Oxidation of C–H bond of benzylic position in aromatic substrates by dehydroacetic acid based on an Iron (III) complex covalently anchored on Fe3O4 nanoparticles

Abstract

In this study, the authors synthesize a novel mononuclear catalyst consisting of an iron (III) complex based on a dehydroacetic acid (DHA) ligand that is covalently anchored to silica-coated magnetic nanoparticles, and characterize it by using XPS, XRD, FT-IR, TGA, VSM, SEM, TEM, EDX, and ICP analyses. This heterogeneously homogenized catalyst was used for the effective and selective catalytic oxidation of a diverse range of C–H bonds of the benzylic position of aromatic substrates in water at room temperature. To the best of our knowledge, this is the first report of the DHA anchored on a nanomagnet. The DHA ligand tuned the Lewis acidity of the center of the metal, and this led to a greater dispersion of the catalyst in the aqueous solution. The magnetic catalyst was easily recovered by using a permanent magnet and reused for at least six cycles without a significant reduction in the conversion. The leaching test of the catalyst was also investigated during this process, and the results illustrated that the oxidation of the C–H bond occurred via a heterogeneous pathway.