共查询到19条相似文献,搜索用时 125 毫秒
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水溶性膦配体的合成及进展 总被引:4,自引:0,他引:4
水溶性膦配体的合成及进展郑晓来,王艳华,左焕培(大连理工大学,大连116012)关键词水溶性膦配体,均相络合催化,水/有机两相反应1.前言贵金属催化剂的分离回收问题一直是均相络合催化研究领域的一个热点。近年来,水/有机两相催化体系(Aqueous/o... 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
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温控配体与液/液两相催化 总被引:2,自引:2,他引:2
以作者近年的研究工作为主,对液/液两相催化研究领域取得的进展做一综述.着重介绍了以温控配体为基础的新型液/液两相催化过程温控相转移催化(thermoregulatedphasetransfercatalysis,TRPTC)和温控相分离催化(thermoregulatedphase-separablecatalysis,TPSC)的基本原理及其在高碳烯烃氢甲酰化、芳香硝基化合物的CO选择性还原及烯烃加氢等反应中的应用.基于温控配体在水中的“浊点”特性而提出的温控相转移催化概念,为从根本上解决水/有机两相催化
的适用范围受底物水溶性限制的问题提供了一条新途径.而利用温控配体在某些有机溶剂中存在临界溶解温度(CST)的特性而实现的温控相分离催化,则使在高于临界溶解温度的反应温度时为均相的反应体系,在低温(<CST)时则分成两相,催化剂自成一相,形成一种具有“均相反应、两相分离”特色的液/液两相催化新体系. 相似文献
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首次将具有“温控相转移催化”功能的非离子表面活性水溶性膦/铑配合物用于以CO为还原剂的水/有机两相芳香硝基物选择还原反应,以邻氯硝基苯为底物考察了反应温度、CO压力,底物浓度,催化剂浓度和水/有机两相体积比等对反应转化率和选择性的影响。结果表明,当反应条件为150℃和4MPa,反应32h时,邻氯硝基苯的转化率为98%,邻氯苯胺的选择性接近100%,动力学研究表明,底物浓度和催化剂浓度分别对反应速率呈一级,反应的表观活化能Ea=131.3kJ/mol。 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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水溶性铑膦配合物催化烯烃氢甲酰化反应研究进展 总被引:1,自引:0,他引:1
水/有机两相体系中水溶性铑膦配合物催化的烯烃氢甲酰化反应由于具有环境友好和催化剂容易分离等优点而受到广泛关注. 其中水溶性催化剂体系已经用于丙烯氢甲酰化反应制备丁醛的工业化生产. 然而, 长链烯烃在含有催化剂的水相中溶解性较差, 反应速率较慢. 综述了有关加速水/有机两相体系中长链烯烃氢甲酰化反应的方法和进展, 包括使用具有表面活性的膦配体, 以及在催化体系中添加环糊精和表面活性剂等促进剂. 另外, 还讨论了有关内烯烃氢甲酰化反应和提高直链醛选择性的方法. 相似文献
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水溶性双金属催化剂在硝基化合物加氢反应中的协同效应 总被引:3,自引:0,他引:3
采用水溶性催化剂在两相体系下进行的催化反应既保持了均相催化剂的优点,又可通过简单的相分离达到使产物与催化剂分离的目的[’1.对于水溶性催化剂在两相体系中催化加氢反应,文献中大多采用水溶性铐一瞬、铱一脚和钉一碟络合物为催化剂对a、“不饱和醛、酮、酸等化合物的选择加氢进行考察[’‘.然而对水溶性把一脚络合物催化加氢反应性能研究的报道甚少[‘j.在多相催化中,双(或多)金属的协同效应是常见的现象,但在均相及高分子负载的催化体系中双(或多)金属的协同效应的报道较少[‘].我们曾报道了高分子负载的Pd/RU双… 相似文献
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对二十余年来聚合物支载的有机催化剂的合成、性能及其在催化反应中的应用,包括负载催化剂的回收和重复使用等进行了综述.用于支载体的聚合物包括交联聚合物、线型聚合物及树形聚合物;支载的有机催化剂包括手性及非手性催化剂两类.本文作为第一部分将介绍聚合物支载的非手性有机催化剂,包括相转移催化剂、氧化催化剂、酸以及碱催化剂. 相似文献
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对二十余年来聚合物支载的有机催化剂的合成、性能及其在催化反应中的应用,包括负载催化剂的回收和重复使用等进行了综述。用于支载体的聚合物包括交联聚合物、线型聚合物及树形聚合物;支载的有机催化剂包括手性及非手性催化剂两类。本文作为第二部分将介绍聚合物支载的手性有机催化剂,重点介绍近年来颇受重视的氨基酸及多肽类有机催化剂的研究及其应用进展。 相似文献
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The water soluble catalytic system comprising of CuCl2 and 2,2-biquinoline-4,4-dicarboxylic acid dipotassium salt(BQC) is highly efficient organic metallic catalysts for selective oxidation of benzyiic and alicyciic compounds to the corresponding ketones, ex:indan to indanone,ethyl benzene to acetophenone. 相似文献
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Carbonylation of olefins, alcohols and halides using homogeneous as well as heterogeneous catalysts has been discussed. Highlights
of contributions on the activity, selectivity and stability of catalysts for carbonylation reactions are discussed. Kinetics
and mechanism including characterization of the intermediate catalytic species has also been reviewed. The performance of
anchored Pd complexes on mesoporous supports (MCM-41 and MCM-48), water soluble Pd complexes and supported Pd catalysts in
