A novel strategy towards the catalytic hydroamination of alkenes: Exploiting geometrically constrained phosphorus(III) species for the activation of ammonia

氨在烯烃加氢胺化反应中的催化应用代表了现代催化中的“圣杯”之一，其典型地由过渡金属主导。然而，氨的有效活化受到Werner型胺络合物（M←NH3）的有利形成的严重阻碍。此外，超过100 kcal/mol的N-H键强度是将氨直接掺入有机分子中需要克服的另一个障碍。相比之下，能够通过N-H键断裂活化氨的主族化合物的数量超过了过渡金属的报道，代表了具有成本效益的替代品。过渡金属催化中的流行策略将被研究，以允许NH3在不饱和有机底物中的催化掺入，即磷-配体协同性和氧化还原非无辜配体平台的利用。除了利用大量的三齿、双配位钳形配体库之外，还将评估不常见的供体部分以解释以磷为中心的氧化还原化学的热力学调节。

The catalytic utilization of ammonia for hydroamination of olefins represents one of the “Holy Grails” in modern catalysis which is typically dominated by transition metals. However, efficient activation of ammonia is severely hindered by favored formation of Werner-type amine complexes (M←NH3). Additionally, the N-H bond strength of over 100 kcal/mol is another obstacle to overcome for the direct incorporation of ammonia into organic molecules. In contrast, main group compounds capable of activating ammonia via N-H bond cleavage outnumber the reports for transition metals, representing a cost-efficient alternative.This proposal aims to develop novel strategies to activate ammonia by geometrically constrained phosphorus(III) compounds. Popular strategies in transition metal catalysis will be investigated to allow for catalytic incorporation of NH3 in unsaturated organic substrates, namely phosphorus-ligand cooperativity and utilization of redox non-innocent ligand platforms. Besides exploiting the vast library of tridentate, meridionally coordinating pincer ligands, uncommon donor moieties will also be evaluated to account for thermodynamic tuning of phosphorus centered redox chemistry.