Sökning: "kinetic isotope effect"

Visar resultat 11 - 15 av 18 avhandlingar innehållade orden kinetic isotope effect.

1. 11. Palladium(II)-Catalyzed Oxidative Carbocyclization/Functionalization of Allenynes

   Författare :Teresa Bartholomeyzik; Jan-Erling Bäckvall; Antonio Bermejo-Gómez; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Palladium catalysis has emerged as an outstanding tool in synthetic organic chemistry for the mild and selective formation of carbon-carbon and carbon-heteroatom bonds. This thesis has been directed towards the extension of palladium(II)-catalyzed carbocyclization chemistry under oxidative conditions. LÄS MER

3. 12. Asymmetric Transfer Hydrogenation of Aromatic Ketones : Catalyst Development and Mechanistic Studies

   Författare :Sofia Nordin; Torbjörn Frejd; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; transfer hydrogenation; aza-norbornyl structure; amino acid derivatives; amino alcohols; ruthenium; concerted mechanism; asymmetric catalysis.; Organisk kemi; Organic chemistry; Organisk kemi; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis describes the development and evaluation of new chiral Ru(arene)(amino alcohol) catalysts for the transfer hydrogenation of aromatic ketones using isopropanol as the hydrogen source. Two mechanistic studies of the Ru(arene)(amino alcohol) catalyzed transfer hydrogenation of acetophenone were also conducted. The Ru(arene)[(1S,3R,4R)-3. LÄS MER

4. 13. Turbulent transport in tokamak plasmas: linear-, quasi- and non-linear simulations

   Författare :Emil Fransson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fusion – Plasma physics – Turbulent transport – Gyrofluid – Gyrokinetic;

   Sammanfattning : An attractive energy source is nuclear fusion with its abundance of fuel, intrinsic safety and limited environmental impact. Although the concept of fusion energy was established in the 1920s, to develop fusion as an energy source has been challenging. LÄS MER

5. 14. Monitoring climate and plant physiology using deuterium isotopomers of carbohydrates

   Författare :Angela Augusti; Jürgen Schleucher; Vaughan Hurry; Howard Griffiths; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate reconstruction; deuterium; elevated CO2; isotopomer; nuclear magnetic resonance; photorespiration; tree-ring cellulose.; Plant physiology; Växtfysiologi;

   Sammanfattning : Climate is changing and it is certain that this change is due to human activities. Atmospheric greenhouse gases have been rising in an unprecedented way during the last two centuries, although the land biosphere has dampened their increase by absorbing CO2 emitted by anthropogenic activities. LÄS MER

7. 15. Expanding the Amino Acid Alphabet by Design : Enhanced and Controlled Catalytic Activity in Folded Polypeptide Catalysts

   Författare :N. Johan V. Lindgren; Lars Baltzer; Harri Lönnberg; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Chemistry; Kemi; Organic Chemistry; organisk kemi;

   Sammanfattning : This thesis addresses structure and reactivity of polypeptide catalysts in reactions that mimic the hydrolysis of RNA and DNA. A designed helix-loop-helix motif was used as a scaffold where the amino acid residues were systematically varied. LÄS MER