Sökning: "Hydrogenations"
Visar resultat 11 - 15 av 21 avhandlingar innehållade ordet Hydrogenations.
11. Controlling the Reactivity and Selectivity in Iridium- and Rhodium-Catalyzed Asymmetric Hydrogenation
Sammanfattning : The work presented in this thesis is mainly focused on the development of iridium- or rhodium-catalyzed asymmetric hydrogenation featuring a number of practical concepts including cascade reaction, kinetic resolution, desymmetrization, and dearomatization. The protocols rely on gaining control of the reactivity among different olefins or olefin precursor as well as maintaining chemo- and stereo-selectivity in the hydrogenation. LÄS MER
12. Enantio- and Regioselective Iridium-Catalyzed Hydrogenation of Olefins : From Development to Total Synthesis
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
13. New Tools for Green Catalysis : Studies on a Biomimetic Hybrid Catalyst and a Novel Nanopalladium Catalyst
Sammanfattning : The first part of this thesis describes an improved synthetic route to hybrid (hydroquinone-Schiff base)cobalt catalysts. Preparation of the 5-(2,5-hydroxyphenyl)salicylaldehyde building block was improved by altering the protective groups of the hydroquinone (HQ) starting material. LÄS MER
14. Reactivity and Selectivity Studies in Iridium-Catalyzed Asymmetric Hydrogenation
Sammanfattning : Transition-metal catalyzed stereoselective hydrogenation constitutes an indispensable method for the preparation of chiral molecules. The work in this thesis describes the development of efficient catalytic asymmetric hydrogenations with a focus on the elucidation of reactivity patterns and chemoselectivity in hydrogenations. LÄS MER
15. Catalytic Asymmetric Ketone and Alkene Reductions Using Transition Metal Complexes
Sammanfattning : This thesis contains seven papers dealing with iridium and ruthenium based catalytic asymmetric reductions, either of ketones into chiral alcohols, or olefins into chiral alkanes. The first part of the thesis describes how we have designed and evaluated new bicyclic ligands containing either N,S or N,N chelating atoms. LÄS MER