Mesoporous Graphitic Carbon Nitride Photocatalyzed 6‑Substituted Phenanthridines Synthesis from 2‑Isocyanobiaryls

Abstract Mesoporous graphitic carbon nitride (mpg‐CN) has been successfully employed as a highly efficient photocatalyst for the annulation of 2‐isocyanobiaryls with ethers to synthesize 6‐substituted phenanthridines. This method facilitates the preparation of a diverse range of 6‐substituted phenanthridines, demonstrating a broad substrate scope under mild and environmentally benign reaction conditions. The versatility of this approach allows for the incorporation of various functional groups, making it a valuable tool for the synthesis of complex phenanthridine derivatives. Notably, this transition metal‐free heterogeneous photocatalytic system offers significant advantages over traditional methods, which often rely on expensive precious metal catalysts. The system achieves reduced costs and enhanced sustainability by eliminating the need for such metals. Additionally, the recyclability of the mpg‐CN catalyst is a key feature, as it can be reused for five consecutive cycles without significant loss of catalytic activity. This durability not only improves the economic feasibility of the process but also aligns with the principles of green chemistry by minimizing waste. The combination of mild conditions, cost‐effectiveness, and recyclability positions this method as a practical and scalable alternative for the synthesis of 6‐substitued phenanthridines.