Synthesis of 2-Aminobenzo[b]thiophenes via an Intramolecular Dehydrogenative C–S Bond Formation Effected by Iodine(III) Reagents

A direct synthesis of medicinal chemistry-relevant 2- aminobenzo[b]thiophenes has been achieved from substituted thioamides of 2-arylacetic acids through a fast intramolecular cross-dehydrogenative cyclization, mediated by hydroxy(tosyloxy)iodobenzene (HTIB, Koser’s reagent). This synthetic approach is operationally simple, uses easily accessible substrates, and tolerates a variety of substituents at different sites, providing an opportunity for diversification.