Sökning: "secondary alcohols"
Visar resultat 11 - 15 av 56 avhandlingar innehållade orden secondary alcohols.
11. Synthetic Transformations via Metal- and Enzyme-Catalyzed Dynamic Kinetic Resolution
Sammanfattning : This thesis deals with the preparation of a new half-sandwich type ruthenium(II)- catalyst for racemization of optically active secondary alcohols and the development of a highly efficient method in combination with lipases such as Candida antarctica lipase B and Pseudomonas cepacia lipase for dynamic kinetic resolution of various functionalized alcohols under mild reaction conditions.It was shown that the RuCl(CO)2(η5-C5Ph5) complex can racemize optically active aliphatic and aromatic secondary alcohols at room temperature in rather short times. LÄS MER
12. Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation
Sammanfattning : This thesis covers the development of two new methods for the asymmetric reduction of ketones and ketone intermediates. The protocols developed are based on the use of a ruthenium pseudo-dipeptide catalyst that previously has been shown to be efficient and selective in the asymmetric reduction of carbonyl compounds. LÄS MER
13. Hypervalent Iodine Reagents in Metal-Free Arylations and Vinylations : Investigation of Suitable Coupling Partners and Synthesis of New Reagents
Sammanfattning : This thesis concerns the development of metal-free reactions to obtain carbon-heteroatom and carbon-carbon bonds. This is achieved by transferring carbon ligands from hypervalent iodine reagents to suitable nucleophiles. LÄS MER
14. Studies of Biomimtic Oxidations and Racemizations
Sammanfattning : This thesis deals with studies of ruthenium-catalyzed hydrogen transfer reactions for oxidations and racemization.Through optimisation of the substrate-selective redox catalyst, the electron and proton transfer mediator (a benzoquinone derivative), and the oxygen-activating metal macrocycle a highly efficient biomimetic oxidation of secondary alcohols was obtained. LÄS MER
15. Iridium Catalysed Asymmetric Hydrogenation of Olefins and Dynamic Kinetic Resolution in the Asymmetric Hydrogenation of Allylic Alcohols
Sammanfattning : The work described in this thesis is focused on exploring the efficacy of iridium-catalysed asymmetric hydrogenation of precursors to chiral alcohols and chiral cyclohexanes. A range of allylic alcohols including γ,γ-dialkyl allylic alcohols and (Z)-allylic alcohols were prepared and evaluated in the asymmetric hydrogenation using iridium catalysts resulting in chiral alcohols in high yields and excellent enantioselectivity. LÄS MER
