【作者】 王雯娟；

【导师】 杨建国；

【作者基本信息】 华东师范大学 ， 物理化学， 2008， 博士

【摘要】 绿色化学己成为当前化学研究的热点和前沿,它旨在从源头上消除污染。传统化学反应及相关化学工业是当今世界严重污染的主要来源,污染的很大部分来自于反应过程中使用的大量的易挥发性有机溶剂以及较难处理的催化剂。离子液体作为一种新型的绿色溶剂和催化材料,因其具有不挥发、不可燃、比较宽的液态温度范围、比较高的热稳定性、可调的溶解性以及优良的电化学性质等特性,已被成功地应用于有机合成、电化学、分离提取及材料科学等领域。随着离子液体理论研究的深入及应用技术的飞速发展,需要设计和开发更多新型的、并具有特殊功能的离子液体材料,以满足不同领域的应用需求,同时也需要研究并丰富离子液体基础化学理论。然而,目前大多数离子液体的合成过程比较复杂,阻碍了离子液体的大规模工业化进程。因此研究开发高效、简单和清洁的离子液体合成方法,并能够将其成功地应用于重要的有机化学反应中,成为目前离子液体研究的一项重要内容。本论文的研究工作是设计制备出不同的新型功能化离子液体,可作为高效清洁的催化剂或溶剂应用于一些重要的酸催化有机反应,克服了传统无机强酸或者Lewis酸催化剂带来的反应时间长,废酸液污染环境以及腐蚀设备,产物与催化剂难以分离而且催化剂不易回收利用,产物色泽深等缺点,并且取得了很好的实验结果。这将进一步开拓功能化离子液体在有机合成反应中的应用领域,同时也发展了一些重要的高效清洁的有机合成方法。论文首先阐述了离子液体的研究背景,说明了离子液体的种类、合成方法、离子液体的基本物性,离子液体在分析化学、有机合成、高分子聚合以及其他反应的应用,指出当前离子液体工业化进程的局限性是成本高、分离困难、回收复杂等因素。针对这些问题,本论文首先利用价格便宜的起始原料,合成一系列具有Brφnsted酸的功能化离子液体,包括[HMIM]BF₄、[（CH₂）₄SO₃HMEM][HSO₄]、[BMEM][HSO₄]、[BMEM][H₂PO₄]、[TMBSA][HSO₄]、[TEBSA][HSO₄]以及一些文献从未报道过的新的功能化的离子液体[（Ac）₂BIM]Br、[NMP][HSO₄]、[MORBSA][HSO₄]、[MORPSA][HSO₄],醋酸甲氧基丙胺盐离子液体等,并且应用¹H NMR,IR对所合成离子液体进行了表征,确定了离子液体的组成、结构。然后,将这些新型的功能化离子液体用于一些重要的酸催化有机反应如羟醛缩合反应,Prins成环反应,乙酰化反应、Henry反应和Knoevenagel缩合反应。中,研究了其催化性能,并获得了以下有意义的研究结果:1)利用制备的[HMIM]BF₄、[（CH₂）4SO₃HMIM][HSO₄]、[（Ac）₂BIM]Br、[NMP][HSO₄]四种离子液体作为催化剂用于2,4-二异丙基-5,5-二甲基-1,3-二噁烷的缩合反应,而文献从未有过将离子液体作用于该反应的报道。首先考察了四种不同酸性功能化离子液体对反应的影响。结果表明,当采用不同离子液体为催化剂时,对产率有明显差异。采用[HMIM]BF₄时,反应转化率比较低,但是离子液[（CH₂）₄SO₃HMIM][HNO₄]、[（Ac）₂BIM]Br以及[NMP][HSO₄]作为催化剂时,其催化活性明显高于传统的强液体酸类催化剂,反应的转化率都比较高,最高达92.5%,选择性也相应地提高。然后,我们选用[（Ac）₂BIM]Br离子液体作为催化剂对不同的反应条件进行考察。其中包括离子液体的量、反应时间、原料比等对反应转化率的影响。结果表明随着离子液体量的增加,酸量增多,活性中心增加,反应转化率增大;随着反应时间的增加,反应转化率有明显提高。最后,在回流的条件下进行催化剂的活性重复性实验,结果表明离子液体[（Ac）₂BIM]Br作为催化剂制备青叶噁烷在重复使用8次后活性基本不变,说明该离子液体作为该反应的催化剂具有良好的催化活性以及稳定性。由实验结果可以看出,以酸性功能化离子液体作为催化剂缩合反应生成青叶噁烷与传统浓硫酸作催化剂相比,具有反应时间短,催化活性高等优点。最为突出的特点是产物与催化剂极易分离,并且可以重复使用,不污染环境,具有一定的工业应用价值。这也寻求了一条在较温和的反应条件下,高选择性地合成青叶噁烷的新路线。2)将[HMIM]BF₄、[（CH₂）₄SO₃HMIM][HSO₄]、[（Ac）₂BIM]Br、[NMP][HSO₄]、[BMIM][HSO₄]、[BMIM][H₂PO₄]等六种离子液体为催化剂,应用于苯乙烯与甲醛溶液Prins成环反应。分别考察了不同离子液体催化剂对反应的影响。文献中有过Lewis酸离子液体对Prins反应的影响,但未见有将Bronsted酸性离子液体作为本反应催化剂的报道。结果表明,除了[HMIM]BF₄与[（Ac）₂BIM]Br作为催化剂反应性能比较差以外,其余酸性离子液体在反应中均显示出了良好的催化性能。接下来,选择[BMIM][HSO₄]考察催化剂用量、物料配比、反应时间等对Prins反应的影响并且得到了该反应的适宜条件。在此条件下,苯乙烯的转化率可达90%以上。最后考察了离子液体[BMIM][HSO₄]对苯乙烯与甲醛的Prins成环反应催化性能的重复性,结果表明反应在重复5次后,其原料的转化率以及选择性都基本没有下降,均超过90%。由此可见,选择合适的Brφnsed酸性离子液体作为苯乙烯与甲醛的Prins成环反应的催化剂具有稳定,高效,可重复性等特点。3)选用离子液体[TMBSA][HSO₄]和[MORBSA][HSO₄]作为催化剂,研究了在离子液体催化下的乙酰化反应。这也是首次将Brφnsted酸性离子液体作为催化剂应用于乙酰化反应。结果表明,这两种离子液体对乙酰化反应均表现出良好的催化性能,反应条件温和,不需要加热,在室温条件下靠反应体系自身的放热即可以完成反应,催化活性和选择性高,反应时间短,反应后催化剂很容易回收。除此之外,催化剂经过5次重复循环使用后,活性和选择性没有下降,反应过程中不使用任何有毒的有机溶剂,并且该反应几乎不产生副产物,是一个典型的对环境友好的原子经济反应,具有很好的工业应用前景。实验结果表明应用该种磺酸根的Brφnsed酸性离子液体作为催化剂具有污染小、操作简便、收率好、反应快捷等特点,是一种乙酰化反应的有效方法,这对环境保护以及绿色化学的宗旨是相一致的。4)将功能化离子液体醋酸甲氧基丙胺盐作催化剂用于Henry反应和Knoevenagel缩合反应中。结果表明,醋酸甲氧基丙胺盐离子液体是Henry反应较理想的一种催化剂,可催化一系列醛和硝基甲烷的缩合,并以高产率生成相应产物,同时反应在无溶剂条件下发生,简化了操作过程。而Henry反应以离子液体作为催化剂可以快速地完成,是因为离子液体的高极性。离子液体高的极性有助于反应中间体的形成,使得Henry反应可以在相当短的时间内完成。而其在不同的醛和活泼亚甲基化合物的Knoevenagel缩合反应中也表现出了良好的催化性能。该反应在较低温度（≤50℃）并且在无溶剂条件下进行,产物具有很好的选择性并且分离也非常方便,可以直接从反应体系中过滤,通过洗涤获得纯品。此外,对苯甲醛与丙二腈的反应考察了离子液体作为催化剂的重复性能。结果表明,醋酸甲氧基丙胺盐离子液体作为催化剂对于该反应具有良好的重复性能。最后考察了该离子液体作用于Knoevenagel缩合反应的可能的机理。更多还原

