Iron-Catalyzed SO2-Retaining Smiles Rearrangement through Decarboxylation.

Radical Smiles rearrangements have emerged as powerful methodologies for constructing carbon-carbon bonds through intramolecular radical addition and fragmentation under milder conditions, with SO2 released as a byproduct. However, SO2-retaining Smiles rearrangements, which can yield valuable alkyl sulfone derivatives, have been scarcely explored. In this study, we present an unprecedented iron-catalyzed SO2-retaining Smiles rearrangement initiated by the decarboxylation of aliphatic carboxylic acids. This approach provides a mild, cost-effective, and versatile pathway to sulfone-containing compounds, demonstrating broad substrate scope and functional group tolerance. It offers a promising strategy for synthesizing γ- and δ-aryl substituted alkyl sulfones, which are traditionally challenging to produce.