A new procedure for the oxidation of sulfides to sulfones utilizing heterogeneous
ruthenium reagent has been developed. A small amount of ruthenium trichloride (RuCl3) supported on alumina and excess sodium metaperiodate (NaIO4) was used to produce the ruthenium oxidizing catalyst in the reaction mixture. Sodium
metaperiodate oxidized the pre-catalyst RuCl3 to RuO4 and also maintained a constant supply of RuO4 by oxidizing lower valent ruthenium ions during the course of the reaction. An environmentally
friendly solvent mixture of dimethyl carbonate (DMC) and water was employed. A wide
variety of aromatic sulfides were oxidized to sulfones in good to excellent yields
by utilizing this procedure.
Key words
sulfides - sulfones - RuO
4
- dimethyl carbonate - green chemistry