Highly efficient selective oxidation of sulfides to sulfoxides by montmorillonite-immobilized metalloporphyrins in the presence of molecular oxygen

• Immobilized metalloporphyrins was used as catalyst in the oxidation of sulfides.
• Manganese porphyrin is more selective than cobalt and iron porphyrin catalysts.
• Catalyst could be reused consecutively five times without loss of activity.

Highly efficient and selective oxidation of sulfides to sulfoxides with dioxygen catalyzed by cationic meso-tetrakis (1-methyl-4-pyridyl) (TM4PyP) metalloporphyrins immobilized into montmorillonite (MT) interlayer was achieved. Manganese (II) porphyrin (MnTM4PyP-MT) presented excellent activity for the oxidation of sulfides under ambient conditions. In the model oxidation, thioanisole was converted completely and the selectivity towards sulfoxide was up to 95%. This catalyst also showed high activity and selectivity for the most sulfides. The catalyst could be reused consecutively five times without significant loss of activity.