Search for dissertations about: "diols"

Showing result 1 - 5 of 36 swedish dissertations containing the word diols.

2. 1. Synthesis and asymmetric transformations of diols by enzyme- and ruthenium catalysis

   Author : Karin Leijondahl; Jan-Erling Bäckvall; Kurt Faber; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamic kinetic asymmetric transformation; diols; enzymatic transformations; catalysis; ruthenium; transfer hydrogenation; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

   Abstract : The major part of this thesis describes the synthesis of aliphatic secondary diols and the development of lipase- and ruthenium-catalyzed asymmetric transformations of these diols. Several acyclic 1,4-diols and 1,5-diols were synthesized, and by combining a lipase-catalyzed asymmetric transformation with a ruthenium-catalyzed epimerization, enantiomerically- and diastereomerically enriched diacetates were obtained. READ MORE

4. 2. Ruthenium-catalyzed redox reactions and lipase-catalyzed asymmetric transformations of alcohols

   Author : Michaela Edin; Jan-E. Bäckvall; Manfred T. Reetz; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ruthenium; lipase; catalysis; alcohols; diols; Chemistry; Kemi;

   Abstract : The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed redox reactions that lead to racemization or epimerization and lipase-catalyzed asymmetric trans-formations in one-pot.A mechanistic study of the unexpected facile formation of meso-diacetate products found in enzyme-catalyzed acetylations of alkanediols with Candida antarctica lipase B (CALB) was first performed. READ MORE

5. 3. Oxidation of 1,2-Diols Using Alcohol Dehydrogenases : From Kinetic Characterization to Directed Evolution

   Author : Cecilia Blikstad; Mikael Widersten; Stefan Lutz; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; enzyme kinetics; alcohol dehydrogenase; directed evolution; enzyme engineering; diol; α-hydroxy aldehyde; Biokemi; Biochemistry;

   Abstract : The use of enzymes as catalysts for chemical transformations has emerged as a “greener” alternative to traditional organic synthesis. An issue to solve though, is that enzymes are designed by nature to catalyze reactions in a living cell and therefore, in many cases, do not meet the requirements of a suitable biocatalyst. READ MORE

6. 4. Enantioselective Synthesis of Sec-Alcohol Derivatives and Diols via Combined Ruthenium and Enzyme Catalysis

   Author : Linnéa Borén; Jan-Erling Bäckvall; Romas Kazlauskas; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; catalysis; kinetic resolution; ruthenium catalyst; Dynamic kinetic resolution; Dynamic Kinetic Asymmetric Transformation; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

   Abstract : The first part of this thesis describes the synthesis of enantiopure secondary alcohol derivatives. These syntheses are carried out via the combination of an enzyme as a resolution catalyst and a ruthenium catalyst as a racemization catalyst, in what is called dynamic kinetic resolution (DKR). READ MORE

7. 5. Synthesis and evaluation of bicyclic 1,3-diols (BODOLs) as ligands for asymmetric catalysis

   Author : Ian Sarvary; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; yeast reductions; supramolecular chemistry; diethylzinc; computation; structure of Ti-diolates; diol ligands; titanates; asymmetric catalysis; asymmetric synthesis;

   Abstract : Several ligands based upon 2-substituted bicyclic[2.2.2]octane-2,6-diols (BODOLs) were synthesized and evaluated in two catalytic reactions: I) the Ti(IV)-mediated catecholborane asymmetric reduction of prochiral ketones and II) as catalysts in the asymmetric addition of diethylzinc to aromatic aldehydes. READ MORE