Sökning: "desymmetrization"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet desymmetrization.

  1. 1. Methods for Asymmetric Olefination Reactions; Development and Application to Natural Product Synthesis

    Detta är en avhandling från Stockholm : KTH

    Författare :Daniel Strand; KTH.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antitumor agents; Asymmetric Horner-Wadsworth-Emmons; Desymmetrization; Metal-catalyzed olefination; Mucocin; Palladium-catalyzed allylic substitution; Parallel kinetic resolution; Pyranicin; Pyragonicin; Rhenium; Stereoconvergent synthesis; Stereodivergent synthesis; Stereoselective synthesis; Tetrahydropyran; Wittig reaction; NATURAL SCIENCES Chemistry Organic chemistry; NATURVETENSKAP Kemi Organisk kemi;

    Sammanfattning : This thesis deals with the development and application of methods for asymmetric olefinations, in particular Horner-Wadsworth-Emmons (HWE) reactions, in the synthesis of certain natural products.Relying on asymmetric HWE reactions to access key building blocks, two natu-ral products, pyranicin and pyragonicin, were synthesized from common late intermediates. LÄS MER

  2. 2. General Protocols for the Preparation of Tröger's Base Analogues and Molecular Recognition by Designed Tröger's Base Receptors

    Detta är en avhandling från Organic Chemistry, Lund University

    Författare :Jacob Jensen; [2002]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Organisk kemi; non-covalent bonds.; molecular recognition; desymmetrization; metal-mediated reactions; Tröger s base; synthetic protocols;

    Sammanfattning : 2,8-Dihalo substituted analogues of Tröger’s base were prepared via the Tröger’s base condensation reaction. These compounds were used as synthetic intermediates for the preparation of otherwise inaccessible functionalized Tröger’s base analogues. LÄS MER

  3. 3. Synthesis and Applications of P-chirogenic Phosphine Boranes

    Detta är en avhandling från Organic Chemistry, Lund University

    Författare :Magnus Johansson; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cytisine; gold I catalysis lipase; P-chirogenic; desymmetrization; phosphine; enantioselective cyclopropanation. enantioselective deprotonation; chirality; asymmetric synthesis; borane;

    Sammanfattning : AbstractThis thesis reports the independent synthesis of both enantiomers of P-chirogenic phosphine ligands and the building blocks thereof, which are suitable for parallel synthesis efforts and for the generation of more diverse libraries of P-chirogenic compound. The use of P-chirogenic phosphine boranes in transition metal-catalyzed reactions, such as palladium-catalyzed allylic alkylation and amination, is also described. LÄS MER

  4. 4. Asymmetric Formation and Isomerization of Three-Membered Rings : Catalyst Development and Evaluation

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Sophie Bertilsson; Uppsala universitet.; [2001]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; allylic alcohol; α-amino acid derivative; aza-Diels-Alder reaction; aziridination; cyclopropanation; desymmetrization; epoxide rearrangement; kinetic resolution; lithium amide; rhodium-carboxylate; Kemi; NATURAL SCIENCES Chemistry; NATURVETENSKAP Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : Enantiopure α-amino acid derivatives were prepared using a protocol which allows for highly controlled regio- and chemoselectivity in the hydrogenation/ hydrogenolysis of aza-Diels-Alder adducts. One of the resulting α-amino esters, (1S,3R,4R)-2-azabicyclo[2.2.1]heptane-3-carboxylic acid ethyl ester, was utilized further as a catalyst precursor. LÄS MER

  5. 5. Allylic alcohols and aziridines from alkenes : Studies in asymmetric catalysis

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Mikael J. Södergren; Uppsala universitet.; [2000]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Enantioselective; allylic alcohols; epoxide rearrangement; lithium amides; desymmetrization; kinetic resolution; allylic oxidation; alkenes; aziridination; Kemi; NATURAL SCIENCES Chemistry; NATURVETENSKAP Kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : The development of methodology for asymmetric catalytic transformation of alkenederivatives is summarized. The studies concern the [a] Cu(I)-catalyzed allylic oxidation,[b] isomerization of epoxides to allyl alcohols, and [c] Cu(I)-catalyzed alkeneaziridination, respectively.[a] The preparation of exo-2-azabicyclo[2.2. LÄS MER