共查询到18条相似文献,搜索用时 93 毫秒
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B酸性功能化离子液体是功能化离子液体研究领域的热点,综述了当前B酸性功能化离子液体在绿色有机合成中的应用。不足之处在于:(1)B酸性功能化离子液体的酸度测定尚缺乏准确有效和简捷通用的表征方法,因而不能建立酸度与催化性能之间的定量关系;(2)研究报道的各种类型的B酸性功能化离子液体或在物化性能或在成本上不尽人意,因而设计全新结构的B酸性功能化离子液体或对报道的B酸性功能化离子液体的化学修饰仍是B酸性功能化离子液体研究中的重要内容。 相似文献
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合成了一系列酸性的醚基功能化离子液体,对其进行了表征和测定。通过乙腈探针红外光谱法确定了最强酸性的催化剂,并将其用于催化异丁烷与2-丁烯的烷基化反应。结果表明:1-甲氧基乙基-3-甲基咪唑溴氯铝酸离子液体([MOEMIM]Br/AlCl3)在AlCl3摩尔比为0.75时酸性最强,催化烷基化反应效果最佳;在反应温度35℃,异丁烷与2-丁烯体积比10:1的反应条件下催化烷基化反应,可得到C8选择性66.6%的烷基化油;其催化效果远优于非醚基功能化氯铝酸离子液体的催化效果;该催化剂可循环利用。 相似文献
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本文介绍了酸性离子液体的分类与合成方法,综述了近年来Lewis酸性离子液体、Br?nsted酸性离子液体、B-L双酸性离子液体在酯化反应中的研究进展,对酸性离子液体的酸性表征方法进行总结,提出酸性离子液体在酯化反应中的问题与研究方向。 相似文献
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主要总结了国内外利用酸性离子液体催化合成生物柴油的进展,介绍了离子液体特性及其催化制备生物柴油的优点。简述了酸性离子液体在酯化和制备生物柴油反应中的应用,对酸性离子液体催化制备生物柴油的研究方向进行了展望。 相似文献
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功能化离子液体催化邻苯二甲酸二辛酯的合成及其工艺 总被引:2,自引:0,他引:2
利用功能化酸性离子液体催化合成邻苯二甲酸二辛酯(DOP), 结果表明,其催化效果比非功能化的中性离子液体好,催化剂循环使用率高,其中,功能化酸性离子液体[HSO3-PMIM][HSO4]的催化活性最好,并确定了用其催化合成DOP的优化工艺条件:酐醇物质的量比1∶3,反应温度140 ℃,反应时间2.5 h, 离子液体最佳用量为反应体系总质量的15%,环己烷作带水剂,此条件下,酯化率可达98.6%以上 。 相似文献
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为将离子液体代替三氟乙酸制备二叔丁基蒽,设计合成了2种Br?nsted酸性磺酸功能化离子液体与3种Lewis酸性氯铝酸盐离子液体,并将其用于蒽与叔丁醇的烷基化反应。研究发现,Br?nsted酸性磺酸功能化离子液体无催化活性,在L酸性氯铝酸盐离子液体存在时反应可以快速进行,且通过控制[Et3NH][Al2Cl7]离子液体用量得到了目标产物二叔丁基蒽,并采用单因素实验对反应温度和时间、原料配比、离子液体用量进行优化,在最佳工艺条件下,蒽的转化率为99.5%,二叔丁基蒽的产率为94.1%,反应效果明显好于传统催化剂三氟乙酸,为工业化应用提供了新思路。 相似文献
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功能化离子液体及其在食品工业中的应用 总被引:4,自引:0,他引:4
介绍了功能化离子液体的制备,综述了功能化离子液体在食品工业领域的最新应用进展,重点讨论了功能化离子液体在食品工业的原料合成、分析提纯和生物技术方面的应用进展,分析了功能化离子液体在食品工业应用中存在的问题,提出了功能化离子液体在食品工业中的发展方向. 相似文献
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Br?nsted-Lewis双酸性离子液体同时具备B酸性和L酸性,是融合双酸性固体酸与离子液体的特征发展起来的一类新型催化剂。本文综述了近年来B-L双酸性离子液体的合成、表征及催化剂应用等方面的进展,在此基础上,总结出B-L双酸性离子液体的三个特征。其一,利用一种催化剂就可以催化分别需要B酸和L酸催化的分步反应,使反应一锅化,简洁可控。其二,B酸性和L酸性之间存在相互增强的协同作用,使其具有更好的催化性能,或可提高反应转化率或产物选择性。其三,液体催化剂在传质和扩散等方面均优于双酸性固体酸。上述特征使B-L双酸性离子液体替代并超越传统酸性催化剂成为可能,在工业应用中显示良好的发展前景。 相似文献
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合成了基于吡啶、三乙胺阳离子不同阳阴摩尔组成的[Py]Cl-AlCl3、[Py]Cl-ZnCl2、Et3NHCl-AlCl3及Et3NHCl-ZnCl2离子液体;测定了不同摩尔组成[Py]Cl-AlCl3和[Py]Cl-ZnCl2离子液体熔点,最后以制备的四种阳阴摩尔比均为4∶6的离子液体催化合成六氯环三磷腈,结果表明具有中等Lewis酸性的ZnCl2离子液体所得产物的产量高、选择性好,而强酸性的AlCl3离子液体并不适合该反应的合成。 相似文献
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Yanlong Gu Juan Zhang Zhiying Duan Youquan Deng 《Advanced Synthesis \u0026amp; Catalysis》2005,347(4):512-516
Four non-chloroaluminate acidic ionic liquids have been used as catalysts for Pechmann condensations of phenols under solvent-free conditions. SO3H-functionalized trifluoromethanesulfonate imidazolium ionic liquid has proved to be the most active catalyst. Ionic liquid loads as low as 5 mol % can be used leading to high yields with activated phenols at an oil bath temperature of 80 °C. The acidities of the four ionic liquids have also been tested using the Hammett method in dichloromethane. The results are consistent with their catalytic activities as observed in the Pechmann reaction of resorcinol. This methodology offers significant improvements for the synthesis of coumarins with regard to yield of products, simplicity in operation, and green aspects by avoiding toxic catalysts and solvents. 相似文献
