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杂多酸催化的碳碳键和碳氮键形成研究
Investigation on Phosphotungstic Acid-Catalyzed C-C and C-N Bond Formation
【作者】 沈业兵;
【导师】 王官武;
【作者基本信息】 中国科学技术大学 , 有机化学, 2009, 博士
【摘要】 作为可持续发展战略的一部分,环境保护在当今社会越来越受到重视。在化工生产中,人们期望用无毒无害的溶剂和催化剂代替以往传统的有机溶剂和贵重并且有毒的重金属催化剂。于是,“绿色化学”的概念就应运而生了。在绿色有机合成中,人们使用无溶剂直接加热或者以水做溶剂的方法,把有机溶剂的使用量降至最低。一些有机小分子和可回收利用的催化剂被广泛用于各类有机反应。本篇论文主要描述了杂多酸催化下的C-C和C-N键的生成,以及无溶剂直接加热下合成十氢氧杂蒽二酮和9-芳基十氢吖啶二酮。主要内容如下:1.在磷钨酸催化下,1,3-二羰基化合物与醇能够顺利偶合,脱除一分子的水,生成烷基化的1,3-二羰基化合物。反应在甲苯中进行时,二芳基甲醇能与各类1,3-二羰基化合物反应,成率很高;但对于1-苯乙醇,只能得到很低的产率。通过研究我们发现,当反应在硝基甲烷室温下进行时,1-苯乙醇也能够很高的产率。2.磷钨酸能够催化1,3-二羰基化合物对烯烃,如苯乙烯和降冰片烯的加成反应,生成烷基化产物。反应在有机溶剂中效果不好,而在无溶剂加热条件下,反应能够高效地进行。对于各种1,3-二酮类化合物,都能以很高的产率得到产物;此外苯甲酰乙酸乙酯也能够与降冰片烯顺利反应。3.氨基化合物在有机合成中非常重要,在磷钨酸的催化下,各种磺酰胺和苯甲酰胺类化合物能够与醇发生脱水偶合反应,以非常高的产率得到烷基化的氨基衍生物。醇的范围非常广,二苯甲醇、1-苯乙醇、烯丙醇衍生物等含苄醇结构的地物能够以最高接近定量的产率得到产物。普通烷基醇如环己醇,甚至最简单的甲醇和乙醇也能顺利反应,产率中等。在这个反应中,磷钨酸能够顺利回收,并在此被用于催化反应,活性没有降低。此外我们还对反应的机理进行了一些探讨。4.磺胺、酰胺及带有强吸电子基团的苯胺等氨基化合物对未活化的烯烃的加成反应也能够在磷钨酸的催化下顺利进行,得到马氏加成产物。降冰片烯、环己烯和苯乙烯等烯烃被高效地胺氢化。5.在无溶剂直接加热条件下,用甲磺酸作为催化剂,醛和达米酮能够迅速脱水偶合,生成9-芳基十氢氧杂蒽二酮类化合物。当体系中加入氮源,如醋酸铵或者苯胺时,不需要催化剂即能发生偶和反应,生成9-芳基十氢吖啶二酮化合物。
【Abstract】 As a part of the sustainable development strategy,environmental protection has been paid more and more attentions in modern society.Environmentally safe solvents and catalysts are preferred to the traditional ones which are usually toxic and precious organic solvents and heavy metal catalysts.As a result,the conception "green chemistry" came into being.In a green organic synthesis,procedures involving direct thermal heating or utilizing water as solvent are always welcomed to minimize the use of organic solvents.Some small organic molecules and catalysts that can be recovered and reused are employed extensively in various organic transformations.In this thesis, investigations focused on heteropoly acids-catalyzed C-C and C-N bond formation reactions and the synthesis of xanthenediones and acridinediones under thermal conditions are described.1.12-Phosphotungstic acid(PWA) has been used as an efficient,eco-friendly,and air- and moisture-stable catalyst to promote the direct dehydrative substitution of the hydroxy group of benzylic and allylic alcohols with variousβ-dicarbonyl compounds.When 1-phenyl-ethanol was employed as alkylating agent,the reaction was performed in nitromethane at room temperature to afford high yield. The loading of catalyst was extremely low.2.Direct hydroalkylation of styrene and norborene with 1,3-dicarbonyl compounds has been developed by using PWA as the catalyst.Reactions proceeded without any solvent,providing a clean and eco-friendly access to alkylated pentanediones.3.Under the catalysis of PWA,various amino compounds including sulfonamides, benzamides,and anilines could react with alcohols to afford alkylated amino derivatives in high yields.Various alcohols are tolerable under the present conditions including benzylic alcohols,allylic alcohols as well as simple aliphatic alcohols(methanol and ethanol).The potential reusable property of heteropoly acid makes this protocol more attractive.4.The aminohydrogenation of simple alkenes including styrene,norborene and cyclohexene with sulfonamide,benzamides or electron-deficient anilines were also catalyzed by PWA to afford Markovnikov adducts in high yields.5.In the absence of any solvent,the reactions of various aromatic aldehydes with 5,5-dimethyl-1,3-cyclohexanedione catalyzed by methanesulfonic acid under thermal heating conditions smoothly afforded xanthenediones in nearly quantitative yields.Under the same melt conditions,rapid and highly efficient synthesis of acridinediones could also be achieved using ammonium acetate and p-toluidine as the nitrogen source.
【Key words】 green chemistry; atom-economical reaction; solvent-free reaction; heteropoly acid; aminohydrogenation; hydroalkylation; dehydrative coupling;