Tosylation of alcohols: an effective strategy for the functional group transformation of organic derivatives of polyoxometalates

Recently, the organic functionalization of polyoxometalates (POMs) has drawn increasing interest, and an easy and effective route to achieve organic derivatives is of great importance. Herein, the first reported synthesis of a tosyl ester derivative of the polyoxometalate (Bu(4)N)(2)[V(6)O(13){(OCH(2))(3)CCH(2)SO(3)C(7)H(4)}(2)]·2.5CH(3)CN (compound 1) was performed by using DMAP as an activating reagent and triethylamine as an HCl scavenger. The tosyl ester was transformed into an azide or halide group by using sodium azide or sodium bromide, respectively, as the nucleophilic agent. Two derivatives of POMs, (Bu(4)N)(2)[V(6)O(13){(OCH(2))(3)CCH(2)N(3)}(2)]·4CH(3)CN (compound 2) and (Bu(4)N)(2)[V(6)O(13){(OCH(2))(3)CCH(2)Br}(2)] (compound 3), were easily obtained. All the compounds were structurally and compositionally characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, NMR spectroscopy, ESI-MS, UV-Vis spectroscopy and TGA. This work provides a new route for the functional group transformation of organic derivatives of polyoxometalates.