Copper-Catalyzed Intramolecular Chalcogenoamination of Enynyl Azides: Synthesis of 5-Selenyl/Sulfenyl Nicotinates.

A novel methodology for the synthesis of 5-selenyl/sulfenyl nicotinates involving copper-catalyzed organochalcogenyl aza-annulation of enynyl azide with diorganyl-dichalcogenides has been described. This method offers difunctionalization of alkynes via regioselective intramolecular chalcogenoamination in one pot to provide substituted 5-chalcogenyl nicotinates in good to excellent yields. The resulting nicotinates provide access to their oxides, sulfones, and acid derivatives.