K. Takeda et al. / Journal of Organometallic Chemistry 611 (2000) 449–454
453
(OCH2CH3), 19.1 (CMe3), 26.4 (t-Bu), 40.9 (d, J=
148.2 Hz, CH), 63.6, 63.7 (OCH2), 127.7, 128.4, 129.6,
and 138.1 (Ar). HRMS Calc. for C17H3O3PSSi:
374.1501. Found: 374.1512. Complex 11: a colorless oil,
Rf=0.32 (1:2 hexane–AcOEt). IR (film): 1250, 1025
mmol) in THF. The solution was allowed to warm to
0°C, diluted with saturated aqueous NH4Cl (20 ml), and
then extracted with Et2O (3×20 ml). The combined
organic phases were washed with saturated brine (40
ml), dried, and concentrated. The residual oil was sub-
jected to column chromatography (silica gel, 400 g;
elution with 50:1 hexane–Et2O) to give 21 (2.20 g, 55%)
and 20 (1.16 g, 39%).
1
cm−1. H-NMR (500 MHz, CDCl3): l 1.12, 1.32 (each
3H, t, J=7.1 Hz, OCH2CH3), 2.64 (1H, dd, J=10.9,
8.1 Hz, SH) 3.77–3.87 (1H, m, OCH2), 3.95–4.03 (1H,
m, OCH2),4.08 (1H, dd, J=18.8, 8.1 Hz, CH), 4.12–
4.21 (2H, m, OCH2), 7.28 (1H, tm, J=7.5 Hz, ArꢀH),
7.33 (2H, tm, J=7.5 Hz, ArꢀH), 7.45 (2H, dm, J=7.5
Hz, ArꢀH). 13C-NMR (125 MHz, CDCl3): l 16.4, 16.6
(OCH2CH3), 38.4 (d, J=148.2 Hz, CH), 63.7, 63.8
(OCH2), 128.2, 128.8, 129.0, and 136.6 (Ar). HRMS
Calc. for C11H17O3PS: 260.0636. Found: 260.0654.
To a solution of 21 (2.20 g, 5.13 mmol) in CH2Cl2 (51
ml) was added an excess of 5% HF in MeCN, and the
solution was stirred at room temperature for 90 min.
The mixture was poured into a saturated aqueous
NaHCO3 solution and then extracted with Et2O (3×50
ml). Combined organic phases were successively washed
with H2O (50 ml) and saturated brine (50 ml), dried, and
concentrated. The residual oil was subjected to column
chromatography (silica gel, 170 g; elution with 50:1
hexane–Et2O) to give 22 (1.44 g, 90%). Complex 22: a
colorless oil, Rf=0.32 (hexane). IR (film) 1595, 1490,
3.1.2. Reaction of 8 with methyllithium
To a cooled (−98°C) solution of 8 (185 mg, 494
mmol) in THF (5 ml) was added MeLi (0.37 M, 1.34 ml,
496 mmol). After being stirred at the same temperature
for 15 min, the reaction was quenched by the addition
of AcOH (29 ml, 507 mmol). The mixture was passed
through a short pad of silica gel and concentrated. The
residual oil was subjected to column chromatography
(silica gel, 18 g; elution with 1:1 hexane–AcOEt) to give
11 (21 mg, 16%), 12 (48 mg, 41%), and 13 (48%),
1
1255 cm−1. H-NMR (500 MHz, CDC13): l 0.44 (6H,
s, SiMe2) 10.69 (9H, s, t-Bu), 2.19 (1H, s, SH), 7.19 (2H,
t, J=7.3 Hz, ArꢀH), 7.27 (4H, t, J=7.3 Hz, ArꢀH),
7.43 (4H, t, J=7.3 Hz, ArꢀH). 13C-NMR (125 MHz,
CDC13): l −2.9 (SiMe2), 20.1 (CMe3), 28.2 (t-Bu), 47.7
(CꢀS), 126.1, 128.0, 129.3, and 148.3 (Ar). HRMS Calc.
for C19H26SSi: 314.1525. Found: 314.1553.
