Investigations of Metal-Element Multiple Bonding and New Methods for Metal-Mediated Bond Activations

金属元素多重键合和金属介导的键激活新方法的研究

• 批准号: 0132099
• 负责人: Terry Tilley
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2008-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0132099&HistoricalAwards=false
• 关键词: Investigations; Metal; Element; Multiple; Bonding

Professor T. Don Tilley, Department of Chemistry, University of California at Berkeley is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division to investigate complexes that contain a transition metal-main group element multiple bond and to develop new methods for transition metal mediated bond activations. A primary reaction type by which transition metal centers cleave chemical bonds involves the migration of a group from a donor atom to the metal (alpha - migration). This process produces a metal-element multiple bond, which is a functionality with a rich reaction chemistry and which is important in many metal-mediated transformations. Although alpha-migrations are well established for metal-carbon bonded systems, they are much less developed in M-N, M-O, M-Si, M-P, and other metal heteroatom systems. This proposal aims to assess the generality and synthetic utility of alpha-migration as a route to isolable species containing multiple bonds between various main group and transition metal fragments. In doing so, several fundamental questions will be addressed: (a) Can alpha-migration be used to generate new types of metal-element multiple bonds? (b) How does the electron count at the transition metal center influence alpha-migration chemistry? (c) Does a formally charged metal center promote the alpha-migration process? (d) What substituents in addition to hydrogen participate in alpha-migration chemistry? (e) Can the design and implementation of new ligand sets provide access to new bond activations? (f) Can alpha-migrations be incorporated into new catalytic cycles? To address these questions, specially designed complexes containing metals from throughout the transition series will be prepared. Many of these will feature coordinative unsaturation, and ligands designed to facilitate bond activations.The goal of this work is to provide a basis for the development of new and useful metal-mediated chemical processes. The discovery of new bonding patterns and reactivity modes will be followed by attempts to use this information in the design of new catalytic cycles. Many of these investigations will focus on silylene complexes that have recently been discovered, but as other metal-element multiple bonded compounds are obtained, their reactivities will be explored in the search for useful transformations.

T. Don Tilley教授，加州大学伯克利分校化学系，受到化学系无机、生物无机和有机金属化学项目的支持，研究含有过渡金属-主族元素多键的配合物，并开发过渡金属介导键激活的新方法。过渡金属中心劈开化学键的主要反应类型包括一个基团从给原子向金属的迁移（α -迁移）。该过程产生的金属-元素多键是一种具有丰富反应化学性质的官能团，在许多金属介导的转化中起着重要作用。虽然α -迁移在金属-碳键合体系中已经很好地建立起来，但在M-N、M-O、M-Si、M-P和其他金属杂原子体系中还不太发达。本提案旨在评估α -迁移的普遍性和综合效用，作为一种途径，可分离的物种包含多个键之间的各种主基团和过渡金属碎片。在这样做时，将处理几个基本问题：(a) α迁移能否用于产生新型金属-元素多重键？(b)过渡金属中心的电子数如何影响α迁移化学？(c)正式带电的金属中心是否促进α迁移过程？(d)除氢外，还有哪些取代基参与α迁移化学？(e)新配体集的设计和实现能否提供获得新键激活的途径？(f) α迁移能否纳入新的催化循环？为了解决这些问题，将制备特别设计的含有整个过渡系列金属的配合物。其中许多将具有配位不饱和和配体设计，以促进键激活。这项工作的目的是为开发新的和有用的金属介导的化学过程提供基础。在发现新的键合模式和反应模式之后，将尝试使用这些信息来设计新的催化循环。许多这些研究将集中在最近发现的硅烯配合物上，但随着其他金属元素多键化合物的获得，它们的反应性将在寻找有用的转化中得到探索。