Chiral N-arylated diamine – Copper complexes catalyzed asymmetric Henry reaction

Abstract

Asymmetric Henry reaction between benzaldehyde derivatives and nitomethane leading to 2-nitro-1-aryl-ethanol has been developed. It was found that N,N’-diarylated diamine ligands and N-aryl diamine induce enantioselectivity when(or when they are) combined to copper (II). The presence of triethylamine is crucial in case of N,N’-binaphthalene diamine at only low temperature (−20°C), however in case of N-naphthalene diamine ligand there is no need of adding an external base. Good enantioselectivities (up to 83%) with good isolated yield were obtained using a catalytic loading of 10% mol at room temperature.