Synthesis and characterization of chiral ionic liquids based on quinine, l-proline and l-valine for enantiomeric recognition

Naturally based ionic liquids with indole-3-acetate anions and cations derived from cinchona alkaloids

“…It should be noted that the obtained results are in line with the toxicity data provided for other quinine-based quaternary salts that did not contain long alkyl substituents. 34 However, due to the enhanced amphiphilicity, compound 4 was assessed as slightly toxic (10–100 mg dm −3 ) towards B. cereus and C. albicans , and compounds 5 and 6 expressed slight toxicity towards P. putida and moderate toxicity (1–10 mg dm −3 ) towards B. cereus . IL 6 was also moderately toxic towards C .…”

Chiral Ionic Liquids: Structural Diversity, Properties and Applications in Selected Separation Techniques

“…Increasing the diversity of ionic liquid structures resulted in the adoption of new rules for labelling them, with reference to the special (dedicated) functional group that characterizes them, to the original features of a given salt-or regarding their use, e.g., as sweet [45], energetic [46], chiral [47], fluorescent [48], polymeric [49], magnetic [50] and many others. On the other hand, the possible methods of the structural combination of ionic liquids focusing on expanding their structure with The most common cationic parts include imidazolium (im, e.g., C 1 C 2 im, emim, EMIM: 1-ethyl-3-methylimidazolium), ammonium (N x x x x , e.g., N 1 8 8 8 : methyl(trioctyl)ammonium), pyridinium (py, e.g., C 6 py: 1-hexylpyridinium), phosphonium (P x x x , e.g., P 4 4 4 12 : tributyl(dodecyl)phosphonium), sulfonium (S x x x ), pyrrolidinium (pyrr), piperidinium (pip), morpholinium (morph), etc.…”

“…Increasing the diversity of ionic liquid structures resulted in the adoption of new rules for labelling them, with reference to the special (dedicated) functional group that characterizes them, to the original features of a given salt—or regarding their use, e.g., as sweet [ 45 ], energetic [ 46 ], chiral [ 47 ], fluorescent [ 48 ], polymeric [ 49 ], magnetic [ 50 ] and many others. On the other hand, the possible methods of the structural combination of ionic liquids focusing on expanding their structure with specific components resulted in the introduction of another term, namely task-specific ionic liquids (TSILs).…”

Quinine based ionic liquids: A tonic for base instability

“…This could potentially allow for use in fluorescence-based applications. As well as acting as basic catalysts the quinine ionic liquids have a wide range of potential uses based on their fluorescence, their antimicrobial properties [47] and their potential for enantiomeric separations [21] or enantiomeric reactions [48].…”

“…This stability, combined with the developments in synthesising ionic liquids from renewables [16,17,18,19] makes quinine an ideal starting material for base stable ionic liquids. Quinine has been tethered to an imidazolium cation [20], and recently high melting quinine ionic liquids were synthesised and tested for enantiomeric recognition [21]. To the best of our knowledge quinine ionic liquids melting below 100 °C are unknown.…”