Mechanisms of Transition Metal Catalyzed Reactions in Hydrocarbons

在化学系有机动力学项目的支持下，加州理工学院的罗伯特·格拉布斯教授将继续致力于一系列催化剂的研究，这些催化剂已经能够影响广泛的应用。催化剂表现出很高的活性和选择性，这是通过对机理和结构功能关系的研究来理解的。在下一个授权期内，将开发和探索新的配体合成方法，这将有助于从根本上了解控制这些系统效率的因素。从这些研究中将产生一种有效的方法来生成一系列N-杂环卡宾，这些卡宾可以用于除烯烃歧化以外的许多催化过程。虽然已经用Ru、Os和Ir制备了活性复分解催化剂，但到目前为止，还没有关于基于铁的中等效率复分解催化剂的报道。应支持和稳定亚铁的配位体系统将被制备和研究，以确定从Ru催化剂中学到的一些经验是否可以应用于铁基系统。拟议研究的另一个目标是探索合成新型聚乙烯(PE)的途径，用于开发和测试结构-性能关系模型。将开发新的路线来完善线性和单分散PE，继续探索环状PE，并开发合成超支化PE的新方法。已经建立了合作，以充分表征和比较每一种拓扑结构不同的材料的性能。此外，开发两个烯烃之间的官能团(官能团歧化)交换催化剂的新策略，类似于烯烃歧化反应，涉及两个烯烃之间的碎片交换。这一策略将为烯烃的氧化、氮杂环化和水合提供新的途径。将特别强调开发一种用于烯烃加成水的反马科夫尼科夫催化剂。为了帮助这些研究，将使用快速筛选技术，并将进行基础机理研究。加州理工学院的格拉布斯教授提出的这项建议将生产新的聚合物材料，工业和学术界的其他小组将使用这些材料来探索结构与性质的关系。在过去的项目中，发表了65篇与烯烃复分解化学有关的出版物和14项专利。这些出版物要么是由NSF直接资助的，要么是由NSF资助开发的催化剂使其成为可能。NSF资助的项目的学术影响通过每篇论文被引用90次的排名前两名的项目得到证明。该研究项目已培养出一批学生，他们现在是主要学术和工业机构的杰出研究人员。它吸引了来自世界各地的博士后研究员和学生，并为2-4名本科生提供为期10周的支持，让他们接触到学术研究。格拉布斯教授的研究是许多工业过程的基础，并正在为美国创造新的就业机会。

With the support of the Organic Dynamics Program in the Chemistry Division, Professor Robert Grubbs at The California Institute of Technology will continue to work on a family of catalysts that have been able to impact a broad range of applications. The catalysts have displayed high levels of both activity and selectivity, the understanding of which has resulted from studies of mechanisms and structure function relationships. During the next granting period, new methods will be developed and explored for the synthesis of ligands that will aid in the fundamental understanding of the factors that control the efficiency of these systems. Out of these studies will come an efficient method for generating an array of N-heterocyclic carbenes that can be used in many catalytic processes beyond olefin metathesis. Although active metathesis catalysts have been prepared from ruthenium, osmium and iridium, to date there are no reports of even a moderately efficient metathesis catalyst based on iron. Ligand systems that should support and stabilize iron alkylidenes will be prepared and investigated to determine if some of the lessons learned from ruthenium catalysts can be applied to iron-based systems. Another objective of the proposed research is to explore routes to the synthesis of new forms of polyethylene (PE) to be used to develop and test models of structure-property relationships. New routes will be developed to perfect linear and monodispersed PE, continue the exploration of cyclic PEs, and develop new approaches to the synthesis of hyper-branched PE. Collaborations have been established for the full characterization and comparison of the properties of each of these topologically diverse materials. Additionally, a new strategy to develop catalysts for the interchange of functional groups (functional group metathesis) between two olefins, similar to olefin metathesis, which involves the interchange of fragments between two olefins. This strategy will provide new routes for the oxidation, aziridination, and hydration of olefins. Special emphasis will be on the development of a catalyst for the anti Markovnikov addition of water to olefins. To aid in these investigations, rapid screening techniques will be used and fundamental mechanistic studies will be carried out.This proposal by Professor Grubbs at The California Institute of Technology will produce new polymeric materials that other groups both in industry and academia will use to explore structure-property relationships. The past program produced over 65 publications and 14 issued patents related to olefin metathesis chemistry. These publications were either directly funded by NSF or were made possible by catalysts developed using NSF funding. The academic impact of the NSF funded program is demonstrated by being ranked in the top two of most cited programs with 90 citations per paper. The research program has produced a number of students who are now outstanding researchers in major academic and industrial institutions. It brings postdoctoral fellows and students from around the world, and supports 2-4 undergraduates for a ten week period, exposing them to academic research. Professor Grubbs' research is the basis for a number of industrial processes and is creating new employment opportunities in the US.