Polycyclic aromatic hydrocarbons (PAHs) represent an emerging class of π‐conjugated molecules in the area of optoelectronic devices and materials. Unprecedented synthetic routes to various PAHs from simple phenol derivatives by a palladium‐catalyzed annulative dimerization of phenylene triflate through twofold inter‐ and intramolecular C−H activation have been established. The initially formed partially fused PAHs can be smoothly transformed into a variety of fully fused PAHs by the Scholl reaction. Furthermore, the reactions of phenanthrene‐substituted aryl triflates proceeded regioselectively. The findings inspired the development of a rapid and efficient synthesis of polybenzoacene derivatives. This study not only allows transformation of phenyl triflates, but also discloses a new retrosynthetic strategy towards PAHs, especially polybenzoacenes.

Polycyclic aromatic hydrocarbons (PAHs) represent an emerging class of π‐conjugated molecules in the area of optoelectronic devices and materials. Unprecedented synthetic routes to various PAHs from simple phenol derivatives by a palladium‐catalyzed annulative dimerization of phenylene triflate through twofold inter‐ and intramolecular C−H activation have been established. The initially formed partially fused PAHs can be smoothly transformed into a variety of fully fused PAHs by the Scholl reaction. Furthermore, the reactions of phenanthrene‐substituted aryl triflates proceeded regioselectively. The findings inspired the development of a rapid and efficient synthesis of polybenzoacene derivatives. This study not only allows transformation of phenyl triflates, but also discloses a new retrosynthetic strategy towards PAHs, especially polybenzoacenes.

During the preparation of the first author's PhD thesis, the authors of this Communication found several errors in the Supporting Information (SI): 1. In Figure S2-S4, the simulated IR and Raman spectra of compound 6 c were prepared from an unoptimized structure. The figure was corrected with the optimized structure 6 c. The Raman and IR spectra of 2 c and 6 c were re-measured for confirmation, and the corrected figures are shown in the revised SI. 2. The MS values of compounds S16,

Polycyclic aromatic hydrocarbons (PAHs) are an emerging class of aromatic molecules in materials science. In their Communication on page 6551, K. Itami, K. Murakami et al. present the development of a palladium‐catalyzed annulative dimerization of phenylene triflate by twofold inter‐ and intramolecular C−H activation. This transformation forms two C−C bonds in one go, and thus enables the rapid synthesis of a variety of PAHs.

Polycyclische aromatische Kohlenwasserstoffe (PAHs) sind eine wichtige Klasse von aromatischen Molekülen in den Materialwissenschaften. In ihrer Zuschrift auf S. 6613 präsentieren K. Itami, K. Murakami et al. die Entwicklung einer Palladium‐katalysierten anellierenden Dimerisierung von Phenylentriflat durch zweifache inter‐ und intramolekulare C‐H‐Aktivierung. Diese Umwandlung erzeugt zwei C‐C‐Bindungen in einem Schritt, was die schnelle Synthese einer Vielfalt von PAHs erlaubt.