Asymmetric reduction of imines with trichlorosilane catalyzed by valine-derived formamide immobilized onto magnetic nano-Fe3O4

Abstract

Magnetic nano-Fe₃O₄-supported organocatalysts were synthesized by anchoring valine-derived formamide onto the surface of Fe₃O₄ magnetic nanoparticles, which were applied in the asymmetric reduction of imines with trichlorosilane at room temperature in toluene. The high level of yield and enantioselectivity catalyzed by magnetic nano-Fe₃O₄-supported organocatalysts was obtained. In the immobilization process, Cu^I-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) “click chemistry” was used as the anchored bridge. The magnetic nanoparticles can simplify the recovery of the organocatalyst and its separation from the reaction system. By an external magnet, the catalyst can be recycled and reused five times without a remarkable activity decline.