Sökning: "Hydrogenations"

Visar resultat 1 - 5 av 16 avhandlingar innehållade ordet Hydrogenations.

  1. 1. Asymmetric Hydrogenations Syntheses of Ligands and Expansion of Substrate Scope

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Pradeep Cheruku; Uppsala universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Catalysis; Asymmetric; Hydrogenations; Reductions; Olefins; Imines; Enol phosphinates; Transition metal; Complexes; Iridium; Enamines; Ruthenium; Ligands; Trifluoromethyl; Diphenylvinylphosphine oxides; Vinyl phosphonates; NATURAL SCIENCES Chemistry; NATURVETENSKAP Kemi;

    Sammanfattning : 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. LÄS MER

  2. 2. Selective transfer hydrogenations : Catalyst development and mechanistic investigations

    Detta är en avhandling från Stockholm : Institutionen för organisk kemi

    Författare :Jenny Wettergren; Stockholms universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric catalysis; transfer hydrogenation; transition metal; amino acids; amino alcohols; NATURAL SCIENCES Chemistry Organic chemistry; NATURVETENSKAP Kemi Organisk kemi; Organic Chemistry; organisk kemi;

    Sammanfattning : 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. LÄS MER

  3. 3. Chemo- and Enantioselective Hydrogenations The Struggle of Expanding the Substrate Scope of Iridium Catalyzed Asymmetric Hydrogenations of Olefins

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Mattias Engman; Uppsala universitet.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES Chemistry Organic chemistry; NATURVETENSKAP Kemi Organisk kemi; Organisk kemi; Organic Chemistry;

    Sammanfattning : 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. LÄS MER

  4. 4. Asymmetric Hydrogenations of Imines, Vinyl Fluorides, Enol Phosphinates and Other Alkenes Using N,P-Ligated Iridium Complexes

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Jarle Sidney Diesen; Uppsala universitet.; [2008]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Organic chemistry; Catalysis; Asymmetric; Hydrogenations; Reductions; Alkenes; Imines; Vinyl fluorides; Enolphosphinates; Transition metal; Complexes; Iridium; Organisk kemi; MEDICINE Chemistry; MEDICIN Kemi;

    Sammanfattning : 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. LÄS MER

  5. 5. Asymmetric Hydrogenations using N, P - Ligated Iridium Complexes

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Alexander Paptchikhine; Uppsala universitet.; [2012]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric hydrogenation; iridium; birch; boronates; fluorine;

    Sammanfattning : 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. LÄS MER