Asymmetric nitroaldol reaction catalyzed by a chromium(III)-salen system

Chiral chromium(III)-salen-type complexes derived from 1,2-diaminocyclohexane and 1,2-diphenylethylenediamine were found to catalyze the enantioselective Henry reaction. Various arylaldehydes, trans-cinnamaldehyde, and cyclohexanecarbaldehyde reacted with nitromethane in the presence of (i-Pr)(2)NEt and salen-CrCl (2 mol %) to give the corresponding adducts in 40-76% ee and in moderate to good yields. (c) 2007 Elsevier Ltd. All rights reserved.