Electrophilic Attack on Coordinated Ligands Involved in Catalysis by Organometallic Complexes

科罗拉多州立大学化学系的Jack R.Norton博士对有机金属过渡金属络合物的反应性进行了研究，重点是氢化物配体在对映选择性反应中的行为，该奖项是无机化学、生物无机化学和金属有机化学计划的奖项。第一个项目是开发一种在酸存在下检测氢化物配体的核磁共振方法，以测试质子转移同位素效应的热力学驱动力，并开发光学活性氢化物络合物，这种络合物可以将氢化物以显著不同的速率转移到底态的相反的前手性表面。接下来是含氧和含氮配体的质子加成。在一个相关的项目中，将研究由茂锆促进的氨基酸的对映选择性合成，特别关注提高反应的产率和选择性。本课程将研究CO催化下的Zr-C键的质子化断裂，以及利用氮化锆络合物制备对映体富集型氨基醇。这个项目有两个主要主题：金属氢化物的反应和锆化学。金属氢化物研究旨在开发新的方法，将氢从金属氢化物转移到有机化合物，同时保持所需的立体定向。在C-C和C-N键形成的反应中，锆化合物是潜在有用的试剂。这一结果将对理解氢气与金属化合物反应的基本行为以及开发用于有机合成的新试剂具有重要意义。

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research by Dr. Jack R. Norton of the Chemistry Department, Colorado State University, on the reactivity of organometallic transition metal complexes, with emphasis on the behavior of hydride ligands in enantioselective reactions. The first project is to develop an NMR method to detect hydride ligands in the presence of acid in order to test the thermodynamic driving force for proton tranfer isotope effects, and to develop optically active hydride complexes that can transfer hydride to opposite prochiral faces of a substate at substantially different rates. Proton addition to oxygen- and nitrogen-containing ligands will be followed. In a related project, enantioselective synthesis of amino acids promoted by zirconocenes will be investigated with particular attention on increasing the yield and selectivity of the reaction. Protic cleavage of Zr-C bonds catalyzed by CO will be studied as will the use of zirconium nitrene complexes to prepare enantiomerically enriched amino alcohols. This project has two main themes: reactions of metal hydrides and zirconium chemistry. The metal hydride studies are designed to develop new ways to transfer hydrogen from a metal hydride to an organic compound while maintaining a desired stereospecific orientation. The zirconium compounds are potentially useful agents for reactions in which C-C and C-N bonds are formed. The results will be relevant to understanding the fundamental behavior of hydrogen reactions with metal compounds and to developing new reagents for organic synthesis.