芳烃直接三氟甲基化及芳香羧酸脱羧三氟甲基化反应研究

发布时间：2018-05-17 17:09

本文选题：三氟甲基化 + 无金属反应　；参考：《湘潭大学》2017年硕士论文

【摘要】：三氟甲基具有独特的物理化学性质,向芳香化合物中引入三氟甲基已成为有机合成领域的研究热点。目前,三氟甲基化芳烃已在医药、农药、染料等领域取得广泛应用。然而,已报道的芳烃三氟甲基化反应,大多需要使用昂贵的三氟甲基化试剂或金属催化剂,因此,开发成本低廉、环境友好的芳烃三氟甲基化新方法具有重要意义。本文的研究工作分为两部分:温和条件下芳烃直接三氟甲基化及芳香羧酸脱羧三氟甲基化反应研究。第一部分:过硫化物作为一类常用的引发剂,广泛应用于自由基类型的反应,相比有机过氧化物而言,其更具安全性和稳定性。在最初的尝试中,我们以1,3,5-三甲氧基苯为底物,CF3SO2Na为三氟甲基源,Na2S2O8为引发剂,得到了三氟甲基化的产物。条件优化实验表明,该反应可得到高达98%的分离产率。底物拓展实验发现,选用的大部分底物均可以较高的产率转化为相应的产物,且该反应具有较好的官能团容忍性。相比已报道的芳烃三氟甲基化反应,该方法具有对水兼容、环境友好、条件温和、成本低廉,及可实现扩量反应等优点。第二部分:在上一体系的研究过程中,我们意外地发现2,4,6-三甲氧基苯甲酸经过长时间反应可得到脱羧三氟甲基化的产物。条件优化实验表明,该反应可得到高达77%的分离产率。底物拓展实验发现,富电子程度较高的底物均可以较高的产率转化为相应的产物。相比已报道的脱羧三氟甲基化反应,该方法具有对水兼容、环境友好、条件温和,及可实现扩量反应等优点。
[Abstract]:The introduction of trifluoromethyl to aromatic compounds has become a hotspot in the field of organic synthesis because of its unique physical and chemical properties. At present, trifluoromethylated aromatic hydrocarbons have been widely used in medicine, pesticides, dyes and other fields. However, most of the reported trifluoromethylation reactions require expensive trifluoromethylation reagents or metal catalysts. Therefore, it is of great significance to develop low-cost and environmentally friendly trifluoromethylation methods for aromatic hydrocarbons. The research work is divided into two parts: direct trifluoromethylation of aromatic hydrocarbons and decarboxylation of aromatic carboxylic acids under mild conditions. Part I: persulfides are widely used as initiators for free radical reactions, which are more safe and stable than organic peroxides. In the initial attempt, the trifluoromethylation product was obtained by using 1 ~ (3) C _ (3) O _ (5) -trimethoxybenzene as the substrate and C _ (3) so _ (2) Na _ (2) Na _ (2) S _ (2) O _ (8) as the initiator of trifluoromethyl source. The optimum conditions showed that the separation yield was up to 98%. The substrate expansion experiments showed that most of the substrates selected could be converted into the corresponding products with higher yield, and the reaction had good tolerance of functional groups. Compared with the reported trifluoromethylation of aromatic hydrocarbons, this method has the advantages of water compatibility, environmental friendliness, mild conditions, low cost, and the ability to realize the expansion reaction. Part two: in the course of the study of the previous system, we found by accident that the product of decarboxyltrifluoromethylation could be obtained by the long reaction of 2o 4N 6 trimethoxybenzoic acid. The optimum conditions showed that the separation yield was as high as 77%. The results of substrate expansion experiments show that the higher electron rich substrates can be converted into the corresponding products with higher yields. Compared with the reported decarboxyltrifluoromethylation reaction, this method has the advantages of water compatibility, environmental friendliness, mild conditions, and the ability to realize the expansion reaction.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.25

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