Transition Metal Metallacycles: Synthesis via Remote Intramolecular C-H Bond Activation and Utility in Main-GroupHeterocyclic Synthesis

俄勒冈大学化学系David R.Tyler博士得到化学部合成有机化学项目的支持，通过远程分子内C-H键活化，开发用于合成主族杂环的金属环。将制备一系列具有分子内C-H活化的一个或多个位置并且始终包含至少一个可进行伽马活化的位置的早期过渡金属乙烯基络合物。将测定这些络合物对C-H活化反应的化学选择性和区域选择性。通过系统地改变取代基在乙烯基上的位置和性质以及过渡金属的性质，将发展对有利于远程激活的空间和电子因素的理解。所得信息将用于协助合理制备金属环络合物，特别是具有现有合成方法无法获得的取代基型式的金属环丁烯。这些金属环化合物将被开发，主要侧重于开发该化合物在形成杂环化合物中的催化用途。过渡金属常用于重要有机化学品的制备。该项目旨在开发新的方法来制备各种迄今难以获得的物种。这些杂环化合物具有重要的实验室、工业和生物学意义。此外，该项目还将探索远离过渡金属的碳氢键的活化。这一阶段的研究将提供过渡金属如何活化有机化合物的基本信息。

Dr. David R. Tyler, Department of Chemistry, University of Oregon is supported by the Synthetic Organic Chemistry Program of the Chemistry Division for the development of metallacycles for the synthesis main group heterocycles by remote intramolecular C-H bond activation. A series of early transition metal vinyl complexes that present one or more sites for intramolecular C-H activation and that always include at least one site that is accessible for gamma-activation will be prepared. The chemo- and regio- selectivity of the C-H activation reactions by these complexes will be determined. Through systematic variation in the placement and nature of the substituents on the vinyl group and the nature of the transition metal, an understanding of the steric and electronic factors favoring remote activation will be developed. The resulting information will be used to assist in the rational preparation of metallacyclic complexes, particularly metallacyclobutenes bearing substituent patterns unavailable through the use of existing synthetic procedures. There metallacyclic complexes will be exploited, with primary focus on the development of catalytic uses of the complexes in the formation of heterocyclic compounds. Transition metals are often used to effect the preparation of important organic chemicals. This project aims at developing new methods to prepare a variety of heretofore difficult to obtain species. These `heterocyclic` compounds have great laboratory, industrial, and biological significance. In addition, this project will explore the activation of carbon-hydrogen bonds that are remote from a transition metal. This phase of the investigation will provide fundamental information on how organic compounds can be activated by transition metals.