Y. Landais, P. Renaud et al.
3008C; final time=10 min; carrier gas : He; Column: 30 m, DB5; diame-
ter: 0.25 mm; film thickness: 0.25 mm.
colorless oil (56 mg, 73%), 28c as a colorless oil (9 mg, 7%), 27 as a col-
orless oil (20,5 mg, 44%), and 29c was eluted with petroleum ether/
AcOEt (90/10) as a colorless oil (16 mg, 16%). Analytical data for 27
matched those described above.
Compound 26c: Rf =1 (petroleum ether); 1H NMR (CDCl3, 300 MHz):
d=1.67–1.59 (m, 1H), 1.45 (septet, J=6.9 Hz, 1H), 1.29–1.18 (m, 1H),
0.89 (d, J=6,9 Hz, 3H), 0.85 (d, J=6.9 Hz, 3H), 0.86–0.81 (m, 2H), 0.68
(s, 1H), 0.64–0.56 (m, 2H), 0.12 (s, 9H), 0.09 ppm (s, 9H); 13C NMR
(CDCl3, 75 MHz): d=46.5, 40.0, 38.8, 20.7, 19.7, 18.7, 18.6, 6.3, ꢀ0.2,
ꢀ0.6 ppm; IR (neat): n˜ =2954, 2869.2, 1456, 1387, 1059.1, 831.4,
788.94 cmꢀ1; HRMS (EI): m/z calcd for C14H34Si3 [M]+.: 286.1968; found:
286.1967.
General procedure A: Addition of silyl radicals to sulfones: Catecholbor-
ane (2 equiv) was added dropwise at 08C to a solution of the olefin
(1 equiv, 1m) and DMA (0.1 equiv) in CH2Cl2. The mixture was stirred at
458C for 3 h. Then, tert-butanol (1 equiv) was added at 08C and the mix-
ture was stirred for 15 min at room temperature. CH2Cl2 was then evapo-
rated under vacuum and strictly in the absence of O2. Benzene (degassed
with freeze–pump–thaw cycles (3ꢄ), the volume depending on the de-
sired concentration in sulfone) was transferred into the flask. The sulfone
was then added and the solution was heated to 658C. Subsequently,
DTBHN (0.1 equiv) was added every 1.5 h, until the solution turned
black. Benzene was evaporated and the desired product was purified by
flash column chromatography through silica gel.
Compound 28c: Rf =0.85 (petroleum ether); 1H NMR (CDCl3,
200 MHz): d=7.40–7.35 (m, 2H), 7.30–7.24 (m, 3H), 2.36–2.28 (m, 2H),
Alkynylsilane (7): The general procedure A was followed. Alkene 3
(150 mg, 0.50 mmol), catecholborane (0.1 mL, 1.00 mmol), and DMA
(4 mg, 0.05 mmol) in CH2Cl2 (0.5 mL) were used. The reaction mixture
was quenched with tert-butanol (0.046 mL, 0.50 mmol). The radical reac-
tion was performed with 6 (242 mg, 1.00 mmol), and DTBHN (10 mg,
0.06 mmol, 2 additions) in benzene (degassed, 0.25m in sulfone, 4 mL).
Products were purified by flash column chromatography through silica
gel (petroleum ether/AcOEt : 98/2), affording 7 as a white solid (130 mg,
66%). An analytical sample was recrystallized from methanol. Rf =0.5
(petroleum ether/AcOEt 98/2); m.p. (methanol) 1348C; 1H NMR
(CDCl3, 300 MHz): d=7.73–7.71 (m, 4H), 7.59–7.56 (m, 2H), 7.48–7.17
(m, 12H), 7.15–7.13 (m, 1H), 3.36 (visible quint, J=6 Hz, 1H), 1.11 ppm
(d, J=6 Hz, 6H); 13C NMR (CDCl3, 75 MHz): d=156.4, 137.2, 135.7,
134.4, 132.2, 131.0, 130.9, 129.8, 129.0, 128.4, 128.0, 125.9, 125.4, 123.0,
109.1, 90.2, 34.7, 24.2 ppm; IR (neat): n˜ =3066.9, 2960.8, 2156.2, 1428.4,
1109.4, 830.5, 755.9, 698.0 cmꢀ1; HRMS (ESI): m/z calcd for C29H26SiNa
[M+Na]+: 425.1701; found: 425.1704.