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Shahnaz Rostamizadeh Negar Zekri Leili Tahershamsi 《Polycyclic Aromatic Compounds》2013,33(5):542-560
Generally ionic liquids have gained increasing attention in organic synthesis as catalyst and solvent. However, there are some drawbacks, including the difficulties in the product purification, ionic liquid recycling, and use of excess amounts of the expensive ionic liquid when the ionic liquid is used in the organic reactions. In addition, the high viscosity of ionic liquids can lead to mass transfer limitations in fast chemical reactions. These problems can be overcome by the use of supported ionic liquid phases. In this article, a simple, efficient and green method has been developed for the synthesis of bisphenolic antioxidants by the reaction of 2-tert-butyl-4-methylphenol and aldehydes in the presence of nanosilica supported dual acidic ionic liquid (NSSDAIL) as robust and reusable catalyst under solvent-free conditions. Three different NSSDAILs were synthesized and characterized using SEM, BET, IR, and XRD techniques. High yields of the products, short reaction times, use of a non corrosive, non toxic and reusable catalyst, and use of solvent-free condition are the worthwhile advantages of the current method. 相似文献
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Francisco J. Hernández‐Fernández Antonia P. de los Ríos Luis J. Lozano‐Blanco Carlos Godínez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(11):1423-1435
Ionic liquids have shown potential as green reaction media compared with organic solvents, mainly due to their lack of vapour pressure. In non‐aqueous enzymology, ionic liquids are opening up new fields. The advantages of using ionic liquids over the use of organic solvents as reaction medium for biocatalysis include enhancement of enzyme activity, stability and selectivity. In this work, the enzymatic synthesis of esters in ionic liquids has been extensively reviewed. Numerous examples of the application of ionic liquids as reaction medium for the enzymatic production of esters have been included. The effect of the nature of the ionic liquid on activity, selectivity and stability of enzymes which catalyze esters synthesis has been carefully analysed. Innovative reaction methodologies for the biosynthesis of esters, including ionic liquid/supercritical carbon dioxide biphasic systems and the integrated reaction/separation processes using supported liquid membranes based on ionic liquids have been revised. Copyright © 2010 Society of Chemical Industry 相似文献
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