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Visar resultat 1 - 5 av 127 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Concerted and stepwise solvolytic elimination and substitution reactions : evidence for solvent-promoted E2 reaction

    Författare :Qingshui Meng; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 2. Palladium-Catalyzed Nucleophilic Substitution of Alcohols : Mechanistic Studies and Synthetic Applications

    Författare :Supaporn Sawadjoon; Joseph Samec; Takao Ikariya; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; palladium; nucleophilic substitution; mechanism; Organic Chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with the palladium-catalyzed nucleophilic substitution of π-activated alcohols in which the C–O bond of a non-manipulated hydroxyl group is cleaved. The thesis is divided in two chapters describing two different catalytic systems. LÄS MER

  4. 3. 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

  5. 4. Direct Catalytic Nucleophilic Substitution of Non-Derivatized Alcohols

    Författare :Anon Bunrit; Joseph Samec; Joseph Moran; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nucleophilic substitution; catalysis; alcohols; stereospecific; Lewis acid; Brønsted acid base; bifunctional; heterocycles; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis focuses on the development of methods for the activation of the hydroxyl group in non-derivatized alcohols in substitution reactions. The thesis is divided into two parts, describing three different catalytic systems. LÄS MER

  7. 5. Computer-Assisted Organic Synthesis. Addition to Carbonyl Carbons and Aromatic Substitution

    Författare :Ingvar Lagerstedt; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CAOS; torsional strain; selectivity; aromatic substitution reaction;

    Sammanfattning : This thesis concerns the computer-assisted modelling of additions to ketones and aromatic substitution, and how this modelling can be used within an existing program for synthesis planning. I include a review of existing computer-assisted organic synthesis (CAOS) programs, and discuss how some of these programs deal with knowledge representation. LÄS MER