• Media type: E-Book; Thesis
  • Title: Synthesis of enantiomerically pure helical aromatics such as NHC ligands and their use in asymmetric catalysis
  • Other titles: Übersetzung des Haupttitels: Die Synthese von enantiomerenreinen helikalen Aromaten wie NHC Liganden und deren Anwendung in asymmetrischer Katalyse
  • Contributor: Karras, Manfred [Author]; Schmidt, Bernd [Degree supervisor]; Starý, Ivo [Degree supervisor]; Veselý, Jan [Degree supervisor]
  • Corporation: Universität Potsdam
  • Published: Potsdam, 2018
  • Extent: 1 Online-Ressource (121 Seiten, 3104 KB); Illustrationen, Diagramme
  • Language: English
  • Identifier:
  • Keywords: Asymmetrische Synthese > Katalyse > Heterocyclische Carbene
  • Origination:
  • University thesis: Dissertation, Universität Potsdam, 2018
  • Footnote:
  • Description: Various ways of preparing enantiomerically pure 2-amino[6]helicene derivatives were explored. Ni(0) mediated cyclotrimerization of enantiopure triynes provided (M)- and (P)-7,8-bis(p-tolyl)hexahelicene-2-amine in >99% ee as well as its benzoderivative in >99% ee. The stereocontrol was found to be inefficient for a 2- aminobenzo[6]helicene congener with an embedded five-membered ring. Helically chiral imidazolium salts bearing one or two helicene moieties have been synthesized and applied in enantioselective [2+2+2] cyclotrimerization catalyzed by an in situ formed Ni(0)-NHC complex. The synthesis of the first helically chiral Pd- and Ru-NHC complexes and their application in enantioselective catalysis was demonstrated. The latter shows promising results in enantioselective olefin metathesis reactions. A mechanistic proposal for asymmetric ring closing metathesis is provided.
  • Access State: Open Access