Synthesis of chiral imidazolinone-based ionic liquids

The chiral ionic liquids have broad applications as inducers for asymmetric reactions. Chiral imidazolidinones are important sorts of aminocatalysts, which have been attracted much attention in research of enantioselective organocatalysis field. From the view of greening and economization, 7 new chiral imidazolidinone ionic liquids with different anions are synthesized from L-tyrosine, which is a kind of natural chiral materials, through esterfication, amination, cyclization, [3+2] cycloaddition, etc. The structures and properities were characterized by ¹H NMR, ¹³C NMR, ESI-MS, IR, [a]_D²⁰, DSC and TGA methods.