Oxidation of tetralin with molecular oxygen by vanadium-substituted polyoxometalate

The oxidation of neat 1, 2, 3 and 4-tetrahydronaphthalene (tetralin) with molecular oxygen was carried out in the presence of unsubstituted and vanadium-substituted Wells-Dawson type phosphotungstates, namely, K6P2W18O62 and α2-K8HP2V3W15O62, in heterogeneous system. Oxidation of tetralin by vanadium-substituted phosphotungstate resulted in the formation of 1-tetralol and 1-tetralone as major products, 4-hydroxy-1-tetralone and naphthalene as minor products. Conversion of tetralin increased significantly by substituting vanadium in K6P2W18O62. For vanadium-substituted polyoxometalates and the unsubstituted one, selectivity with respect to 1-tetralone increased by increasing the reaction time.