钯催化芳基C-H键直接单芳基化反应研究

发布时间：2018-11-08 17:13

【摘要】：联芳基化合物在有机化学中占有重要的地位。许多天然产物、医药、农药和生物活性分子中都含有联芳基结构单元。由于其本身固有的结构特性,联芳基化合物也可以应用于染料、有机半导体、功能材料等领域。加之,含有杂原子的多环联芳基化合物在不对称催化中可以做为有效的配体骨架。因此,芳-芳键的构建在合成界引起了的极大关注,同时也取得了很大的进展。过渡金属催化的芳-芳基偶联反应是合成联芳基化合物传统的方法,如Suzuki-Miyaura偶联、Negishi偶联、Stille偶联、Heck偶联反应等,许多课题组还将这些传统方法进行进一步的完善和改进。这些工作总体来说有两点不足:1)大多数反应使用有机金属化合物为原料,这不仅增加了反应成本,而且由于有机金属化合物相对较高的反应活性,使得对反应的操作有较高的要求;2)化合物实现芳基化时,不可控的生成双芳基化产物,而不能选择性的实现单芳基化产物。所以发展一个低成本的、有效的实现单芳基化的催化体系是非常有必要的。在本文中,我们发展了一类Pd(OAc)_2/TFA/O_2的催化系统,完成了芳基碳氢与碘苯的直接偶联合成联芳基化合物,反应的底物范围广泛,产率较高。与之前发展的一些方法比较,此反应系统没有银盐参与,实现了单芳基化选择性。这个方法可以广泛应用于联芳基化合物的合成中,为该类化合物在医药、农药、染料以及功能材料方面的应用提供了方便。
[Abstract]:Diaryl compounds play an important role in organic chemistry. Many natural products, pharmaceuticals, pesticides, and bioactive molecules contain diaryl units. Because of its inherent structural properties, biaryl compounds can also be used in dyes, organic semiconductors, functional materials and other fields. In addition, polycyclic aryl compounds containing heteratoms can be used as effective ligands in asymmetric catalysis. Therefore, the construction of aryl-aromatic bonds has attracted great attention in the synthesis field, and great progress has been made at the same time. The aryl-aryl coupling reaction catalyzed by transition metals is a traditional method for the synthesis of biaryl compounds, such as Suzuki-Miyaura coupling, Negishi coupling, Stille coupling, Heck coupling reaction and so on. Generally speaking, there are two shortcomings in these efforts: 1) most reactions use organometallic compounds as raw materials, which not only increases the cost of the reaction, but also because of the relatively high reaction activity of organometallic compounds. So that the operation of the reaction has higher requirements; 2) when the compound is aromatization, it can't control the formation of the double arylation product, but it can not selectively realize the single arylation product. Therefore, it is necessary to develop a low-cost and efficient catalytic system for monoarylation. In this paper, we have developed a kind of catalytic system of Pd (OAc) _ 2/TFA/O_2, and we have completed the direct coupling of aryl hydrocarbon with iodized benzene to synthesize diaryl compounds. The substrate range of the reaction is wide and the yield is high. Compared with some methods developed before, this reaction system achieved monoarylation selectivity without the participation of silver salt. This method can be widely used in the synthesis of biaryl compounds and provides convenience for their applications in medicine, pesticides, dyes and functional materials.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.251

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