Sökning: "Aziridination"

Hittade 5 avhandlingar innehållade ordet Aziridination.

  1. 1. Concerted or Stepwise? : β-Elimination, Nucleophilic Substitution, Copper Catalysed Aziridination and Ruthenium Catalysed Transfer Hydrogenation Studied by Kinetic Isotope Effects and Linear Free-Energy Relationships

    Författare :Per Ryberg; Heinz F. Koch; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Kinetic isotope effect; linear free energy relationship; elimination; substitution; aziridination; transfer hydrogenation; Organisk kemi; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis describes the use of kinetic isotope effects, linear free energy relationships and stereochamical studies to distinguish between different mechanistic alternatives and to obtain information about transition state structure.In the first part fluorine and deuterium kinetic isotope effects were determined for the base promoted HF elimination from 4-fluoro-4-(4’-nitrophenyl)butane-2-on. LÄS MER

  2. 2. Development of organocatalytic asymmetric transformations

    Författare :Ismail Ibrahem; Armando Cordova; Stephen Hanessian; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric Catalysis; α-amino acids; Aldehydes; Ketones; α-Aminomethylation; Aziridination; Hydrophosphination; Diarylprolinol; Proline derivatives; Organic synthesis; Organisk syntes; Organic Chemistry; organisk kemi;

    Sammanfattning : The ability of amino acids and amino acid derivatives to mediate various organocatalytic asymmetric transformations has been investigated and applied in the development of various reactions. This work describes the development of a direct catalytic asymmetric α-aminomethylation of ketones and aldehydes, a catalytic asymmetric aziridination, hydrophosphination and amination of α,β-unsaturated aldehydes. LÄS MER

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

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

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

    Författare :Sophie Bertilsson; Tobias Rein; Uppsala universitet; []
    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; Chemistry; 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. Development of Catalytic Enantioselective Approaches for the Synthesis of Carbocycles and Heterocycles

    Författare :Luca Deiana; Armando Córdova; Andrei Malkov; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organocatalysis; Asymmetric Catalysis; Heterogeneous Catalysis; Aziridines; Pyrazolidines; Cyclopentanes; organisk kemi; Organic Chemistry;

    Sammanfattning : In biological systems, most of the active organic molecules are chiral. Some of the main constituents of living organisms are amino acids and sugars. They exist predominantly in only one enantiomerically pure form. LÄS MER