Solvent-free Baeyer-Villiger oxidation with H2O2 as oxidant catalyzed by multi-SO3H functionalized heteropolyanion-based ionic hybrids

Three novel multi-SO3H functionalized heteropolyanion-based ionic hybrids were synthesized and characterized, which as heterogeneous catalysts for Baeyer-Villiger oxidation using 35% aqueous H2O2 as oxidant show high catalytic activity under solvent-free conditions, the target lactones were obtained with yields of 69% to 88% in 3 h at 50 degrees C. Three ionic hybrids could be recovered readily and their catalytic activity almost completely retained after ten recycles. (C) 2015 Elsevier B.V. All rights reserved.