We here present four examples of fluoride catalyzed P–C
couplings, further procedures are deposited in the ESIw to this
article.
the reaction mixture was stirred for 10 min at 100 1C. Then
hydrazine monohydrate (3.50 mL, 72.01 mmol) and ethanol
(10.00 mL) were added and the reaction mixture was refluxed
for 15 h. The work-up corresponds to the procedure presented
above, the product was obtained as a yellow solid (6.33 g, 81%).
1H-NMR (CDCl3, 200.13 MHz): d = 6.65 (d, 3JHH = 2.3 Hz,
1H, H-6P), 7.34–7.46 (m, 12H, H-2Ph, H-3Ph, H-4Ph, H-2P,), 7.63
Syntheses
Large-scale synthesis of (E)-[2-((30-N,N-dimethylamino)prop-
20-en-10-onyl)phenyl]diphenylphosphine (3a). In a flame-dried,
nitrogen flushed three-necked flask CsF (176 g, 1.16 mol) was
suspended in dry DMF (700 mL) and (E)-3-(N,N-dimethyl-
amino)-1-(20-fluorophenyl)prop-2-en-1-one (2a) (178 g,
921.23 mmol) was added. After dropwise addition of
diphenyl(trimethylsilyl)phosphine (1a) (238 mL, 929.45 mmol),
the reaction mixture was stirred for 48 h at room temperature.
The mixture was diluted with H2O (800 mL) and CH2Cl2
(800 mL), the layers were separated and the aqueous layer
was extracted with CH2Cl2 (3 ꢁ 200 mL). The combined
organic layers were washed with H2O (3 ꢁ 400 mL), dried over
MgSO4 and the solvent was removed in vacuo. The product was
obtained as a yellow solid (314 g, 95%). 1H-NMR (CDCl3,
400.13 MHz): d = 2.69 + 2.94 (2 s, 6H, H-10E, H-11E), 5.40
3
3
(d, JHH = 2.2 Hz, 1H, H-7P), 7.78 (d, JHH = 7.1 Hz, 2H,
H-3P) ppm. 13C-NMR (CDCl3, 100.61 MHz): d = 102.8 (s, 1C,
C-6P), 125.7 (d, JCP = 6.9 Hz, 2C, C-3P), 128.5 (d, JCP =
3
3
7.0 Hz, 4C, C-3Ph), 128.7 (s, 2C, C-4Ph), 132.1 (s, 1C, C-7P),
132.6 (s, 4C, C-4P), 133.7 (d, 3JCP = 19.5 Hz, 1C, C-2Ph), 134.1
3
3
(d, JCP = 19.5 Hz, 2C, C-2P), 137.0 (d, JCP = 11.9 Hz, 2C,
C-1Ph), 137.10 (d, 3JCP = 11.2 Hz, 1C, C-1P), 148.9 (s, 1C, C-5P)
ppm. 31P-NMR (CDCl3, 91.01 MHz): d = ꢀ4.4 (s) ppm.
(4-Cyanophenyl)cyclohexylphenylphosphine (3q). In a flame-
dried, nitrogen flushed three-necked flask CsF (497 mg,
3.27 mmol) was suspended in dry DMF (15 mL) and stirred
for 30 min at room temperature. 4-Fluorobenzonitrile (2j)
