Water-Soluble Hypervalent Iodine(III) Having an I–N Bond. A Reagent for the Synthesis of Indoles

A readily accessible and bench-stable water-soluble hypervalent iodine­(III) reagent (phenyliodonio)sulfamate (PISA) with an I–N bond was synthesized, and its structure was characterized by X-ray crystallography. With PISA, various indoles were synthesized via C–H amination of 2-alkenylanilines involving an aryl migration/intramolecular cyclization cascade with excellent regioselectivity in aqueous CH₃CN. Notably, using this new method as the key step, not only two drug molecules, indometacin and zidometacin, but also another bioactive molecule, pravadoline, were synthesized.