In conclusion, we have synthesized a family of extended cyclobutadiene-containing PCHs with diverse structures, by means of efficient [4+2] or palladium-catalyzed [2+2+2] cycloaddition reactions of a novel aryne building block derived from benzo [b]biphenylene. The set of extended phenylenes synthesized include CBD-oligoacenes (with up to nine linearly-fused rings), angularly-fused analogues and a star-shaped benzobiphenylene trimer. Importantly, our approach allowed the synthesis of stable, unsubstituted (or barely substituted) CBD-oligoacenes, which according to preliminary examination of their emission spectra might display effective electronic coupling in the solid state, as unsubstituted acenes do. Experimental and computational studies on the whole series of newly synthesized systems reveal an important degree of electron delocalization along the polycyclic skeletons despite the presence of the antiaromatic cyclobutadiene rings, with more pronounced delocalization observed in the linearly fused CBD-oligoacenes. The current density plotted onto the ACID isosurface indicates a complex pattern of currents that unveils the presence of clockwise peripherical current originating from the σ contributions of the four-membered rings, thus providing new insights into the aromatic and antiaromatic interactions within these intriguing molecular architectures.