Metal‐Free Synthesis of Selenodihydronaphthalenes by Selenoxide‐Mediated Electrophilic Cyclization of Alkynes

Abstract A transition‐metal‐free, selenium mediated electrophilic cyclization reaction was realized through a one‐pot procedure between simple alkynes and triflic anhydride‐activated selenoxides to give selenium containing dihydronaphthalene products. This method gave good to very high yields for all products, including selenium‐substituted phenanthrene, dihydroquinoline, 2 H ‐chromene, and coumarin, which can be further transformed to other functionalized compounds.