A divanadium-substituted phosphotungstate TBA(4)[gamma-PW10O38V2(mu-OH)(mu-O)] (I, TBA = tetra-n-butylammonium) reacts with one equivalent H+ to form a bis-mu-hydroxo species [gamma-PW10O38V2(mu-OH)(2)](3-) (I') in organic media. The strong electrophilic oxidants such as [gamma-PW10O38V2(mu-OH)(mu-OOH)](3-) (II) and [gamma-PW10O38V2(mu-eta(2):eta(2)-O-2)](3-) (III) are formed by the reaction of the bis-mu-hydroxo species with H2O2. In the presence of I and H+, H2O2-based oxidations such as (i) epoxidation of alkenes (17 examples including electron-deficient ones), (ii) hydroxylation of alkanes (11 examples), and (iii) oxidative bromination of alkenes, alkynes, and aromatics with Br- as a bromo source (12 examples including chlorination) chemo-, diastereo-, and regioselectively proceed to give the corresponding oxidized products in moderate to high yields with high efficiencies of H2O2 utilization. (C) 2011 Elsevier B.V. All rights reserved.