Catalytic Activation and Oxidation of C-H and C-C Bonds by Soluble Metal Complexes

该项目由无机生物无机和有机金属化学项目资助，将支持宾夕法尼亚州立大学A. Sen教授对过渡金属、均相催化的继续研究。森教授将对两种新的催化系统进行深入研究，这两种催化系统为有机分子的选择性、金属催化、氧化功能化提供了希望。这些系统中的第一个是铂（II）介导的远端C-H键在某些功能化有机化合物中的羟基化。第二种是铑催化烷烃（包括甲烷和乙烷）的C-H和C-C键的羟基化和羟基羰基化，使用分子氧作为氧化剂。催化剂前驱体不含可氧化配体，因此有可能不会发生催化剂降解。在这两种情况下，需要解决的是有机金属中间体的结构和反应性，C-H （C-C）活化步骤的性质，以及观察到的选择性的机制起源。本研究关注的是基于过渡金属的均相催化剂的发展，这种催化剂可能允许饱和烃的选择性功能化。均相催化反应通常比非均相催化反应具有更大的选择性。然而，工业上只使用后一种催化剂来促进饱和碳氢化合物的反应，因为已知的均相催化剂即使发生反应，通常也不够活跃。本研究基于的初步发现表明，均相催化剂最终可能用于这些分子的选择性功能化。如果催化活性足够大，就很有可能产生商业上可行的工艺。

This project supported by the Inorganic Bioinorganic and Organometallic Chemistry Program will support the continuation of studies of transition metal, homogeneous catalysis by Professor A. Sen of the Pennsylvania State University. Professor Sen will perform in-depth investigations of two new catalytic systems that offer promise for selective, metal catalyzed, oxidative functionalization of organic molecules. The first of these systems is the platinum(II) mediated hydroxylation of remote C-H bonds in certain functionalized organic compounds. The second is the rhodium catalyzed hydroxylation and hydroxycarbonylation of C-H and C-C bonds of alkanes, including methane and ethane, using molecular oxygen as the oxidant. The catalyst precursors contain no oxidizable ligands so that there is the possibility that catalyst degradation will not occur. To be addressed in both cases are the structure and reactivity of the organometallic intermediates, the nature of the C-H (C-C) activation step, and the mechanistic origins of the observed selectivities. This research is concerned with the development of homogeneous catalysts based upon transition metals that may allow for the selective functionalization of saturated hydrocarbons. Homogeneously catalyzed reactions typically offer much greater selectivity than heterogeneous reactions, when they can be used. However, only the latter types of catalysts are used industrially to promote reactions of saturated hydrocarbons because known homogeneous catalysts normally are not sufficiently reactive, if they even react. The initial discoveries upon which this research is based suggest that homogeneous catalysts may ultimately be used for the selective functionalization of such molecules. If the catalytic activities are great enough, there is a high probability that commercially viable processes will result.