Synthetic Strategies to 3 H ‐Pyrrolo[2,3‐ c ] Quinolines

ABSTRACT 3 H ‐Pyrrolo[2,3‐ c ]quinoline is a typical tricyclic heterocyclic scaffold with a fused 6‐6‐5 ring system. This class of compounds exhibits outstanding medicinal and biological activities and possesses excellent metal‐ion detection performance, making it a research hotspot in medicinal and materials chemistry. This review summarizes the synthetic strategies for 3 H ‐pyrrolo[2,3‐ c ]quinoline reported in the recent literature and classifies these methods according to their ring formation modes. For each category of synthetic strategy, the reaction mechanisms, key steps, typical examples, and advantages and limitations of representative methods (including the Pictet–Spengler reaction, Morgan–Walls reaction, Heck/Suzuki coupling reactions, Fischer indole synthesis, and Bartoli indole synthesis) are elaborated in detail. Furthermore, this review discusses the current research challenges in this field and the exploration status of ring formation strategies. Finally, the potential applications of novel indole synthesis reactions and artificial intelligence‐assisted drug design in the development of efficient synthetic methods for 3 H ‐pyrrolo[2,3‐c]quinoline are highlighted. This review aims to provide a comprehensive reference for the design and development of novel synthetic strategies for this important tricyclic scaffold.