Polydentate Lewis Acid Acceptor Bowls and Chalices

多齿路易斯酸受体碗和圣杯

• 批准号: 424957011
• 负责人: Professor Dr. Norbert W. Mitzel
• 金额: --
• 依托单位: Arbeitsgruppe Anorganische Chemie und Strukturchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/424957011?language=en
• 关键词: Polydentate; Lewis; Acid; Acceptor; Bowls

Supramolecular chemistry deals with the association of molecules to larger structures. These associations are not connected by covalent bonds, but by weaker, reversible interactions. Lewis acid-base interactions have already been studied in great detail, but mostly on complex scaffolds with several base functions that complex relatively simple acid particles (mostly cations). Selectivity is achieved by the spatial arrangement of the base functions. The inverse situation of poly-Lewis acids has only been very poorly investigated so far. The reasons for this lie in the high sensitivity of these compounds to air and water, the larger number of bonds at the Lewis acid centres and the larger changes in the receptor structure during the formation of Lewis acid-base complexes.However, the concept of poly-Lewis acids with defined spatial structure of the acid functions allows the recognition and complexation of anions and Lewis bases as well as the construction of supramolecular architectures. Properties and reactivity of the base fraction can thus be specifically influenced. The aim of this project is therefore to develop a series of new Lewis acid groups and to position them in a defined way on rigid molecular frameworks alongside known functions. In this way, we want to present systems for the optimal binding of Lewis-base substrates. New acid groups are those with strong electron withdrawing substituents (perchloro-catecholate, perfluoroalkyl and perfluoroaryl, possibly combined) at silicon or boron functions. Perfluoroarylboryl, dialkylaluminium and -gallium groups have already been tested. In the run-up to the project, these groups are to be classified systematically and quantitatively on the basis of simple model compounds with regard to their Lewis acid properties. As rigid donor-free and easy to functionalize frameworks, we want to use tribenzotriquinacene derivatives on the one hand, which allow three or six substituents to be attached on both sides in a bowl-like or chalice-like manner, which can then be functionalized with Lewis acids. The second subproject concerns the development of chalice-shaped tridentate Lewis acids by hydrometallation of planar precursors. We recently observed a reaction in which the hydrosilylation of hexadehydrotribenzo[12]annule, a planar ring-shaped molecule with three alkyne functions, leads to selective C3-symmetric triple addition with folding of all benzene rings to one side. The functionalization of the backbone and the spatial orientation of the new Lewis acid centers are therefore concerted. We want to test the chelating Lewis-acid systems with regard to their complexing properties and the selective recognition of multiple Lewis-based substrates. We will also try to build up larger cage-like associates with suitable bases.

超分子化学研究的是分子与更大结构的结合。这些结合不是通过共价键连接，而是通过较弱的可逆相互作用连接。Lewis酸碱相互作用已经进行了非常详细的研究，但主要是在具有几个碱基功能的复杂支架上，这些支架复杂了相对简单的酸颗粒（主要是阳离子）。选择性是通过基函数的空间排列来实现的。到目前为止，对聚路易斯酸的相反情况的研究还很少。其原因在于这些化合物对空气和水的高度敏感性，刘易斯酸中心的键数较多，在刘易斯酸碱配合物形成过程中受体结构的变化较大。然而，具有明确的酸功能空间结构的聚路易斯酸的概念允许阴离子和路易斯碱的识别和络合以及超分子结构的构建。因此，碱馏分的性质和反应性会受到特别的影响。因此，该项目的目的是开发一系列新的刘易斯酸基团，并将它们与已知功能一起以明确的方式定位在刚性分子框架上。通过这种方式，我们想要为刘易斯碱底物的最佳结合提供系统。新的酸基是那些在硅或硼官能团上具有强吸电子取代基（高氯儿茶酚酸盐、全氟烷基和全氟芳基，可能是组合）的酸基。全氟芳基硼基、二烷基铝和镓基团已经进行了测试。在项目准备阶段，将根据简单模型化合物的路易斯酸性质对这些基团进行系统和定量的分类。作为刚性的无给体和易于功能化的框架，我们一方面想使用三苯并三醌衍生物，它允许以碗状或杯状的方式在两侧连接三个或六个取代基，然后可以用路易斯酸进行功能化。第二个子项目涉及通过平面前驱体的金属加氢化来开发杯状三齿刘易斯酸。我们最近观察到一个反应，六氢三苯[12]环（一个具有三个炔功能的平面环状分子）的硅氢化反应导致所有苯环向一侧折叠的选择性c3对称三重加成。因此，主链的功能化和新刘易斯酸中心的空间取向是一致的。我们想测试螯合刘易斯酸系统的络合性能和对多种刘易斯基底物的选择性识别。我们也会尝试在合适的基地上建立更大的类似笼子的伙伴。