Metal free direct formation of various substituted pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5-amines and their further functionalization

Abstract

Original substituted pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5-amines have been prepared following a Groebke–Blackburn–Bienaymé MCR combined with an N-deprotection and a spontaneous final cyclization step in moderate to good yields. The flexibility of the described method enables the introduction of diverse groups in the 6 and 7 positions on the resulting scaffold using commercially available starting materials. Furthermore, a Buchwald–Hartwig cross coupling with a wide range of aryl and hetaryl halides has been successfully reported using our heterocyclic primary amine derivatives.