Iodine(III)-Aluminum or -Ammonium Salts for the Oxidative Aromatic Inorganic Functionalization

Strategies for introducing halogens and other inorganic groups in aromatic systems, usually involve non-general and strong oxidative protocols which resulted in poor functional group compatibility. Iodine(III) reagents have emerged as an excellent alternative for the aromatic inorganic functionalization due to their low toxicity and strong oxidative character. In this context, the synergistic combination of different iodine(III) reagents and aluminum or ammonium salts including AlCl3, AlBr3, Al(NO3)(3), NH4Cl, NH4Br and NH4I have recently demonstrated a great versatility for introducing the chlorine, bromine, iodine and nitro groups in aromatic systems, mainly phenols, anilines and some heterocycles. Using these common salts, their anions are softly oxidated by iodine(III) reagents, allowing the in situ formation of non-described halogenating and nitrating species and in consequence, the introduction of these inorganic groups under an umpolung reactivity as chemical electrophilic synthons.