In Situ-Generated (Hypo) iodite Ions-Catalyzed Oxidative Amidation of Unactivated Methylarens

Iodine is most stable with an oxidation state -1; however, it forms stable polycoordinate, multivalent compounds.Current researches focus on its use in carbon-carbon and carbon-heteroatom bond forming reactions.[1] Zhang et al. demonstrated that 1-(4′-diacetoxyiodo benzene)-3-methylimidazolium tetrafluoroborate [dibmim][BF4] catalyze the selective oxidation of alcohols to carbonyl compounds.[2] Zhdankin and co-worker presented that 2-Iodylphenol ethers can selectively oxidize sulfides to sulfoxides and alcohols to the respective aldehydes or ketones.[3] Herein, we demonstrate that the direct oxidative amidation of unactivated methylarenes with hydrochloric salts of amines in the presence of in situ-generated (Hypo) iodite with TBHP for the first time. Various secondary and tertiary amides were synthesized in good to excellent yields in One-Pot manner under our conditions. Hypervalent iodine-catalyzed oxidative amidation of methylarens to the corresponding amides by using an environmentally available oxidant (tert-butyl hydroperoxide, 70% aqueous solution) is discussed. This oxidizing agent presented a high degree of selectivity for the oxidation of toluene to amide without oxidation to carboxylic acid. This reaction involves the metal-free oxidation, mild reaction condition and tert-butyl alcohol as the only by-product.