Helicity: A Non-Conventional Stereogenic Element for Designing Inherently Chiral Ionic Liquids for Electrochemical Enantiodifferentiation

• Published in: Molecules
• Main Authors: Francesca Fontana, Greta Carminati, Benedetta Bertolotti, Patrizia Romana Mussini, Serena Arnaboldi, Sara Grecchi, Roberto Cirilli, Laura Micheli, Simona Rizzo
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Subjects: azahelicenes; ionic liquids; enantiodifferentiation; chiral additives; inherent chirality; chiral voltammetry
• Online Access: https://www.mdpi.com/1420-3049/26/2/311

Configurationally stable 5-aza[6]helicene (<b>1</b>) was envisaged as a promising scaffold for non-conventional ionic liquids (IL)s. It was prepared, purified, and separated into enantiomers by preparative HPLC on a chiral stationary phase. Enantiomerically pure quaternary salts of <b>1</b> with appropriate counterions were prepared and fully characterized. <i>N</i>-octyl-5-aza[6]helicenium bis triflimidate (<b>2</b>) was tested in very small quantities as a selector in achiral IL media to perform preliminary electrochemical enantiodifferentiation experiments on the antipodes of two different chiral probes. The new organic salt exhibited outstanding enantioselection performance with respect to these probes, thus opening the way to applications in the enantioselective electroanalysis of relevant bioactive molecules.