Oxidation reactions using sodium metaperiodate supported on silica gel

Abstract

No reaction occurred when solutions of 2,5-di-t-butylhydroquinone, dibenzyl sulphide, trans-cyclohexane-1,2-diol or hydrazobenzene in methylene chloride were stirred with powdered sodium metaperiodate at 20 °C for several hours. However, these and several closely related substrates were oxidized in good yield, generally within a few hours, when solutions in methylene chloride, and in some cases benzene or ether, were stirred with sodium metaperiodiate supported on silica gel. The supported reagent was prepared by evaporating to dryness an aqueous solution of sodium metaperiodate in the presence of silica gel, followed by heating at 120 °C in vacuo. The reagent appears to consist mainly of a monomolecular layer of sodium metaperiodate bound to the silica gel by the surface hydroxy-groups, together with a minor amount of crystalline anhydrous sodium metaperiodate.