Sökning: "asymmetric synthesis"

Visar resultat 1 - 5 av 147 avhandlingar innehållade orden asymmetric synthesis.

  1. 1. Absolute Asymmetric Synthesis

    Författare :Anders Lennartson; Anders Lennartsson; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :absolute asymmetric synthesis; enantioselective synthesis; chirality; optical resolution; spontaneous resolution; conglomerate; organozinc reagents; organometallic chemistry; coordination chemistry; supramolecular chemistry; intermolecular interactions; optical resolution;

    Sammanfattning : Absolute asymmetric synthesis is the synthesis of optically active products from achiral or racemic precursors only. This has generally been regarded as impossible and is relevant in the discussion of the origins of biomolecular homochirality. LÄS MER

  2. 2. Asymmetric Hydrogenations : Syntheses of Ligands and Expansion of Substrate Scope

    Författare :Pradeep Cheruku; Pher Andesson; Jay Siegel; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Catalysis; Asymmetric; Hydrogenations; Reductions; Olefins; Imines; Enol phosphinates; Transition metal; Complexes; Iridium; Enamines; Ruthenium; Ligands; Trifluoromethyl; Diphenylvinylphosphine oxides; Vinyl phosphonates; Chemistry; Kemi;

    Sammanfattning : Asymmetric hydrogenation has emerged as a versatile methodology to obtain a wide range of chiral precursors. This thesis focused on the synthesis of new chiral ligands and the expansion of the substrate scope of asymmetric hydrogenations. LÄS MER

  3. 3. Stereoselective Synthesis of Amino Alcohols : Applications to Natural Product Synthesis

    Författare :Staffan Torssell; Peter Somfai; Pher G Andersson; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Amino alcohol; asymmetric 1.3-dipolar cycloaddition; azomethine ylide; carbenoid; carbonyl ylide; cross-metathesis; omuralide; oxazolidine; rhodium; sphingosine; stemoamide; stereoselective synthesis; total synthesis.; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis is divided into four separate parts with amino alcohols as the common feature. The first part of the thesis describes the development of an efficient three-component approach to the synthesis of α-hydroxy-β-amino esters. LÄS MER

  4. 4. Asymmetric Synthesis of C-Glycosylated Amino Acids : Incorporation in Collagen Glycopeptides and Evaluation in a Model for Rheumatoid Arthritis

    Författare :Tomas Gustafsson; Jan Kihlberg; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Total synthesis; stereoselective synthesis; chiral glycine templates; Evan’s alkylation; asymmetric hydrogenation; alpha-amino acid synthesis; C-glycoside; rheumatoid arthritis; MHC; T cell; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis describes stereoselective syntheses of four amino acids, three of which are C-glycosidic analogues of glycosylated amino acids. The overall goal of the project was to probe the interactions between MHC molecules, glycopeptide antigens and T cell receptors, that are essential for development of collagen induced arthritis. LÄS MER

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

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

    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