Silver-Catalyzed Intermolecular [3 + 2]/[5 + 2] Annulation of <i>N</i>‑Arylpropiolamides with Vinyl Acids: Facile Synthesis of Fused 2<i>H</i>‑Benzo[<i>b</i>]azepin-2-ones

A silver-catalyzed oxidative intermolecular [3 + 2]/[5 + 2] annulation of N-arylpropiolamides with 4-vinyl acids for producing fused 2H-benzo­[b]­azepin-2-ones is described. This radical-mediated annulation reaction features broad substrate scope and excellent selectivity, and enables the formation of three new C–C bonds through oxidative decarboxylation, [3 + 2]/[5 + 2] annulations, and C­(sp2)-H functionalization cascades. Employing this silver-catalyzed oxidative strategy, common terminal alkynes were successfully converted into cyclopentenes via intermolecular [3 + 2] annulation.