Palladium/carboxylic acid-catalyzed alkenylation of heteroarenes and electron-deficient arenes using alkynes underwent C(sp(2))-H bond activation in arene substrates to give the corresponding alkenylarenes straightforwardly. The versatility of this transformation is demonstrated by the double alkenylation of functionalized thiophenes and 5,6-difluorobenzothiadiazole with alkynes and provides a one-step access to vinylene-arylene-vinylene units.