共查询到16条相似文献,搜索用时 187 毫秒
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温控非水液/液两相催化,是指一类由两种或多种液态有机物组成的催化反应体系,其特点是体系的相态变化可通过温度来调控,即体系在高温时相互混溶呈均相,低温不溶分成两相,催化剂和产物分别处于两相,从而为解决均相催化剂分离难的问题开拓了一个新方向,是液/液两相催化研究领域最引人注目的进展之一.首次以"温控"为主线将氟两相催化作为温控液/液两相催化的一个特定类型纳入"温控非水液/液两相催化"范畴,并与其它通过温度来调控的有机液/液两相和作者提出的温控相分离催化串在一起作一较为详细的评述. 相似文献
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本文以作者在温控水/有机两相及温控非水液/液两相催化领域的研究工作为主线,对这一领域的研究进展作一评述,重点是环绕经典水/有机两相催化体系存在“应用范围受底物水溶性限制”的根本问题展开。特别是对“温控相转移催化”作了较为详细的介绍,同时,按体系介质不同,对氟两相体系、PEG两相体系、离子液体两相体系等非水液/液两相体系以及温控相分离催化分别作了阐述。 相似文献
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温控相分离催化的高碳烯烃氢甲酰化反应研究 总被引:2,自引:0,他引:2
考察了非离子表面活性膦配体P[p-C6H4O(CH2CH2O)nH]3(PETPP,n=6~12,N=3n)在有机溶剂中的溶解度-温度关系,发现其在甲苯中具有临界溶解温度(CST)现象。基于PETPP在甲苯中低温分相、高温互溶的CST特性,提出了温控相分离催化的新概念。并将其应用于癸烯氢甲酰化反应,转化率及醛收率分别达到98.7%和96.0%,催化剂循环使用10次,活性基本保持不变。 相似文献
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金属络合物的相转移催化分析与分离 总被引:2,自引:0,他引:2
以可简单分离回收、可反复使用为目标,详细介绍了相转移催化的变化发展过 程.通过对溶剂的选择,使得催化剂选择性地溶解在某一液相中,而使产物溶解在 另一液相中,如水-有机两相催化体系;通过温度的变化,简单地实现了在较高温 度下反应为均相体系以提高催化剂的活性,而在较低温度下实现了催化剂与产物不 相溶使得催化剂得以简单分离,如温控型水-有机两相催化体系、氟-有机两相催化 体系、温控型含氟催化剂、温控型有机金属催化剂等. 相似文献
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温控相转移催化——水/有机两相催化新进展 总被引:14,自引:0,他引:14
综述了“温控相转移催化”的原理,温控膦配体的设计、合成及其在水溶性极小的底物高碳烯烃的水/有机两相氢甲酰化反应中的应用效果. 相似文献
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键联聚乙二醇高分子担载锰(Ⅲ)卟啉的合成及催化烯烃环氧化反应性能研究 总被引:1,自引:0,他引:1
本文研究了键联聚乙二醇高分子担载锰(Ⅲ)卟啉的合成,以及在CH_2Cl_2/H_2O两相体系中催化苯乙烯环氧化反应的性能.探索了催化反应体系中溶液pH值、NaOCl浓度、轴向配体及相转移催化剂对催化反应的影响.结果说明键联聚乙二醇高分子担载锰(Ⅲ)卟啉是烯烃环氧化反应的一种有效催化剂,其中聚乙二醇链可以络合Na,使OCl富集于金属卟啉周围,起到较好的相转移催化作用.在催化反应的各影响因素中,水相pH值对反应的影响最大. 相似文献
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A brief overview of our recent research results of thermoregulated liquid/liquid biphasic catalysis is presented. Emphasis is given to the general principles of thermoregulated phase-transfer catalysis (TRPTC) and thermoregulated phase-separable catalysis (TPSC). In addition, the applications of TRPTC and TPSC in biphasic catalysis are also discussed. The introduction of TRPTC to biphasic system is free from the shortcomings of classical aqueous/organic two-phase catalysis, in which the application scope is restrained by the water solubility of the substrate. Meanwhile, TPSC provides a very simple and reliable way to deal with the separation of catalyst in homogeneous catalysis. The common advantages of TRPTC and TPSC are characterized by homogeneous catalysis coupled with convenient biphasic separation. 相似文献
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A series of polyether-substituted triazolium ionic liquids catalysts have been first synthesized for resolving the problem of separation and reuse of Stetter catalysts. The catalysts possess the properties of critical solution temperature (CST) and inverse temperature-dependent solubility in toluene/heptane solvents. Based on these properties, the catalysts can achieve the catalytic process named as thermoregulated phase-separable catalysis (TPSC) with the characteristic of homogeneous reaction at higher temperature and phase-separation at lower temperature. The novel TPSC system has been successfully applied for Stetter reaction of furfural or butanal with ethyl acrylate. The experimental results have showed that the novel catalysts exhibit excellent TPSC with high recycling efficiency. 相似文献
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Wate-soluble polyether phosphites alkyl polyethylene glycol ophenylene phosphite(APGPPS)were alcoholysis of phosphorus chloride with plyoxyethylene alkyl ether.With appropriate HLB(hydrophile-lypophile balance),the phosphites possess clear cloud points below 100℃,Addition of some inorganic salts decreases cloud points of the phosphites.When the phosphiites have long polyether chain binding to short-chain alkyl group,their cloud points could be extrapolated from figure of dependece of cloud points on addition of inorganic salts.Utilizing octylpolyglycol-phenylene-phosphite(OPGPP)(APGPP,R:Octyl)/Rh complex formed in situ as catalyst,over 90% conversion of 1-decene was obtained ,avoiding the limitation of water insolubility of substrates.Preliminary results indicated that micellar catalysis and thermoregulated phase-transfer catalysis(TRPTC)coexist in the reaction system.Below cloud point,micellar catalysis induced by plyether phosphites may be existed.When temperature is increased to above cloud point of the phosphies,this reaction works mainly in TRPTC.The catalysts could be easily spearated by simple decantation,but followed by considerable loss in activity after three successive reaction runs.Preliminary results indicated hydrolysis of OPGPP happened during the reaction.which may explain for the bad loss in activity.The catalyst was reused up to seven times with-out clear decrease in activity when OPGPP/Rh ratio was increased to 50. 相似文献
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近年来,水/有机两相催化已成为均相催化多相化研究的主流[1].其中,新型水溶性膦配体的合成和两相催化新体系的设计尤为引人关注[2].最近我们发现[3],聚醚型水溶性膦-铑催化剂在高温下可溶入有机相对反应进行催化,而在冷却后又重返水相和产物分离.本文通... 相似文献