Synthesis, characterization, and catalytic activity of ionic liquids based on biosources

New room-temperature ionic liquids were synthesized from natural and easily available feedstocks (choline hydroxide and amino acids) following an economical and green route in which the only by-product was water. They were successfully applied as catalysts for the Knoevenagel test reaction between benzaldehyde and different active methylene compounds, at room temperature and under solvent-free conditions, to produce α,β-unsaturated carbonyl compounds, exhibiting good conversions and high selectivities. The catalytic role of cholinium and aminoacetate ions in the Knoevenagel condensation is discussed.