Synthesis of (Hetero)aryl Fused 4 <i>H</i> -Quinolizin-4-ones from <i>N</i> -Ts Substituted (Hetero)arylamides and Pyridotriazoles

This paper describes a practical synthetic method of (hetero)aryl fused 4<i>H</i>-quinolizin-4-ones via (hetero)aryl sp² C-H carbenoid functionalization of (hetero)aryl amides using pyridotriazoles with good functional group tolerance. This process demonstrates excellent site-selectivity, enabling the C-H functionalization reaction directed by an amide group by overcoming the interference of strong coordination between <i>N</i>-heterocycles and metal catalysis. The synthetic method represents an efficient strategy with attractive application prospects, including late-stage modification of drug molecules, total synthesis of natural products, and live-cell imaging.