528 Yamamoto et al.
17 Hz), 1.76 (s, 3H), 1.18 ppm (s, 3H); 11B NMR
(CDCl3): δ = –9.4 ppm; 19F NMR (CDCl3): δ =
−44.7 ppm; 31P NMR (CDCl3): δ = 86.1 ppm;
elemental analysis: calcd (%) for C22H22BF4OP: C
62.89, H 5.28; Found: C 62.89, H 4.91.
(m, 5H), 7.45–7.44 (m, 1H), 7.22–7.17 (m, 5H), 4.93
2
2
(dd, 1H, JH-H = 16 Hz, JP-H = 7 Hz), 4.67 (dd, 1H,
2 JH-H = 16 Hz, 2 JP-H = 20 Hz), 1.69 (s, 3H), 1.15 ppm
(s, 3H); 31P NMR (CDCl3): δ = 86.8 ppm; elemental
analysis: calcd (%) for C22H22BrOP: C 63.94, H 5.37;
Found: C 63.78, H 5.35.
1-Benzyl-1-phenyl-3,3-dimethyl-3H-2,1-benzoxa-
phosphonium Chloride (4). A solution of 3 (200 mg,
0.826 mmol) in dry Et2O (0.5 mL) was treated
with benzyl chloride (0.14 mL, 1.2 mmol) and
then stirred overnight at rt. The resulting white
precipitate was washed with dry Et2O and then
subjected to recrystallization in CH2Cl2/Et2O to give
a white crystalline solid of 4 (240 mg, 0.651 mmol,
79%). Mp: 118–123◦C (dec); 1H NMR (CDCl3):
δ = 9.67–9.64 (m, 1H), 8.57–8.51 (m, 2H), 7.74–7.64
(m, 5H), 7.37–7.36 (m, 2H), 7.16–7.15 (m, 4H), 6.60
1-Benzyl-1-fluoro-1-phenyl-3,3-bis (trifluorome-
thyl)-3H-2,1-benzoxaphosphole (5ꢀ). A solution of 3ꢀ
(308 mg, 0.879 mmol) in dry CH3CN (3 mL) was
treated with benzyl bromide (0.15 mL, 1.3 mmol)
and stirred for 1 day at rt. The resulting white pre-
cipitate was washed with dry Et2O, and then the solid
was dissolved into dry CH2Cl2 (5 mL). The solution
was transferred to KF (150 mg, 2.63 mmol), and the
mixture was stirred overnight at rt. The mixture was
treated with ice/water, extracted with Et2O, and the
organic layer was dried over anhydrous MgSO4. Af-
ter evaporation of the solvents, the crude solid was
purified by recrystallization from Et2O/n-hexane to
give colorless crystals of 5ꢀ (230 mg, 0.500 mmol,
2
2
(dd, 1H, JH-H = 16 Hz, JP-H = 8 Hz), 4.38 (dd, 1H,
2 JH-H = 16 Hz, 2 JP-H = 18 Hz), 1.77 (s, 3H), 1.17 ppm
1
1
57%). Mp: 186–195◦C; H NMR (CDCl3): δ = 8.33–
(s, 3H); H NMR (CD3CN): δ = 8.52–8.48 (m, 1H),
8.09–8.04 (m, 2H), 7.85–7.66 (m, 5H), 7.46–7.42 (m,
8.28 (m, 1H), 7.86–7.81 (m, 1H), 7.69–7.66 (m, 2H),
7.42–7.15 (m, 10H), 3.94–3.79 ppm (m, 2H); 19F NMR
2
2H), 7.22–7.14 (m, 4H), 5.09 (dd, 1H, JH-H = 15
2
2
1
3
Hz, JP-H = 20 Hz), 4.67 (dd, 1H, JH-H = 15 Hz,
2 JP-H = 7 Hz), 1.68 (s, 3H), 1.12 ppm (s, 3H); 31P
NMR (CDCl3): δ = 87.4 ppm. Elemental analysis:
calcd (%) for C22H22ClOP + 0.5H2O: C 69.93, H 6.14;
Found: C 69.78, H 5.92.
