[65201-77-6] · C16H36INO4 · Tetra-n-butylammonium Periodate · (MW 433.43)
Physical Data: mp 158-159 °C.
Solubility: sol CH2Cl2, CHCl3, benzene, DMSO; insol H2O, alcohol.
Form Supplied in: white crystalline solid; readily available.
Handling, Storage, and Precautions: tetrabutylammonium periodate is best stored in the dark because it readily turns yellow on exposure to light. There is no loss of oxidizing power on prolonged storage.
Due to its ease of preparation1 and its solubility in common organic solvents, tetrabutylammonium periodate (1) is a useful reagent for the oxidation of organic compounds under homogeneous reaction conditions.
Treatment of sulfides with (1) in refluxing CHCl3 selectively provided the sulfoxides in good yields.1a Thus, oxidation of methyl p-methylphenyl sulfide gave the corresponding sulfoxide in 86% yield. An advantage of this method is that the sulfoxides are readily isolated by simple filtration through a column of silica gel. Oxidant (1) and catalytic amounts of meso-tetraphenyporphyrinatoiron(III) chloride (2) have been found to be effective for the selective oxidation of sulfides to sulfoxides (eq 1).1b Sulfides that usually resist oxidation, such as p-nitrophenyl phenyl sulfide and di-t-butyl sulfide, are also efficiently oxidized to the corresponding sulfoxides. Alkenic bonds are tolerated under the reaction conditions.
a-Hydroxy carboxylic acids are efficiently oxidized to the aldehydes by treatment with (1) in refluxing CHCl3 (eq 2).1a Reaction times were found to be shorter than the usual Sodium Periodate method, which required extended reaction times.
Benzaldehyde derivatives were also obtained in good yields by the oxidative decarboxylation of arylacetic acids with (1) in refluxing 1,4-dioxane.2 This method was found to be better than the hypochlorite route, which gave over-oxidation products. Treatment of phenacyl bromides with (1) in refluxing 1,4-dioxane gave good yields of the corresponding benzoic acids (eq 3).1a This oxidation was found to be specific for phenacyl bromides since chloroacetone was not oxidized under the same reaction conditions.
Benzyl halides are efficiently converted to benzaldehydes by treatment with (1) in refluxing 1,4-dioxane.3 This oxidation was found to be specific for benzyl halides since compounds such as phenethyl bromide were not oxidized under the same conditions. Oxidant (1) has also been shown to be effective for the oxidative cleavage of stannylene derivatives of 1,2-glycols to give high yields of the aldehydes.4 It was also shown that allylic and benzylic alcohols were oxidized to the corresponding aldehydes by the use of (1) and catalytic amounts of either trans-[RuO2(py)4][BF4]2.H2O (3) or trans-[Ru2O6(py)4] in CH2Cl2 at rt.5 For example, piperonyl alcohol was oxidized using
Andrew G. Wee
University of Regina, Saskatchewan, Canada