Impressive Catalytic Capacity to Synthesis of Benzamide Derivatives in the Presence of Cu(II)–EDTA Complex Supported on Magnetic Nanoparticles

The direct amidation of alcohols and amines using supported heterogeneous catalysts has been rarely studied [1]. In the area of magnetic catalysts, no attempt has been focused on the direct amidation from alcohols and amines in the presence of supported heterogeneous catalysts on the magnetic nanoparticles. In continuation of our interest in using magnetic nanoparticles [2] as a catalyst support in the oxidative amidation of aromatic aldehydes with amine hydrochloride salts [3], herein, we demonstrate the application ofFe3O4@EDTA–Cu(II) for the amide synthesis via alcohol dehydrogenation in One-Pot direct oxidative amidation. The Fe3O4 nanoparticles were functionalized by EDTA and the Cu–EDTA complex was stable under oxidation conditions with high efficiency in solvent. This atom-economical and cost effective transformation can be used as the most favorable replacement for the synthesis of amides. Superparamagnetic Fe3O4@EDTA–Cu(II) nanoparticles were readily prepared and identified as an effective catalyst for the tandem transformation of benzyl alcohols and amine hydrochloride salts into the corresponding amides with tert-butyl hydroperoxide (TBHP) as an oxidant. After completion ofthe reaction, the catalyst can be removed from the reaction vessel by assistance ofan external magnet and reused at least six times without significant loss of its activity.