<p>A palladium-catalyzed oxidative intramolecular cross-dehydrogenative coupling (CDC) strategy has been developed for the efficient synthesis of a novel class of polycyclic fused heterocycles, namely 9-tosyl-9<i>H</i>-indolo[3,2-<i>c</i>][1,2,3]triazolo[1,5-<i>a</i>]quinolines. This synthetic approach involves a sequential process consisting of Sonogashira coupling, cyclization, and oxidative C–H/C–H cross-coupling between indole and triazole moieties to deliver the desired fused products. The protocol proceeds under mild reaction conditions, utilizing palladium acetate as the catalyst, copper acetate hydrate as the oxidant, and acetic acid as an additive in DMF, enabling efficient annulation to construct complex molecular frameworks in moderate to good yields. A diverse range of substrates were explored to evaluate the scope and functional group tolerance of this method. The structures of the synthesized compounds were fully characterized by NMR spectroscopy, high-resolution mass spectrometry (HRMS), and single-crystal X-ray diffraction analysis. This methodology offers several advantages, broad substrate scope, operational simplicity, and avoidance of pre-functionalized substrates. Overall, this work expands the synthetic utility of palladium-catalyzed CDC reactions for the efficient construction of structurally complex fused polycyclic heteroaromatic compounds, which are of potential interest in pharmaceutical chemistry, materials science, and optoelectronic applications.</p> Graphical abstract <p></p>