A green methodology for C–S cross-coupling reaction over Cu^II attached to magnetic natural talc (γ-Fe₂O₃/talc/Cu^II NPs) as a heterogeneous and ligand-free catalyst

Abstract

Herein a prominent, efficient, facile and environmentally benign catalytic activity of γ-Fe₂O₃/talc/Cu^II NPs (as a superparamagnetic composite with average diameter of about 20-30 nm) has been shown in C–S cross-coupling reactions. A wide variety of aryl iodides, aryl bromides and aryl chlorides with electron-donating or electron-withdrawing substituents reacted with S₈ or thiourea forming the corresponding substituted diphenyl sulfides under eco-friendly and mild process conditions. The results demonstrated remarkable catalytic activity of the nanostructured catalyst such as chemoselectivity and functional group tolerance. γ-Fe₂O₃/talc/Cu^II NPs as a magnetic catalyst was stable under reaction conditions and can be recycled at least five times with minimal loss of catalytic activity. Moreover, the use of commercially available and chemically stable sulfur transfer agent, eco-friendly and low-cost solvent and base as well as operational simplicity and easier work-up procedure make this method a promising candidate for potential applications in some organic reactions.

GRAPHICAL ABSTRACT

Keywords:

• Magnetic catalyst
• copper nanoparticles
• γ-Fe₂O₃/talc/Cu^II NPs
• banana extract
• C–S cross-coupling reaction
• heterogeneous catalyst

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors gratefully acknowledge the partial support of this study by Ferdowsi University of Mashhad Research Council (Grant No. p/3/56444).