Heterol Dianions of Group 14 Elements as Building Blocks for the Synthesis of Polarized Multiply-Bonded Compounds and Bicyclic Carbene Analogues

第 14 族元素的杂醇二价阴离子作为合成极化多重键化合物和双环卡宾类似物的结构单元

• 批准号: 431534440
• 负责人: Professor Dr. Thomas Müller
• 金额: --
• 依托单位: Institut für Chemie (IfC)
• 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/431534440?language=en
• 关键词: Heterol; Dianions; Group; 14; Elements

A major line of development of modern molecular chemistry is to provide compounds that are able to activate selectively inert, small molecules such as dihydrogen, dinitrogen or carbon dioxide, but also individual, very strong bonds in more complex molecules (e.g. C-F or C-H bonds) for chemical processes. Ideally, this activation takes place in a thermodynamic regime, which allows the integration of the activation step in catalytic processes. Transition metal complexes provide ideal electronic conditions for this purpose, since the change of the coordination as well as of the oxidation state of the central metal is easy to accomplish. The disadvantage of many transition metals is their limited availability and in some cases their toxicity. Therefore, the use of abundant and physiologically harmless main group elements such as Silicon, Boron or Aluminium for such bond activation processes is absolutely desirable. In the last decade, several classes of main group element compounds have emerged, which are able to provide the basic processes of the chemical bond activation such as oxidative addition and reductive elimination (metallomimetika). These are: analogues of carbenes, heteroalkenes and the combination of sterically hindered Lewis acids and bases, frustrated Lewis pairs. Especially in the case of the carbene analogues and the hetero alkenes, these processes sometimes have significant thermodynamic driving forces or open up new, unforeseen reaction paths. Both factors hamper their integration in catalytic reactions and require targeted modifications of the main group element compounds. In our proposed project, we show opportunities to synthesize a series of polar heteroalkenes and of bicyclic carbene analogous from heterocyclopentadienes and easily accessible dichlorides of main group elements. Both substance classes have novel properties due to their special bonding situations, which will be explored in this project. The investigations will focus on fundamental issues of the availability and stability of new compounds. In addition, reactivity studies will be conducted, which allow to evaluate their potential in bond activation reactions. On success of the proposed project we will have access to two classes of novel main group element compounds, which are in principle able to act as metallomimetika. The proposed studies are focused on the synthesis and the topological and electronic structure of these novel compounds and will allow first indications on their reactivity.

现代分子化学的主要发展是提供能够激活有选择性惰性的化合物，例如二氢，二氢，二氮或二氧化碳等小分子，但同时在更复杂的分子（例如C-f或c-h键）中也非常牢固，以实现化学过程。理想情况下，这种激活发生在热力学状态下，这允许在催化过程中整合激活步骤。过渡金属复合物为此目的提供了理想的电子条件，因为协调的变化以及中央金属的氧化状态很容易完成。许多过渡金属的缺点是它们的可用性有限，在某些情况下是其毒性。因此，在这种键激活过程中使用丰富和生理无害的主要群体（例如硅，硼或铝）是绝对需要的。在过去的十年中，出现了几类主要组元素化合物，它们能够提供化学键激活的基本过程，例如氧化添加和还原性消除（Metallomimetika）。这些是：碳烯，异质烯烃的类似物以及在空间阻碍的刘易斯酸和碱的组合，沮丧的刘易斯对。尤其是在卡宾类似物和杂烯烯烃的情况下，这些过程有时具有明显的热力学驱动力或打开新的，不可预见的反应路径。这两种因素都阻碍了它们在催化反应中的整合，并需要对主要组元素化合物进行靶向修饰。在我们提出的项目中，我们展示了合成一系列极性异质烯烃的机会，并从异环腺苷和易于访问的主要组元素的二氯化体中类似的双环碳纤维类似。由于其特殊的粘结情况，这两个物质类都具有新颖的特性，这将在该项目中探讨。调查将侧重于新化合物的可用性和稳定性的基本问题。此外，还将进行反应性研究，以评估其在键激活反应中的潜力。关于拟议项目的成功，我们将可以访问两类新型的主要组元素化合物，这些化合物原则上可以充当金属素eTika。拟议的研究集中在这些新型化合物的合成以及拓扑和电子结构上，并将允许对其反应性提出第一指示。