4
Tetrahedron
1
2-[2-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-
yield; H NMR (400 MHz, CDCl3) δ (ppm) 8.74 (d, J = 5.2 Hz,
1H), 8.05 (t, J = 7.6 Hz, 1H), 7.94 (s, 1H), 7.89 (d, J = 8.0 Hz,
1H), 7.77 (d, J = 8.0 Hz, 1H), 7.58 (d, J = 7.6 Hz, 1H), 7.48 (t, J
= 7.2 Hz, 1H), 1.45 (s, 12H); 13C NMR (100 MHz, CDCl3) δ
(ppm) 154.8, 143.6, 142.1, 140.2, 132.7 (d, JCF = 31.4 Hz), 128.1
(q, JCF = 3 Hz) , 125.1 (q, JCF = 3.6 Hz) , 124.4 (q, JCF = 271.3
Hz) , 123.8, 121.2, 118.1, 80.6, 26.9; HRMS (ESI) calcd for
C18H20BF3NO2 ([M+H]+): 350.1534, found: 350.1539.
ACCEPTED MANUSCRIPT
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yl)phenyl]pyridine (2a). Yellow solid, 51.9 mg, 94% yield. H
NMR (400 MHz, CDCl3) δ (ppm) 8.66 (d, J = 5.6 Hz, 1H), 7.95
(t, J = 7.6 Hz, 1H), 7.79 (d, J = 8.0 Hz, 1H), 7.72 (d, J = 7.2 Hz,
1H), 7.65 (d, J = 7.6 Hz, 1H), 7.41 (t, J = 7.2 Hz, 1H), 7.38–7.33
(m, 1H), 7.29 (t, J = 7.6 Hz, 1H), 1.43 (s, 12H); 13C NMR (100
MHz, CDCl3) δ (ppm) 156.5, 143.1, 141.8, 137.1, 131.4, 127.8,
122.6, 121.2, 117.4, 80.2, 26.9.
2-[4-methyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2b). White solid, 37.6 mg, 64% yield .The
product was isolated by short-column chromatography
(petroleum ether/ethyl acetate/triethylamine 4:1:1% to 0:1:1%)
2-[4-cyano-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2i). White solid, 52.1 mg, 85% yield; the
1
reaction was carried in acetronile instead of hexane. H NMR
(400 MHz, CDCl3) δ (ppm) 8.75 (d, J = 5.6 Hz, 1H), 8.08 (t, J =
8.0 Hz 1H), 7.99 (s, 1H), 7.89 (d, J = 8.0 Hz, 1H), 7.75 (d, J =
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on silica gel (300-400 mesh). H NMR (400 MHz, CDCl3) δ
(ppm) 8.62 (d, J = 4.8 Hz, 1H), 7.91 (t, J = 7.6 Hz, 1H), 7.73 (d,
J = 8.0 Hz, 1H), 7.58-7.46 (m, 2H), 7.30 (m, 1H), 7.09 (d, J = 7.6
Hz, 1H), 2.39 (s, 3H), 1.43 (s, 12H); 13C NMR (100 MHz, CDCl3)
δ (ppm) 156.7, 143.0, 141.6, 141.6, 134.6, 132.2, 128.6, 122.1,
121.1, 117.1, 80.1, 27.0.
8.0 Hz, 1H), 7.60 (m, 1H), 7.55 -7.49 (m, 1H), 1.43 (s, 12H); 13
C
NMR (100 MHz, CDCl3) δ (ppm) 154.1, 143.6, 142.4, 140.6,
135.2, 131.7, 124.3, 121.4, 119.4, 118.4, 114.5, 80.6, 26.9;
HRMS (ESI) calcd for C18H20BN2O2 ([M+H]+): 307.1612, found:
307.1615.
