Synergetic copper/zinc catalysis: synthesis of aryl/heteroaryl-fused 1 H -pyrrolo[3,2- c ]pyridines.

Scaffolds having a 1 H -pyrrolo[3,2- c ]pyridine core show significant biological activity. Herein, we report a synergetic copper/zinc-catalyzed one-step annulation reaction of 2-amino (hetero)arylnitriles with ynamide-derived buta-1,3-diynes to deliver 1 H -pyrrolo[3,2- c ]quinoline-2,4-diamine derivatives in moderate to good yields. The annulation reaction follows a double cyclization pathway. The gram-scale synthesis of 1 H -pyrrolo[3,2- c ]quinoline-2,4-diamine proves the practicality of this protocol.