Sökning: "kinetic asymmetric transformation"
Visar resultat 1 - 5 av 14 avhandlingar innehållade orden kinetic asymmetric transformation.
1. Asymmetric transformation of ß- and γ-functionalized alcohols : Study of combined ruthenium-catalyzed racemization and enzymatic resolution
Sammanfattning : The major part of this thesis describes the asymmetric synthesis of β- and γ-amino alcohols through the combination of ruthenium catalyzed racemization and enzymatic kinetic resolution. The dynamic kinetic resolution, DKR, protocol for chlorohydrins was improved by employing Bäckvall’s catalyst, which is a base activated racemization catalyst, in combination with Burkholderia cepacia lipase. LÄS MER
2. Asymmetric transfer hydrogenation of ketones : Catalyst development and mechanistic investigation
Sammanfattning : The development of ligands derived from natural amino acids for asymmetric transfer hydrogenation (ATH) of prochiral ketones is described herein. In the first part, reductions performed in alcoholic media are examined, where it is found that amino acid-derived hydroxamic acids and thioamides, respectively, are simple and versatile ligands that in combination with [RhCp*Cl2]2 efficiently catalyze this particular transformation. LÄS MER
3. Chemoenzymatic Resolution in Dynamic Systems : Screening, Classification and Asymmetric Synthesis
Sammanfattning : This thesis is divided into four parts, all centered around Constitutional Dynamic Chemistry (CDC) and Dynamic Kinetic Resolution (DKR) using biocatalysts for selective transformations, and their applications in screening of bioactive compounds, organic synthesis, and enzyme classification. In part one, an introduction to CDC and DKR is presented, illustrating the basic concepts, practical considerations and potential applications of such dynamic systems, thus providing the background information for the studies in the following chapters. LÄS MER
4. Allylic alcohols and aziridines from alkenes : Studies in asymmetric catalysis
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
5. Enantioselective Synthesis of Sec-Alcohol Derivatives and Diols via Combined Ruthenium and Enzyme Catalysis
Sammanfattning : The first part of this thesis describes the synthesis of enantiopure secondary alcohol derivatives. These syntheses are carried out via the combination of an enzyme as a resolution catalyst and a ruthenium catalyst as a racemization catalyst, in what is called dynamic kinetic resolution (DKR). LÄS MER
