Late-Stage Heteroarylation of Hetero(aryl)sulfonium Salts Activated by α-Amino Alkyl Radicals.

We report a late-stage heteroarylation of aryl sulfonium salts through activation with α-amino alkyl radicals in a mechanistically distinct approach from previously reported halogen-atom transfer (XAT). The new mode of activation of aryl sulfonium salts proceeds in the absence of light and photoredox catalysts, engaging a wide range of hetarenes. Furthermore, we demonstrate the applicability of this methodology in synthetically useful cross-coupling transformations.

Cine-Substitutions at Five-Membered Hetarenes Enabled by Sulfonium Salts.

We report a nucleophilic substitution reaction of five-membered hetarylsulfonium salts that results in a change of the substitution pattern on the arene. The products of these cine-substitutions are hard to access synthetically otherwise. The sulfonium salts that serve as starting materials are generated by a highly site-selective C-H functionalization reaction.