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14
Can. J. Chem. Vol. 86, 2008
Trimethyl[(3-methoxyphenyl)ethynyl]silane, 4e [Chem.
4-[(Trimethylsilyl)ethynyl]phenol, 4p [Chem. Abstr.
88075-18-7]
Abstr. 40230-92-0]
1
1
H NMR (200 MHz, CDCl ) δ: 7.39 (dt, J = 9.0, 2.4 Hz,
H NMR (500 MHz, CDCl ) δ: 7.35 (d, J = 3.5 Hz, 2H),
3
3
1
2
H), 7.26 (s, 1H), 7.13 (t, J = 9.0 Hz, 1H), 7.06 (dt, J = 8.5,
7.53 (d, J = 3 Hz, 2H), 5.30 (s, 1H), 0.23 (s, 9H).
.4 Hz, 1H), 3.36 (s, 3H), 0.37 (s, 9H).
N,N-Dimethyl-4-[(trimethylsilyl)ethynyl]aniline, 4q
[Chem.Abstr. 40230-97-5]
3
3
-[(Trimethylsilyl)ethynyl]phenol, 4f [Chem. Abstr.
1
88061-72-1]
H NMR (500 MHz, CDCl3) δ: 7.31 (d, J = 9.0 Hz, 2H),
1
H NMR (500 MHz, CDCl ) δ: 7.16 (t, J = 7.5 Hz, 1H),
6.55 (d, J = 9.0 Hz, 2H), 2.92 (s, 6H), 0.21 (s, 9H).
3
7
1
.06 (d, J = 8.0 Hz, 1H), 6.96 (s, 1H), 6.81 (d, J = 6.0 Hz,
4
7
-[(Trimethylsilyl)ethynyl]aniline, 4r [Chem. Abstr.
H), 5.10 (s, 1H), 0.27 (s, 9H).
5867-39-9]
1
H NMR (200 MHz, CDCl ) δ: 7.27 (d, J = 6.8 Hz, 2H),
3
1
-[(Trimethylsilyl)ethynyl]aniline, 4g [Chem. Abstr.
3
6
.57 (d, J = 6.8 Hz, 2H), 3.80 (bs, 2H), 0.22 (s, 9H).
10598-30-6]
1
H NMR (200 MHz, CDCl ) δ: 7.65 (t, J = 8.0 Hz, 1H),
3
6
3
.86 (dt, J = 8.0, 3.0 Hz, 1H), 6.78 (s, 1H), 6.63 (dt, J = 8.0,
General procedure for the competitive coupling
reactions
The intermolecular competition was carried out using
iodobenzene (1.0 mmol, 204 mg, 0.11 mL) and the substi-
.0 Hz, 1H), 3.50 (s, 2H), 0.27 (S, 9H).
Trimethyl[(4-nitrophenyl)ethynyl]silane, 4h [Chem. Abstr.
tuted iodobenzene, 2a–2r (1.0 mmol), Pd(PPh ) (0.02 mmol,
7
5867-38-8]
3 4
1
2
3 mg), CuI (0.06 mmol, 11 mg), triethylamine (0.21 mL),
H NMR (200 MHz, CDCl ) δ: 8.18 (d, J = 6.6 Hz, 2H),
.50 (d, J = 6.7 Hz, 2H), 0.31 (s, 9H).
3
and trimethylsilylacetylene (0.05 mmol, 5 mg, 7 µL) com-
bined in THF (2.5 mL) and stirred under argon at room tem-
perature, 21 °C. After a standard reaction time of 5 h, a GC of
the mixture was run (internal standard biphenyl), and the rela-
tive rates of reactivity were calculated. The reported rates are
an average of a minimum of two experiments.
7
4
7
-[(Trimethylsilyl)ethynyl]benzonitrile, 4i [Chem. Abstr.
5867-40-2]
1
H NMR (500 MHz, CDCl ) δ: 7.59 (d, J = 6.4 Hz, 2H),
3
7
.53 (d, J = 6.4 Hz, 2H), 0.26 (s, 9H).
