Soft–Hard Acid/Base-Controlled, Oxidative, N‑Selective Arylation of Sulfonanilides via a Nitrenium Ion

In iodine­(III)-catalyzed, dehydrogenative arylations of sulfonanilides, the functionalization of C–C bonds is preferred over the functionalization of C–N bonds. Herein, an unprecedented N-selective arylation of sulfonanilides using soft–hard acid–base (SHAB) control by a nitrenium ion over a carbenium ion is reported. Treatment of sulfonanilides with iodine­(III) led to the formation of nitrenium ions (soft), which preferentially react with biphenyls (soft) over bimesityl (hard) to generate C–N bonds. The iodine­(III) was generated in situ by using PhI and mCPBA at room temperature.