Copper‐Catalyzed Carbon‐Nitrogen/Carbon‐Selenium Bonds Formation: Synthesis of 2‐(Organochalcogenyl)‐indolizines

Abstract The copper‐catalyzed cyclization of propargylpyridines with diorganyl dichalcogenides was applied to the synthesis of 2‐(organochalcogenyl)‐indolizines. A systematic study of the cyclization system revealed that the mutual action between copper(I) iodide and diorganyl dichalcogenides is essential for the formation of indolizines in good yields avoiding the formation of hydrogenated indolizine. The standard reaction conditions were compatible with many functional groups in the substrates, such as methyl, chlorine, fluorine, methoxy and trifluoromethyl. This protocol was efficient with diorganyl diselenides and ditellurides but ineffective with diorganyl disulfides. In addition, the obtained 2‐(organochalcogenyl)‐indolizines were readily transformed into more complex products by reaction with boronic acids using palladium‐catalyzed cross‐coupling conditions. magnified image