Versatile supramolecular copper(II) complexes for Henry and Aza-Henry reactions

Chiral supramol. metal-org. frameworks assembled from copper complexes catalyze Henry and aza-Henry reactions of arom. and aliph. aldehydes and N-protected arom. imines in high yield and good to excellent enantioselectivity.  Thus, a method for the synthesis of the title compds. [i.e., copper-chiral cyclohexanediamine complexes] is reported here.  A Henry reaction of 4-nitrobenzaldehyde with nitromethane gave (alphaS)-4-nitro-alpha-(nitromethyl)benzenemethanol.  Reactions can be performed in the absence of base in ethanol or water.  An aza-Henry reaction of N-[(4-nitrophenyl)methylene]carbamic acid 1,1-dimethylethyl ester with nitromethane gave N-[(1S)-1-(4-nitrophenyl)-2-nitroethyl]carbamic acid 1,1-dimethylethyl ester.