carbonylation of aryl alcohols and olefins has been discussed in the context of catalyst-product separation. Some aspects
of kinetic modelling and reaction engineering of these multiphase catalytic reactions have also been reviewed. 相似文献
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Susanta Hazra Ekta Malik Abhishek Nair Vikas Tiwari Pritam Dolui Anil J. Elias 《化学:亚洲杂志》2020,15(13):1916-1936
Designing reactions in aqueous media has been one of the major challenges in modern organic synthesis, especially to avoid the use of large amounts of organic solvents whose disposal is a matter of grave concern from an environmental perspective. The oxidation of alcohols and amines is an essential and important step in the synthesis of many valuable products including polymers and pharmaceuticals. In recent times, there has been a surge in the use of water as a solvent in many organic reactions. This review focuses specifically on the oxidation reactions of alcohols and amines carried out in water media using transition metal catalysts, metal‐free catalysts and photocatalysts. 相似文献
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Chen Xu Chuanhui Zhang Hong Li Xueyuan Zhao Liang Song Xuebing Li 《Catalysis Surveys from Asia》2016,20(1):13-22
The oxidation of alcohols to carbonyl compounds is one of the most fundamental reactions in synthetic organic chemistry. In order to achieve the realization of dehydrogenation reactions with high atomic efficiency, suitable catalysts and oxidants are considered as the key factors to obtain the optimum activity and aldehydes/ketones selectivity. This review aims to make an overview on the reasonable reaction mechanism and promising catalytic system of alcohols dehydrogenation. 相似文献
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Kavita R. Jain Author Vitae Author Vitae 《Journal of organometallic chemistry》2007,692(25):5532-5540
In the last decade considerable progress has been made in research on organorhenium(VII) oxide catalysts, particularly with respect to methyltrioxorhenium(VII) (MTO). Heterogeneous systems have been developed with particular emphasis on the supporting systems including inorganic and organic carrier materials. As a result efficient and reasonably selective catalysts are now available for a variety of catalytic reactions like olefin epoxidation in particular and other oxidation reactions, metathesis, etc. Besides the MTO/UHP system, polymer supports for the organometallic catalysts are now also successfully applicable. The systems exhibit in several cases the required properties of stability, selectivity, activity and recyclability. 相似文献
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The oxidation of organic compounds is of extreme importance in synthetic chemistry. The catalysts provide high selectivity towards the oxidation products employing with the oxidants. This review is not intended to give a complete survey of all oxidation catalysis reactions by different catalysts but rather to give a summary of some important catalytic oxidation reactions by different metal and non-metal based catalysts. 相似文献