Stabilization of Unique Chemical Bonding Environments and Exploration of Small Molecule Reactivity

作为我的团队正在进行的研究的一部分，在这项提案中，我们将专注于以下项目，这些项目跨越了我们的专业领域，包括主要组别和过渡金属合成化学。在Masuda研究小组的经验和优势的基础上，我建议继续研究并扩大我们在以下领域的知识： 1.半分子螯合配体：探索小分子反应性和催化作用的金属络合物 我们将扩展我们对四芳基环戊二烯配体的配位化学的研究，并探索所得到的金属络合物的反应性。该配体的半活性来源于强结合的阴离子环戊二烯基和较弱结合的芳基。我建议继续这个项目，有更令人兴奋的目标，包括利用半易分解的四芳基团的潜在氧化还原性质来帮助稳定低氧化态的金属中心。然后，这些物种可以用作低氧化态金属的合成子。将测试这些化合物与小分子的进一步反应能力和催化性能。 立体结构的双齿配体在主基团、过渡金属和f-嵌段金属的配位化学中具有重要的作用。通常，这些双齿配体由亚胺、胺、膦亚胺、羰基、硫代羰基、烷氧化物和膦氧化物等给体组成。在非对称体系中，可以使用不同的施主来利用施主原子的硬度和软性的差异。叶立德在有机化学中广为人知，特别是作为Wittig试剂，在配位化学领域中被用作软的2电子给体。在叶立德的文献中，很少有含有荧亚甲基基团的例子。我们建议制备各种螯合配体，其中一侧具有典型的给体(N，O，S)，另一侧具有灵活的碳基叶立德/亚荧基-磷烷片段。这种配位排列将允许分离通过硬亚胺和软叶立德片段配位的6元金属络合物，或者通过硬亚胺和芳基荧基阴离子的软、5元、6电子部分配位的假6元螯合物。这两种类型的络合之间有可能存在流变性，这种流变性可以用来影响金属络合物的反应活性。 2.与N-杂环卡宾和膦自由基小分子的反应活性 十多年来，我一直在探索单线态卡宾和膦自由基与各种小分子的反应活性。这些体系包括具有反应性E-E键、E-H键和扩展体系的体系。我建议将单重态卡宾和膦自由基与一些奇异的小分子/官能团反应，形成具有新的和意想不到的性质的新的官能团。

As part of the ongoing research within my group, in this proposal we will be focusing on the following projects that span our areas of specialty including main group and transition metal synthetic chemistry. Building upon the experience and strengths in the Masuda Research Group, I propose to continue research and expand upon our knowledge in the following areas: 1. Hemilabile chelating ligands: metal complexes for exploration of small molecule reactivity and catalysis We will extend our investigation of the coordination chemistry our teraryl cyclopentadienyl ligands and explore the reactivity of the resulting metal complexes. The hemilability of this ligands results from the strongly bound anionic cyclopentadienyl group and the more weakly -bound aryl group. I propose to continue with this project with more exciting targets including utilizing the potential redox properties of the hemilabile teraryl group to help stabilize low-oxidation state metal centers. These species can then be used as synthons for lower oxidation state metals. These will be tested for further reactivity with small molecules and in catalysis. Sterically bulky, bidentate ligands have proven to be very important in coordination chemistry of main group, transition, and f-block metals. Often, these bidentate ligands consist of donors such as imines, amines, phosphinimines, carbonyls, thiocarbonyls, alkoxides, and phosphine oxides. In the unsymmetrical systems, different donors may be used to exploit differences in the hardness and softness of the donor atoms. Ylides are well known in organic chemistry, particularly as Wittig reagents, and are used as soft, 2-electron donors in the area of coordination chemistry. There are few examples in the literature of ylides that contain the fluorenylidene group. We propose to prepare a variety of chelating ligands, where one side has an typical donor (N, O, S) and the other has the flexible, carbon-based ylide/fluorenylidene-phosphorane fragment. This ligand arrangement will either allow for the isolation of 6-membered metal chelates coordinated via the hard imine and the soft ylide fragment, or pseudo-6-membered chelates coordinated through the hard imine and the soft, 5-membered, 6- electron portion of the aromatic fluorenyl anion. It is possible that there will be fluxionality between the two types of chelation and this fluxionality can be exploited to affect the reactivity of metal complexes. 2. Reactivity with small molecules with N-Heterocyclic carbenes and phosphinyl radicals For well over a decade, I have explored the reactivity of singlet carbenes and phosphinyl radicals with a wide variety of small molecules. These include systems with reactive E-E bonds, E-H bonds, and extended -systems. I propose on targeting the reaction of singlet carbenes and phosphinyl radicals with a number of exotic small molecules/functional groups to form new functional groups with new and unexpected properties.