Chiral ionic liquids (CILs) tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)-prolinate were investigated as chiral additives in the Pd-catalyzed enantioselective hydrogenation of α,β-unsaturated ketones. These CILs were easily prepared in one step from the aminoacid and tetrabutylammonium hydroxide and characterized (NMR, IR, optical rotation, elemental analysis, DSC, viscosity, decomposition temperature). The research strategy was to assess the antimicrobial toxicity (>20 strains) and biodegradability (OECD 301D) of the CILs at the same time as undertaking the asymmetric catalysis study. The Pd-catalyzed enantioselective hydrogenation of the carbon–carbon double bond of α,β-unsaturated ketones under mild conditions (room temperature, 1 atm of H2) in different solvents with CILs present. The best results were obtained in i-PrOH after 18 hours of reaction with a i-PrOH/IL ratio of 5. While all three CILs have low antimicrobial toxicity to a wide range of bacteria and fungi, tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)-prolinate did not pass the Closed Bottle biodegradation test.
D-Xylose-based ionic liquids have been prepared from D-xylose following a five steps reaction sequence, the key step being a click cycloaddition. These ionic liquids (ILs) have been characterized through classical analytical methods (IR, NMR, mass spectroscopy, elemental analysis) and their stability constants, Tg and Tdec, were also determined. Considering their properties and their hydrophilicity, these compounds could be alternative solvents for chemical applications under mild conditions.