Cu(II)–Schiff base complex‐functionalized magnetic Fe₃O₄ nanoparticles: a heterogeneous catalyst for various oxidation reactions

Abstract

Cu(II)–Schiff base complex‐functionalized magnetic Fe3O4 nanoparticles were prepared and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy techniques. This compound acts as a highly active and selective catalyst for the oxidation of sulfides and thiols. These reactions can be carried out in ethanol or solvent‐free conditions in the presence of hydrogen peroxide with complete selectivity and very high conversion under mild reaction conditions. The designed catalytic system prevents effectively the over‐oxidation of sulfides to sulfones. Separation and recycling can also be easily done using a simple magnetic separation process. Copyright © 2015 John Wiley & Sons, Ltd.

Cu(II) immobilized on Fe$_{3}$O$_{4}$@Agarose nanomagnetic catalyst functionalized with ethanolamine phosphate--salicylaldehyde Schiff base: a magnetically reusable nanocatalyst for preparation of 2-substituted imidazolines, oxazolines, and thiazolines

“…25 Nowadays, agarose (linear polysaccharide) is well known as an excellent coating for Fe 3 O 4 NPs due to high surface area and its good dispersion, 26,27 which prevent the aggregation of magnetic nanoparticles.…”

Schiff base complexes of Ni, Co, Cr, Cd and Zn supported on magnetic nanoparticles: As efficient and recyclable catalysts for the oxidation of sulfides and oxidative coupling of thiols

“…On the other hand, salen complexes of transition metals are stable compounds that have been used as catalysts for various organic reactions. Among transition metals, Ni, Co, Cr, Cd and Zn Schiff-base complexes are amongst the most versatile catalysts known for organic transformations [13,14].…”

“…The selective oxidation of organosulfur compounds is of great importance in synthetic, biological, and industry [14]. Disulfides are important in both biological (including DNA cleavage, stabilisation of peptides in proteins,) and industrial processes (e.g.…”

“…Disulfides are important in both biological (including DNA cleavage, stabilisation of peptides in proteins,) and industrial processes (e.g. applications in vulcanization of rubbers and elastomers) [14]. Furthermore, disulfides are important reagents in organic synthesis, and can be used as a protecting group for thiol [15], sulfonylation of enolates and other anions [16], synthesis of organo-sulfur compounds via C-S bond formation [17] and they are also important starting materials in the preparation of sulfenyl and sulfinyl reagents [18].…”

Schiff base complex of Cu immobilized on MCM-41 as reusable catalyst for efficient oxidative coupling of thiols and oxidation of sulfides using hydrogen peroxide

“…For example, many methods have been reported in the presence of various catalysts and using different oxidant (e.g. metal oxidants, organic oxidant, peroxides, halogens, and air) [33] [35,36], melamine hydrogen peroxide [37] and urea hydrogen peroxide [38] have been used as oxidant for oxidation of sulfides and oxidative coupling of thioles previously. Concerning the green oxidant, H 2 O 2 (with only H 2 O as a byproduct) in particular have received attention because of their environmental implications, readily available, high atom efficiency and lower costs than when used other oxidizing agents [39].…”