Electrifying Phthalimide‑N‑Oxyl (PINO) Radical Chemistry: Anodically Induced Dioxygenation of Vinyl Arenes with N‑Hydroxyphthalimide

An electrochemical process of free-radical difunctionalization of vinyl arenes with N-hydroxyphthalimide resulting in vicinal dioxyphthalimides was discovered. The reaction proceeds with the use of pyridinium perchlorate and pyridine as a supporting electrolyte and a base, respectively. The present approach involves the anodic generation of stabilized phthalimide-N-oxyl (PINO) radical, which adds to the carbon–carbon double bond of vinyl arenes and recombines with the subsequently formed benzylic radical. A wide range of dioxyphthalimides were obtained in yields up to 81%.