Iron-catalyzed continuous-flow synthesis of sulfoxide with hydrogen peroxide

to iron oxide species, thereby enhancing catalytic efficiency. Sulfoxides were continuously produced in >90% yield for up to 150 h. Although over-oxidation to sulfones occurred, the selectivity for some sulfoxides (defined as sulfoxide/(sulfoxide + sulfone)) reached up to 98%, with no residual sulfides, by fine-tuning the flow rate of the reaction solution.