1
-[4-[(Trimethylsilyl)ethynyl]phenyl]ethanone, 4j [Chem.
GC conditions
Abstr. 75883-03-3]
The reaction mixtures were analyzed by a flame ioniza-
tion detector (FID) and DB-5 High Temp column. The initial
oven temperature was 50 °C, which was ramped by
1
H NMR (500 MHz, CDCl ) δ: 7.89 (d, J = 5.2 Hz, 2H),
3
7
.54 (d, J = 5.2 Hz, 2H), 2.61 (s, 3H), 0.27 (s, 9H).
5
°C/min to the final temperature of 200 °C, which was held
Methyl 4-[(trimethylsilyl)ethynyl]benzoate, 4k [Chem.
for 5 min. At least two GC runs were performed for each
sample to ensure reproducibility.
Abstr. 75867-41-3]
1
H NMR (500 MHz, CDCl ) δ: 7.97 (d, J = 6.8 Hz, 2H),
3
7
.52 (d, J = 6.8 Hz, 2H), 3.92 (s, 3H), 0.26 (s, 9H).
Computational details
All geometry optimizations were performed with
Gaussian03 (22), using the Perdew–Burke–Ernzerhof
(PBE0) hybrid density functional (23–25) with the 6–
31+G(d) basis set for all atoms except for iodine and the
Midi! basis set (26) for iodine. All geometries were con-
firmed to be minima by frequency calculations. In case of
rotational isomerism (m-CO CH , m-OCH , and m-OH), the
(
[1,1′-Biphenyl]-4-ylethynyl)trimethylsilane, 4l [Chem.
Abstr. 75867-42-4]
1
H NMR (500 MHz, CDCl ) δ: 7.49 (d, J = 6.0 Hz, 2H),
3
7
1
1
0
.44 (m, 4H), 7.34 (t J = 6.0 Hz, 2H), 7.26 (t, J = 6.0 Hz,
H), 0.19 (s, 9H). 13C NMR (125 MHz, CDCl ) δ: 141.1,
3
40.3, 132.4, 128.8, 127.6, 127.0, 126.9, 122.0, 105.0, 94.8,
.3.
2
3
3
lower-energy conformer, determined through either elec-
tronic energies or Gibbs free energies, given in Fig. S2 in the
2
Trimethyl[(4-ethylphenyl)ethynyl]silane, 4m [Chem. Abstr.
supplementary information was used in the analyses. Wave
3
93857-27-7]
functions were analyzed with the Proaim module from the
AIMPAC (27) series of programs for charges (q) and
quadrupole moments (Qzz); both are obtained from integra-
tions of the electron density over the atomic basin. For p-
C H (torsional angle 90°) and p-Ph (torsional angle 40°),
1
H NMR (500 MHz, CDCl ) δ: 7.39 (d, J = 8 Hz, 2H),
.10 (d, J = 8 Hz, 2H), 2.62 (q, J = 7 Hz, 2H), 1.21 (t, J =
.5 Hz, 3H), 0.27 (s, 9H).
3
7
7
2
5
Trimethyl[(4-methylphenyl)ethynyl]silane, 4n [Chem.
wave functions were also obtained for the planarized geome-
tries and these were used in the analyses. Total energies as
well as the q and Qzz data used in the correlations are given
Abstr. 4186-14-5]
1
H NMR (500 MHz, CDCl ) δ:7.11 (d, J = 3.2 Hz, 2H),
3
2
6
.83 (d, J = 3.2 Hz, 2H), 2.34 (s, 3H), 0.26 (s, 9H).
in Table S1 of the supplementary information.
Trimethyl[(4-methoxyphenyl)ethynyl]silane, 4o [Chem.
Acknowledgments
Abstr. 3989-14-8]
1
H NMR (200 MHz, CDCl ) δ: 7.42 (d, J = 8.7 Hz, 2H),
Financial support by the Natural Sciences and Engi-
neering Research Council of Canada (NSERC) is gratefully
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6
.81 (d, J = 8.7 Hz, 2H), 3.60 (s, 3H), 0.70 (s, 9H).
©
2008 NRC Canada