Site‐Selective Late‐Stage Aromatic [18F]Fluorination via Aryl Sulfonium Salts

Site‐selective functionalization of C−H bonds in small complex molecules is a long‐standing challenge in organic chemistry. Herein, we report a broadly applicable and site‐selective aromatic C−H dibenzothiophenylation reaction. The conceptual advantage of this transformation is further demonstrated through the two‐step C−H [18F]fluorination of a series of marketed small‐molecule drugs. A broadly applicable and site‐selective late‐stage aromatic [18F]fluorination reaction is reported. A collection of three electronically different dibenzothiophenes enables 18F labeling of a series of small complex molecules.