Sökning: "Regioselectivity"

Visar resultat 6 - 10 av 54 avhandlingar innehållade ordet Regioselectivity.

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

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

   Sammanfattning : 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. LÄS MER

3. 7. Engineered Alcohol Dehydrogenases for Stereoselective Chemical Transformations

   Författare :Thilak Reddy Enugala; Mikael Widersten; Manfred T. Reetz; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alcohol dehydrogenase-A; biocatalysts; protein engineering; enzyme kinetics; sec-alcohols; ketones; stereoselectivity; regioselectivity; substrate selectivity and promiscuity.; Biokemi; Biochemistry;

   Sammanfattning : Enzymes are biomolecules built from amino acids and catalyze the chemical transformations in a cell. Enzymes are by nature stereoselective, biodegradable, environmentally friendly, and can perform catalysis in aqueous solutions and at ambient temperatures. LÄS MER

4. 8. Stereoselective Nucleophilic Additions to α-Amino Aldehydes: Application to Natural Product Synthesis

   Författare :Per Restorp; Peter Somfai; Timothy J. Donohoe; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stereoselective synthesis; Substrate-control; α-Amino aldehydes; Mukaiyama aldol; Allylsilanes; [3 2]-Annulation; -Alexine; DGDP; Vinyl epoxides; Regioselectivity; Alkyne nucleophiles; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis deals with the development and application of new synthetic methodology for stereo- or regioselective construction of carbon-carbon bonds in organic synthesis. The first part of this thesis describes the development of a divergent protocol for stereoselective synthesis of chiral aminodiols by employing Mukaiyama aldol additions to syn- and anti-α-amino-β-silyloxy aldehydes. LÄS MER

5. 9. Extending the Reach of Computational Approaches to Model Enzyme Catalysis

   Författare :Beat Anton Amrein; Shina Caroline Lynn Kamerlin; Adrian Mulholland; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; epoxide hydrolase; enantioselectivity; regioselectivity; enantioconvergence; biocatalysis; empirical valence bond; computational directed evolution;

   Sammanfattning : Recent years have seen tremendous developments in methods for computational modeling of (bio-) molecular systems. Ever larger reactive systems are being studied with high accuracy approaches, and high-level QM/MM calculations are being routinely performed. LÄS MER

7. 10. A Catalytic and Mechanistic Investigation of Palladium-Phosphine Catalysed Aqueous Hydroxycarbonylation. Steric and Electronic Properties of the Ligands

   Författare :Adriana Ionescu; Kemiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Oorganisk kemi; Inorganic chemistry; Naturvetenskap; Natural science; Isomerisation of hydroxyalkenes; Mechanism; Regioselectivity; Steric and electronic properties; Hydroxycarbonylation of styrene; Water-soluble phosphines; Palladium; Aqueous catalysis;

   Sammanfattning : The steric and electronic properties of eight water-soluble phosphines (1-8) were investigated by different methods. Phosphines 1-6 were tested as ligands in palladium catalysed hydroxycarbonylation of styrene. LÄS MER