Stereoselective Synthesis of Acylethenyl Tetrahydropyridino- and Deazepanopyrrolo1,2-cimidazolidines via Annulation of Cyclic Imines with Acylethynylpyrroles

Abstract A new and efficient strategy for the stereoselective synthesis of tetrahydropyridino- and deazepanopyrrolo1,2-cimidazolidines has been developed. Annulation of acylethynylpyrroles with six- and seven-membered cyclic imines (MeCN/THF, 20–25 °C, 24–72 h) leads to tetrahydropyrrolo1′,2′:3,4imidazo1,2-apyridines and hexahydropyrrolo1′,2′:3,4imidazo1,2-aazepines with (E)-acylethenyl moiety in 28–96% yields.