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diethyl ether (60.0 mL) and stirred for 1 h. The reaction was
4.5. Preparation of 3-allylbenzoboroxole, 7c
cooled to ꢀ78 ꢁC and n-butyl lithium (25.4 mL, 2.4 M solu-
tion, 63.6 mmol) was added dropwise and stirred for 1 h. Tri-
isopropylborate (14.6 mL, 63.6 mmol) was added to the
mixture at ꢀ78 ꢁC and stirred for 6 h while gradually warm-
ing to room temperature. The reaction mixture was acidified
to pH 1 using 2 M H2SO4 and worked up with ether
(3ꢂ100 mL) and water. The organic layer was separated
and dried (Na2SO4), and concentrated in vacuo. Purification
using silica gel column chromatography (4:1 hexanes–ethyl
acetate) yielded the desired compound 7a (84% yield). Mp:
Procedure similar to that of 7a. 1H NMR (500 MHz, CDCl3):
d 7.87–7.89 (1H, m), 7.74 (1H, d, J¼7.3 Hz), 7.44–7.50 (1H,
m), 7.35–7.37 (1H, m), 6.07 (1H, br s), 5.83–5.87 (1H, m),
5.28–5.48 (1H, m), 5.02–5.17 (2H, m), 2.70–2.78 (1H, m),
2.46–2.54 (1H, m); 13C NMR (125 MHz, CDCl3): d 133.4,
133.1, 131.2, 131.0, 130.6, 127.4, 121.2, 118.1, 81.0, 40.6;
11B NMR (160 MHz, DMSO): d 32 (s); CI-MS: m/z 219
(MꢀOH+2OCH3)+, 173 [100%, (MꢀH)+]; HRMS-CI:
219.0646 (calculated), 219.0563 (observed).
1
96–98 ꢁC, H NMR (500 MHz, CDCl3): d 7.70–7.83 (m,
1H), 7.4–7.54 (m, 3H), 6.15 (br s, 1H), 5.19 (s, 2H); 13C
NMR (125 MHz, CDCl3): d 153.6, 131.5, 131.3, 130.9,
127.5, 121.3, 71.8; 11B NMR (160 MHz, DMSO): d 33 (s).
4.6. Preparation of 1-(2-(pyridin-2-yl)phenyl)
but-3-en-1-ol, 8c
Procedure similar to that of 8a. 1H NMR (500 MHz, CDCl3):
d 8.61–8.63 (1H, m), 7.84 (1H, dt, J¼1.81 and 7.74 Hz),
7.54–7.58 (2H, m), 7.36–7.44 (3H, m), 7.32 (1H, ddd,
J¼1.12, 4.94, and 7.57 Hz), 6.31 (1H, br s), 5.71–5.83 (m,
1H), 4.95–5.03 (m, 2H), 4.59–4.63 (1H, dd, J¼6.22 and
8.24 Hz), 2.60–2.68 (m, 1H), 2.46–2.52 (m, 1H); 13C
NMR (125 MHz, CDCl3): d 159.8, 147.9, 142.2, 139.6,
137.6, 135.6, 130.8, 129.1, 127.7, 127.6, 124.2, 122.2,
116.6, 71.7, 39.3.
4.2. Preparation of 1-(2-(pyridin-2-yl)phenyl)
methanol, 8a
To a stirred solution of Pd(PPh3)4 (30.0 mg) and 2-bromo-
pyridine (0.16 mL, 1 mmol) in toluene (3.0 mL) were added
benzoboroxole 7a (67.0 mg, 0.5 mmol) and Na2CO3
(0.3 mL, 20% w/v), and stirred for 4 h at 90 ꢁC. After the
completion of the reaction (TLC), the reaction mixture
was cooled to room temperature and worked up with water
and ether. The combined organic layers were dried
(Na2SO4), concentrated, and purified by column chromato-
graphy (silica gel, 3:2 hexanes–ethyl acetate) to obtain
4.7. Preparation of 3-phenylbenzoboroxole, 7d
Procedure similar to that of 6a. Mp: 142–144 ꢁC, 1H NMR
(500 MHz, CDCl3): d 7.42 (1H, dd, J¼7.40 and 7.50 Hz),
7.24–7.37 (7H, m), 7.16 (1H, d, J¼7.66 Hz), 6.18 (1H, br
s), 5.42 (1H, s); 13C NMR (125 MHz, CDCl3): d 156.8,
140.1, 131.6, 131.4, 130.4, 128.8, 128.4, 137.6, 126.0,
122.3, 83.8; 11B NMR (160 MHz, DMSO): d 33 (s); ESIMS:
m/z 233.1 [100%, (M+Na)+]; HRMS-ESI: 233.0260 (calcu-
lated), 233.0737 (observed).
