Electrophilic Attack on Coordinated Ligands Involved in Catalysis by Organometallic Complexes

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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.