Iodine(III)‐Mediated Free‐Aniline Iodination through Acetyl Hypoiodite Formation: Study of the Reaction Pathway

Abstract The first iodine(III)‐mediated para ‐selective iodination protocol for free anilines as well as the mechanistic elucidation of the reaction pathway is described. The developed method proceeded under clean, non‐toxic, efficient, and in general mild reaction conditions. To the best of our knowledge this report describes for the first time a procedure focused specifically on the introduction of an iodine atom in free anilines using PIDA [(diacetoxyiodo)benzene] and ammonium iodide which formed in situ acetyl hypoiodite (AcO‐ I ) as the halogenating species. Our DFT calculations suggest a reaction mechanism that highlights the catalytic role of the ammonium cation in the AcO‐ I formation and halogenation. Considering there are few procedures for the iodine atom introduction in anilines using non‐acidic conditions, herein we described an initial report on a mild and operationally simple alternative using iodine(III) reagents.