【Abstract】 Worldwide demand for environmentally friendly chemical processes and products requires the development of novel and cost-effective approaches to pollution prevention. Green chemistry is a highly effective approach to pollution prevention because it applies innovative scientific solutions to real-world environmental situations. It is best defined as the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and applications of chemical products. Recent years, ionic liquid as an environmentally benign media has been used in many organic synthesis and chemical procedures because of their favorable properties such as negligible vapor pressure, high thermal stability, recyclability and tunable acidity. More recently, some functional acidic ionic liquids have been used in some organic reactions. These acidic ionic liquids based upon poor nucleophilic anions have received increasing attention because they are immiscible with a number of organic solvent and have been proved to be effective catalysts for a variety of reaction. Their acidity can significant improve the reaction conversion and they can easily be recycled in the reaction. In some homogeneous reaction, the reaction system can be separated into two phase due to using these ionic liquids and it is good to separate the products.In this research, kinds and application of ionic liquid were developed. This dissertation mainly falls into several parts: the literature review, synthsis the functional ionic liquids and application in some chemical reaction.In the review section, we mainly introduced the development, buildup, synthesis and application of ionic liquids, especially the functional ionic liquids.The synthsisi and application of functional ionic liquid include following parts.1) In this article, several Br（?）nsted acidic ionic liquids [HMIM]BF₄、[（CH₂）₄SO₃HMIM] [HSO₄]、[（Ac）₂BIM]Br and [NMP][HSO₄] were synthesized andused to synthesize the 2,4-diisopropyl-5,5 -dimethyl-1,3 -dioxane through acetalizationof TMPD and isobutyraldehyde. Results show that these functional acidic ionic liquids can avoid the separation issue of products and reactants. Most of them can catalyze the reaction with high catalytic activity, short reaction time, high conversion （≥90 %）. As one of the most effective acidic ionic liquids, [（Ac）₂BIM]Br was selected to investigate further effects of different reaction condintions and possibility of reusability. As it