was stirred under a flow of N2(g). Bubbling (evolution of H2(g))
was observed immediately upon addition of catalyst. After 1 h
the solution was concentrated under vacuum to approx. 0.5 mL
and hexanes (3 mL) were added to give a cloudy suspension.
This mixture was cooled at −22 ◦C overnight to afford a white
crystalline material. The solid was isolated by vacuum filtration,
washed with cold (−22 ◦C) pentane (3 × 1 mL), and dried under
vacuum (227 mg, 90%). Anal. Calc. for C25H22SSi: C 77.99, H
5.76; Found: C 77.72, H 5.85. 1H NMR (300 MHz, C6D6) d 1.87
(s, 3H, S(C6H4)CH3), 6.57 (d, 2H, JHH = 8.0 Hz, S(C6H4)CH3),
7.06–7.18 (m, 9H, Hm,p-SiPh3), 7.24 (d, 2H, S(C6H4)CH3), 7.72 (m,
plug of Celite in a Pasteur pipet to give a clear, colorless solution.
The hexanes were removed under vacuum to afford a white solid
(375 mg, 85%). Anal. Calc. for C21H22SSi: C 74.94, H 6.59; Found:
1
C 75.39, H 6.56. H NMR (300 MHz, C6D6) d 0.74 (t, JHH
=
7.2 Hz, 3H, SiS(CH2)2CH3), 1.40 (sextet, 2H, SiSCH2CH2CH3),
2.40 (t, 2H, SiSCH2C2H5), 7.12–7.18 (m, 9H, Hm,p-SiPh3), 7.77–
7.91 (m, 6H, Ho-SiPh3); 13C{ H} NMR (75.47 MHz, C6D6) d 13.7,
1
26.4, 30.2, 130.7, 134.6, 136.5. Mp 71–73 ◦C.
[Me2Si(STolp)]2 (12). To
a flask containing sym-tetra-
methyldisilane (100 mg, 0.852 mmol) and p-cresol (211 mg,
1.70 mmol) in hexanes (3 mL) was added B(C6F5)3 (0.1 mL of
0.5 mg mL−1 hexanes solution, 0.05 mg, 1 × 10−4 mmol). Upon
addition of catalyst, bubbling (evolution of H2(g)) was observed.
The mixture was stirred and vented to the glovebox atmosphere
for 1 h, during which time white crystals formed in the flask.
This white solid was isolated by vacuum filtration on a sintered
glass frit, washed with cold (−22 ◦C) pentane (3 × 1 mL) and
dried under vacuum (293 mg, 95%). Anal. Calc. for C18H26S2Si2:
1
6H, Ho-SiPh3); 13C{ H} NMR (75.47 MHz, C6D6) d 21.2, 128.6,
130.2, 130.8, 135.9, 136.8. Mp 86–88 ◦C.
PhMe2Si(SPrn) (8). This reaction was carried out as described
above for 4, using dimethylphenylsilane (100 mg, 0.734 mmol),
n-propanethiol (56 mg, 0.73 mmol) and B(C6F5)3 (0.1 mL of
0.5 mg mL−1 hexanes solution, 0.05 mg, 1 × 10−4 mmol), to afford
a clear, colorless oil (152 mg, 100%). Anal. Calc. for C11H18SSi: C
62.78, H 8.62; Found: C 62.45, H 8.54. 1H NMR (300 MHz, C6D6)
d 0.46 (s, 6H, Si(CH3)2), 0.78 (t, JHH = 7.2 Hz, 3H, S(CH2)2CH3),
1.44 (sextet, 2H, SCH2CH2CH3), 2.28 (t, 2H, SCH2CH2CH3),
1
C 59.59, H 7.22; Found: C 59.48, H 7.24. H NMR (300 MHz,
C6D6) d 0.35 (s, 12H, Si(CH3)2), 1.99 (s, 6H, 2S(C6H4)CH3), 6.79
(d, 4H, JHH = 8.0 Hz, 2S(C6H4)CH3), 7.39 (d, 4H, 2S(C6H4)CH3);
1
7.17–7.24 (m, 3H, Hm,p-SiPh), 7.59–7.66 (m, 2H, Ho-SiPh);13C{ H}
1
13C{ H} NMR (75.47 MHz, C6D6) d −0.1, 21.3, 130.3, 135.9,
137.3. Mp 97–98 ◦C.
NMR (75.47 MHz, C6D6) d 0.0, 13.7, 26.6, 29.4, 128.6, 130.3,
134.5, 137.9.
[Ph2Si(STolp)]2 (13). sym-Tetraphenyldisilane (0.200 mg,
0.546 mmol) and p-thiocresol (136 mg, 1.08 mmol) were combined
in toluene (2 mL). To this faintly yellow solution, solid B(C6F5)3
(20 mg, 0.039 mmol) was added, which caused a small amount of
bubbling (evolution of H2(g)). The mixture was stirred under N2
(open to oil bubbler) for 72 h, at which point a white suspension
was observed. The toluene was removed under vacuum and the
white solid was transferred to a sintered glass frit, where it was
washed with cold pentane (3 × 1 mL) and filtered under vacuum.
The product was then dried under vacuum (290 mg, 94%). Anal.
Calc. for C38H34S2Si2: C 74.69, H 5.61; Found: C 74.66, H 5.80.
