The Smiles–Truce Rearrangement

<jats:title>Abstract</jats:title> <jats:p>The Smiles–Truce rearrangement is an intramolecular nucleophilic aromatic substitution reaction that typically proceeds with aryl group transfer from sulfur, oxygen, or nitrogen to an internal carbon nucleophile. The traditional mechanistic paradigm includes three‐steps: the generation of a carbanion or carbon‐centered radical, cyclization to the ipso position of the arene with formation of a dearomatized spirocyclic intermediate, and rearomatization via ejection of the heteroatom to finalize aryl group transfer to carbon. This method can be used to synthesize a wide variety of aromatic scaffolds from readily accessible starting materials such as sulfonamides or aryl ethers. Stereoselective aryl group transfer can be achieved via multiple strategies depending on the identity of the heteroatom leaving group and the nature of the carbon‐based nucleophile.</jats:p> <jats:p>This chapter includes an in‐depth overview of the reaction mechanism, stereoselectivity, and scope of the Smiles–Truce rearrangement, including recent trends that involve visible light photocatalysis and sulfonamide‐based enantioselective rearrangements. Notable applications in complex synthetic contexts are also discussed alongside one example of a multikilogram‐scale reaction. A comparison of the Smiles–Truce rearrangement to transition‐metal‐catalyzed aryl cross‐coupling strategies is included to highlight the strengths and drawbacks of the rearrangement. General technical advice and experimental details are provided for a diverse cross‐section of rearrangement methods that include the generation of carbanions and carbon‐centered radicals. These examples are supplemented by an extensive tabular survey that covers the literature from 1970 into the first quarter of 2024.</jats:p>