1.74–1.52 (m, 3H), 1.00–0.98 (m, 2H), 0.88 (d, J=4 Hz, 6H), 0.83ACHTUNGTRENNUNG(s, 3H),
0.20 ppm (s, 27H); 13C NMR (CDCl3, 50 MHz): d=131.6, 128.3, 127.5,
124.2, 90.9, 80.6, 39.0, 37.4, 35.0, 25.1, 17.5, 17.3, 17.2, 14.3, 1.7 ppm; IR
(neat): n˜ =2977.6, 2903.2, 1493, 1246.3, 831.1 cmꢀ1; HRMS (ESI): m/z
calcd for C25H48Si4Na [M+Na]+: 483.2730; found: 483.2731.
Compound 29c: Rf =0.3 (petroleum ether/AcOEt, 90:10); 1H NMR
(CDCl3, 400 MHz): d=3.74–3.64 (m, 2H), 1.65–1.49 (m, 3H), 1.06 (d, J=
14 Hz, 1H), 0.97 (d, J=14 Hz, 1H), 0.89 (s, 3H), 0.85 (d, J=2.8 Hz, 3H),
0.83 (d, J=2.8 Hz, 3H), 0.19 ppm (s, 27H); 13C NMR (CDCl3, 75 MHz):
d=59.8, 41.9, 37.1, 36.0, 25.7, 18.3, 17.6, 17.4, 1.7 ppm; IR (neat): n˜ =
3293.3, 2957.2, 2892.8, 1456.7, 1384.9, 1244.4, 1061.2, 1042.6, 1014.5,
827.1 cmꢀ1; HRMS (ESI): m/z calcd for C17H44OSi4 [M+Na]+: 399.2367;
found: 399.2367.
Oximation of 8 with 21c: Following the general procedure A, alkene 21c
(180 mg, 0.500 mmol), catecholborane (0.1 mL, 1.000 mmol), and DMA
(4 mg, 0.050 mmol) in CH2Cl2 (0.5 mL), then quenched with tert-butanol
(0.046 mL, 0.500 mmol). The radical reaction was performed with
9
Adamantyl oxime (10) and adamantyl sulfide (11): Following general
procedure A was followed. Alkene 3 (150 mg, 0.50 mmol), catecholbor-
ane (0.1 mL, 1.00 mmol), and DMA (0.1 equiv) in CH2Cl2 (0.5 mL) were
used. The reaction was quenched with tert-butanol (0.046 mL,
(137 mg, 0.500 mmol), 8 (322 mg, 1.500 mmol), and DTBHN (10 mg,
0.060 mmol, 2 additions) in benzene (degassed, 0.25m in sulfone, 2 mL).
Products were purified by flash column chromatography through silica
gel, affording 26c as a colorless oil (108 mg, 76%) with petroleum ether
as the eluent, 10 as a colorless oil (52 mg, 39%) with petroleum ether/
AcOEt (98/2) as the eluent, and 29c as a colorless oil (26 mg, 14%) with
petroleum ether/AcOEt (90/10) as the eluent. Analytical data for 10,
26c, and 29c matched those previously reported.
0.50 mmol). The radical reaction was conducted with
9 (137 mg,
0.50 mmol), 1-bromoadamantane (322 mg, 1.50 mmol), and DTBHN
(10 mg, 0.06 mmol, 2 additions) in benzene (degassed, 0.25m in sulfone,
2 mL). Products were purified by flash column chromatography through
silica gel, affording 11 as a white solid (33 mg, 27%) eluted with petrole-
um ether, and 10 as a colorless oil (33 mg, 25%) eluted with petroleum
ether/AcOEt (98/2).
Compound 10: Rf =0.35 (petroleum ether/AcOEt 98/2); 1H NMR
(CDCl3, 200 MHz): d=7.39–7.28 (m, 5H), 7.22 (s, 1H), 5.04 (s, 2H), 2.01
(brs, 3H), 1.79–1.64 ppm (m, 12H); 13C NMR (CDCl3, 50 MHz): d=
158.9, 137.8, 128.5, 128.4, 127.9, 75.7, 40.1, 36.7, 35.8, 28.0 ppm; IR (neat)
n˜ =2904.4, 2847.6, 1724.6, 1626.1, 1440.6, 1297.6, 1192.2, 1209.4, 1174.6,
1134.7, 942.4, 836.2 cmꢀ1; HRMS (ESI): m/z calcd for C18H23NONa [M+
Na]+: 292.1677; found: 292.1679.
