Entwicklung anion-chiraler ionischer Flüssigkeiten und ihre Anwendung in der Katalyse
type: CreativeWork
description: The aim of this dissertation was the investigation of anion-chiral ionic liquids (ILs) in catalytic reactions in order to investigate a potential chirality transfer. Thus chirality has been incorporated into the anion of the molten salt. There are several examples of catalytic reactions known in literature to be heavily influenced by the choice of the anions covering a large scope of influence from conversion to even enantioselectivity. It was aimed to combine this effect with the structural variability of the ionic liquids as neoteric solvents. In the first part of this project the structural motive, i.e. complexes of aluminum and boron using chiral alcohols as ligands, could successfully be applied in the synthesis of anion-chiral salts. This motive showed a large variability concerning the choice of the ligand. Within this work it was possible to synthesize five borates that could be attributed as ionic liquids because of their low melting point of below 100°C. Room temperature liquids seemed to be accessible using asymmetric cations and ligands with low molecular weight. For sodium dimalatoborat as a representative for borates the structural stability of these salts has been discussed. This was based on the results of an X-ray single crystal structure analysis and NMR-experiments of this compound. A main focus has been laid upon the central chirality, which has been introduced through the application of a dissymmetric ligand. In addition to the aluminum and boron based compounds also the synthesis of a chiral sulfate-based IL using chiral alcohols has been examined. A room temperature IL could be yielded with (S)-lactic acid as ligand. In the second part of the dissertation the hitherto synthesized room temperature ILs have been applied as solvents in the organocatalytic aza-Baylis-Hillman reaction, a rhodium-catalyzed hydrogenation, as well as in the synthesis of alpha-aminophosphonates using lanthanum triflate as catalyst. In the latter reaction diethylphenyl-…
abstract: The aim of this dissertation was the investigation of anion-chiral ionic liquids (ILs) in catalytic reactions in order to investigate a potential chirality transfer. Thus chirality has been incorporated into the anion of the molten salt. There are several examples of catalytic reactions known in literature to be heavily influenced by the choice of the anions covering a large scope of influence from conversion to even enantioselectivity. It was aimed to combine this effect with the structural variability of the ionic liquids as neoteric solvents. In the first part of this project the structural motive, i.e. complexes of aluminum and boron using chiral alcohols as ligands, could successfully be applied in the synthesis of anion-chiral salts. This motive showed a large variability concerning the choice of the ligand. Within this work it was possible to synthesize five borates that could be attributed as ionic liquids because of their low melting point of below 100°C. Room temperature liquids seemed to be accessible using asymmetric cations and ligands with low molecular weight. For sodium dimalatoborat as a representative for borates the structural stability of these salts has been discussed. This was based on the results of an X-ray single crystal structure analysis and NMR-experiments of this compound. A main focus has been laid upon the central chirality, which has been introduced through the application of a dissymmetric ligand. In addition to the aluminum and boron based compounds also the synthesis of a chiral sulfate-based IL using chiral alcohols has been examined. A room temperature IL could be yielded with (S)-lactic acid as ligand. In the second part of the dissertation the hitherto synthesized room temperature ILs have been applied as solvents in the organocatalytic aza-Baylis-Hillman reaction, a rhodium-catalyzed hydrogenation, as well as in the synthesis of alpha-aminophosphonates using lanthanum triflate as catalyst. In the latter reaction diethylphenyl-…
author: Gausepohl, Rolf
language: ger
keywords: info:eu-repo/classification/ddc/540, Homogene Katalyse, Salzschmelze, Chiralität <Chemie>, Borate, Aluminate, Chemie, aza-Baylis-Hillman, Organokatalyse, chirales Lösungsmittel, Anioneneinfluss, chirality, ionic liquid, chiral reaction medium, organocatalysis, chiral solvent
date published: 2006
date modified: 2026-07-30T19:43:10Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University