Polyarylenes and Poly(arylenevinylene)s, V. Synthesis of Tetraalkyl‐Substituted Oligo(1,4‐naphthylene)s and Cyclization to Soluble Oligo(peri‐naphthylene)s²⁾

A homologous series of oligo(1,4‐naphthylene)s from the binaphthyl 6 to the sexinaphthylene derivative 10 were synthesized successively. The Pd(O)‐catalyzed reaction between aryl bromides and arylboronic acids was used as a coupling method. By appropriate choice of the stoichiometry, the method allowed isolation of the intermediates 20 and 21 . Under the influence of potassium in 1,2‐dimethoxyethane the 1,4‐bridged naphthylenes 6 — 10 were partially cyclized to perylene and terrylene units. This anionic cyclization displayed a high regioselectivity. Complete cyclization to the oligorylenes 3b, 4b and 5b was achieved under the influence of AlCl 3 and CuCl 2 on the bichromophoric systems 24 , 25 and 28 . The synthetic sequence allowed substitution by tert ‐butyl groups, so that the oligorylenes 2b , 3b , 4b and 5b were amenable to spectroscopic investigations. The trends in absorption maxima and fluorescence are discussed.