(1.31 g, 10.81 mmol) was added and the reaction mixture was
stirred for further 10 min at room temperature. After addition
of cyclohexylphenyl(trimethylsilyl)phosphine (1d) (2.83 g,
10.70 mmol), the reaction mixture was stirred for 20 h at
60 1C and the solvent was removed in vacuo. The residue was
diluted with aqueous NH4Cl (50 mL) and CH2Cl2 (50 mL), the
layers were separated and the aqueous layer was extracted
with CH2Cl2 (3 ꢁ 20 mL). The combined organic layers were
washed with H2O (3 ꢁ 20 mL), dried over MgSO4 and the
solvent was removed in vacuo. The product was obtained
as a yellow-brown oil (2.25 g, 72%). 1H-NMR (CDCl3,
600.13 MHz): d = 1.14–1.34 (m, 5H, Hcy), 1.65–1.79
(m, 5H, Hcy), 2.17–2.23 (m, 1H, Hcy), 7.36–7.37 (m, 3H, Har),
7.43–7.46 (m, 2H, Har), 7.50–7.53 (m, 2H, Har), 7.57–7.58
(m, 2H, Har) ppm. 13C-NMR (CDCl3, 150.92 MHz): d =
3
3
(d, JHH = 12.6 Hz, 1H, H-8E), 7.04 (dd, JHP = 3.3 Hz,
3JHH = 7.0 Hz, 1H, H-2E), 7.26–7.34 (m, 12H, H-2Ph, H-3Ph
,
H-4Ph, H-3E, H-4E), 7.38 (ddd, 4JHP = 1.2 Hz, 3JHH = 7.4 Hz,
3JHH = 7.5, 1H, H-5E), 7.64 (m, 1H, H-9E) ppm. 13C-NMR
(CDCl3, 100.62 MHz): d = 36.51 + 44.38 (s, 6C, C-10E,
3
C-11E), 95.89 (s, 1C, C-8E), 127.10 (d, JCP = 5.5 Hz, 1C,
3
C-5E), 127.76 (s, 2C, C-4Ph), 127.82 (d, JCP = 6.5 Hz, 4C,
C-3Ph), 128.03 (s, 1C, C-4E), 128.83 (s, 1C, C-3E), 133.15
2
(d, JCP = 19.4 Hz, 4C, C-2Ph), 134.17 (s, 1C, C-1E), 135.55
(d, 2JCP = 19.4 Hz, 1C, C-2E), 138.40 (d, 1JCP = 11.1 Hz, 2C,
2
C-1Ph), 146.94 (d, JCP = 25.9 Hz, 4C, C-6E), 154.28
(s, 1C, C-9E), 190.91 (s, 1C, C-7E) ppm. 31P-NMR (CDCl3,
161.98 MHz): d = ꢀ8.8 (s) ppm.
[4-(Methoxycarbonyl)phenyl]diphenylphosphine (3e). In
a
3
26.3 (s, C-8Cy), 26.9 (d, JCP = 12.5 Hz, 2C, C-7Cy), 29.4
procedure similar to the one discussed above, 4-fluorobenzoic
acid methyl ester (2e) (6.50 mL, 50.18 mmol), diphenyl-
(trimethylsilyl)phosphine (1a) (13.40 mL, 52.33 mmol) and
CsF (1.54 g, 10.14 mmol) in dry DMF (24.00 mL) were
reacted. The reaction mixture was stirred for 50 min at room
temperature. The product was obtained as a colourless solid
(14.83 g, 92%). 1H-NMR (CDCl3, 400.13 MHz): d = 3.91
(s, 3H, H-6B), 7.30–7.39 (m, 12H, H-2Ph, H-3Ph, H-4Ph, H-2B),
2
(d, JCP = 12.5 Hz, C-6Cy), 29.8 (d, JCP = 16.6 Hz, C-6Cy),
2
1
35.4 (d, JCP = 11.1 Hz, C-5Cy), 111.9 (s, C-12Ph), 118.9
3
(s, C-13Ph), 128.7 (d, JCP = 6.9 Hz, 2C, C-3Ph), 129.5
3
(s, C-4Ph), 131.7 (d, JCP = 5.6 Hz, 2C, C-11Ph), 133.7
2
(d, JCP = 18.0 Hz, 2C, C-10Ph), 134.2 (d, JCP = 20.8 Hz,
2
2C, C-2Ph), 135.3 (d, 1JCP = 13.9 Hz, C-1Ph), 145.2 (d, 1JCP
=
20.8 Hz, C-9Ph) ppm. 31P-NMR (CDCl3, 161.98 MHz):
4
3
d = ꢀ2.1 (s) ppm.
7.98 (dd, JHP = 1.4 Hz, JHH = 8.3 Hz, 2H, H-3B) ppm.
13C-NMR (CDCl3, 50.33 MHz): d = 52.1 (s, 1C, C-6B), 128.6
(d, JCP = 7.2 Hz, 4 C, C-3Ph), 129.1 (s, 2C, C-4Ph) 129.2
3
X-Ray structure analyses. Crystal data and refinement
parameters are collected in Table 3. The structures were solved
using a direct method (SIR9229), and completed by subsequent
difference Fourier syntheses, and refined by full-matrix least-
squares procedures.30 Semi-empirical absorption correction
from equivalents (Multiscan)31 was carried out for the struc-
tural elucidation of (2-cyanophenyl)diphenylphosphine (3h),
while for 4-(diphenylphosphino)benzoic acid no absorption
correction has been performed. All non-hydrogen atoms
were refined with anisotropic displacement parameters. All
hydrogen atoms positions were calculated in ideal positions
(riding model) except the hydrogen atom H2O in 4-(diphenyl-
phosphino)benzoic acid, which is bound to the oxygen atom
O2, was located in the difference Fourier synthesis, and was
3
(d, JCP = 6.4 Hz, 2C, C-3B), 130.0 (s, 1C, C-4B), 133.1
2
2
(d, JCP = 18.8 Hz, 2C, C-2B), 133.9 (d, JCP = 20.0 Hz,
1
4C, C-2Ph), 136.11 (d, JCP = 0.6 Hz, 2C, C-1Ph), 144.0
1
(d, JCP = 14.4 Hz, 1C, C-1B), 166.8 (s, 1C, C-5B) ppm.
31P-NMR (CDCl3, 161.98 MHz): d = ꢀ3.6 (s) ppm.
One-pot P–C-coupling with follow-up functionalization,
synthesis of [4-(pyrazol-30-yl)phenyl]diphenylphosphine (4). In
a flame-dried, nitrogen flushed Schlenk tube CsF (0.36 g,
2.37 mmol) was suspended in dry DMF (4.70 mL) and
(E)-3-(N,N-dimethylamino)-1-(40-fluorophenyl)prop-2-en-1-one
(2b) (4.61 g, 23.86 mmol) was added. After dropwise addition of
diphenyl(trimethylsilyl)phosphine (1a) (7.10 mL, 23.80 mmol),
c
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011
New J. Chem., 2011, 35, 2488–2495 2493