FULL PAPER Fe 3 O 4 @S‐ABENZ@VO: Magnetically separable nanocatalyst for the efficient, selective and mild oxidation of sulfides and oxidative coupling of thiols Somaieh Rezaei 1,2 | Arash Ghorbani‐Choghamarani 3 | Rashid Badri 2 | Ahmad Nikseresht 4 1 Department of Chemistry, Khuzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran 2 Department of Chemistry, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran 3 Department of Chemistry, Faculty of Science, Ilam University, PO Box 69315516, Ilam, Iran 4 Department of Chemistry, Payame Noor University, PO Box 19395‐4697, Tehran, Iran Correspondence Arash Ghorbani‐Choghamarani, Department of Chemistry, Faculty of Science, Ilam University, PO Box 69315516, Ilam, Iran. Email: arashghch58@yahoo.com; a. ghorbani@ilam.ac.ir Oxovanadium(IV) immobilized on Fe 3 O 4 @S‐ABEN is reported as a highly effi- cient nanocatalyst for the oxidation of sulfides and oxidative coupling of thiols (using H 2 O 2 as green oxidant), the products of which are obtained in high to excellent yields. The products can be separated by a simple extraction with organic solvent and the catalyst is highly efficient, especially in terms of selec- tivity of desired product. The catalytic system can be recycled and reused with- out significant loss of catalytic activity. KEYWORDS catalytic system, disulfide, magnetic nanoparticles, recyclablility, sulfoxide 1 | INTRODUCTION Organic catalytic reactions have emerged as powerful synthetic tools for the synthesis of highly functionalized compounds. Eco‐friendly and economic heterogeneous catalysts to activate organic functional group transforma- tions are useful and in high demand by academic laboratories and industries. [1–4] One strategy has focused on combining the advantages of different types of catalyst; for example, the high activity and selectivity of homoge- neous catalysts and the ease of separation and recycling of heterogeneous ones. Organic reactions using heteroge- neous catalysts are extremely important for the develop- ment of sustainable chemical processes. [5] In this regard, the development of immobilized catalysts that allow sim- ple work‐up procedures and easy separation of products from reaction mixtures is of great interest. [6] Functional- ized nanoparticles are very promising for applications in catalysis, biolabelling and bioseparation processes. Especially in liquid‐phase catalytic reactions, such small and magnetically separable particles may be useful as quasi‐homogeneous systems that combine the advantages of high dispersion, high reactivity and easy separation. [7] Catalysts supported on magnetic nanoparticles (MNPs), usually iron oxides, can be quickly recovered in the pres- ence of an external magnetic field and subsequently reused. The surface of MNPs can be functionalized and modified to make a wide variety of organic and organo- metallic catalysts. [8] Selective oxidation of sulfides to sulfoxides is a key reaction in synthetic organic chemistry. [9] Sulfoxides are an important class of compounds in organic chemistry with wide applications in chemical synthesis and in the preparation of biologically active compounds, and are even applied in the activation of enzymes. [10] Also, the oxi- dative coupling of thiols to the corresponding disulfides is an important reaction in chemical and biological pro- cesses. [11,12] In view of the importance of sulfoxides and Received: 20 March 2017 Revised: 21 May 2017 Accepted: 2 June 2017 DOI: 10.1002/aoc.3948 Appl Organometal Chem. 2017;e3948. https://doi.org/10.1002/aoc.3948 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/aoc 1 of 7