Synthesis of Aza‐Heterocyclic Compounds with N‐Tosylhydrazones: Formation of Bi‐Indoles via Reductive Molybdenum Catalysis

Abstract In this study, we present a methodology for synthesizing aza‐heterocyclic compounds using N ‐tosylhydrazones as key reagents. Our primary objective was to obtain six or seven‐membered ring heterocycles; however, we unexpectedly observed the formation of bi‐indole compounds in high yields. Furthermore, our synthetic pathway enables modifications at the C3 or C2 position of the indole, leading to the formation of the respective 3′‐phenyl‐2′‐biindole or carbazole derivatives.