1H NMR (300 MHz, C6D6) d 1.84 (s, 6H, 2S(C6H4)CH3), 6.49 (d,
4H, JHH = 8.0 Hz, 2S(C6H4)CH3), 7.03–7.12 (m, 12H, Hm/p-SiPh2),
Ph2MeSi(SPrn) (9). This reaction was carried out as described
above, using diphenylmethylsilane (145 mg, 0.731 mmol), n-
propanethiol (56 mg, 0.73 mmol) and B(C6F5)3 (0.2 mL of
0.5 mg mL−1 hexanes solution 0.1 mg, 2 × 10−4 mmol,) to afford
a clear, colorless oil (189 mg, 95%). Anal. Calc. for C16H20SSi: C
70.51, H 7.40; Found: C 70.26, H 7.09. 1H NMR (300 MHz, C6D6)
d 0.72 (s, 3H, SiCH3), 0.75 (t, JHH = 7.2 Hz, 3H, Si(CH2)2CH3),
1.43 (sextet, 2H, SiCH2CH2CH3), 2.32 (t, 2H, SiCH2CH2CH3),
7.13–7.20 (m, 6H, Hm,p-SiPh2), 7.65–7.74 (m, 4H, Ho-SiPh2);
1
13C{ H} NMR (75.47 MHz, C6D6) d −0.9, 13.7, 26.5, 29.8, 130.5,
135.5, 136.2.
Et3Si(SPrn) (10). This reaction was carried out as described
above for 4, using triethylsilane (100 mg, 0.860 mmol), n-
propanethiol (0.66 mg, 0.85 mmol) and B(C6F5)3 (0.2 mL of
0.5 mg mL−1 hexanes solution, 0.1 mg, 2 × 10−4 mmol), to afford
a clear, colorless oil (130 mg, 80%; some product was lost under
vacuum.). Anal. Calc. for C9H22SSi: C 56.51, H 11.59; Found: C
56.06, H 11.18. 1H NMR (300 MHz, C6D6) d 0.66 (q, JHH = 7.2 Hz,
6H, Si(CH2CH3)3), 0.89 (t, JHH = 7.2 Hz, 3H, S(CH2)2CH3), 1.00
(t, 9H, Si(CH2CH3)3), 1.54 (sextet, 2H, SCH2CH2CH3), 2.33 (t,
1
7.20 (d, 4H, 2S(C6H4)CH3), 7.76–7.84 (m, 8H, Ho-SiPh2); 13C{ H}
NMR (75.47 MHz, C6D6) d 21.1, 127.8, 128.5, 130.1, 130.5, 133.6,
135.3, 137.0, 137.2. Mp 182–183 ◦C.
Ph2Si(H)-SiPh2(STolp)
(14). sym-Tetraphenyldisilane
(0.200 mg, 0.546 mmol) and p-thiocresol (68 mg, 0.54 mmol) were
combined in toluene (1.5 mL). To this faintly yellow solution,
solid B(C6F5)3 (12 mg, 0.024 mmol) was added which caused a
small amount of bubbling (evolution of H2(g)). The mixture was
stirred under N2 (open to oil bubbler) for 1 h, at which point
triphenylphosphine (PPh3; 6 mg, 0.02 mmol) was added. The
toluene was removed under vacuum to give a slightly opaque,
pale yellow oil, which was redissolved in hexanes (1.5 mL) to give
a cloudy solution, with the hexanes-insoluble borane-phosphine
adduct (Ph3P : BAr3) visible as a fine, white precipitate. This
suspension was filtered through a 1 cm plug of Celite in a Pasteur
pipet to give a clear solution. The volatiles were removed under
vacuum to afford a pale yellow, viscous oil (238 mg, 90%). Anal.
Calc. for C31H28S2Si2: C 76.16, H 5.77; Found: C 75.99, H 5.45.
1H NMR (300 MHz, C6D6) d 1.86 (s, 3H, S(C6H4)CH3), 6.55
(d, 2H, JHH = 7.6 Hz, S(C6H4)CH3), 7.01–7.12 (overlapping
m, 12H, Hm/p-SiPh2), 7.24 (d, 2H, S(C6H4)CH3), 7.56–7.62 (m,
1
2H, SCH2CH2CH3); 13C{ H} NMR (75.47 MHz, C6D6) d 6.1, 7.9,
13.9, 27.1, 28.3.
Ph3Si(SPrn) (11). Triphenylsilane (342 mg, 1.32 mmol) and
n-propanethiol (132 mg, 1.32 mmol) were combined in toluene
(2 mL). Solid B(C6F5)3 (13 mg, 0.028 mmol) was added to this
solution and gentle bubbling (evolution of H2) was observed.
The mixture was stirred and vented to the glovebox atmosphere
for 2 h, then the volatiles were removed under vacuum to give
a white solid. This material was dissolved in hexanes (4 mL)
and triphenylphosphine (PPh3; 7 mg, 0.03 mmol) was added to
precipitate the borane catalyst as a hexanes-insoluble phosphine
adduct, which was observed as a fine white suspension in the
hexanes solution. This suspension was filtered through a 1 cm
3408 | Dalton Trans., 2008, 3401–3411
This journal is
The Royal Society of Chemistry 2008
©