Decarboxylative Sulfonylation of Carboxylic Acids under Mild Photomediated Iron Catalysis.

Organic sulfones are an important class of chemical compounds widely used in many research fields. The direct decarboxylative sulfonylation of carboxylic acids is attractive but challenging, particularly when iron is used as a metal catalyst. Herein, we describe a photoinduced iron-catalytic method for the synthesis of sulfones directly using carboxylic acids via a radical-based decarboxylation. This protocol is mild, highly efficient, and easy-to-operate. A broad scope of carboxylic acids and carbon electrophiles could be well tolerated. A mechanism involving the iron-catalyzed decarboxylation, radical transfer, single-electron reduction, and nucleophilic attack is proposed.