Silver‐Catalyzed and Base‐Mediated Double Cyclization for the Streamlined Synthesis of Benzo[4,5]imidazo[2,1‐<i>b</i>]naphtho[2,3‐<i>d</i>]oxazole from <i>ortho</i>‐Alkynylarylketones

We report a novel silver-catalyzed and base-mediated double cyclization strategy for the streamlined synthesis of benzo[4,5]imidazo[2,1-b]naphtho[2,3-d]oxazoles from ortho-alkynylarylketones. The transformation proceeds through an initial ketonization step catalyzed by silver trifluoroacetate (AgTFA), generating a reactive 1,5-diketone intermediate, followed by a sequential double cyclization under basic conditions. This method affords a broad range of benzo[4,5]imidazo[2,1-b]naphtho[2,3-d]oxazoles with good functional group tolerance in moderate-to-good yields. Moreover, this methodology also enhances the synthetic utility of ortho-alkynylarylketones, expanding their applicability in constructing diverse fused heterocycles.