Sökning: "Regioselectivity"

Visar resultat 11 - 15 av 54 avhandlingar innehållade ordet Regioselectivity.

1. 11. Enantio- and Regioselective Iridium-Catalyzed Hydrogenation of Olefins : From Development to Total Synthesis

   Författare :Cristiana Margarita; Pher Andersson; Xavier Verdaguer; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric hydrogenation; Iridium; Regioselectivity; Kinetic resolution; Total synthesis; organisk kemi; Organic Chemistry;

   Sammanfattning : The work presented in this thesis concerns the iridium-catalyzed asymmetric hydrogenation of cyclic olefins and allylic alcohols for the preparation of useful chiral intermediates with various substitution patterns. The strategy provides stereocontrol for both non-functionalized as well as functionalized substrates and aims to be implemented in the stereoselective preparation of chiral building blocks having more than one stereocenter. LÄS MER

3. 12. Control of Aryne Capture Regioselectivity via Fluoroboronate-induced Distortion

   Författare :Matic Hribersek; Lukasz Pilarski; Carl Johan Wallentin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Arynes are valued as extremely versatile electrophilic intermediates. Control over the regioselectivity with which arynes react is typically achieved using comparatively simple and/or chemically inutile substituents close to the reactive triple bond. LÄS MER

4. 13. Palladium-Catalysed Carbon–Carbon Coupling Reactions : Focusing on Microwave Heating, Low Catalyst Concentrations, Aqueous Conditions, Regioselectivity and Medicinal Chemistry Applications

   Författare :Riina K Arvela; Mats Larhed; Anders Hallberg; Michael G Organ; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Suzuki coupling; Heck reaction; palladium; microwave heating; water; vinyl ethregioselective; HIV-1 integrase inhibitor; Pharmaceutical chemistry; Farmaceutisk kemi; farmaceutisk biokemi; Pharmaceutical Biochemistry;

   Sammanfattning : It is widely accepted that palladium is one of the most useful catalysts in organic chemistry, and many palladium(0)-catalysed carbon–carbon bond-forming reactions have been developed over the years. In addition, the ever-growing need for more environmentally benign processes in the chemical industry has driven scientists to look for greener options while developing new methodologies for organic synthesis. LÄS MER

5. 14. Molecular modelling - understanding and prediction of enzyme selectivity

   Författare :Linda Fransson; Karl Hult; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular modelling; regioselectivity; enantioselectivity; molecular dynamics; serine hydrolase; stereospecificity; Biochemistry; Biokemi;

   Sammanfattning : Molecular modelling strategies for evaluation of enzyme selectivity wereinvestigated with a focus on principles of how molecular interactionscould be evaluated to provide information about selectivity. Althoughmolecular modelling provides tools for evaluation of geometrical andenergy features of molecular systems, no general strategies for evaluationof enzyme selectivity exist. LÄS MER

7. 15. Exploring Selectivity and Hysteresis : Kinetic Studies on a Potato Epoxide Hydrolase

   Författare :Diana Lindberg; Mikael Widersten; Gunnar Johansson; Richard N. Armstrong; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Epoxide hydrolase; regioselectivity; selectivity; hysteresis; conformational changes; cooperativity; deep eutectic solvents; methylstyrene oxide; Biochemistry; Biokemi; Biokemi; Biochemistry;

   Sammanfattning : The kinetic mechanism of an α/β hydrolase fold epoxide hydrolase from potato, StEH1, has been studied with the aims of explaining the underlying causes for enantio- and regioselectivity, both being important for product purity. Further effort has been laid upon understanding the causes of a hysteretic behavior discovered in the measurements leading to Paper I. LÄS MER