‡ 3: compound 1 (0.37 g, 0.80 mmol), C(p-C6H4I)4 (0.16 g, 0.19 mmol),
CuI (10.8 mg, 0.06 mmol) and [(Ph3P)2PdCl2] (40.0 mg, 0.06 mmol)
were stirred in NEt3 (10 ml) and DMF (20 ml) for 70 h at 35 ЊC.
Chromatographic work-up gave 2 as yellow crystals (0.35 g, 84.5%).
Deprotection using [nBu4N]F (1.60 mmol) in THF (50 ml, room
1
temperature, 4 h) yielded 3 as white crystals (62 mg, 42%). H NMR
(300 MHz, CDCl3) δ 7.61 (d, J 1.4 Hz, 8H), 7.56 (t, J 1.5 Hz, 4H), 7.45
(d, J 8.6 Hz, 8H), 7.21 (d, J 8.5 Hz, 8H), 3.11 (s, 8H, CCH); 13C NMR
(75 MHz, CDCl3) δ 146.2, 135.1, 131.3, 130.9, 124.0, 122.9, 120.8, 90.3,
87.9, 81.8, 78.5, 48.4; MS (MALDI-TOF) m/z 1828 [2M]ϩ, 914 [M]ϩ.
§ 4: alkyne 3 (54.3 mg, 0.06 mmol) and Co2(CO)8 (0.49 g, 1.43 mmol)
were stirred in CH2Cl2 (10 ml) for 1.5 h at room temperature, the solvent
removed, and the residue purified by column chromatography to give a
deep red crystalline solid (71.9 mg, 28%). IR (KBr disc, cmϪ1) νCO 2093
1
s, 2055 vs, 2020 vs; H NMR (250 MHz, CDCl3) δ 7.67 (d, J 2.0 Hz,
8H), 7.57 (d, J 8.3 Hz, 8H), 7.50 (t, J 1.7 Hz, 4H), 7.18 (d, J 8.8 Hz, 8H),
6.37 (s, 8H, Hcluster); 13C NMR (101 MHz, CDCl3) δ 199.0 (CO), 145.7,
140.4, 139.3, 135.9, 131.7, 130.4, 129.2, 128.3, 91.4, 90.3, 88.5, 72.8,
64.8; MS (MALDI-TOF) m/z 4317 [M Ϫ CO]ϩ.
¶ 6 and 7: alkyne 3 (62 mg, 68 µmol), p-IC6H4C᎐C(TMS) (0.24 g, 0.82
᎐
᎐
mmol), CuI (10.4 mg, 0.05 mmol) and [(PPh3)2PdCl2] (38.1 mg, 0.05
mmol) were stirred in dry NEt3 (5 ml) for 100 h at 39 ЊC. Chromato-
graphic work-up gave compound 5 as yellow crystals (67 mg, 43%); it
was dissolved in THF (30 ml), and 1 M NaOH (30 ml) added; the
solution was stirred for 4 h. Water was added and after extraction with
CH2Cl2, the residue was purified by column chromatography to give 6
as white crystals (21.3 mg, 43%). Reaction of 6 (15.4 mg, 8.98 µmol)
with [Co2(CO)8] under the same conditions as for 4 gave 7 as deep red
1
crystals (27 mg, 41%). 6: H NMR (400 MHz, CDCl3) δ 7.65 (br s,
12H), 7.48–7.46 (m, 40H), 7.24 (d, J 8.6 Hz, 8H), 3.19 (s, 8H, CCH);
13C NMR (75 MHz, CDCl3) δ 146.2, 134.3, 132.1, 131.5, 131.3, 130.9,
124.0, 123.8, 123.1, 122.3, 120.9, 90.3, 90.1, 89.6, 88.1, 83.1, 79.2; MS
(MALDI-TOF) m/z 1713 [M]ϩ. 7: IR (KBr disc, cmϪ1) νCO 2091 s, 2055
vs, 2020 vs; 1H NMR (400 MHz, CD2Cl2) δ 7.79 (d, J 1.6 Hz, 8H), 7.72
(t, J 1.7 Hz, 4H), 7.62 (d, J 8.6 Hz, 8H), 7.56 (d, J 8.4 Hz, 16H), 7.48 (d,
J 8.5 Hz, 16H), 7.24 (d, J 8.6 Hz, 8H), 6.46 (s, 8H, CCH); 13C NMR
(101 MHz, CD2Cl2) δ 199.8 (CO), 199.4 (CO), 199.2 (CO), 146.2, 140.9,
140.6, 138.4, 137.9, 136.3, 131.9, 131.2, 129.9, 129.4, 128.8, 91.8, 91.7,
90.9, 90.8, 89.6, 73.4, 69.5; MS (MALDI-TOF) m/z 7298 [M Ϫ 5CO]ϩ,
7144 [M Ϫ 10 CO]ϩ.
Acknowledgements
This work was supported by the Schweizerischer Nationalfonds
zur Förderung der wissenschaftlichen Forschung and the
University of Basel. We thank Dr G. Scherer for assistance
with the NMR spectroscopic experiments.
1 E. C. Constable, Chem. Commun., 1997, 1073.
2 G. R. Newkome, C. N. Moorefield and F. Vögtle, Dendritic Molecules,
Wiley-VCH, Weinheim, 1996.
3 V. Balzani, A. Juris, M. Venturi, S. Campagna and S. Serroni, Chem.
Rev., 1996, 96, 759.
4 E. C. Constable, C. E. Housecroft and L. A. Johnston, Inorg. Chem.
Commun., 1998, 1, 68.
5 D. Seyferth, T. Kugita, A. L. Rheingold and G. A. P. Yap, Organo-
metallics, 1995, 14, 5362.
6 E. C. Constable, O. Eich, C. E. Housecroft and L. A. Johnston,
Chem. Commun., 1998, 2661.
7 M. Simard, D. Su and J. D. Wuest, J. Am. Chem. Soc., 1991, 113,
4696.
Notes and references
᎐
† 1: 1,3,5-Br3C6H3 (1.35 g, 4.28 mmol), (TIPS)C᎐CH (1.64 g, 8.99
mmol), CuI (81.5 mg, 0.43 mmol) and [(PPh3)2PdCl2] (300 mg, 0.43
᎐
mmol) were stirred in NEt3 (50 ml) for 4 h at 35 ЊC. Treatment with
᎐
(TMS)C᎐CH (1.26 g, 12.8 mmol) under analogous conditions to those
᎐
described above (reaction time 12 h), followed by chromatographic
work-up gave the protected intermediate; this was dissolved in THF
(120 ml) and 1 M NaOH (150 ml) added; the solution stirred for 3.5 h.
After extraction, the residue was purified by column chromatography to
give a colourless oil (1.06 g; 53%). 1H NMR (250 MHz, CDCl3) δ 7.52–
7.50 (m, 3H, Ar), 3.08 (s, 1H, CCH), 1.12 (s, 42H, TIPS); 13C NMR (75
MHz, CDCl3) δ 135.2, 124.2, 122.6, 105.1, 92.4, 82.0, 78.3, 18.7 (TIPS),
11.3 (TIPS); MS (MALDI-TOF) m/z 502 [M ϩ K]ϩ, 486 [M ϩ Na]ϩ.
Communication 9/02093D
1364
J. Chem. Soc., Dalton Trans., 1999, 1363–1364