New Catalytic Reactions for Enhanced Synthetic Efficiency

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In this project funded by the Chemical Catalysis program of the Chemistry Division, Professor Barry Trost of Stanford University is developing catalytic reactions for the synthesis of complex molecules. The research is addressing limitations of raw materials and environmental concerns that require attention by focusing on an important but frequently overlooked issue - atom economy, i.e. the development of reactions in which, to the greatest extent possible, any stoichiometric by-products are minimized and, in the ideal case, eliminated so that the product is the sum of the reactants with any additional reagent being required only catalytically. This proposal explores inventing new paradigms of reactivity. For example, drug discovery programs at pharmaceutical companies have emerged as a result of Professor Trost's invention of new synthetic methods. The proposal outlines a broad study to create new paradigms of reactivity. Two general areas of transition metal catalysis will be explored, that of palladium and ruthenium. The goal is the generation of atom economical methods. The program involving palladium explores for the first time novel substrate types for C-C bond formation. It focuses on an unexpected ligand effect and the impact of substrate selection, especially using substrates bearing nitrogen heteroatoms which, at first glance, would be expected to fail. The program involving ruthenium explores the design of the structure of the catalyst to enable reactivity and selectivity which previously did not exist. It envisions novel ways to carbo- and nitrogen and oxygen heterocycles. It proposes the generation of carbenoids, important reactive intermediates, by simple isomerization of readily available propargyl derivatives thereby avoiding the almost universal use of hazardous diazo compounds.