(CDCl3): δ = –46.9 (dt, 1F, JP-F = 686 Hz, JF-H
=
4
11 Hz), –75.5 (q, 3F, JF-F = 10 Hz), –75.9 (q, 3F,
4 JF-F = 10 Hz) ppm; 31P NMR (CDCl3): δ = −33.5 (d,
1P, 1 JP-F = 686 Hz) ppm.
1-Benzyl-1-fluoro-1-phenyl-3,3-dimethyl-3H-2,1-
benzoxaphosphole (5). A solution of 1 (140 mg,
0.339 mmol) in dry CH2Cl2 (5 mL) was added to
KF (100 mg, 1.72 mmol) and the resulting mixture
was stirred overnight at rt. After evaporation to
dryness, materials soluble to Et2O were collected by
decantation and then the solvent was evaporated.
The resulting solid was purified by recrystallization
from Et2O/n-hexane to give colorless crystals of
5 (54 mg, 0.15 mmol, 45%). 1H NMR (CDCl3):
Single Crystal X-Ray Analyses for 1, 7, and 5ꢀ
For 1, a crystal suitable for the X-ray structural
determination was mounted on a Mac Science
DIP2030 imaging plate diffractometer (Bruker AXS
Japan Co. Ltd., Yokohama, Japan) and irradiated
with graphite monochromated Mo Kα radiation
˚
(λ = 0.71073 A) for data collection. The unit cell pa-
rameters were determined by separately autoindex-
ing several images in each data set using the DENZO
program (HKL Research, Inc., Charlottesville, VA)
[10]. For each data set, the rotation images were
collected in three degree increments with a total ro-
tation of 180◦ about the φ axis. The data were pro-
cessed using SCALEPACK (HKL Research, Inc.). For
7 and 5ꢀ; crystals suitable for X-ray structure deter-
mination were mounted on a Mac Science MXC3
diffractometer (Bruker AXS Japan Co. Ltd.) and ir-
radiated with graphite-monochromated Mo Kα (for
5ꢁ) or Cu Kα (for 7) radiation for data collection.
Data were collected with the 2θ/ω-scan mode. All
data were corrected for absorption and extinction.
The structures were solved by a direct method
using the SHELXS-97 program [10]. Refinement on
F2 was carried out using full-matrix least-squares
by the SHELXL-97 program [11]. All non-hydrogen
atoms were refined using anisotropic thermal
parameters, except for the disordered fluorine
δ = 8.13–8.08 (m, 1H), 7.95–7.89 (m, 2H), 7.46–7.27
2
(m, 7H), 7.21–7.07 (m, 4H), 3.73 (d, 2H, JP-H
=
18 Hz), 1.31 (s, 3H), 1.11 ppm (s, 3H); 19F NMR
(CDCl3): δ = −31.1 (d, 1F, JP-F = 621 Hz) ppm; 31P
1
1
NMR (CDCl3): δ = −35.1 (d, 1P, JP−F = 621 Hz)
ppm; elemental analysis: calcd (%) for C22H22FOP:
C 74.99, H 6.29; Found: C 74.68, H 6.06.
1-Benzyl-1-phenyl-3,3-dimethyl-3H-2,1-benzoxa-
phosphonium Tetrafluoroborate (7). A solution of 6
(51 mg, 0.15 mmol) in CH2Cl2 (2 mL) was treated
with aqueous HBF4 (48 wt%, 0.10 mL, 0.77 mmol)
for 1 h at rt. After drying in vacuo, the resulting
solid was recrystallized from CH3CN/Bu2O to give
colorless crystals of 7 (18 mg, 0.043 mmol, 29%).
Mp: 173–177◦C; 1H NMR (CDCl3): δ = 8.70–8.67
(m, 1H), 8.07–8.02 (m, 2H), 7.78–7.76 (m, 5H),
2
7.23–7.19 (m, 6H), 4.99 (dd, 1H, JH-H = 16 Hz,
2
2
2 JP-H = 7 Hz), 4.22 (dd, 1H, JH-H = 16 Hz, JP-H
=
Heteroatom Chemistry DOI 10.1002/hc