Abstract: | In the presence of a catalytic amount of KI combined with oxidant m CPBA, a convenient catalytic procedure is developed for the preparation of 3‐selanylindoles from indoles and diselenides. In this protocol, KI is first oxidized by m CPBA into hypoiodous acid, which reacts with diselenide to cleave Se‐Se bond. The in situ generated active electrophilic selenium species then reacts with indole, affording 3‐selanylindole via an electrophilic substitution mechanism. This catalytic selenation of indoles has mild reaction conditions and is a simple procedure, which extends the synthetic application of KI in organic synthesis. |