Sodium Periodate (NaIO4) -A Versatile Reagent in Organic Synthesis

All articles of this category Introduction Sodium periodate (sodium metaperiodate), NaIO 4 (mp 300 °C; Figure 1), is commercially available and is applied mainly in aqueous or aqueous-alcoholic solutions. Like the free periodic acid, sodium periodate cleaves ­vicinal diols to carbonyl compounds. [ 1 ] The popularity stems from its specificity, its reactivity under neutral and mild ­conditions which is compatible with a wide range of functionalities, its stability, and its low cost. [ 2 ] Sulfides are transformed by sodium periodate into sulfoxides. It is also a reoxidant of lower-valency ruthenium in oxidations with ruthenium tetroxide. [ 3 ] Figure 1 Tetrabutylammonium periodate, ( n -Bu) 4 NIO 4 (mp 175 °C), which is usually prepared in situ from tetrabutyl­ammonium hydrogen sulfate and sodium periodate, [ 4 ] is useful in two-phase systems, because it dissolves in ­chloroform and other organic solvents. [ 3 ] It is used in ­homogeneous oxidations of sulfides, 2-hydroxy acids, and α-bromoketones. [ 5 ]