F. Homsi et al. / Journal of Organometallic Chemistry 624 (2001) 208–216
215
added slowly to CuF2–2H2O (4.0 g, 29 mmol) in dry
diethylether (20 ml) at 0°C. The resulting slurry was
stirred at r.t. overnight, diluted with pentane, filtered
over Celite, and the filtrate was concentrated to give a
brown oil which distillated at 77°C (0.15 mmHg) to
afford (cyclohexyl)(difluoro)[4-(trifluoromethyl)phenyl]-
130.93 (2C), 140.00, 145.25, 168.12. Anal. Calc. for
C13H10O2: C, 78.77; H, 5.08. Found: C, 78.72; H,
5.01%.
4.5.4. 4%-Methylbiphenyl-4-carboxylic acid (4d)
1H-NMR (200 MHz, acetone-d6) l 2.40 (s, 3H), 7.35
(d, J=7.8 Hz, 2H), 7.60 (d, J=7.8 Hz, 2H), 7.80 (d,
J=7.8 Hz, 2H), 8.15 (d, J=7.8 Hz, 2H). 13C-NMR (50
MHz, DMSO-d6) l 21.69, 127.44 (2C), 127.74 (2C),
130.27, 130.65 (2C), 130.92 (2C), 137.07, 138.75, 145.18,
168.14. Anal. Calc. for C14H12O2: C, 79.23; H, 5.70.
Found: C, 79.20; H, 5.65%.
1
silane as a colorless oil (2.8 g, 65% yield). H-NMR
(200 MHz) l 1.10–1.50 (m, 6H), 1.60–1.95 (m, 5H),
7.60–7.90 (m, 4H). 13C-NMR (50 MHz) l 23.39 (t),
25.21 (2C), 26.32, 27.02 (2C), 123.91 (q), 124.88 (q, 2C),
133.13 (t), 133.60 (q), 134.40 (t, 2C). 19F-NMR (188
MHz) l −64.00 (s, 3 F), −148.00 (s, 2 F). Anal. Calc.
for C13H15F5Si: C, 53.05; H, 5.14. Found: C, 53.20; H,
5.20%.
4.5.5. 2%-Methylbiphenyl-4-carboxylic acid (4e)
1H-NMR (200 MHz, acetone-d6) l 2.20 (s, 3H),
7.10–7.2 (m, 4H), 7.35 (d, J=8.5 Hz, 2H), 8.00 (d,
J=8.5 Hz, 2H). 13C-NMR (50 MHz, DMSO-d6) l
21.07, 126.03, 127.05, 128.84, 130.23 (2C), 131.46,
135.63, 138.56, 140.37, 141.29, 145.20, 168.16. Anal.
Calc. for C14H12O2: C, 79.23; H, 5.70. Found: C, 79.28;
H, 5.67%.
4.5. General procedure for the solid phase
cross-coupling of (aryl)(difluoro)silanes with Wang
resin-tethered iodobenzoic acid
4.5.1. 4%-Butyl-biphenyl-4-carboxylic acid (4a)
To 0.1 g of resin 1 (0.88 mmol g−1, 0.088 mmol) was
added 5 ml of dry THF. After swelling for 30 min, the
following were added in sequential order Pd(PPh3)4
(0.010 g, 5 mol%), 3a% (0.20 g, 0.88 mmol), and TBAF
(0.88 ml, 1 M in THF). The test tube was then capped,
and the reaction mixture was stirred at 80°C for 30 h.
Subsequently, the resin was filtered and washed succes-
sively with 3×THF, 3×DMF, briefly with 2×dilute
KCN in DMSO, 3×DMF, 3×MeOH, 3×CH2Cl2,
and finally 2×MeOH. After drying to a constant
weight, the resin was cleaved with TFA–CH2Cl2 (1:3, 4
ml) for 1 h to give 4a (22 mg), quantitative yield.
