A heterogeneous catalytic system, Pd(OAc)2/n-Bu4NOAc, for the efficient synthesis of diaceno[a,e]pentalenes via a tandem Pd catalytic cycle is reported. The catalytic partner n-Bu4NOAc played indispensable and versatile roles, acting as both the media for recovering active Pd(0) species and their stabilizer. A series of new diaceno[a,e]pentalenes were obtained in moderate to high yields, among which the octacyclic dianthracenopentalene was found to be highly emissive.