Synthesis of 3-Chalcogenylated Benzo[b]furans Enabled by a Multicomponent Reagent System.

A multicomponent reagent system (4-FPhI/mCPBA/(COCl)2/RSSR or RSeSeR) has been applied to accomplish the one-pot synthesis of 3-chalcogenylated benzo[b]furans under mild conditions. A range of 2-alkynylanisole substrates bearing different substituents were compatible with this protocol, affording the corresponding structurally diverse 3-chalcogenylated benzo[b]furans in moderate to excellent yields. The results of control experiments showed that the reaction first generated the electrophilic RSeCl/RSCl species, which promoted the cyclization and chalcogenylation process.