A simple "palladium-free'' synthesis of phenyleneethynylene-based molecular materials revisited

Nucleophilic attack of acetylide anions at the two carbonyl moieties of para-quinones readily affords the corresponding diols. Subsequent reduction with stannous chloride affords a number of useful compounds, including 1,4-bis[( trimethylsilyl) ethynyl] benzene, 1,4-bis[( trimethylsilyl) ethynyl] naphthalene and 9,10-bis[( trimethylsilyl) ethynyl] anthracene. Sequential attack by different acetylide anions followed by reduction provides a useful route to differentially substituted compounds including 1-[(4-nonyloxyphenyl) ethynyl]- 4( phenylethynyl) benzene, a new luminescent liquid-crystalline material.