Search for dissertations about: "regio selectivity"

Showing result 1 - 5 of 14 swedish dissertations containing the words regio selectivity.

  2. 1. A Novel Rearrangement of Allyl Benzyl Ethers and Aspects on the Glyoxylate Ene Reaction

    Author : Johan Wennerberg; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; liverwort; natural product synthesis; phenyl butyraldehydes; allyl benzyl ethers; 2-hydride migration; 1; 4-rearrangement; regio selectivity; shape selectivity; zeolite; Ene reaction; Taxol A-ring; naphthalene derivatives; dihydronaphthalenes; Organic chemistry; Organisk kemi;

    Abstract : This thesis describes an improvement of the glyoxylate ene reaction by using siamyl glyoxaylate and a development of the novel rearrangement of allyl benzyl ethers. The glyoxylate ene reaction was used as a key reaction in a 8-step synthesis of a Taxol A-ring building block. READ MORE

  4. 2. Heck Reactions with Aryl Chlorides : Studies of Regio- and Stereoselectivity

    Author : Gopal K. Datta; Mats Larhed; Anders Hallberg; Martin Oestreich; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Heck reaction; aryl chloride; vinyl ether; regioselective; stereoselective; palladium; chelation control; microwave; Pharmaceutical chemistry; Farmaceutisk kemi;

    Abstract : Homogeneous palladium-catalyzed Heck vinylation of aryl chlorides was investigated under air using Herrmann’s palladacycle and the P(t-Bu)3-liberating salt [(t-Bu)3PH]BF4. Based on the results, controlled microwave heating was utilized to accelerate model Heck reactions with aryl chlorides down to 30 min employing an electron-poor olefin and a mixture of an ionic liquid and 1,4-dioxane as solvent. READ MORE

  5. 3. Characterization and Directed Evolution of an Alcohol Dehydrogenase : A Study Towards Understanding of Three Central Aspects of Substrate Selectivity

    Author : Emil Hamnevik; Mikael Widersten; Gerrit Poelarends; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Alcohol dehydrogenase; ADH-A; Biocatalysis; Directed evolution; Enantioselectivity; Enzyme kinetics; Enzyme mechanisms; Protein Engineering; Regioselectivity; Substrate selectivity; Biokemi; Biochemistry;

    Abstract : Many different chemicals are used in the everyday life, like detergents and pharmaceuticals. However, their production has a big impact on health and environment as much of the raw materials are not renewable and the standard ways of production in many cases includes toxic and environmentally hazardous components. READ MORE

  6. 4. Aspects on the Regio and Stereo Selectivity in the Hydrolsilylation of 1,3-Dienes

    Author : Magnus Gustafsson; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Metallorganisk kemi; Organometallic chemistry; Organisk kemi; Organic chemistry; Lewis acid; electrophilic ring closure; asymmetric hydrosilylation; reaction conditions; isoprene; regioselectivity; oxygen; Wilkinsons catalyst; 15N-1H-HMQC; 31P; heterobidentate ligands; catalyst; palladium; epoxy-allylsilanes; rhodium complexes; dienes;

    Abstract : This thesis is a summary of four papers concerning various aspects on the transition metal catalysed hydrosilylation of 1,3-dienes. The hydrosilylation reaction is formally an addition of a hydrosilane to an unsaturated system and depending on the reaction conditions, control of stereo-, regio-, and chemo-selectivity can be achieved. READ MORE

  7. 5. Selectivity in Palladium- and Enzyme-Catalyzed Reactions : Focusing on Enhancement of Reactivity

    Author : Peter Nilsson; Anders Hallberg; Mats Larhed; Matthias Beller; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; Palladium; Heck; PCR; Microwaves; Farmaceutisk kemi; Pharmaceutical chemistry; Farmaceutisk kemi;

    Abstract : Catalysis has a profound impact on all living species on the earth. Nature’s catalysts, the enzymes, have the ability to selectively promote a specific bio-chemical transformation, given the required substrate. READ MORE