4-MeC6H4I-Mediated Efficient α-Tosyloxylation of Ketones with Oxone® and p-Toluenesulfonic Acid in Acetonitrile

Various alkyl aryl ketones, dialkyl ketones, and cycloheptanone were efficiently converted into the corresponding alpha-tosyloxy ketones in good yields by using Oxone (R) and p-toluenesulfonic acid monohydrate in the presence of p-iodotoluene in acetonitrile. 4-Methoxyacetophenone and 2-acetylthiophene bearing an electron-rich aromatic group could be also converted into the corresponding alpha-tosyloxyketones smoothly in good yields with the present method. Here, p-iodotoluene works as catalyst and p-[(hydroxy)(tosyloxy)]iodotoluene is formed in situ as a reactive species for the alpha-tosyloxylation of ketones. However, one equivalent of p-iodotoluene was required to obtain alpha-tosyloxyketones in good yields and was recovered in 80-20% yields, depending on the reaction conditions.