Direct asymmetric aldol reactions catalyzed by nanocrystalline copper(II) oxide

The direct asymmetric aldol reactions of aromatic and heteroaromatic aldehydes with acetone to afford chiral P-hydroxy carbonyl compounds in good yields and good to moderate enantioselectivities are realized using nanocrystalline copper(II) oxide in the presence of (1S,2S)-(-)-1,2-diphenylethylenediamine at -30 degrees C. The catalyst can be reused for four cycles with consistent activity and enantioselectivity. (c) 2008 Elsevier Ltd. All rights reserved.