钯和钌催化的导向羰基化和氟甲基化反应研究

发布时间：2018-02-28 23:36

本文关键词： 钯催化钌催化导向基碳氢活化羰基化氟甲基化　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：近些年来,过渡金属催化的碳氢活化反应广泛应用于有机材料、天然产物、药物分子以及精细化学品的合成和制备中。在这些反应中,尤其是配体导向的碳氢活化反应因为无需预官能团化、原子经济性等优点,可以有效地缩短反应步骤,提高反应效率,激发了研究者的浓厚兴趣。尽管配体导向的碳氢活化方面的研究成果报道了很多,但是仍然面临着巨大的挑战。一方面,C-H键的能量普遍高于C-C键、C-X键、H-X键,因此如何克服较高的能垒实现C-H键活化就成为一个重要的议题。另一方面,C-H键能量差异很小,因此如何控制反应的选择性就显得尤为重要。后过渡金属因为d轨道和p轨道未充满,可以与孤电子对或π电子相互作用,可以较容易地实现C-H键活化。因此,导向基的引入和选择显得至关重要。本论文主要集中在包括钯催化或钌催化的含氮配体导向的sP2C-H活化反应,具体包括以下内容:1、发展了钯催化的偶氮苯作为导向基的脱羧酰基化反应。该反应提供了一系列邻位酰基化的非对称偶氮苯化合物,对氯、溴、碘和甲氧基等很多官能团都具有良好的适应性。另外,对位取代、邻位取代和双取代的偶氮苯均可以适应该体系。2、首次实现了钯催化的利用草酸单乙酯作为酯基来源这一新颖、高效的C-H酯基化反应。这个方法拓展了最近非常流行的乙酯化。不同的导向基,如肟醚和吡啶,都可以被用在该反应中。另外,这个体系官能团适应性非常好。该反应得到的产物也可以通过简单的操作转化为酮和内酯类化合物。3、成功实现了 2-苯氧基吡啶导向的脱羧酯基化反应。该反应可以得到一系列水杨酸乙酯类衍生物。并且,作为一种普适和简便的方法,该反应可以为合成阿司匹林衍生物提供一种新的策略和思路。4、发展了首例钌催化的含氮芳香杂环导向的间位选择性的氟甲基化反应。这个工作同时扩展了最近广受关注的氟甲基化和钌催化的间位C-H活化反应的概念和范围。另外,这个方法对于无氟的溴乙酸乙酯也可以实现间位C-H活化反应。
[Abstract]:In recent years, the transition metal catalyzed C-H activation reactions are widely used in organic materials, natural products, drug molecules and the synthesis and preparation of fine chemicals synthesis. In these reactions, especially ligand directed C-H activation reactions because no officer group, has the advantages of atom economy, can effectively shorten the reaction steps to improve the reaction efficiency, strong interest, inspire researchers. Although ligand directed C-H activation studies reported a lot, but still faces huge challenges. On the one hand, the C-H bond energy is generally higher than that of the C-C key, C-X key, H-X key, so how to overcome the energy barrier of C-H bond activation has become an important issue is higher. On the other hand, the C-H key energy difference is very small, so how to control the reaction selectivity is particularlyimportant. Transition metal because the D track and P track is not full, and can Lonepairelectrons or pi electron interaction, it is easy to implement C-H activation. Therefore, the guide base and the introduction of choice is very important. This paper mainly focus on including palladium catalyzed or ruthenium catalyzed nitrogen ligand directed sP2C-H activation, including the following: 1, the development of the palladium catalyzed azobenzene as the guide base decarboxylation of acylation reaction. This reaction provides asymmetric azobenzene compounds, a series of ortho acylation of chlorine, bromine, iodine and methoxy groups have good adaptability of many functional groups. In addition, para substituted ortho substituted and disubstituted azobenzene can adapt to the system of.2 for the first time. The palladium catalyzed by oxalic acid ethyl ester as the single source of this novel, C-H ester reaction efficiency. This method provides a very popular recently. Based on different orientation of ethyl ester, such as oxime ether and pyridine, can To be used in the reaction. In addition, the system of functional adaptability is very good. The product of this reaction can also be through simple operation into ketones and lactones.3, the successful implementation of the decarboxylation reaction of 2- ester phenoxy pyridine oriented. This reaction can get a series of ethyl salicylate derivatives and, as a universal and convenient method, the reaction may provide a new strategy for the synthesis of aspirin and thought of.4 derivatives, the first development of ruthenium catalyzed aromatic azacyclo oriented a selective difluoromethylation reaction. The concept and scope of the work of the C-H activation and expansion difluoromethylation and ruthenium catalyzed wide concern among recently. In addition, this method can achieve a C-H activation reaction for ethyl bromide without fluorine.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O621.251

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