Chiral ionic liquids with a focus on their applications in asymmetric Michael additions and
related reactions were reviewed. The examples were classified on the basis of the mode of asymmetric induction
(e.g., external induction/non-covalent interaction or internal induction/covalent bond formation),
the roles in reactions (as a solvent or catalyst), and their structural features (e.g., imidazolium-based chiral
cations, other chiral oniums; proline derivatives). Most of the reactions with high chiral induction are Michael
addition of ketones or aldehydes to chalcones or nitrostyrenes where proline-derived chiral ionic liquids
catalyze the reaction through enamine/ iminium formation. Many reports demonstrate the recyclability
of ionic liquid-tagged pyrrolidines.
Keywords: Michael addition, imidazole ionic liquid, Chiral ionic liquid, asymmetric reaction, chiral solvent, catalysts.
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