General procedure B: Kinetic measurements: Bromide (1 equiv),
(Me3Si)3SiH (>10 equiv), tetradecane (ꢃ1.5 equiv, internal standard),
and AIBN (0.2 equiv) were dissolved in benzene. The solution was de-
gassed by freeze–pump–thaw cycles (3ꢄ) then transferred into a sealed
tube. The mixture was stirred (2–3 h) at 908C. After completion of the
reaction, the solution was cooled down to room temperature and a
sample was analyzed by GC.
Kinetic studies with bromide 31a (results compiled in Table 2)
Experiment A: Performed according to the general procedure B with
bromide 31a (76 mg, 0.184 mmol), tris(trimethylsilyl)silane ((Me3Si)3SiH,
TTMSH; 1.022 g, 4.12 mmol, 1.2m), tetradecane (51 mg, 0.26 mmol), and
AIBN (7 mg, 0.04 mmol) in benzene (3.43 mL).
1
Compound 11: Rf =0.48 (petroleum ether); m.p. 688C; H NMR (CDCl3,
200 MHz): d=7.52–7.48 (m, 2H), 7.34–7.30 (m, 3H), 2.00 (brs, 3H), 1.80
(d, J=2 Hz, 6H), 1.68–1.54 ppm (m, 6H); 13C NMR (CDCl3, 50 MHz):
d=137.8, 130.7, 128.6, 128., 47, 43.7, 36.3, 30.1 ppm; IR (neat): n=
2902.6; 2848.7, 1692, 1573, 1474.3, 1441.50, 1341.0, 1295.8, 1259.2, 1037.4,
1023.5, 837.7, 826.7, 751.1 cmꢀ1; HRMS (ESI): m/z calcd for C16H20SNa
[M+Na]+: 267.1183; found: 267.1183.
Experiment B: Performed according to the general procedure B from
bromide 31a (78 mg, 0.189 mmol), TTMSH (1.46 g, 5.88 mmol, 1.4m), tet-
radecane (55.4 mg, 0.28 mmol), and AIBN (7 mg, 0.04 mmol) in benzene
(4.2 mL).
Compound 27: Spectroscopic data matched those of
a commercial
Experiment C: Performed according to the general procedure B from
bromide 31a (76 mg, 0.184 mmol), TTMSH (1.89 g, 7.620 mmol, 2.05m),
tetradecane (55.4, 0.28 mmol), and AIBN (7 mg, 0.04 mmol) in benzene
(3.7 mL).
sample. Rf =0.44 (petroleum ether); 1H NMR (CDCl3, 200 MHz): d=
7.49–7.44 (m, 2H), 7.32–7.27 (m, 3H), 0.25 ppm (s, 9H); 13C NMR
(CDCl3, 50 MHz): d=132.1, 128.6, 128.3, 123.2, 105.2, 94.2, 0.12 ppm.
Intramolecular homolytic substitution on precursor 21c: The general pro-
cedure A was followed. Alkene 21c (100 mg, 0.27 mmol), catecholborane
(0.06 mL, 0.540 mmol), and DMA (2.4 mg, 0.027 mmol) in CH2Cl2
(0.3 mL) were used, then quenched with tert-butanol (0.025 mL,
0.270 mmol). The radical reaction was performed in benzene (degassed,
0.5m in sulfone, 2.16 mL) with 6 (131 mg, 0.540 mmol), and DTBHN
(5 mg, 0.030 mmol, 2 additions). Products were purified by flash column
chromatography through silica gel (petroleum ether), affording 26c as a
Kinetic studies with bromide 31b (results collected in Table 2)
Experiment A: Performed according to the general procedure B from
bromide 31b (77 mg, 0.175 mmol), TTMSH (925 mg, 3.72 mmol, 1.43m),
tetradecane (52 mg, 0.26 mmol), and AIBN (9 mg, 0.05 mmol) in benzene
(2.6 mL).
Experiment B: Performed according to the general B procedure from
bromide 31b (64 mg, 0.146 mmol), TTMSH (1.054 g, 4.25 mmol, 1.93m),
948
ꢃ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2012, 18, 940 – 950