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Visar resultat 1 - 5 av 10 avhandlingar som matchar ovanstående sökkriterier.
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. 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
3. Transition metal- and lipase-catalyzed reactions : Dynamic resolutions, hydrogen transfer and enzyme engineering
Sammanfattning : This thesis mainly focuses on chemoenzymatic processes and can be divided into three parts: The first part of the thesis, chapters 2-4, is devoted to the development of combined ruthenium- and enzyme-catalyzed dynamic processes. In these processes the metal catalyst racemizes (epimerizes) the alcohol substrate via hydrogen transfer and the enzyme transforms the substrate into enantiomerically enriched product. LÄS MER
4. 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
5. Synthetic Transformations via Metal- and Enzyme-Catalyzed Dynamic Kinetic Resolution
Sammanfattning : This thesis deals with the preparation of a new half-sandwich type ruthenium(II)- catalyst for racemization of optically active secondary alcohols and the development of a highly efficient method in combination with lipases such as Candida antarctica lipase B and Pseudomonas cepacia lipase for dynamic kinetic resolution of various functionalized alcohols under mild reaction conditions.It was shown that the RuCl(CO)2(η5-C5Ph5) complex can racemize optically active aliphatic and aromatic secondary alcohols at room temperature in rather short times. LÄS MER
