Background: Sulfoxides and sulfones have been in the center of attention due to their wide
range of promises in various approaches. The functional groups presented in these compounds serve as
important building blocks in numerous natural, pharmeceutical and agricultural compounds. These deriatives
have been prepared through a multitude of routes which were accompanied by several drawbacks.
Therefore, there has been an ever-increasing interest to find a new methodology that leads to
the production of these compounds via an environmentally benign path bringing about high yields. Recently,
gem-dihydroperoxides have attracted much attention due to their oxidizing power and they have
been utilized in several oxidation processes.
Methods: We carried out a chemoselective oxidation of sulfides to sulfoxides and sulfones on
treatment with urea-2,2-dihydroperoxypropane, a solid oxidant composed of equal amounts of 2,2-
dihydroperoxypropane and urea, using THF as the solvent under catalyst-free conditions at room temperature.
Results: Sulfides possessing a variety of substitutions namely dialkyl, diaryl, ally l and alkyl-aryl were
subjected to the optimized reaction conditions and they could successfully afford different amounts of
sulfoxides and sulfones depending on the amount of the oxidant utilized. Based on the results, electrondonating
groups accelerated the reaction while electron-withdrawing substituents lowered the reactivity.
Conclusion: Urea-2,2-dihydroperoxypropane as a solid oxidant which can be stored for several months
without any loss in its activity has proved its capability to oxidize sulfides to sulfoxides and sulfones
under catalyst-free and mild conditions. This approach is a cost-effective and environmentally benign
methodology via which the products have been synthesized in high yields and short reaction times.