M. Okimoto et al. / Journal of Organometallic Chemistry 694 (2009) 1419–1426
1425
243–244 °C (decomposed); 1H NMR (CDCl3, d) ꢀ0.30 (s, 9H, SiMe3),
2.07 (s, 6H, o-CH3 in mesityl group), 2.23 (s, 3H, p-CH3 in mesityl
group), 6.17–6.28 (m, 2H, phenyl protons), 6.71 (s, 2H, m-H in
mesityl group), 6.78–7.22 (m, 20H, phenyl protons), 7.72 (dd, 2H,
Anal. Calc. for C21H32SSi2: C, 67.67; H, 8.65. Found: C, 67.76; H,
8.60%.
4.2.11. 1,1,1-Triethyl-2-mesityl-3,3,3-trimethyltrisilane (6e) [14a]
The isolation of 6e was carried out by recycling reverse-phase
liquid chromatography using CH3CN as eluent (Rf = 0.25): colorless
oil (42% yield); 1H NMR (C6D6, d) 0.29 (s, 9H, SiMe3), 0.77–0.83 (m,
4
3JHH = 5.6 Hz, JHH = 3.2 Hz, benzo protons); 13C NMR (CDCl3, d)
1.37, 21.11, 25.06, 63.16, 123.15, 123.77, 125.28, 125.59, 126.88,
127.05, 128.36, 129.48, 129.61, 130.49, 132.11, 138.08, 138.49,
138.88, 144.64, 148.21, 149.92; 29Si NMR (CDCl3, d) ꢀ15.91 (Si–
SiMe3), 56.17 (Si–SiMe3); UV–Vis (CH2Cl2, kmax) 288 nm (sh),
309 nm (sh); Anal. Calc. for C46H44Si2: C, 84.61; H, 6.79. Found: C,
84.23; H, 6.90%.
3
6H, Si–CH2–CH3), 1.03 (t, 9H, JHH = 8.0 Hz, Si–CH2-CH3), 2.16 (s,
3H, p-CH3 in mesityl group), 2.43 and 2.58 (brs, 6H, o-CH3 in mesi-
tyl group), 4.35 (s, 1H, 1JSiH = 160 Hz, Si–H), 6.82 and 6.85 (brs, 2H,
m-H in mesityl group); 13C NMR (C6D6, d) 0.89, 5.65, 8.43, 21.08,
25.26, 26.29, 128.46, 128.64, 128.97, 129.20, 137.61; 29Si NMR
(C6D6, d) ꢀ81.23 (SiH), ꢀ13.22 (SiMe3), ꢀ1.98 (SiEt3).
4.2.6. Thermolysis of 7-silanorbornadienes 1: General procedure for
trapping experiment of silylenes 5 with HSiEt3
A mixture of 1 and 100 equivalents of degassed triethylsilane in
a pressure-resistant glass container was refluxed at 250 °C for 2 h
or at 180 °C for 1 h. The obtained mixture was concentrated in va-
cuo. The residue was subjected to bulb-to-bulb distillation or recy-
cling reverse-phase liquid chromatography using CH3CN as eluent,
giving disilane 6.
4.2.12. Photolysis of 7-silanorbornadiene derivatives 1 with a high-
pressure mercury lamp: general procedure for trapping experiment of
silylenes 5 with HSiEt3
A mixture of silanorbornadiene 1 (0.10 mmol) and triethylsilane
(1.0 mmol or 10 mmol) in benzene-d6 (1.0 mL) in a Schlenk tube or
a pressure-resistant glass container was degassed by the freeze–
pump–thaw method three times. The mixture was irradiated with
a high-pressure mercury lamp (k = 313 nm) at room temperature.
After the irradiation, the reaction mixture was concentrated in va-
cuo. The residue was subjected to bulb-to-bulb distillation or recy-
cling reverse-phase liquid chromatography using CH3CN as eluent
to give disilane 6.
4.2.7. 1,1,1-Triethyl-2-mesityldisilane (6a) [14a]
The isolation of 6a was carried out by recycling reverse-phase
liquid chromatography using CH3CN as eluent (Rf = 0.30): colorless
oil (44% yield); 1H NMR (C6D6, d) 0.71 (q, 6H, 3JHH = 8.0 Hz, Si–CH2–
3
CH3), 0.99 (t, 9H, Si–CH2–CH3, JHH = 8.0 Hz), 2.16 (s, 3H, p-CH3 in
mesityl group), 2.46 (s, 6H, o-CH3 in mesityl group), 4.46 (s, 2H,
4.2.13. 1,1,1-Triethyl-2-mesityldisilane (6a)
The isolation of 6a was carried out by recycling reverse-phase
liquid chromatography using CH3CN as eluent (Rf = 0.30): 46%
yield.
1
Si–H, JSiH = 184 Hz), 6.81 (s, 2H, m-H in mesityl group); 13C NMR
(C6D6, d) 4.93, 8.31, 21.29, 24.62, 126.54, 128.55, 138.53, 144.25;
29Si NMR (C6D6, d) ꢀ82.09 (SiH), ꢀ5.52 (SiEt3).
