Site-Selective Late-Stage Aromatic [18 F]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 [18 F]fluorination of a series of marketed small-molecule drugs.