Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"asymmetric hydrogenation"”.
-
Asymmetric hydrogenation catalysed by platinum and iridium
The enantioselective hydrogenation of α-ketoesters over supported platinum metal catalysts which have been modified by chiral molecules has been studied. The aim of this thesis was (a) to gain a greater understanding of the kinetics of asymmetric hydrogenation of methyl pyruvate (MeCOCOOMe) to …
-
Asymmetric hydrogenation of unfunctionalized trisubstituted and tetrasubstituted olefins
A highly reactive chiral catalyst for the asymmetric hydrogenation of aryl trisubstituted olefins was generated by combining the complex (EBTHI)MMe2 (EBTHI = ethylenebistetrahydroindenyl, M = Ti, Zr) with [PhMe2NH]+[(BC6F5)4]- under a hydrogen atmosphere. A number of unfunctionalized trisubstituted …
-
Diastereoselective Synthesis of Planar Chiral N-Substituted Ferrocenes Derived from Epimeric Imidazolones and their Application to Asymmetric Hydrogenation of Quinolines
… iridium complex is found to be effective in the asymmetric hydrogenation of 2-substituted quinolines with enantioselectivities up to 80% at pressures as low as 5 atm.
-
Synthese neuer QUINAPHOS-Derivate und deren Einsatz in der asymmetrischen Katalyse
… respectively, the suitable diastereomers for the asymmetric hydrogenation of functionalised olefins could be separated from the crude products in 55-62% yield. These isolated diastereomers were characterised by means of NMR and X-ray analysis. With the rhodium complexes of the synthesized …
-
Novel Metal Amido-Complexes – Syntheses, Reactivity and Asymmetric Catalysis
… high selectivities and good activities in the asymmetric hydrogenation of ketones, the development of amido-complex catalysts for the enantioselective hydrogenation of imines represents a major focus of this work. A library of novel amines 4 was synthesized by deprotonation of the hydroxyl …
-
Synthese von planar chiralen Imidazoliumsalzen, ihren Metall-Carbenkomplexen und deren Verwendung in der asymmetrischen Katalyse
… chirality plays a significant role in many asymmetric catalytic processes. The concept of planar chirality is often implemented by the application of metallocenes such as ferrocene derivatives. Some industrially important syntheses are amongst those processes, including the preparation of …
-
Water Soluble Phosphines, Their Transitional Metal Complexes, and Catalysts
… phosphine analog. Finally, homogeneous asymmetric hydrogenation was carried out in the presence of a chiral surfactant in an attempt to affect asymmetric induction. The catalytic results showed that at a surfactant/Rh ratio of 25, the asymmetric hydrogenation of AACA-Me …
-
DFT Studies of the Organocatalytic Aldol Reaction and a Frustrated Lewis Pair
… Lewis pair based on a chiral backbone for the asymmetric hydrogenation of imines and enamines was designed and the ability of hydrogen splitting by this new FLP system was examined by computational modeling and calculating the hydrogen activation energy barrier.
-
Synthesis and application of pinene-pyridine derivatives in asymmetric catalysis
… derivatives, and their application in asymmetric catalysis. Both transition metal catalysed and organocatalytic transformations were investigated. Chiral pyridine-phosphines based on α-pinene were synthesised and applied as efficient P,N-ligands for the enantioselective …
-
Accelerating process development of complex chemical reactions
… Our case study was a homogeneous Rh-catalysed asymmetric hydrogenation to produce a chiral γ-lactam, with conversion and diastereoselectivity as objectives. We adapted a state-of-the-art multi-objective machine learning algorithm, based on Gaussian processes, to utilise the descriptors as …
-
Synthesis and application of chiral phosphorous triamide ligands
… The prepared ligand library was evaluated in the asymmetric hydrogenation as well as in two different asymmetric C-C bond forming reactions. All tested structurally very different PTAs show poor performance in the Rh catalysed hydrogenation of dimethyl itaconate. In contrast, better results could …
-
Chirale Phosphortriamide und Phosphin-Phosphoramidite als Liganden für die asymmetrische Katalyse
Asymmetric catalysis with transition metal complexes containing chiral ligands is an efficient tool for the synthesis of enantioenriched compounds, which can be used as active pharmaceutical ingredients, agrochemicals, flavors or fragrances. The development of novel chiral ligands plays a major …
-
Accessing Challenging Fluorinated Motifs Using Photoredox Catalysis And Enabling Technologies
… small molecules has resulted in the pursuit of asymmetric hydrogenation of α–trifluoromethylalkenes to access chiral trifluoromethyl alkane products. This work has been enabled by the co-development of a new analytical technique, molecular rotational resonance spectroscopy, which enables the …