1
calculated from H-NMR integration).
3.1.5. Reaction of 22 with MeLi
3.1.3. t-Butyldimethylsilyl diphenyl sulfide (20)
t-Butyldimethylsilylchloride (1.48 g, 9.77 mmol),
Et3N (1.48 ml, 10.6 mmol), and DMAP (399 mg, 3.26
MeLi (1.14 M in Et2O, 372 ml, 424 mmol) was added
to a cooled (−98°C) solution of 22 (133 mg, 424 g mol)
in THF (3.9 ml). After being stirred at the same temper-
ature for 10 min, the reaction was quenched by the
addition of AcOH (24.3 ml, 424 mmol) in THF (1 ml).
The mixture was diluted with saturated aqueous NH4C1
(20 ml), and extracted with Et2O (3×20 ml). The
combined organic phases were washed with saturated
brine (40 ml), dried, and concentrated. The residual oil
was subjected to column chromatography (silica gel, 20
g; elution with 60:1 hexane–Et2O) to give 20 (107 mg,
81%).
mmol) were added to
a solution of diphenyl-
methanethiol (19) (1.63 g, 8.14 mmol) in CH2Cl2 (20
ml). After being stirred at room temperature for 3 h, the
solution was diluted with CH2Cl2 (5 ml) and washed
with water (20 ml). The aqueous phase was extracted
with CH2Cl2 (3×20 ml), and combined organic phases
were washed with saturated aqueous NH4Cl (40 ml),
and then concentrated. The residual oil was subjected to
column chromatography (silica gel, 250 g; elution with
50:1 hexane–Et2O) to give 20 (2.15 g, 84%). Complex
1
20: a colorless oil, Rf=0.64 (10:1 hexane–Et2O). H-
3.1.6. Thia–Brook rearrangement of 22 into 20 with
DBU
NMR (500 MHz, CDC13): l 0.14 (6H, s, SiMe2), 0.95
(9H, s, t-Bu), 5.26 (1H, s, CH), 7.22 (2H, t, J=7.7 Hz,
ArꢀH), 7.32 (4H, t, J=7.7 Hz, ArꢀH), 7.49 (4H, t,
J=7.7 Hz, ArꢀH). 13C-NMR (125 MHz, CDC13): l
−3.4 (SiMe2), 19.0 (CMe3), 26.5 (t-Bu), 49.9 (CH),
126.9, 128.2, 128.5, and 144.6 (Ar). HRMS Calc. for
C19H26SSi: 314.1525. Found: 314.1544.
Complex 22 (14.9 mg, 47.4 mmol) was dissolved in
CDC13 (877 ml) in a NMR tube, and 10% DBU solution
in CDC13 (70.9 ml, 47.4 mmol) was added. The 1H-NMR
(300 MHz) was recorded at intervals of ca. 30 s at 23°C.
Half-live values were determined by following the disap-
pearance of a peak at 2.19 ppm assigned as SH in 22
and the appearance of a peak at 5.26 ppm assigned as
CH in 20.
3.1.4. (t-Butyldimethylsilyl)diphenylmethanethiol (22)
To a cooled (−80°C) solution of 20 (2.98 g, 9.48
mmol) in THF (12 ml) was added n-BuLi (0.40 M) in
hexane (6.80 ml, 9.48 mmol), and the solution was
stirred at the same temperature for 15 min before the
addition of t-butyldimethylsilylchloride (1.43 g, 9.48
3.1.7. (t-Butyldimethylsilyl)diphenylmethanol (23)
To a cooled (−80°C) solution of 6 (960 mg, 4.36
mmol) in toluene (2 ml) was added dropwise PhLi (1.04
M in cyclohexane–diethylether, 4.20 ml, 4.36 mmol).