Radical Smiles Rearrangements: Aryl Migration for Molecular Editing

ABSTRACT Smiles and Truce–Smiles rearrangements have evolved from classical nucleophilic aromatic substitutions into a versatile platform for radical aryl migration and molecular editing. This Review surveys how visible‐light photoredox catalysis and related photoinduced activation modes‐including electron‐donor–acceptor (EDA) complexes, energy‐transfer and ligand‐to‐metal charge‐transfer (LMCT) processes, metal‐hydride hydrogen atom transfer (MHAT), and radical‐cation pathways—have transformed sulfonyl and sulfinyl groups into bifunctional aryl‐migration handles that operate under remarkably mild conditions. After outlining the mechanistic features that distinguish ionic, radical, and radical‐cation Smiles pathways, we discuss traditional radical Smiles rearrangements that established the feasibility of aryl transfer via open‐shell Meisenheimer‐like intermediates. We then focus on photocatalytic and catalyst‐free radical Smiles and Truce–Smiles reactions, including alkene difunctionalizations, sulfur dioxide (SO 2 ) insertion/relay cascades, decarboxylative and decarbonylative arylations, remote sp 3 carbon–hydrogen (C(sp 3 )–H) functionalization, and emerging applications in polymer synthesis and biocatalysis. Particular emphasis is placed on reagent design (sulfonamides, sulfones, sulfinamides, and sulfoxides), control over SO 2 extrusion versus retention, and recent advances in asymmetric sulfinyl‐Smiles chemistry. We conclude by highlighting current limitations and future opportunities, especially in expanding substrate generality, stereocontrol, and late‐stage functionalization, and in integrating Smiles rearrangements with electrochemical, flow, and data‐driven catalysis for applications in medicinal chemistry and sustainable materials.