In recent years, the synthesis and applications of magnetic nanoparticles (MNPs) have attracted increasing interest in catalysis research [1]. Among the various magnetic nanoparticles under investigation, Fe3O4 nanoparticles are arguably the most extensively studied as the core magnetic support for catalysts because of their simple synthesis, low cost, and relatively large magnetic susceptibility Fe3O4 [2]. Magnetic nanocatalysts can easily be separated and recycled from the products by an external magnet. Selective oxidation of sulfides to sulfoxides is a very important reaction in organic synthesis, since they are useful synthetic intermediates for the construction of various chemically and biologically significant molecules, especially drugs and natural products [3]. Grafting of chlorosulfuric acid on the amino-functionalized Fe3O4 nanoparticles afforded N-propyl sulfamic acid-functionalized magnetic Fe3O4 nanoparticles (MNPs-PSA) as a novel organic–inorganic hybrid heterogeneous catalyst, which is characterized by XRD, FT-IR, SEM [4]. In this study, we employ (MNPs-PSA) Fe3O4 as a recyclable catalyst for the oxidation of sulfides to sulfoxides by hydrogen peroxide under mild and solvent-free conditions at room temperature. This method offers several advantages including high yield, short reaction time, simple work-up procedure, ease of separation, and recyclability of the magnetic catalyst, as well as the ability to tolerate a wide variety of substitutions in the reagents
