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现代绿色有机合成技术在若干缩合反应中的应用

Application of Modern Green Synthetic Technique in Some Condensation Reations

【作者】 张岩

【导师】 商志才;

【作者基本信息】 浙江大学 , 化学, 2011, 硕士

【摘要】 绿色化学又称环境友好化学,清洁化学,它是指以绿色意识为指导,在化学品与化学过程的研究和设计过程中避免或最大程度地减少对环境的负面影响。在绿色化学基础上发展的技术称绿色化工技术或洁净生产技术。绿色化学研究的中心问题是使化学反应及其产物具备如下特点:①采用无毒、无害的原料;②在无毒、无害的反应条件(催化剂、溶剂)下进行;③具有原子经济性,即反应具有高收率,高选择性,极少副产品;④产品及其原料与工艺应是环境友好的,不产生环境污染又不破坏生态平衡。这样来讲,绿色化学可以看作是进入成熟期的更高层次的化学。随着有机化学学科的快速发展,新的有机合成技术也不断涌现出来。有机化学领域中与绿色化学相关的研究主要集中在以下几个方面:(1)非传统溶剂中的有机合成(如水,离子液体及超临界流体作为反应介质);(2)相转移催化反应(Phase Transfer Catalysis,简称PTC);(3)无溶剂有机合成;(4)微波促进的有机合成;(5)多组分反应(Multicomponent Reaction, MCR)。具体来讲,本论文对若干类缩合反应在现代绿色有机合成方法下的可行性进行了比较广泛的研究,主要内容和结果如下:1.无溶剂室温条件下在可循环使用的催化剂固体酸H2SO4·SiO2的作用下,由吡咯或吲哚与醛类化合物进行缩合反应生成双吡咯和双吲哚取代甲烷衍生物。本项工作的优点在于:无溶剂反应条件经济,安全并且环保;实验过程操作简便;反应条件温和;产率较高。2.在室温下、纯水中,加入催化量的碱性氨基酸赖氨酸,可以十分有效地进行丙酮与芳香醛发生的羟醛缩合反应以及含活泼亚甲基化合物与芳香醛之间可发生的诺文格尔反应。这种由水与可溶性氨基酸组合成的绿色催化体系可以循环使用。这两种缩合反应发生条件温和,产率优良。并且我们还发现,即使不引入催化剂,在纯热水相介质中芳香醛与5,5-二甲基-1,3-环己二酮也可以高选择性地发生缩合、高产率地生成氧杂蒽二酮或其开环衍生物。实验中不使用有机溶剂作为反应环境或重金属离子作为催化剂,这无疑显示出以上合成方法的绿色环保的特点。3.在酸性离子液体[Bmin]﹢[HSO4]﹣中,不另加其余催化剂,通过1,3-二羰基化合物与肼之间发生的缩合反应可以在常温下高产率地制备一系列含吡唑环化合物。另外,在离子液体[Bmin]﹢[BF4]﹣中加入组氨酸也可以在常温下有效地进行芳香醛与达米酮之间发生的缩合反应形成开环氧杂蒽二酮类衍生物。4.发明了一种绿色高效的通过多组分反应获得一类新颖不对称化合物的方法。在无溶剂90℃条件下,不需加任何催化剂,芳香醛、吲哚及5,5-二甲基-1,3-环己二酮三者之间可以有效进行多组分反应形成具有手性的包含吲哚的取代甲烷衍生物。这是一类全新的化合物。

【Abstract】 Green chemistry (also known as Environmentally Friendly Chemistry or Clean Chemistry), guided by the environmental awareness, is to decrease even avoid the negative influences on the environment during the research and design of chemical process and chemicals. The technology developed on the basis of green chemistry is called green chemical technology or cleaning technology in production. The chemical reaction and its product based on green chemistry research have the following characteristics:firstly, both the reaction conditions and the materials should be non-toxic; secondly, the reactions should be highly effective with higher chemical selectivity but fewer by-products, or we say these reactions should be atom-economical; thirdly, the products, the materials and the technique should be environmentally friendly. To sum up, green chemistry can be regarded as the chemistry with maturely high level.With the fast growth of organic chemistry, new organic synthetic techniques come to the fore. Studies related with green chemistry in organic chemistry mainly focus on the following aspects:(1) organic synthesis of non-conventional solvent (such as water, ionic liquid, supercritical fluid); (2) Phase Transfer Catalysis; (3) solvent free organic synthesis; (4)organic synthesis stimulated by microwave; (5) Multicomponent Reaction. To be specific, this thesis is a broader study about the feasibility of several kinds of condensation reaction with modern green organic synthetic methods. Main contents and results are as follows:1. We have developed an environmentally friendly, economic and efficient synthetic protocol for the preparation of bis(indolyl)methanes or dipyrromethanes using H2SO4·SiO2 under solvent-free conditions at room temperature. The short reaction procedure and reusability of the catalyst make this method one of the most efficient methods for the synthesis of these two classes of compounds.2. The Knoevenagel and Aldol condensations of aromatic aldehydes with unmodified acetone or acidic methylene compounds proceeded efficiently in pure water in the presence of L-lysine at room temperature. This green catalytic system could be reused, and it provides a green and mild synthetic method for the preparation of these two classes of compounds. We also find that with no addition of catalyst the condensation reaction between aldehydes and 5,5-dimethyl-1,3-cyclohexanedione proceeded efficiently in hot water, which is efficient for the synthesis of xanthenediones and their ring-opening derivatives. The main advantages of this method include high yields, simple experimental procedure, no addition of toxic organic solvents or metal ions, which in line with the tenets of green chemistry.3. A novel pyrazole synthesis approach has been developed by using Br(?)nsted acidic ionic liquid BMImHS04, which acts as dual solvent-catalyst in promoting the condensation of hydrazines with various 1,3-dicarbonyl compounds at room temperature. In addition, at room temperature the ionic liquid l-butyl-3-methylimidazonium tetrafluoroborate [bmim] BF4 was used as another green recyclable alternatives to volatile organic solvents for the condensation between aldehydes and 5,5-dimethy1-1,3-cyclohexanedione in the presence of L-histidine. This is an efficient and green approach for the synthesis of 2,2’-arylmethylene bis(3-hydroxy-5,5-dimethylcyclohex-2-enone).4. We developed a very clean, simple and efficient method for the one-pot multi-component reactions of aromatic aldehydes with indoles and dimedone to obtain the unsymmetrical indole-substituted methane derivatives which are a new class of compounds. The main advantages of this method include high yields, short reaction times, no addition of catalyst or solvent, as well as simple work-up.

  • 【网络出版投稿人】 浙江大学
  • 【网络出版年期】2011年 07期
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