Decarboxylative Arene Ring-Opening of Benzoic Acids.

Benzoic acids are widely utilized in synthetic chemistry, pharmaceuticals, and materials science, yet their potential as precursors for linear synthons is severely constrained by the challenge of cleaving their highly stable aromatic C─C bonds. Here, we report that a PDPP (4-(piperidin-1-yl)pyridine) and copper synergistically catalyzed nitrogenation of benzoic acids with a tailored nitrogenation reagent. This protocol efficiently enables the selective decarboxylation and benzene ring opening processes leading to acyclic dinitrile products. The designed new azide reagent plays an essential role in the PDPP-catalyzed initial step to trigger the selective carboxyl and aromatic C─C bond cleavage process. This synergistic strategy greatly expands the synthetic utility of benzoic acids, providing a direct and practical route to acyclic scaffolds. The aromatic ring-opening products could be further used in cyclization reactions to realize phenyl ring scaffold hopping.