Ag-Catalyzed Oxidative Cyclization Reaction of 1,6-Enynes and Sodium Sulfinate: Access to Sulfonylated Benzofurans

A convenient
protocol for the synthesis of sulfonylated benzofurans
via Ag-catalyzed oxidative cyclization has been established. Chemically
stable and easily available sodium sulfinates were used as the sulfonylation
reagents and building block for the heterocycle construction. With
this novel strategy, various benzofurans bearing dual functional groups
could be obtained in good yields with high chemo- and regioselectivities
under mild conditions.