<abstract xmlns="http://www.w3.org/1999/xhtml">Six new chiral pyrolidinium salts with chiral substituent at quaternary nitrogen atom were synthesized with high overall yields from (-)-menthol as cheap chiral precursor and were identified by NMR and HRMS spectroscopy. It was shown that anion type had the effect on chemical shift of protons adjacent to quaternary nitrogen atom and physical properties of these salts. Salts with NTf2 or NPf2 were in a liquid state at room temperature and characterized with the highest thermal stability among others. Furthermore, chiral ionic liquid with NTf2 anion was used as solvent in Diels-Alder reaction and gave higher yield and stereoselectivity than in ionic liquids with achiral cations. Synthesized chiral salts have the potential as chiral solvents in synthesis and auxiliaries in analytical methods to improve chiral recognition.</abstract>

Six new chiral pyrolidinium salts with chiral substituent at quaternary nitrogen atom were synthesized with high overall yields from (-)-menthol as cheap chiral precursor and were identified by NMR and HRMS spectroscopy. It was shown that anion type had the effect on chemical shift of protons adjacent to quaternary nitrogen atom and physical properties of these salts. Salts with NTf2 or NPf2 were in a liquid state at room temperature and characterized with the highest thermal stability among others. Furthermore, chiral ionic liquid with NTf2 anion was used as solvent in Diels-Alder reaction and gave higher yield and stereoselectivity than in ionic liquids with achiral cations. Synthesized chiral salts have the potential as chiral solvents in synthesis and auxiliaries in analytical methods to improve chiral recognition.

Chiral pyrrolidinium salts derived from menthol as precursor – synthesis and properties

Szczecin, Faculty of Chemical Technology and Engineering, Department of Organic Chemical Technology

Polish Journal of Chemical Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Six new chiral pyrolidinium salts with chiral substituent at quaternary nitrogen atom were synthesized with high overall yields from (-)-menthol as cheap...

Chiral pyrrolidinium salts derived from menthol as precursor – synthesis and properties

Published Online: Oct 10, 2017

Page range: 92 - 98

DOI: https://doi.org/10.1515/pjct-2017-0054

Keywords
pyrrolidinium chiral salts, chiral ionic liquids, menthol, Diels-Alder reaction

© 2017 Ewa Janus et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Chiral pyrrolidinium salts derived from menthol as precursor – synthesis and properties

Published Online: Oct 10, 2017

Page range: 92 - 98

DOI: https://doi.org/10.1515/pjct-2017-0054

Keywordspyrrolidinium chiral salts, chiral ionic liquids, menthol, Diels-Alder reaction

© 2017 Ewa Janus et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
pyrrolidinium chiral salts, chiral ionic liquids, menthol, Diels-Alder reaction