Uronium Hydrogen Sulfate/Urea-Hydrogen Peroxide as a Green and Metal-Free Catalytic System for the Efficient, Chemo-, and Homoselective Oxidation of Sulfides to Sulfoxides

Abstract

An efficient, chemoselective, and metal-free oxidation of sulfides is described using urea-hydrogen proxide (UHP) adduct as a stable, inexpensive, and easily handled reagent in the presence of uronium hydrogen sulfate (UHS). Both UHP and UHS release urea as an environmentally benign byproduct. The advantages of the described method are generality, chemoselectivity, short reaction time, low cost, high atom economy, and green chemistry protocols.

GRAPHICAL ABSTRACT

Keywords:

• Chemoselective
• oxidation
• sulfides
• sulfoxides
• urea hydrogen peroxide (UHP)
• uronium hydrogen sulfate (UHS)

Acknowledgements

Financial support for this work by Persian Gulf University, Bushehr, Iran, and Hamedan University of Medical Sciences, and also the Center of Excellence of Development of Chemical Methods, (CEDCM), Bu-Ali Sina University, Hamedan, Iran, is gratefully acknowledged.

Notes

^aIsolated yield.

^bIn the absence of catalyst.

^cReaction did not complete.

^aConversion.

^aIsolated yields.

^bAll products are known and were identified using comparison of their physical and spectral data (IR, NMR, or MS) with those reported in the literature.

^cUndesired products.

^aNone reported.