Triphenylphosphine → 2,7-Bis(trimethylsilylethynyl)naphthalene

Participants

Reaction Steps

A mixture of naphthalene-2,7-diyl bis(trifluoromethanesulfonate) 1 (1.00 g, 1.19 mmol), CuI (0.023 g, 0.12 mmol), Pd(PPh3)4 (0.14 g, 0.12 mmol) and PPh3 (0.062 g, 0.24 mmol) was dissolved in piperidine (30 ml) in the presence of molecular sieves and under an Ar2 atmosphere. Ethynyltrimethylsilane (0.69 g, 7.06 mmol) was added and the stirred mixture heated at reflux overnight. The solvent was evaporated in vacuo and the resulting brown oil purified by flash column chromatography (5% EtOAc in hexane). 2,7-bis((trimethylsilyl)ethynyl)naphthalene 2 was obtained as a colourless solid (0.69 g, 90%); Rf 0.37 [3% EtOAc in hexane]; mp: 127-129° C. (Lit. 62.5° C., Crisp et al., 1997); δH (CDCl3, 400 MHz) 7.91 (2H, s, 2×ArH), 7.71 (2H, d, J=8.4 Hz, 2×ArH), 7.50 (2H, m, 2×ArH), 0.28 (18H, m, 6×CH3Si); δC (CDCl3, 100 MHz) 132.34 (Ar—C), 132.26 (Ar—C), 131.64 (2×Ar—CH), 129.48 (2×Ar—CH), 127.70 (2×Ar—CH), 121.17 (2×Ar—C), 105.01 (2×C≡C), 95.17 (2×C≡C), −0.03 (6×CH3Si); HRMS m/z calc. C20H25Si2 [M+H]+321.1495. found [M+H]+321.1499; anal.CHN calcd. C20H25Si2 C, 74.9%; H, 7.5%. found C, 74.6%; H, 7.5%.

Provenance & Evidence