Metal free: A novel and efficient aerobic oxidation of toluene derivatives catalyzed by N′, N″, N‴, -trihydroxyisocyanuric acid and dimethylglyoxime in PEG-1000-based dicationic acidic ionic liquid

Abstract A non-metal catalytic system containing of N′, N″, N‴, -trihydroxyisocyanuric acid (THICA) and dimethylglyoxime (DMG) is described for the selective oxidation of toluene derivatives with dioxygen in PEG-1000-based dicationic acidic ionic liquid (PEG 1000 –DAIL). Several toluene derivatives were efficiently oxidized to corresponding acids under mild conditions. The oxidation followed a radical pathway and a possible mechanism was proposed. Both the catalyst and PEG 1000 –DAIL could be reused at least eight times without significantly decreasing the catalytic activity.