2-[4-methoxy-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2c). White solid, 51.2 mg, 83% yield. 1H
NMR (400 MHz, CDCl3) δ (ppm) 8.58 (d, J = 5.2 Hz, 1H), 7.89
(t, J = 7.6 Hz, 1H), 7.67 (d, J = 8.0 Hz, 1H), 7.57 (d, J = 8.4 Hz,
1H), 7.29-7.20 (m, 2H), 6.80 (d, J = 8.4 Hz, 1H), 3.87 (s, 3H),
1.42 (s, 12H); 13C NMR (100 MHz, CDCl3) δ (ppm) 162.6, 156.5,
142.8, 141.8, 129.9, 122.7, 121.3, 116.6, 116.2, 113.6, 80.0, 55.2,
27.0.
2-[4-acetyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2j). Yellow solid, 58.2 mg, 90% yield; the
1
reaction was carried in acetronile instead of n-hexane. H NMR
(400 MHz, CDCl3) δ (ppm) 8.73 (d, J = 5.6 Hz, 1H), 8.26 (s, 1H),
8.06 - 8.00 (m, 1H), 7.95-7.86 (m, 2H), 7.74 (d, J = 8.0 Hz, 1H),
7.50 – 7.43 (m, 1H), 2.65 (s, 3H), 1.45 (s, 12H); 13C NMR (100
MHz, CDCl3) δ (ppm) 155.0, 143.6, 142.1, 131.4, 128.2, 127.3,
127.0, 126.0, 123.7, 121.2, 118.3, 80.5, 26.9; HRMS (ESI) calcd
for C19H23BNO3 ([M+Na]+): 324.1766, found: 324.1762.
2-[4-fluoro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2d). White solid, 51.4mg, 86% yield; 1H
NMR (400 MHz, CDCl3) δ (ppm) 8.64 (d, J = 4.8 Hz, 1H), 7.95
(t, J = 7.6 Hz, 1H), 7.74 (d, J = 8.0 Hz, 1H), 7.62 (dd, J = 8.4
Hzꢀ4.8 Hzꢀ1H), 7.36 (m, 2H), 6.96 (t, J = 8.0 Hz, 1H), 1.42 (s,
12H); 13C NMR (100 MHz, CDCl3) δ (ppm) 165.6 (q, JCF = 250.9
Hz) , 155.5, 143.0, 142.1, 132.8, 123.0 (q, JCF = 8.6 Hz) , 122.3,
118.0 (q , JCF = 19.9 Hz) , 117.1, 114.9 (q, JCF = 23.6 Hz) , 80.2,
26.9.
2-[4-Phenyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2k). Yellow solid, 58.3 mg, 82% yield. H
1
NMR (400 MHz, CDCl3) δ (ppm) 8.66 (d, J = 4.8 Hz, 1H), 7.96 -
7.88 (m, 2H), 7.79 (d, J = 8.0 Hz, 1H), 7.70 (d, J = 8.0 Hz, 1H),
7.68 - 7.62 (m, 2H), 7.50 (d, J = 8.0 Hzꢀ1H), 7.44 (t, J = 7.6 Hz,
2H), 7.34 (dd, J = 7.2 Hzꢀ5.6 Hzꢀ2H), 1.45 (s, 12H); 13C
NMR (100 MHz, CDCl3) δ (ppm) 156.2, 144.0, 143.1, 141.8,
141.7, 136.3, 130.3, 128.6, 127.3, 127.0, 122.5, 121.5, 117.4,
80.2, 27.0, 24.7; HRMS (ESI) calcd for C23H25BNO2 ([M+H]+):
358.1973, found: 358.1976.
2-[4-chloro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2e). White solid, 56.7 mg, 90% yield. 1H
NMR (400 MHz, CDCl3) δ (ppm) 8.64 (d, J = 5.6 Hz, 1H), 7.96
(m, 1H), 7.75 (d, J = 8.0 Hz, 1H), 7.65 (d, J = 1.2 Hz, 1H), 7.56
(d, J = 8.0 Hz, 1H), 7.40-7.34 (m, 1H), 7.29-7.22 (m, 1H), 1.42 (s,
12H); 13C NMR (100 MHz, CDCl3) δ (ppm) 155.3, 143.1, 142.1,
137.9, 135.3, 131.5, 127.9, 122.9, 122.3, 117.4, 80.3, 27.0ꢁ
HRMS (ESI) calcd for C17H20BClNO2 ([M+H]+): 316.1270,
found: 316.1276.
