Search for dissertations about: "Hydrogenations"
Showing result 1 - 5 of 21 swedish dissertations containing the word Hydrogenations.
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1. Asymmetric Hydrogenations : Syntheses of Ligands and Expansion of Substrate Scope
Abstract : Asymmetric hydrogenation has emerged as a versatile methodology to obtain a wide range of chiral precursors. This thesis focused on the synthesis of new chiral ligands and the expansion of the substrate scope of asymmetric hydrogenations. READ MORE
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2. Selective transfer hydrogenations : Catalyst development and mechanistic investigations
Abstract : By generating a library of amino acid-based ligands, pseudo-dipeptides, and combining them with transition metals, we have created selective and efficient ruthenium and rhodium catalysts for the asymmetric transfer hydrogenation of ketones. The ruthenium-catalyzed reaction was studied in detail, and we found that alkali metals play a crucial role for the reactivity and selectivity of the reaction. READ MORE
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3. Chemo- and Enantioselective Hydrogenations : The Struggle of Expanding the Substrate Scope of Iridium Catalyzed Asymmetric Hydrogenations of Olefins
Abstract : The asymmetric hydrogenation of olefins is a facile and popular method of reaching chiral products. Whereas ruthenium- and rhodium-catalyzed asymmetric hydrogenations have a long history, the use of iridium in this area is new but fast-growing. READ MORE
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4. Asymmetric Hydrogenations of Imines, Vinyl Fluorides, Enol Phosphinates and Other Alkenes Using N,P-Ligated Iridium Complexes
Abstract : The research described in this thesis is directed toward the efficient, enantioselective synthesis of chiral products that have useful functionality. This goal was pursued through catalytic asymmetric hydrogenation, a reaction class that selectively introduces one or two stereocenters into a molecule in an atom-efficient step. READ MORE
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5. Asymmetric Hydrogenations using N, P - Ligated Iridium Complexes
Abstract : The research described in this thesis focuses on the catalytic asymmetric hydrogenation of prochiral olefins using N, P – chelated iridium catalysts. This catalytic system is tolerant to a wide range of substrates and performs better than the well-known ruthenium- and rhodium-catalytic systems for substrates devoid of coordinating groups in proximity of the olefin. READ MORE
