【作者】 谭家能；

【导师】 顾彦龙；

【作者基本信息】 华中科技大学 ， 物理化学， 2011， 硕士

【摘要】 多组分反应(MCRs)因为能够以最便捷、有效的方式构建复杂分子,因此受到了广大化学工作者的广泛关注。最近,随着绿色化学理念逐步被研究者所接收,在环境友好体系中的新型多组分反应研究成为当今化学研究所关注的焦点课题之一。本文在环境友好溶剂体系中发展了多个1,3-二取代-5-吡唑啉酮、甲醛参与的多组分反应,包括(1)苯乙烯,乙烯基二茂铁或者2-苯基吲哚在无溶剂或者丙三醇溶剂中与1,3-二取代-5-吡唑啉酮、甲醛反应生成复杂的吡唑啉酮并二氢吡喃化合物;(2)由于1,3-二取代-5-吡唑啉酮可以由苯肼和β-二羰基酯缩合制备,我们在丙三醇或[MIm-CO2H]BF4中构建了苯肼,β-二羰基酯,甲醛,苯乙烯或吲哚的四组分“一锅两步”反应。该类多组分反应不仅提高了合成效率,而且由于反应不使用催化剂、在环境友好溶剂中进行,实现了废弃物最小化。本文还发展了一种水相串联反应,发现Baylis-Hillman醇可以在水中被IBX氧化为2-甲烯基-1,3-二羰基中间体,该中间体生成后可以被苯乙烯、β-二羰基酯、苯甲酰胺和低活性吲哚等多种亲核试剂捕捉。该方法不仅提供了一种替代Knoevenagel反应生成2-甲烯基-1,3-二羰基中间体的方法,而且因为不使用甲醛,一些对甲醛不稳定的亲核试剂也可以在该反应中得到应用。该类串联反应具有以下特点:(1)反应溶剂为水;(2)氧化剂IBX被消耗后副产2-碘代苯甲酸,该副产物回收便捷,可以重复再利用;(3)反应底物普适性好。因此该串联反应体系被认为是一种绿色合成方法。更多还原

【Abstract】 The study of multicomponent reactions (MCRs) is a promising, hot field of chemistry, since they allow complex molecules to be created by using one reaction in a fast, efficient and time-saving manner. So developing new MCRs with environmentally benign methods has been recognized as one of the most important topics of green chemistry.In this theme, many multicomponent reactions of 1,3-disubstituted 5-pyrazolones and formaldehyde were developed in environmentally benign solvent systems. Styrenes, vinylferrocene and 2-phenylindoles could easily react, under solvent-free conditions or in glycerol solvent, with 1,3-disubstituted 5-pyrazolones and paraformaldehyde in the absence of any catalyst to afford a variety of complex molecules in moderate to excellent yields. Particularly, these MCRs are proved to be combinable with the synthesis of 1,3-disubstituted 5-pyrazolones from phenylhydrazines andβ-ketone esters in glycerol or a carboxylic acid-functionalized ionic liquid, [MIm-CO2H]BF4. Therefore, some two-step sequential reactions of phenylhydrazines,β-ketone esters, formaldehyde and styrenes or indoles were developed for the first time. All these MCRs were conducted in environmentally benign solvent systems that not only minimize generation of wastes but also simplify the work-up procedure.A cascade domino reaction was also developed in water. Water proved to be an efficient solvent for oxidation of a Baylis-Hillman adduct with IBX. The generated product, a methylene intermediate, could be trapped in situ by many nucleophiles in water, such as styrenes,β-dicarbonyl compounds, benzamide and less reactive indoles. This strategy offers an alternative way to Knoevenagel methylenylation ofβ-dicarbonyl compounds with formaldehyde for the formation of a methylene intermediate, thus allows the use of some nucleophiles that are chemically unstable to formaldehyde. The use of water as solvent, good recycling ability of IBX oxidant and wide substrate scopes make these reactions very attractive from the viewpoint of green chemistry.更多还原