紫外光诱导芳基乙酸脱羧交叉偶联反应研究

发布时间：2018-05-05 15:16

本文选题：紫外光 + 脱羧反应　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：构筑C-C键的反应是有机合成化学中的一大基本反应,因此,有很多关于碳碳键的合成方法包括傅克烷基化反应、缩合反应、偶联反应,最重要的是过渡金属催化的C-C键偶联反应。然而,这些方法或多或少需要强酸、高温、额外的推动力和通常昂贵有毒的金属催化剂,既难以处理又非环境友好。二芳基甲烷类化合物是一类非常重要的化工原料和有机合成中间体,也是药物活性分子和复杂天然产物的重要结构单元。本文研究在紫外光诱导下芳基乙酸脱羧与1,4-对苯二腈(1,4-DCB)交叉偶联反应生成C-C键,得到了一系列产率介于中等到良好的二芳基甲烷衍生物。相比较传统的过渡金属催化偶联反应,起始原料羧酸廉价易得,理论副产物是二氧化碳,无污染且易从反应体系中分离。除此之外,光化学反应还有其独特的优势,例如环境友好、条件温和、操作简单等。将不同的芳基乙酸在最优条件下进行了普适性研究,芳环上有给电子基团的羧酸适用于这一合成策略,而含有吸电子基团的通常难以反应。通过GC-MS检测,以TEMPO(2,2,6,6-四甲基哌啶)为自由基捕获剂对可能的反应机理进行了验证,芳基乙酸与1,4-对苯二腈发生单电子转移,之后脱去二氧化碳,发生偶联进而得到二芳基甲烷化合物。在此基础上,还探究了与异氰酸酯以及烯烃类的偶联反应,得到了相应的一系列的苯乙酰胺化合物和末端烯烃产物,产率良好。
[Abstract]:The formation of C-C bond is a basic reaction in organic synthesis chemistry. Therefore, there are many methods for the synthesis of carbon-carbon bond, including Fourier alkylation reaction, condensation reaction, coupling reaction. The most important is the transition metal catalyzed C-C bond coupling reaction. However, these methods require more or less strong acids, high temperatures, additional impetus, and often expensive toxic metal catalysts, which are difficult to deal with and not environmentally friendly. Diarylmethane compounds are very important chemical raw materials and organic synthesis intermediates, and are also important structural units of drug active molecules and complex natural products. In this paper, the cross coupling reaction of aryl acetic acid decarboxylation with 1'4- '-p-phenylacrylonitrile (1' -4-DCB) under UV irradiation has been studied to form C-C bond, and a series of diarylmethane derivatives with intermediate to good yields have been obtained. Compared with the traditional transition metal catalytic coupling reaction, carboxylic acid is cheap and easy to obtain. The theoretical by-product is carbon dioxide, which is pollution-free and easy to be separated from the reaction system. In addition, photochemical reaction has its unique advantages, such as environmental friendliness, mild conditions, simple operation and so on. The universality of different aryl acetic acid was studied under the optimum conditions. The carboxylic acid with electron donating group on aromatic ring is suitable for this synthesis strategy, but it is usually difficult to react with electron absorbing group. The possible mechanism of the reaction was verified by GC-MS, using TEMPO2O2O2O2O2O2O2O6O6 (tetramethylpiperidine) as the free radical trapping agent. The single electron transfer of aryl acetic acid and 1'4- terephthalonitrile was carried out, and then carbon dioxide was removed. Diarylmethane compounds were obtained by coupling. On this basis, the coupling reaction with isocyanates and alkenes was also investigated. A series of phenylacetamide compounds and terminal olefin products were obtained in good yield.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O644.19

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