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

Iterative strategies are reported for the synthesis of some large monodispe rse [Il]phenacenes, which an polycyclic aromatic hydrocarbon derivatives ha ving n benzene rings fused in an extended phenanthrene-like structural moti f. The key carbon-carbon bond-forming steps involve either Wittig or McMurr y coupling reactions to give diarylethylenes, and oxidative photocyclizatio ns of those diarylethylenes. tert-Butyl substituents on the phenacene frame work serve as solubilizing groups. (C) 2001 Elsevier Science Ltd. All right s reserved.