Selenium-centered electrophilic reagents play an important role in modern organic synthesis; their cyclization reactions lead to both carbocyclic compounds via formation of new carbon–carbon bond and heterocycles [1]. Our studies on reactions of selenium dichloride and dibromide with unsaturated chalcogenides [2–4] showed that selenium dihalides are efficient reagents for the synthesis of heterocyclic compounds [2, 3]. ...
