Metal-Element Multiple Bonds Stabilized by Trisamidophosphines: Synthesis, Structure and Reactivity

许多化学转化，如烯烃或炔的转化，依赖于金属配合物与多界异质元素(E)，往往在这些转化中发挥关键作用。本文的研究主要集中在含有M=ER和ME构建单元（E = CR， N， P， As等）的金属元素双键和三键的（IV）族和(V)族金属配合物上。为了稳定活性ME片段，计划使用三氨基膦配体支架。由于后一种配体已经得到了详细的研究，因此拟进行的合成工作主要是针对这类新配体的配位化学和ME基序的反应性。钛、锆和铪的阴离子烷基烯、亚胺和膦烯是最初的目标，随后的反应性研究旨在利用这些M=ER阴离子（M = Ti, Zr, Hf; E = N， P, As）的预期亲核性，以揭示这些化合物的潜在应用。以氮、磷、砷为末端基团的钒、铌、钽阴离子配合物的合成也将发挥重要作用。开发含有ME三键（M = V, Nb, Ta; E = N， P, As）的复合物的新合成途径具有根本意义，而反应性研究将在工作过程中变得越来越重要。从长远来看，后一种反应性研究的目的是发现和建立这种金属配合物的应用，例如在均相催化方面。由于M=SiR2和M=BR亚结构在早期过渡金属的情况下尚未得到详细的研究，因此将研究三酰胺膦来稳定这种结构基序的跨界使用，并指导这些系统的可能应用。

Numerous chemical transformations, such as alkene or alkyne metathesis, rely on metal complexes with multiply-bound heteroelements (E), which often play key roles in these trans-formations. The studies proposed herein are focused on group (IV) and group (V) metal complexes that contain M=ER and ME building blocks (E = CR, N, P, As, etc.) with metal-element double and triple bonds. In order to stabilize the reactive ME fragments, the use of trisamidophosphine ligand scaffolds is planned. As the latter ligands have been studied in detail already, the intended synthetic efforts are directed mainly towards the coordination chemistry of this new class of ligands and the reactivity of ME motifs. Anionic alkylidenes, imides and phosphinidenes of titanium, zirconium and hafnium are targeted initially and subsequent reactivity studies are meant to exploit the expected nucleophilicity of such M=ER anions (M = Ti, Zr, Hf; E = N, P, As) in order to reveal potential applications of these compounds. The synthesis of anionic vanadium, niobium and tantalum complexes with terminal nitrido, phosphido and arsenido moieties is going to play a crucial role as well. The development of new synthetic pathways to complexes containing ME triple bonds (M = V, Nb, Ta; E = N, P, As) is of fundamental relevance, while reactivity studies will gain in importance over the course of the work. In the long term, the latter reactivity studies are meant to discover and establish applications of such metal complexes, for example in homogeneous catalysis. As M=SiR2 and M=BR substructures have not been studied in much detail in case of early transition metals, the frontier-crossing use of trisamidophosphins to stabilize such structural motifs will be examined and directed towards possible applications of these systems.