的转化率可达66.1%;研究发现,固体催化剂QPSt/SiO2表面接枝聚合物PSt的季铵化程度对其催化活性有很大的影响,季铵化程度过大与过小催化活性都较低,当季铵化程度为20%左右时,催化剂的活性最高.     

相转移催化法制备侧链带有醛基的聚苯乙烯交联微球

首先使氯甲基聚苯乙烯交联微球（CCMPSt）在有机相中充分溶服,然后通过相转移催化剂（季铵盐）的作用,将水相中对羟基苯甲醛所产生的负氧离子转移至有机相,使之与CCMPSt微球表面的苄氯基团发生亲核取代反应,从而将CCMPSt微球转变为侧链带有醛基的聚苯乙烯交联微球（Aldehyde—CPSt）．本研究重点考察了各种因素对液-液-固三相体系中相转移催化过程及取代反应的影响规律,较深入地探讨了反应机理．研究结果表明,通过相转移催化剂的作用,可将亲核取代试剂对羟基苯甲醛负氧离子不断地从水相转移至有机相,在有机相与交联微球CCMPSt的界面发生取代反应,从而将CCMPSt微球顺利地转变为功能微球Aldehyde—CPSt．有机溶剂的极性越强,对CCMPSt微球的溶服性能越好,取代反应速率越快;相转移催化剂季铵离子上的碳链对称性越好及碳链越长,相转移催化的效果越好;有机相与水相的比例对相转移催化效果也有较大的影响．     

相转移催化维悌希反应研究

近年来,有关相转移催化维悌希反应的报道大都限于烷基三苯季鏻盐的研究,对于带功能基的烷基三苯基季鏻盐的相转移维悌希反应报道甚少。相转移疆悌希反应在有机合成中的应用,尤其是对活性物质(如昆虫性信息素)的合成是非常有意义的。本文报道ω-羟基烷基三苯基季锛盐与脂肪醛的相转移维悌希反应,具体合成步骤如下:     

手性季鏻盐相转移催化剂在不对称反应中的应用

手性相转移催化是不对称催化领域的重要分支之一,扮演着越来越重要的角色。本论文综述了几类新型手性季鏻盐催化剂的设计合成,及其在催化不对称Henry反应、不对称氢磷酰化反应、不对称烷基化反应、不对称Michael加成反应、不对称Mannich反应、不对称aldol反应、不对称质子化反应及不对称胺化反应中的催化活性和对映选择性,重点介绍了不同催化剂和反应底物之间立体效应和电子效应的影响,并对手性季鏻盐催化剂的发展进行了展望。     

聚苯乙烯负载季鏻盐型树脂的制备及催化效应

用高分子材料负载季鏻盐相转移催化剂的开发和研究已有报导^[1,2]。Reeves^[3]和Idoux^[4]曾用氯甲基聚苯乙烯树脂经多步反应制得催化剂。Tomoi通过CF₃SO₃H催化ω-溴代烯烃与树脂付-克烷基化反应制得溴烃基树脂,再与三烃基膦反应制成高分子负载季磷盐催化剂, 具有良好的相转移催化效应。     

相转移催化反应研究——Ⅰ.相转移催化剂在二卤卡宾与对-甲基苯乙烯加成反应中结构效应

本文研究了不同结构的季铵盐、季鏻盐、常用冠醚以及N,N＇-二取代氦杂冠醚等相转移催化剂,催化产生的二溴卡宾与对-甲基苯乙烯的加成反应。结果证明,具有对称烷基结构的季铵盐的催化性能优于碳链较长、对称性较差的手铵盐。在冠醚类相转移催化剂中,新型N,N＇-二取代氮杂冠醚优于常用冠醚及穴醚[2.2.2]。在十九种相转移催化剂中,以N,N＇-双(3＇、6＇-二氧杂癸烷基)-1,7,10,16-四氧杂-4,13-二氮杂环十八烷[简称二丁基2.2(2.2)]的催化性能最佳。简要讨论了鎓盐及大环多醚的PTC反应机理及催化性能,还比较了氘代氯仿、氘代氢氧化钠重水体系进行的相转移催化反应。     

吡啶鎓盐系列相转移催化剂的制备及性能

合成了一系列对芳香亲核取代反应（氟化反应）有良好反应活性4－二烷基氨基吡啶Weng盐系列相转移催化剂，研究了该系列催化剂的催化活性，并筛选出活性最佳的催化剂。在催化活性最好的4－（二甲氨基）。N－（2－乙基）己基吡啶Weng盐（Cat2)作用下，对氯硝基苯氟化，得率98．6％，反应时间1.5h。     

