Search for dissertations about: "Asymmetric chemoenzymatic synthesis"

Found 5 swedish dissertations containing the words Asymmetric chemoenzymatic synthesis.

  2. 1. Chemoenzymatic Resolution in Dynamic Systems : Screening, Classification and Asymmetric Synthesis

    Author : Yan Zhang; Olof Ramström; Sabine Flitsch; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; constitutional dynamic chemistry; dynamic systemic resolution; dynamic kinetic resolution; enzyme catalysis; transesterification; enzyme promiscuity; asymmetric synthesis; pattern recognition; self-inhibition.;

    Abstract : 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. READ MORE

  4. 2. Ruthenium-Catalyzed Hydrogen Transfer Reactions : Mechanistic Studies and Chemoenzymatic Dynamic Kinetic Resolutions

    Author : Madeleine Warner; Jan-Erling Bäckvall; Andreas Pfaltz; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Hydrogen transfer; ruthenium catalysis; kinetic resolution; dynamic kinetic resolution; racemization; asymmetric synthesis; organisk kemi; Organic Chemistry;

    Abstract : The main focus of this thesis lies on transition metal-catalyzed hydrogen transfer reactions. In the first part of the thesis, the mechanism for racemization of sec-alcohols with a ruthenium complex, Ru(CO)2Cl(η5-C5Ph5) was studied. READ MORE

  5. 3. Studies on Metalloenzymatic Dynamic Kinetic Resolutions and Iron-Catalyzed Reactions of Allenes

    Author : Karl P. J. Gustafson; Jan-Erling Bäckvall; Johannes de Vries; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Racemization; Dynamic Kinetic Resolution; Enzyme Catalysis; XAS; Asymmetric Synthesis; organisk kemi; Organic Chemistry;

    Abstract : The main focus of this thesis lies in the development of new transition metal-catalyzed chemoenzymatic dynamic kinetic resolutions (DKR) of both alcohols and amines. The first part of the thesis deals with the development of new heterogeneous systems for the DKR of amines. READ MORE

  6. 4. Ruthenium-catalyzed redox reactions and lipase-catalyzed asymmetric transformations of alcohols

    Author : Michaela Edin; Jan-E. Bäckvall; Manfred T. Reetz; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ruthenium; lipase; catalysis; alcohols; diols; Chemistry; Kemi;

    Abstract : The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed redox reactions that lead to racemization or epimerization and lipase-catalyzed asymmetric trans-formations in one-pot.A mechanistic study of the unexpected facile formation of meso-diacetate products found in enzyme-catalyzed acetylations of alkanediols with Candida antarctica lipase B (CALB) was first performed. READ MORE

  7. 5. Transition metal- and lipase-catalyzed reactions : Dynamic resolutions, hydrogen transfer and enzyme engineering

    Author : Patrik Krumlinde; Jan-Erling Bäckvall; Johannes G. de Vries; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dynamic kinetic resolution; dynamic kinetic asymmetric transformation; hydrogen transfer; directed evolution; enzyme engineering; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

    Abstract : 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. READ MORE