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

手性 N-杂环卡宾作为金属介导的不对称过程的有机催化剂和配体

• 批准号: GR/S52100/02
• 负责人: David Lindsay
• 金额: --
• 依托单位: University of Reading
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=GR%2FS52100%2F02
• 关键词: Chiral; Heterocyclic; Carbenes; Organocatalysts; Ligands

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.

不对称金属介导的过程在有机合成中至关重要。多年来，手性膦提供了手性金属配合物的不对称性的来源。然而，近年来，N-杂环卡宾（NHC）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，以至于它们现在在这一作用中与膦竞争并超过膦。然而，在更专业的不对称催化领域，NHC仍然落后于膦。本文所述的研究涉及新的手性NHC金属的制备及其在不对称合成，特别是在不对称烯烃复分解过程中的应用。同样重要的是要认识到NHC也可以与主族金属和非金属形成络合物，然后络合物也可以用于合成。这一领域是迄今为止尚未开发的，本研究项目将探讨NHC主族络合物在有机合成中的潜力。此外，游离NHC本身显示出的特性使手性NHC成为亲核有机催化剂的有吸引力的候选者。最后，它建议调查的制备和反应的完全新的，卡宾类物种，这可能会作为配体以类似的方式卡宾。