Novel Class of Reversible Chiral Ionic Liquids Derived from Natural Amino Acids: Synthesis and Characterization

A novel class of reversible chiral ammonium-based ionic liquids has been designed and synthesized. These chiral ammonium carbamate salts were quickly obtained by adding 1 atmosphere of CO2 gas to chiral silylated amines, easily prepared at gram scale and in some steps from natural amino acids as bio-renewable substrates. Some physical properties of these reversible chiral ionic liquids such as reversibility temperature, thermal degradation, miscibility, and stability have been determined. The spectroscopic characteristics of the silylated amine and ionic liquid states have also been compared. The properties of reversibility, chirality, and ease of preparation should make these silylamine-ionic liquid phases as promising solvents and/or catalysts for several applications, especially in asymmetric catalysis fields.