1
84 mg (91%) of 8a. H NMR (500 MHz, CDCl3): d 8.54
(1H, d, J¼4.93 Hz), 7.74 (1H, dt, J¼1.82 and 7.76 Hz),
7.52 (1H, dt, J¼1.03 and 7.96 Hz), 7.31–7.45 (m, 4H),
7.22 (1H, ddd, J¼1.12, 4.95, and 7.55 Hz), 6.29 (1H, br s),
4.38 (2H, s); 13C NMR (125 MHz, CDCl3): d 159.0, 148.0,
140.4, 139.7, 137.4, 131.0, 130.0, 129.0, 128.0, 123.8,
122.1, 64.6.
4.8. Preparation of phenyl 1-(2-(pyridin-2-yl)phenyl)
methanol 8d
4.3. Preparation of 3-vinylbenzoboroxole, 7b
1
Procedure similar to that of 7a. Mp: 74–76 ꢁC, H NMR
Procedure similar to that of 8a. 1H NMR (500 MHz, CDCl3):
d 8.50–8.60 (m, 1H), 7.15–7.76 (m, 12H), 5.60 (s, 1H), 1.57
(br s, 1H); 13C NMR (125 MHz, CDCl3): d 159.7, 147.6,
143.8, 142.8, 139.7, 137.5, 130.7, 130.0, 129.0, 128.6,
127.8, 126.8, 126.4, 124.1, 122.1, 74.2.
(500 MHz, CDCl3): d 7.76 (1H, d, J¼7.28 Hz), 7.48 (1H,
dd, J¼6.92 and 7.38 Hz), 7.37 (1H, dd, J¼7.22 and
7.30 Hz), 7.27 (1H, d, J¼7.6 Hz), 6.39 (1H, br s), 5.88
(1H, ddd, J¼7.41, 10.09, and 17.3 Hz), 5.62 (1H, d,
J¼7.35 Hz), 5.52 (1H, d, J¼17.03 Hz), 5.29 (1H, d,
J¼10.17 Hz); 13C NMR (125 MHz, CDCl3): d 155.2,
137.0, 131.5, 131.3, 130.6, 127.9, 121.9, 117.6, 83.3; 11B
NMR (160 MHz, DMSO): d 33 (s); CI-MS: m/z 205
[100%, (MꢀOH+2OCH3)+], 159 (MꢀH)+; HRMS-CI:
205.0381 (calculated), 205.0410 (observed).
4.9. Preparation of 3-decylbenzoboroxole, 7e
Procedure similar to that of 6a. 1H NMR (500 MHz, CDCl3):
d 7.75 (1H, d, J¼7.24 Hz), 7.46 (1H, dd, J¼7.38 and
7.47 Hz), 7.35 (1H, dd, J¼7.22 and 7.34 Hz), 7.29 (1H, d,
J¼7.76 Hz), 6.46 (1H, br s), 5.28 (1H, dd, J¼3.75 and
7.57 Hz), 1.93–2.02 (m, 2H), 1.25–1.78 (m, 12H), 0.75–
0.97 (m, 7H); 13C NMR (125 MHz, CDCl3): d 131.5, 131.1,
130.9, 130.6, 127.2, 120.9, 82.1, 41.4, 36.4, 31.9, 29.6,
29.5, 29.3, 26.2, 24.8, 22.6, 14.1; 11B NMR (160 MHz,
DMSO): d 31 (s); ESIMS: m/z 297 [100%, (M+Na)+];
HRMS-ESI: 297.1959 (calculated), 297.1991 (observed).
4.4. Preparation of 1-(2-(pyridin-2-yl)phenyl)
prop-2-en-1-ol, 8b
Procedure similar to that of 8a. 1H NMR (500 MHz, CDCl3):
d 8.60 (1H, d, J¼4.96 Hz), 7.83 (1H, dt, J¼1.84 and
7.77 Hz), 7.57 (1H, dt, J¼1.01 and 7.94 Hz), 7.52 (1H, dd,
J¼1.66 and 7.57 Hz), 7.37–7.48 (3H, m), 7.30 (1H, ddd, J¼
1.08, 4.95, and 7.56 Hz), 6.88 (1H, br s), 5.99 (1H, ddd,
J¼4.34, 10.60, and 17.22 Hz), 5.34 (1H, dt, J¼1.88 and
17.23 Hz), 5.11 (2H, dt, J¼1.88 and 10.63 Hz); 13C NMR
4.10. Preparation of 1-(2-(pyridin-2-yl)phenyl)-1-
undecanol, 8e
(125 MHz, CDCl3):
d
159.6, 147.4, 141.9, 139.6,
Procedure similar to that of 8a. 1H NMR (500 MHz, CDCl3):
d 8.62–8.64 (1H, m), 7.84 (1H, dt, J¼1.82 and 7.73 Hz), 7.53–
7.57(2H, m), 7.42–7.44(2H, m), 7.35–7.38(1H, m), 7.31(1H,
138.5, 137.6, 130.7, 129.1, 129.0, 127.9, 124.1, 122.2,
114.5, 72.8.