Gram-Scale Synthesis of Sulfoxides via Oxygen Enabled by Fe(NO₃)₃·9H₂O

Sulfoxides, as an essential pivot, are commonly found in pharmaceuticals and bulk chemicals. A practical synthetic protocol is depicted via application of readily obtainable Fe(NO₃)₃·9H₂O as a catalyst and oxygen as a green oxidant for selective oxidation from thioethers to sulfoxides under ecofriendly and mild conditions. Various sulfoxides are all achieved in gram-scale with superior selectivity and efficiency. This protocol showcases broad-spectrum functional group compatibility, offering efficient access to sulfoxide construction for drug discovery and process optimization.