Palladium‐Catalyzed Selectivity Controlled Highly Efficient Carbonylative Synthesis of Isoquinoline‐1,3(2<i>H</i>,4<i>H</i>)‐diones and Indanones

Abstract Compared to the methods that rely on complex and structurally unique substrates for the synthesis of heterocyclic compounds through intra‐ and intermolecular cyclization, strategies starting from simple and readily available substrates, combined with finely tuned catalytic system to achieve different chemoselectivity, offer significant advantages in terms of efficiency, cost‐effectiveness, and versatility. Herein, we present a palladium‐catalyzed carbonylation strategy that enables the selective and efficient synthesis of isoquinoline‐1,3(2 H ,4 H )‐dione and indanone derivatives via distinct reaction pathways. Notably, the chemoselectivity was not determined by the differences in reactivity at the reaction sites but instead arises from the generation of distinct active palladium species under nearly identical reaction conditions, which subsequently react on the same reaction site but lead to different products.