SiO₂-supported RuCl₃/3-(dichloroiodo)benzoic acid: Green catalytic system for the oxidation of alcohols and sulfides in water

A green, recyclable and efficient catalytic oxidative system based on SiO₂-supported RuCl₃ and 3-(dichloroiodo)benzoic acid for the oxidation of alcohols and sulfides in water is developed. This catalytic oxidative system effects clean and efficient oxidation of a wide range of alcohols to the corresponding aldehydes and ketones, or sulfides to sulfoxides in high conversions with excellent chemoselectivity, under mild conditions and with an easy-work-up procedure. Furthermore, the SiO₂-RuCl ₃ catalyst can be recovered by simple filtration and recycled in up to six consecutive runs without significant loss of activity. The reduced form of 3-(dichloroiodo)benzoic acid, 3-iodobenzoic acid, can be easily separated from reaction mixtures and converted back to 3-(dichloroiodo)benzoic acid by treatment with bleach and aqueous HCl in about 90% overall yield.