4.2.8. 1-Chloro-2,2,2-triethyl-1-mesityldisilane (6b) [14a]
4.2.14. Formation of 6b and reaction with PhLi
The isolation of 6b was carried out by bulb-to-bulb distillation
(185–220 °C (bath temperature)/0.80 mmHg): colorless oil (70%
yield); 1H NMR (C6D6, d) 0.69–0.85 (m, 6H, Si–CH2–CH3), 0.98 (t,
9H, 3JHH = 8.0 Hz, Si–CH2–CH3), 2.10 (s, 3H, p-CH3 in mesityl group),
(1) A mixture of 1b (123 mg, 0.200 mmol) and triethylsilane
(0.32 mL, 2.0 mmol) in benzene-d6 (2.0 mL) was irradiated for
48 h to give a mixture of 6b and 7. (2) A solution of PhLi in cyclo-
hexane–Et2O (1.04 M, 0.23 mL, 0.24 mmol) was added to the mix-
ture of 6b and 7 in Et2O (2.0 mL) over 1 min at 0 °C. The reaction
mixture was stirred for 5 min at 0 °C and for another 5 h at room
temperature. Then, methyliodide (0.015 mL, 0.25 mmol) was
added to the reaction mixture at 0 °C. The mixture was stirred
for 5 min and was allowed to warm to room temperature. The reac-
tion mixture was concentrated in vacuo and the residue was sub-
jected to reverse-phase column chromatography (50 mL) using
CH3CN–THF (2/1) as eluent (Rf = 0.55) to give 8.
1
2.51 (s, 6H, o-CH3 in mesityl group), 6.00 (s, 1H, JSiH = 204 Hz, Si–
H), 6.73 (s, 2H, m-H in mesityl group); 13C NMR (C6D6, d) 3.38, 8.01,
21.09, 24.44, 128.17, 129.30, 140.45, 144.42; 29Si NMR (C6D6, d)
ꢀ14.74 (SiH), ꢀ6.35 (SiEt3).
4.2.9. 2,2,2-Triethyl-1-mesityl-1-(N-phenylamino)disilane (6c)
The isolation of 6c was carried out by bulb-to-bulb distillation
(230–250 °C (bath temperature)/0.15 mmHg): colorless oil (53%
3
yield); 1H NMR (C6D6, d) 0.72 (q, 6H, JHH = 8.0 Hz, Si–CH2–CH3),
1,1,1-Triethyl-2-mesityl-2-phenyldisilane (8) [14a]: colorless oil
0.98 (t, 9H, 3JHH = 8.0 Hz, Si–CH2–CH3), 2.12 (s, 3H, p-CH3 in mesityl
(43% yield); 1H NMR (C6D6, d) 0.87 (q, 6H, JHH = 8.0 Hz, Si–CH2–
3
3
3
group), 2.53 (s, 6H, o-CH3 in mesityl group), 3.45 (d(br), 1H, JHH
CH3), 1.03 (t, 9H, JHH = 8.0 Hz, Si–CH2–CH3), 2.17 (s, 3H, p-CH3 in
3
1
= 2.8 Hz, N–H), 5.92 (d, 1H, JHH = 4.0 Hz, JSiH = 195 Hz, Si–H),
6.71-6.82 (m, 5H, m-H in mesityl group and phenyl protons),
7.05–7.12 (m, 2H, phenyl protons); 13C NMR (C6D6, d) 4.15, 8.32,
21.26, 23.86, 116.24, 118.73, 128.73, 129.46, 129.58, 139.23,
144.26, 148.09; 29Si NMR (C6D6, d) ꢀ40.36 (SiH), ꢀ9.56 (SiEt3);
Anal. Calc. for C21H33NSi2: C, 70.92; H, 9.35; N, 3.94. Found: C,
70.57; H, 9.42; N, 3.57%.
mesityl group), 2.48 (s, 6H, o-CH3 in mesityl group), 5.54 (s, 1H,
1JSiH = 177 Hz), 6.85 (s, 2H, m-H in mesityl group), 7.16–7.18 (m,
3H, phenyl protons), 7.68–7.70 (m, 2H, phenyl protons); 13C NMR
(C6D6, d) 5.20, 8.56, 21.30, 25.46, 128.24, 128.92, 128.99, 135.47,
135.86, 138.98, 144.80; 29Si NMR (C6D6, d) ꢀ48.64 (SiH), ꢀ6.98
(SiEt3).
4.2.15. 2,2,2-Triethyl-1-mesityl-1-(phenylthio)disilane (6d)
The isolation of 6d was carried out by bulb-to-bulb distillation
(240–250 °C (bath temperature)/0.50 mmHg): 35% yield.
4.2.10. 2,2,2-Triethyl-1-mesityl-1-(phenylthio)disilane (6d)
The isolation of 6d was carried out by bulb-to-bulb distillation
(230–250 °C (bath temperature)/0.30 mmHg): colorless oil (48%
yield); 1H NMR (C6D6, d) 0.73–0.91 (m, 6H, Si–CH2–CH3), 1.04 (t,
9H, 3JHH = 8.0 Hz, Si–CH2–CH3), 2.09 (s, 3H, p-CH3 in mesityl group),
Acknowledgments
1
2.56 (s, 6H, o-CH3 in mesityl group), 5.79 (s, 1H, JSiH = 198 Hz, Si-
This work was supported by a Grant-in-Aid for Scientific Re-
search (No. 19020048) from the Ministry of Education, Culture,
Sports, Science and Technology, Japan. M.O. thanks the Japan Soci-
ety for the Promotion of Science (JSPS) for ‘‘Research Fellowship for
Young Scientists”.
H), 6.75 (s, 2H, m-H in mesityl group), 6.86–6.95 (m, 3H, phenyl
protons), 7.48–7.52 (m, 2H, phenyl protons); 13C NMR (C6D6, d)
4.60, 8.24, 21.11, 24.75, 126.47, 128.99, 129.26, 133.66, 135.51,
139.69, 144.66; 29Si NMR (C6D6, d) ꢀ28.00 (SiH), ꢀ5.18 (SiEt3);