Heterogeneous chiral copper complexes of amino alcohol for asymmetric nitroaldol reaction.

Chiral amino alcohols supported on mesoporous silicas were synthesized and evaluated as a new class of chiral ligands in copper-catalyzed nitroaldol reaction under heterogeneous and mild reaction conditions. The activity and enantioselectivity of the present catalytic system is immensely influenced by the presence of achiral and chiral bases as an additive. The heterogenized chiral copper(II) complex of amino alcohol was found to be an effective recyclable catalyst for the nitroaldol reaction of different aldehydes such as aromatic, aliphatic, alicyclic, and α-β unsaturated aldehydes to produce nitroaldol products with remarkably high enantioselectivity (≥99%) and yields.