Solid-Solid Catalysis by Ultrafine Crystallites of Heteropoly Compound for Pinacol Rearrangement

Cs2.5H0.5PW12O40 consisting of ultrafine crystallites efficiently catalyzes pinacol rearrangement of 1,1,2-triphenyl-1,2-ethanediol at room temperature in solid-solid reaction system, giving the corresponding aldehyde selectively, while p-toluenesulfonic acid, H-ZSM-5, HY, SiO2-Al2O3, SO42−/ZrO2 and Nb2O5 nH2O were inactive. The activity of Cs2.5H0.5PW12O40 in the solid-solid reaction was higher than that in solid-liquid (CHCl3) system.