Sökning: "asymmetric hydrogenation"
Visar resultat 16 - 20 av 59 avhandlingar innehållade orden asymmetric hydrogenation.
16. Development of New Chiral Bicyclic Ligands : Applications in Catalytic Asymmetric Transfer Hydrogenation, Epoxidations, and Epoxide Rearrangements
Sammanfattning : This thesis describes the synthesis and application of new chiral bicyclic ligands and their application in asymmetric catalysis. The studies involved: [i] The development of novel chiral bicyclic amino sulfur ligands and their use in transfer hydrogenation. LÄS MER
17. Asymmetric Hydrogenation of Functionalized Olefins Using N,P-Ligated Iridium Complexes
Sammanfattning : Transition-metal-catalyzed asymmetric hydrogenation is one of the most efficient, straightforward, and well-established methods for preparing enantiomerically enriched compounds. Over the past decades, significant progress has been made with iridium, rhodium and ruthenium complexes to asymmetric hydrogenate a selection of olefins, such as, α,β-unsaturated carboxylic acid derivatives, ketones, imines and phosphonates. LÄS MER
18. Convergent and Tandem Strategies in Iridium-Catalyzed Asymmetric Hydrogenation of Olefins
Sammanfattning : The work presented in this thesis describes the development of enantioselective methods and their corresponding mechanistic studies to expand the field of catalytic asymmetric hydrogenation. Efficient catalytic systems based on iridium complexes were designed and employed in convergent and tandem strategies to prepare important optically enriched organic compounds. LÄS MER
19. 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
20. Cluster-Based Catalysts for Asymmetric Synthesis
Sammanfattning : In this work, the synthesis and characterisation of new low-valence transition metal carbonyl clusters, and an investigation into their viability to act as catalysts/catalyst precursors in asymmetric synthesis, are described. Carbonyl clusters based on ruthenium and osmium have been tested as (pre)catalysts for asymmetric hydrogenation of alpha-unsaturated carboxylic acids, and cobalt carbonyl clusters have been used as (pre)catalysts in (asymmetric) Pauson-Khand synthesis. LÄS MER