shown, ionic liquid still stable enough and has less impact on the catalytic activity after eight reusability.2) Br（?）nsted acidic ionic liquids [BMIM][HSO₄] and [BMM][H₂PO₄] were synthesized. We proceeded the Prins reaction, used to prepare dioxanes, has been limited by complex catalyst separation used six Br（?）nsted acidic ionic liquids as environmentally benign catalysts under mild reaction conditions for the first time. This process is highly effective, environmentally benign, and very selective. Furthermore, [BMIM][HSO₄] ionic liquid was conveniently separated with the products and easily recycled to catalyze Prins reaction again with excellent yields. The use of novel acidic ionic liquids in this reaction provides a better and practical alternative to the existing procedures and provides great promise toward further useful applications. This process will pave a way for large scale applications of Prins reaction.3) Br（?）nsted acidic ionic liquids [TMBSA][HSO₄]、[TEBSA][HSO₄]、[MORBSA][HSO₄] and [MORPSA][HSO₄] were synthesized. [TMBSA][HSO₄] and [MORBSA][HSO₄] ionic liquids catalyzed efficiently acetylation of acetic anhydride with various alcohols, hydroxyesters and phenols under solvent-free condition. Results showed that [TMBSA][HSO₄] and [MORBSA][HSO₄] ionic liquids able to promote quantitative acetylation at low temperature, in high conversion and selectivity （≥95 %）. This process is highly effective, environmentally benign, very selective and easily recycled with excellent conversion and selectivity.4) Methoxyl propylamine acetate functional ionic liquid was synthesized and used as an environmentally benign catalyst for Henry and Knoevenagel condensation reactions under solvent-free condition for the first time. This ionic liquid was shown to effectively catalyze Henry reactions and Knoevenagel reaction of active nitromethane compounds with various aldehydes. Yields from the catalyzed reactions were over 90 %under solvent-free condition. Furthermore, methoxyl propylamine acetate ionic liquid was conveniently separated with the products and easily recycled to catalyze Knoevenagel reaction again with excellent yields.In a word, ionic liquids play an important role in significantly enhancing the reactivity as well as reducing formation of byproducts. It provides better conversion and shorter reaction time than other methods previously reported. The significant advantages offered by this method are fast reaction and high conversion of product. The obvious advantage is recyclability of the catalyst. The use of these new novel ionic liquids in this reaction can be considered as an interesting new alternation. It provides a better and practical alternative to the existing procedures and great promise toward further useful applications.更多还原