A mild and efficient procedure for asymmetric Michael additions of cyclohexanone to chalcones catalyzed by an amino acid ionic liquid

A mild and efficient procedure for Michael additions of cyclohexanone to chalcones has been developed. In the presence of amino acid ionic liquid [EMlm][Pro] (200 mol %), cyclohexanone reacted with various chalcones to afford Michael adducts in high yields (85-98%) and moderate to good enantioselectivities (16-94% ee), accompanied by an unexpected solvent-dependent inversion of the enantioselectivity. (C) 2008 Elsevier Ltd. All rights reserved.