Zur Aromatenfunktionalisierung in Gegenwart ionischer Flüssigkeiten
type: CreativeWork
description: The goal of this dissertation was to identify ionic liquids with a catalytic effect on the test reactions (aromatic Halex reaction and Friedel-Crafts-Acylation). Beside that, ionic liquids have been synthesized in pure form and characterised by NMR, cyclovoltammetrie, UV-vis-spectroscopy and viscosimetry.The substrates for the Halex-reactions were 2,6-Dichlorobenzonitrile, 4-Chlorobenzonitrile, 2-Chloropyridine and 1,3,5-Trichlorobenzonitrile, the fluorinating agents were KF and CsF. Ionic liquids with cations of the dialkylimidazolium-type proofed to be efficient catalysts for the investigated reactions, while the ionic liquids with pyridinium- and ammonium cations showed rather negative effects for the reaction. The choice of the anion is of importance as well. For each substrate, a different combination of cation and anion showed catalytic effects, what shows that results from one aromatic starting material cannot be transferred to another substrate.For the acylation reaction, it could be shown that ionic liquids with the bis(trifluoromethylsulfonyl)amide-anion can dissolve large amounts of AlCl3. Depending on the ionic liquid used, the amount of lewis-acid and the temperature, twophasic liquid systems could be obtained that showed to be efficient catalysts for the investigated reaction. The ionic liquid could be recovered after the reaction.FeCl3 did not show catalytic effects in similar systems.
abstract: The goal of this dissertation was to identify ionic liquids with a catalytic effect on the test reactions (aromatic Halex reaction and Friedel-Crafts-Acylation). Beside that, ionic liquids have been synthesized in pure form and characterised by NMR, cyclovoltammetrie, UV-vis-spectroscopy and viscosimetry.The substrates for the Halex-reactions were 2,6-Dichlorobenzonitrile, 4-Chlorobenzonitrile, 2-Chloropyridine and 1,3,5-Trichlorobenzonitrile, the fluorinating agents were KF and CsF. Ionic liquids with cations of the dialkylimidazolium-type proofed to be efficient catalysts for the investigated reactions, while the ionic liquids with pyridinium- and ammonium cations showed rather negative effects for the reaction. The choice of the anion is of importance as well. For each substrate, a different combination of cation and anion showed catalytic effects, what shows that results from one aromatic starting material cannot be transferred to another substrate.For the acylation reaction, it could be shown that ionic liquids with the bis(trifluoromethylsulfonyl)amide-anion can dissolve large amounts of AlCl3. Depending on the ionic liquid used, the amount of lewis-acid and the temperature, twophasic liquid systems could be obtained that showed to be efficient catalysts for the investigated reaction. The ionic liquid could be recovered after the reaction.FeCl3 did not show catalytic effects in similar systems.
author: Metlen, Andreas
language: ger
keywords: info:eu-repo/classification/ddc/660, Technische Chemie, Salzschmelze, Fluorierung, Acylierung, Friedel-Crafts-Reaktion, Phasentransfer-Katalyse, Katalyse, Chemische Reaktion, Chemische Synthese
date published: 2006
date modified: 2026-07-30T19:43:02Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University