Reaction Steps
Nitrogen was bubbled through a solution of 3,5-bis[2-(3,5-di-tert-butylphenyl)vinyl]phenyl acetylene (3) (1.00 g, 1.88 mmol) and 3,5-dibromobenzaldehyde (191 mg, 0.725 mmol) in tetrahydrofuran (10 mL) and triethylamine (15 mL) for 15 min. Tetrakis(triphenylphosphine)palladium(0) (60 mg, 52 μmol) and copper(I) iodide (18 mg, 94 μmol) were added and nitrogen bubbled through the solution for a further 15 min and the mixture then stirred at 70° C. for 17.5 h. Once cool, the solvent was removed and the residue purified by column chromatography over silica with dichloromethane-light petroleum (1:2) as eluent to give 3,5-bis({3,5-bis[2-(3,5-di-tert-butylphenyl)vinyl]phenyl}-ethynyl)benzaldehyde (4) (714 mg, 85%) as a white solid. mp>250° C. (dec.) (Found: C, 89.5; H, 8.5; C87H102O requires C, 89.8; H, 8.8%); νmax(KBr)/cm−1 2215w (C≡C), 1703 (C═O), 1595 (C═C) and 957 (C═C—H trans); λmax(CH2Cl2)/nm 318 (log(ε/dm3 mol−1cm−1) 5.12) and 330sh (4.93); δH(400 MHz, CDCl3) 1.41 (72 H, s, t-butyl), 7.15 and 7.30 (8 H, d, J 16.5, vinylic H), 7.42 (4 H, dd, J 1.5, sp H), 7.44 (8 H, d, J 1.5, sp H), 7.69 (4 H, d, J 1, bp H), 7.71 (2 H, s, bp H), 8.02 (1 H, dd, J 1.5, cp H), 8.06 (2 H, d, J 1.5, cp H) and 10.01 (1 H, s, CHO); δc(100.6 MHz, CDCl3) 31.5, 34.9, 87.1, 91.6, 121.0, 122.5, 123.1, 124.9, 125.3, 126.8, 128.3, 131.0, 132.0, 136.1, 136.7, 138.3, 139.6, 151.1 and 191.0; m/z (MALDI) 1163.1 (M+, 100%).
