高碘化物（Ⅲ）作用下β-酮酸的脱酸反应研究

发布时间：2018-08-31 08:39

【摘要】：催化脱羧反应作为仿生合成反应,因具有环境友好、反应条件温和、反应效率高等优点,得到了有机合成化学家的广泛研究。该类反应的底物主要为烯醇酯类、β-酮酸及其酯类化合物。目前,对于β-酮酸的催化脱羧反应的研究主要集中于脱羧后烯醇化作为亲核试剂对亲电体的一些偶联反应,反应的催化剂多为双官能团的有机非金属催化剂,金属催化剂,比如,镍、镱、铱也有应用。高碘化物作为潜在的金属催化剂替代物,具有与金属催化剂类似的反应性质,相比金属催化剂而言,有环境友好、反应温和等优点。目前高碘化物作用下β-酮酸的催化脱羧反应报道较少。我们选择了碘苯二乙酸这一应用广泛的高碘试剂,对高碘化物作用下β-酮酸的脱羧催化反应进行了初步研究,研究结果如下:(1)实现了β-酮酸的脱羧酰氧基化,通过对反应条件的优化,得到了β-酮酸脱羧酰氧基化的最优条件。在最优条件下,对反应的底物耐受性进行了探究,发现不论是缺电子芳基、富电子芳基、杂环、脂肪族的β-酮酸,反应皆可以高效的进行。同时,丙酸、环己甲酸作为酰氧基来源,也可以很好的实现相应的脱羧酰氧基化。最后,通过一些验证实验,提出了该反应可能的反应机理。(2)以羰基α-溴化物作为反应中间体,实现了β-酮酸的脱羧叠氮化反应。通过对反应条件的优化,得到了最优的反应条件,在最优条件下,对底物的耐受性进行了探究,发现不论是富电子还是缺电子芳基、杂环、萘环、脂肪族以及羰基α位甲基化的β-酮酸,反应皆可以高效的实现。最后在机理验证实验的基础上,提出了该反应可能的反应机理。(3)从β-酮酸出发,一锅法制备得到酰基叠氮类化合物。通过条件筛选,得到了最优的反应条件。在最优条件下,对底物进行了扩展,发现富电子或者吸电子的芳基β-酮酸可以比较好的实现向酰基叠氮类化合物的转化,而脂肪族的β-酮酸不能实现,这可能与脂肪族酰基叠氮化合物的低沸点有关。最后通过一些机理验证实验,结合已知文献,提出了该反应可能的反应机理。
[Abstract]:As a bionic synthesis reaction, catalytic decarboxylation has been extensively studied by organic synthetic chemists because of its advantages of environmental friendliness, mild reaction conditions and high reaction efficiency. The main substrates of this reaction are enolates, 尾 -ketoacids and their esters. At present, the studies on the catalytic decarboxylation of 尾 -ketoacid are mainly focused on the coupling reaction of decarboxylenol with nucleophilic reagents to electrophilic bodies. The catalysts for the reactions are mostly bifunctional organo-nonmetallic catalysts. For example, nickel, ytterbium and iridium also have applications. As a potential substitute for metal catalysts, periodate has similar reaction properties as metal catalysts. Compared with metal catalysts, it has the advantages of environmental friendliness and mild reaction. At present, the catalytic decarboxylation of 尾 -ketoacid under the action of periodate is less reported. The decarboxylation of 尾 -ketoic acid under the action of periodate was studied. The results are as follows: (1) decarboxylation of 尾 -ketoic acid was achieved. The optimum conditions of 尾 -ketoacid decarboxylation were obtained by optimizing the reaction conditions. Under the optimal conditions, the tolerance of the substrate to the reaction was investigated. It was found that the reaction could be carried out efficiently, whether it was electron-deficient aryl, electron-rich aryl, heterocyclic, aliphatic 尾 -ketoacid. At the same time, propionic acid, cyclohexanoic acid as a source of acyl oxygen, can also achieve the corresponding decarboxylation. Finally, the possible mechanism of the reaction was proposed through some verification experiments. (2) the decarboxylation of 尾 -ketoic acid was realized by using carbonyl 伪 -bromide as the intermediate of the reaction. The optimum reaction conditions were obtained by optimizing the reaction conditions. Under the optimal conditions, the tolerance of the substrates was investigated. It was found that the aryl, heterocyclic and naphthalene rings were both electron-rich and electron-deficient. Aliphatic and carbonyl 伪-methylated 尾-ketoacids are highly effective. Finally, on the basis of the mechanism verification experiment, the possible reaction mechanism was proposed. (3) Acyl-azide compounds were prepared by one-pot method from 尾 -ketoacid. The optimal reaction conditions were obtained by screening the conditions. Under the optimal conditions, the substrate was expanded, and it was found that the E-rich or electron-absorbing aryl 尾 -ketoacid could better realize the conversion to acyl-azide compounds, but the aliphatic 尾 -ketoacid could not be realized. This may be related to the low boiling point of aliphatic acyl azide compounds. Finally, the possible mechanism of the reaction was put forward by some mechanism verification experiments and some known literatures.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.251

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