Phenacenes:: a family of graphite ribbons.: Part 3:: Iterative strategies for the synthesis of large phenacenes

Iterative strategies are reported for the synthesis of some large monodisperse [Il]phenacenes, which an polycyclic aromatic hydrocarbon derivatives having n benzene rings fused in an extended phenanthrene-like structural motif. The key carbon-carbon bond-forming steps involve either Wittig or McMurry coupling reactions to give diarylethylenes, and oxidative photocyclizations of those diarylethylenes. tert-Butyl substituents on the phenacene framework serve as solubilizing groups. (C) 2001 Elsevier Science Ltd. All rights reserved.