Palladium-Catalyzed Denitrogenative Carbonylation of Benzotriazinones in Batch and Flow: Divergent Synthesis of Phthalimides and Phthalic Diamides

A palladium-catalyzed denitrogenative carbonylation of aryl 1,2,3-benzotriazin-4(3H)-ones using carbon monoxide has been developed, enabling an efficient one-step synthesis of phthalimides and phthalic diamides. This method features a broad substrate scope, good functional group tolerance, and nitrogen gas as the sole byproduct. A novel and safer continuous-flow protocol was also established, reducing CO usage to just two equivalents in less than 40 min. Scalability and versatility were demonstrated in a gram-scale experiment using a novel approach that addresses the inherent challenges of employing a gaseous reagent and generating a gaseous byproduct.