G. Hennrich, A. M. Echavarren / Tetrahedron Letters 45 (2004) 1147–1149
1149
Characterization of compounds
ture of 10, and to Johnson Matthey PLC for a generous
loan of PdCl2.
1,3,5-Trifluoro-2,4,6-tris(trimethylsilanylethynyl)benzene
(7). Mp 78–80 °C; 1H NMR (200 MHz): d ¼ 0:26 (s,
References and notes
27H, CH3); 13C NMR (75 MHz): d ¼ 162:96 (d, JCF
¼
263:1 Hz, Ar–F), 88.55 (Ar), 88.02, 85.87 (CBC), 0.53
(CH3); EIþ-MS m=z 420 (43, [Mþ]). HRMS found:
420.1391; calculated for C21H27Si3: 420.1373. Rf ¼ 0:47
(Hex).
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C.; Wilkins, C. L. Angew. Chem., Int. Ed. 1998, 37, 1226–
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Naemura, K.; Wakabayashi, T.; Shida, T.; Achiba, Y.
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Lee, S. J.; Lee, S. H.; Son, K. H.; Kim, Y. H.; Doo, J.-Y.;
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Chem. Mater. 2001, 13, 1438–1440.
1,3,5-Triethynyl-2,4,6-trifluorobenzene (9). Mp 94–
96 °C (subl.); 1H NMR (200 MHz): d ¼ 3:53 (s, 3H,
CBCH); 13C NMR (75 MHz): d ¼ 163:92 (dm,
JCF ¼ 256:8 Hz, Ar–F), 98.13 (m, Ar), 88.43, 87.18
(CBC); EIþ-MS m=z 204 (100, [Mþ]). HRMS found:
204.0189; calculated for C12H3F3: 204.0187. Rf ¼ 0:67
(20:1 Hex–Et2O).
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3935; Deacon, G. B.; Smith, R. M. N. Aust. J. Chem. 1982,
35, 1587–1597.
1,3-Bis(ethynyl)-2,4-difluoro-6-methoxybenzene
(10).
1
Mp 97–98 °C (subl.); H NMR (200 MHz): d ¼ 6:48 (d,
JHF ¼ 11:0 Hz, 1H, ArH), 3.91 (s, 3H, OCH3), 3.49 (s,
1H, C@CH), 3.43 (s, 1H, CBCH); 13C NMR (75 MHz):
d ¼ 165:28 (dd, JCF ¼ 257:8, 10.5 Hz, Ar–F), 164.13 (dd,
JCF ¼ 256:8, 8.4 Hz, Ar–F), 162.20 (ArC–OCH3), 95.57–
95.18 (m, ArC–H), 86.51–86.15 (m, ArCACBC), 71.59,
69.83 (CBC); EIþ-MS m=z 192 (100, [Mþ]). HRMS
found: 192.0388; calculated for C11H6OF2: 192.0387.
Rf ¼ 0:29 (20:1 Hex–Et2O).
10. Takahashi, S.; Kuroyama, K.; Sonogashira, K.; Hagihara,
N. Synthesis 1980, 627–630.
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1697.
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Synthesis. 3rd ed.; John Wiley & Sons: New York, 1999;
Chapter 8.
Acknowledgements
The present work was supported by the MCyT (Project
ꢀ
PB97-0002-C2 and Ramon y Cajal contract to G.H.).
We are also grateful to Profs. Pilar Prados and Javier de
ꢀ
Mendoza, Dr. Beatriz Souto Perez (SIDI) for the X-ray
spectroscopic determination of the single crystal struc-
13. Stang, P. J. In Modern Acetylene Chemistry; Stang, P. J.,
Diederich, F., Eds.; VCH: Weinheim, 1995.