Chiral N-Heterocyclic Carbenes as Organocatalysts and Ligands for Metal-Mediated Asymmetric Processes

不对称金属介导的过程在有机合成中至关重要。多年来，手性膦一直是手性金属配合物不对称的来源。然而，近年来，n -杂环碳烯（NHCs）已经开始在许多金属介导的过程中作为配体发挥突出作用，在某种程度上，它们现在可以与膦相媲美，甚至超过膦。然而，在更专业的不对称催化领域，NHCs仍然落后于膦。本文主要研究了新型手性NHC金属配合物的制备及其在不对称合成中的应用，特别是在不对称烯烃复合反应中的应用。同样重要的是要认识到，NHCs也可以与主基团金属和非金属形成配合物，然后配合物也可能在合成中有用。这一领域迄今尚未开发，本研究项目将探讨NHC主基团配合物在有机合成中的潜力。此外，游离NHCs本身显示的特性使手性NHCs成为亲核有机催化剂的有吸引力的候选者。最后，我们建议研究一种完全新颖的类碳碳化合物的制备和反应，这些类碳碳化合物可能以类似碳碳化合物的方式作为配体。

Asymmetric metal-mediated processes are vital in organic synthesis. For many years, chiral phosphines have provided the source of asymmetry in chiral metal complexes. In recent years, however, N-heterocyclic carbenes (NHCs) have begun to play a prominent role as ligands in many metal-mediated processes, to the extent that they now rival, and surpass, phosphines in this role. However, in the more specialised field of asymmetric catalysis, NHCs still lag beh phosphines. The research described herein is directed towards the preparation of new chiral NHC metal complexe their application in asymmetric synthesis, and in particular in asymmetric alkene metathesis processes. It is also important to recognise that NHCs may also form complexes with main group metals and non-metals, and that then complexes may also be useful in synthesis. This area is so far unexplored, and this research project will investigate the potential of NHC main group complexes in organic synthesis. Additionally, the free NHCs themselves display properties that make the chiral NHCs attractive candidates for nucelophilic organocatalysts. Finally, it is proposed to investigate preparation and reactions of completely novel, carbene-like species, which may act as ligands in a similar manner carbenes.