Iron-Mediated Nitrate Reduction at Ambient Temperature for Deaminative Sulfonylation and Fluorination of Anilines.

Preparation of arylsulfonic acids and derivatives can be achieved under mild conditions from aryldiazonium salts, although conventional methods often require isolation or accumulation of these potentially hazardous intermediates. Herein, we present that iron nitrate reduction at 25 °C enables the in situ generation of diazonium salts, which allows direct deaminative chlorosulfonylation and fluorination from anilines via aryldiazonium salts as fleeting intermediates. Other sulfonic acid derivatives, such as sulfonamides, sulfonyl fluorides, and sulfonic acids, are readily accessible from this method.