Low-Coordinate Germanium and Tin Compounds for Small Molecule Activation and Catalysis

主族元素催化被认为是经典过渡金属催化转化的一种可持续的替代方法，近年来引起了人们的极大兴趣。了解小分子在特定金属中心的活化及其有效的合成探索是开发新型催化工艺的前提。最近的研究表明，在各种主族体系中，基于低配位14族金属的主族体系不仅可以进行类似过渡金属的反应，而且还表现出独特的反应活性，这可能是新的催化转化的基础。最近，我们发现N-杂环亚胺(NHI)负载的低配位硅化合物具有独特的反应活性，能够在非常温和的反应条件下激活小分子的sigma-键和pi-键。在这一点上，将这一知识转移到具有较高金属性的较重的第14族类似物是非常实际和重要的。本项目的主要目的是研究新型合理设计的低配位NHI稳定的锗和锡化合物，如四烯类、重烯类、同核和异核炔类似物在小分子活化反应中的应用及其在催化中的应用。作为一种基于我们以前的研究经验和结果的结构良好的方法，这项研究将对基本理解低配位主族金属中心的催化转化和催化活性的先决条件产生重要影响。工作方案分为两个主要部分。A部分介绍了目标NHI支持的锗和锡化合物的合成方法。B部分包括对催化转化的反应性研究和实际开发的详细说明。这个为期三年的研究项目是为两名博士生设计的：一名研究锗，另一名研究锡化学。

Recent years showed significant interest to the field of main group element catalysis, which is considered as a sustainable alternative to the classical transition metal catalyzed transformations. The knowledge about activation of small molecules at a given metal center and its effective synthetic exploration are the prerequisites for the development of novel catalytic processes. The most recent studies demonstrated, that among various main group systems those based on low-coordinate group 14 metals can undergo not only transition metal-like reactions but also exhibit characteristic reactivity which may serve as a basis for novel catalytic transformations. Recently, we found that N-heterocyclic imine (NHI) supported low-coordinate silicon compounds show unique reactivity and are capable to activate sigma- and pi-bonds of small molecules under very mild reaction conditions. At this point, the transfer of this knowledge to heavier group 14 analogues with higher metallic character is very actual and important. The main objective of this project is to study novel rationally designed low-coordinate NHI stabilized germanium and tin compounds, such as tetrylenes, heavier alkene- and homo- and heteronuclear alkyne analogues, in small molecule activation reactions and their application in catalysis. As a well-structured approach based on our previous research experience and results, this study will have an essential impact on fundamental understanding of catalytic transformations at low-coordinate main group metal centers and prerequisites of catalytic activity. The work programme is divided into two main parts. Part A describes synthetic approaches to the target NHI-supported germanium and tin compounds. Part B includes detail description of the reactivity studies and practical development of catalytic transformations. The three-year research project is designed for two PhD students: one will work on germanium and another on tin chemistry.