Chiral protic imidazolium salts with a (-)-menthol fragment in the cation: synthesis, properties and use in the Diels-Alder reaction.

ABSTRACT: New chiral protic imidazolium salts containing a (1R,2S,5R)-(-)-menthol substituent in the cation and four different anions (chloride, hexafluorophosphate, trifluoromethanesulfonate and bis(trifluoromethylsulfonyl)imide) were efficiently prepared and extensively characterized. Detailed NMR analysis was performed, and a comparison of the chemical shifts of the protons and carbons of the imidazolium cation as a function of the combined anion was discussed. The specific rotation, solubility in commonly used solvents, thermal properties including phase transition temperatures, and thermal stability were also determined. Three of the synthesized tertiary salts (Cl, PF₆ or OTf anion) were crystalline solids; 1-H-3-[(1R,2S,5R)-(-)-mentho

SUBMITTER: Janus E 

PROVIDER: S-EPMC9115648 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature