Sökning: "hydride transfer"
Visar resultat 6 - 10 av 29 avhandlingar innehållade orden hydride transfer.
6. Structural studies on the extracellular flavocytochrome cellobiose dehydrogenase from Phanerochaete chrysosporium
Sammanfattning : Microorganisms that degrade lignocellulose play an important role in maintaining the global carbon cycle. Under cellulolytic conditions, the fungus Phanerochaete chrysosporium produces an extracellular flavocytochrome, cellobiose dehydrogenase (CDH), with a proposed role in lignocellulose degradation. LÄS MER
7. Transition metal-catalyzed reduction of carbonyl compounds : Fe, Ru and Rh complexes as powerful hydride mediators
Sammanfattning : A detailed mechanistic investigation of the previously reported ruthenium pseudo-dipeptide-catalyzed asymmetric transfer hydrogenation (ATH) of aromatic ketones was performed. It was found that the addition of alkali metals has a large influence on both the reaction rate and the selectivity, and that the rate of the reaction was substantially increased when THF was used as a co-solvent. LÄS MER
8. Transition metal-catalysed hydrogen transfer processes for C-C and C-N bond formation : Synthetic studies and mechanistic investigations
Sammanfattning : This thesis focusses on synthetic studies and mechanistic investigations into reactions involving hydrogen-transfer processes.In the first part, the development of an efficient method for the synthesis of β-hydroxy ketones (aldols) and β-amino ketones (Mannich products) from allylic alcohols and aldehydes is described. LÄS MER
9. Transition metal-catalyzed hydrogen transfer processes
Sammanfattning : The first part describes the synthesis of new analogues of Bäckvall’s catalyst with varying electronic properties and their application in the racemization of sec-alcohols. The racemization involves two key steps: (i) β-hydride elimination (dehydrogenation of the alcohol) and (ii) hydride re-addition to the intermediate ketone. LÄS MER
10. 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
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
