Sökning: "asymmetric hydrogenation"
Visar resultat 6 - 10 av 59 avhandlingar innehållade orden asymmetric hydrogenation.
6. 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
7. Asymmetric transfer hydrogenation of ketones : Catalyst development and mechanistic investigation
Sammanfattning : The development of ligands derived from natural amino acids for asymmetric transfer hydrogenation (ATH) of prochiral ketones is described herein. In the first part, reductions performed in alcoholic media are examined, where it is found that amino acid-derived hydroxamic acids and thioamides, respectively, are simple and versatile ligands that in combination with [RhCp*Cl2]2 efficiently catalyze this particular transformation. LÄS MER
8. Hydrogenation, Transfer Hydrogenation and Hydrogen Transfer Reactions Catalyzed by Iridium Complexes
Sammanfattning : The work described in this thesis is focused on the development of new bidentate iridium complexes and their applications in the asymmetric reduction of olefins, ketones and imines. Three new types of iridium complexes were synthesized, which included pyridine derived chiral N,P-iridium complexes, achiral NHC complexes and chiral NHC-phosphine complexes. LÄS MER
9. 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
10. Self-adaptable catalysts : Importance of flexibility and applications in asymmetric catalysis
Sammanfattning : The topic of this thesis is the design and synthesis of biaryl-based self adaptableligands for asymmetric metal catalysis. The results discussed in papers I-III are covered, together with some unpublished results concerning substrate-adaptable catalysts. A general survey of self-adaptable catalysts is presented first. LÄS MER