Synthesis of N‐butylphthalimide catalyzed by quaternary phosphonium salt‐type triphase catalysts based on cross‐linked polystyrene microspheres

Chloroacylation reactions of cross‐linked polystyrene (CPS) microspheres were conducted with two kinds of ω‐chloroacyl chlorides, chloroacetyl chloride, and 4‐chlorobutyryl chloride as reagent, respectively, and the chloromethylation reaction of CPS microspheres was also performed using 1,4‐bis (chloromethoxy) butane as reagent, obtaining three kinds of modified CPS microspheres on which the exchangeable chlorine atoms were introduced. Subsequently, the reactions of these modified microspheres with triphenylphosphine were carried out, respectively, and three kinds of quaternary phosphonium salt (QPS)‐type triphase catalysts (TPC) were prepared. These catalysts were used in the N‐alkylation reaction of phthalimide, namely the reaction of phthalimide in water phase with 1‐bromobutane in organic phase, resulting in N‐butylphthalimide. The effects of main reaction conditions on the triphase‐transfer catalysis reaction were examined, and the relationship between the structure and catalytic activity for these TPC was investigated. The experimental results indicate that the prepared QPS‐type TPC are effective for the N‐alkylation reaction of phthalimide carried out between oil phase and water phase. The polarity of the organic solvent and the temperature affect the reaction rate greatly. The result of the reaction in nitrobenzene having the highest polarity among the used several solvents is the best. It will make the reaction to speed up to raise temperature. The chemical structures of the TPC have crucial influences on the catalytic activity of the TPC. The catalyst with a longer spacer arm, which links the catalytic group to the matrix microspheres, has higher activity. The bonding density of QPS group on the polymer microspheres affects the hydrophilic and hydrophobic property of the TPC and, accordingly, affects the catalytic activity greatly. There is a maximum conversion of 1‐bromobutane as the bonding density of QPS group on TPC is 0.94 mmol/g. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 677–686, 2011     

Phase-transfer reactions catalyzed by phosphonium salts bound to macroporous polystyrene supports

The rate of reaction of alkyl halides with aqueous sodium acetate or cyanide catalyzed by phosphonium salts supported on insoluble polystyrene resins, and rates of ion-exchange of the chloride ion in the catalysts against the acetate ion, were studied as a function of catalyst particle size, the percentage of ring substitution, the morphology of polymer support, and distance between active site and polymer backbone. Rates of 1-bromooctane or benzyl chloride with macroporous, 7–25% ring-substituted catalysts increased with increasing ring substitution. Rates with macroporous catalysts increased as a heptamethylene spacer was introduced between the active site and the polymer backbone. Rates of ion-exchange with macroporous catalysts were facilitated with increasing ring substitution or by the introduction of the spacer chain. A relation between the catalytic activity of macroporous or microporous catalysts and ion-exchange rates under triphase conditions was discussed.     

Insoluble polystyrene-bound quaternary onium salt catalysts for the synthesis of cyclic carbonates by the reaction of oxiranes with carbon dioxide

The addition reaction of oxiranes ( 26a—e ) with carbon dioxide (CO₂) was performed using insoluble polystyrene beads containing pendant quaternary ammonium or phosphonium salts as catalysts under atmospheric pressure. The reaction of 26a—e with CO₂ proceeded smoothly catalyzed by 1–2 mol % of the polymer-supported quaternary onium salts to give the corresponding cyclic carbonates ( 27a—e ) in high yields at 80–90°C. In this reaction system, the catalytic activity of the polymer-supported quaternary onium salts was strongly affected by the following factors: degree of ring substitution (DRS) of the onium salt residues to the polymer, degree of crosslinking (DC) of the polystyrene beads, chain length of the alkylene spacer between the polymer back-bone and the onium salt, hydrophobicity of the alkyl group on the onium salts, and kind of onium salts. That is, the polymer-supported quaternary phosphonium salts with low DRS and DC and with long alkylene spacer chain were found to have higher catalytic activity than low molecualr weight quaternary onium salts. The above polymer-supported catalysts can easily be separated at the end of a reaction by filtration and can be reused for at least seven runs. It was also found that the rate of reaction was proportional to the products of catalyst concentration and oxirane concentration. © 1993 John Wiley & Sons, Inc.     

POLYMER—SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE—TRANSFER REACTIONS

In this study was to investigate,by phase-transfer catalysis,the activity of single and mixed ammonium and phosphonium salts grafted on a “gel-type“ stryene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide.A wide variety of catalysts with different quaternary groups and different quaternary chain length substitutents were examined.The activity of single“onium“salts increases as a consequence of the association of ammonium and phosphonium salts grafted onn the same polymeric support.The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the -onium and of the functionalization degree with phosphonium groups.     