1H-NMR (200 MHz, acetone-d6) l 0.85–1.00 (t, J=7.4
Hz, 3H), 1.25–1.50 (m, 2H), 1.50–1.78 (m, 2H), 2.60–
2.75 (t, J=7.4 Hz, 3H), 7.30 (d, J=8.1 Hz, 2H), 7.57
(d, J=8.1 Hz, 2H), 7.70 (d, J=8.1 Hz, 2H), 8.20 (d,
J=8.1 Hz, 2H). 13C-NMR (50 MHz, DMSO-d6) l
12.45, 20.87, 32.07, 33.80, 125.28 (2C), 125.57 (2C),
127.09, 127.48 (2C), 128.54 (2C), 135.73, 141.62, 144.07,
165.54. Anal. Calc. for C17H18O2: C, 80.28; H, 7.13.
Found: C, 80.25; H, 7.16%.
4.5.6. 3%-Methylbiphenyl-4-carboxylic acid (4f)
1H-NMR (200 MHz, acetone-d6) l 2.40 (s, 3H), 7.22
(m, 1H), 7.38 (m, 1H), 7.50 (m, 1H), 7.80 (d, J=8.0
Hz, 2H), 8.10 (d, J=8.0 Hz, 2H). 13C-NMR (50 MHz,
DMSO-d6) l 22.04, 125.04, 127.75 (2C), 128.57, 129.94,
130.89 (2C), 139.25, 139.95, 145.38, 168.15. Anal. Calc.
for C14H12O2: C, 79.23; H, 5.70. Found: C, 79.19; H,
5.63%.
4.5.7. 4%-Fluorobiphenyl-4-carboxylic acid (4g)
1H-NMR (200 MHz, acetone-d6) l 7.20–7.35 (m,
2H), 7.75–7.85 (m, 4H), 8.10 (d, J=8.5 Hz, 2H).
13C-NMR (50 MHz, DMSO-d6) l 113.37, 116.44 (d,
2C), 118.18, 127.06 (2C), 130.03 (d, 2C), 130.33, 143.60,
162.70, 167.51. Anal. Calc. for C13H9FO2: C, 72.22; H,
4.20. Found: C, 72.05; H, 4.05%.
Acknowledgements
The authors sincerely acknowledge the financial sup-
port provided by the Japan Society for the Promotion
of Science (JSPS) for F.H. and the Science and Tech-
nology Agency (STA). We also thank the Ministry of
Education, Science, Sports and Culture, Japan, for the
grant-in-aids for COE Research on Elements Science,
no. 12CE2005.
4.5.2. 4%-Methoxybiphenyl-4-carboxylic acid (4b)
1H-NMR (200 MHz, acetone-d6) l 3.80 (s, 3H), 7.10
(d, J=8.3 Hz, 2H), 7.65 (d, J=8.3 Hz, 2H), 7.75 (d,
J=8.3 Hz, 2H), 7.95 (d, J=8.3 Hz, 2H). 13C-NMR (50
MHz, DMSO-d6) l 53.86, 112.84 (2C), 124.94 (2C),
126.69, 126.84 (2C), 128.54 (2C), 130.87, 143.68, 158.30,
165.55. Anal. Calc. for C14H12O3: C, 73.67; H, 5.30.
Found: C, 73.65; H, 5.25%.
References
4.5.3. Biphenyl-4-carboxylic acid (4c)
1H-NMR (200 MHz, acetone-d6) l 7.35–7.6 (m, 3H),
7.70 (d, J=6.9 Hz, 2H), 7.80 (d, J=6.9 Hz, 2H), 8.15
(d, J=6.9 Hz, 2H). 13C-NMR (50 MHz, DMSO-d6) l
127.78 (2C), 127.93 (2C), 129.26, 130.05 (2C), 130.61,
[1] F. Diederich, P.J. Stang (Eds.), Metal-Catalyzed Cross-Coupling
Reactions, Weinheim, Germany, 1998.
[2] See for example: (a) J.V. Duncia, D.J. Carini, A.T. Chiu, A.L.
Johnson, W.A. Price, P.C. Wong, R.R. Wexler, P.B.M.W.M.