Allylation of 5-Methylfurfural Catalyzed by Phase-Transfer Reagents in Aqueous Media

Allylation of 5-methylfurfural with allyl halide and zinc was performed by using quaternary ammonium and phosphonium salts as phase-transfer catalysts. The phosphonium salt showed higher activity than the ammonium salt. Excellent yields were obtained with both catalysts.     

The Effect of Iodide Ion in Phase-Transfer Catalytic Syntheses of Benzyl Esters

In order to examine the effect of iodide ions on reaction catalyzed by phase-transfer technique, we made kinetic studies, under the influence of added Na1, on the synthesis of benzyl esters from benzyl chloride and sodium carboxylate. These carboxylates include sodium acetate, sodium benzoate, sodium salicylate and sodium formate; the catalyst was a quaternary ammonium salt. The results reveal that iodide ions at a suitable concentration accelerate the reaction, whereas iodide ions in excess poison the catalyst. The optimum concentration varies with the reaction system. This critical concentration depends upon the distribution coefficient of the intermediates formed in the reactions.     

在交联聚合物微球GMA/MMA表面接枝固载聚乙二醇的研究

以乙二醇二甲基丙烯酸酯为交联剂,采用悬浮聚合方法,制备了甲基丙烯酸缩水甘油酯(GMA)和甲基丙烯酸甲酯(MMA)的交联微球GMA/MMA.使用Lewis酸催化剂,通过环氧键的开环反应,将聚乙二醇(PEG)偶合接枝在交联微球GMA/MMA表面,实现了PEG的固载化,制得了三相相转移催化剂PEG-GMA/MMA.重点考察了各种因素对PEG接枝固载过程的影响,并研究了反应机理.实验结果表明,以交联微球GMA/MMA为载体,可以顺利地实现PEG的固载化,这是制备PEG三相相转移催化剂的简捷途径.实验发现,Lewis酸也能催化环氧键的开环反应,而且比质子酸的催化更加有效.溶剂的极性对偶合接枝反应的影响较大,采用极性大的溶剂有利于PEG的接枝固载.偶合接枝体系中,过高的催化剂用量会导致PEG双端羟基参与接枝反应,使载体表面大分子之间发生附加交联,不利于PEG的接枝固载.在适宜的反应条件下,接枝微球PEG-GMA/MMA表面的PEG接枝度可达0.20 g/g.     

Hydroxylation of cyclohexane with molecular oxygen catalyzed by highly efficient heterogeneous Mn(III) porphyrin catalysts prepared by special synthesis and immobilization method

A novel method to synthesize and immobilize porphyrins as well as manganese porphyrins on crosslinked polystyrene (CPS) microspheres was designed. The chloromethyl groups of chloromethylated CPS microspheres (CMCPS microspheres) were first oxidized to aldehyde groups via Kornblum oxidation reaction, obtaining aldehyde group-functionalized microspheres, and then, the synchronous synthesis and immobilization of porphyrins on CPS microspheres were carried out via the Adler reaction between solid–liquid phases, obtaining three kinds of functional microspheres, on which phenyl porphyrin (PP), p-chlorophenyl porphyrin (CPP) and p-nitrophenyl porphyrin (NPP) were immobilized. Finally, three manganese porphyrin-immobilized microspheres, MnPP–CPS, MnCPP–CPS and MnNPP–CPS, were prepared, these solid catalysts were used in the catalytic hydroxylation reaction of cyclohexane with molecular oxygen as oxidant, and their catalytic performances were mainly investigated in this work. Some surprising experimental results were obtained. The prepared immobilized manganese porphyrin catalysts display amazing catalytic activity and selectivity, and cyclohexane conversion can get up to 45?% and cyclohexanol selectivity in the reaction product can be up to 90–100?%.     

交联聚苯乙烯微球固载的双齿席夫碱型氧钒(Ⅳ)配合物催化分子氧氧化苯甲醇

利用水杨醛(SA)和氨甲基(MA)交联聚苯乙烯(CPS)微球反应,制得键合有双齿席夫碱配体SAAM的交联聚苯乙烯SAAM-CPS微球,再与硫酸氧钒发生螯合配位反应,制备了固载有席夫碱型氧钒(Ⅳ)配合物催化剂,采用红外光谱、扫描电镜及热失重等手段对催化剂进行了表征,并用于催化分子氧氧化苯甲醇反应,考察了催化剂用量、反应温...