2-[5-methyl-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2l). White solid, 38.2 mg, 65% yield. The
product was isolated by flash-column chromatography
(petroleum ether/ethyl acetate/triethylamine 4:1:1% to 0:1:1%)
1
on silica gel (300-400 mesh). H NMR (400 MHz, CDCl3) δ
(ppm) 8.63 (d, J = 5.2 Hz, 1H), 7.90 (m, 1H), 7.74 (d, J = 8.0 Hz,
1H), 7.59 (d, J = 7.2 Hz, 1H), 7.45 (s, 1H), 7.30 (t, J = 6.0 Hz,
1H), 7.22 (d, J = 6.8 Hz, 1H), 2.36 (s, 3H), 1.41 (s, 12H); 13C
NMR (100 MHz, CDCl3) δ (ppm) 156.6, 143.2, 141.6, 137.4,
137.3, 132.3, 131.2, 122.4, 121.8, 117.2, 80.1, 26.9, 21.3.
2-[4-bromo-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2f). Yellow solid, 55.2 mg, 77% yield. 1H
NMR (400 MHz, CDCl3) δ (ppm) 8.65 (d, J = 5.2 Hz, 1H), 7.96
(t, J = 7.6 Hz, 1H), 7.81 (s, 1H), 7.76 (d, J = 8.0 Hz, 1H), 7.51 (d,
J = 8.0 Hz, 1H), 7.40 (dd, J = 8.4 Hzꢀ6.8 Hzꢀ2H), 1.42 (s,
12H); 13C NMR (100 MHz, CDCl3) δ (ppm) 155.4, 143.1, 142.1,
135.7, 134.5, 130.8, 127.1, 123.0, 122.6, 117.4, 80.3, 27.0.
2-[5-cyano-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl]pyridine(2m). Yellow solid, 52.0 mg, 85% yield; the
1
reaction was carried in acetronile instead of hexane. H NMR
(400 MHz, CDCl3) δ (ppm) 8.73 (d, J = 5.6 Hz, 1H), 8.07 (t, J =
7.6 Hz, 1H), 7.93 (s, 1H), 7.89–7.82 (m, 2H), 7.68 (d, J = 7.6 Hz,
1H), 7.54–7.48 (m, 1H), 1.43 (s, 12H); 13C NMR (100 MHz,
CDCl3) δ (ppm) 154.0, 143.5, 142.5, 137.8, 134.3, 132.2, 124.4,
124.1, 119.0, 118.0, 111.6, 80.6, 26.9; HRMS (ESI) calcd for
C18H20BN2O2 ([M+H]+): 307.1612, found: 307.1614.
2-[4-Methoxycarbonyl-2-(4,4,5,5-tetramethyl-1,3,2-
dioxaborolan-2-yl)phenyl]pyridine(2g). Yellow solid, 45.4 mg,
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67% yield. H NMR (400 MHz, CDCl3) δ (ppm) 8.72 (d, J = 5.2
Hz, 1H), 8.36 (s, 1H), 8.01 (t, J = 6.8 Hz, 2H), 7.87 (d, J = 8.0 Hz,
1H), 7.72 (d, J = 8.0 Hz, 1H), 7.44 (t, J = 6.0 Hz, 1H), 3.93 (s,
3H), 1.45 (s, 12H); 13C NMR (100 MHz, CDCl3) δ (ppm) 167.3,
155.0, 143.5, 142.0, 141.1, 132.5, 132.2, 129.5, 123.6, 121.0,
118.2, 80.4, 52.0, 27.0; HRMS (ESI) calcd for C19H23BNO4
([M+H]+): 340.1715, found: 340.1718.
2-[2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-
(trifluoromethyl)phenyl]pyridine(2n). Yellow solid, 57.8 mg,
1
83% yield. H NMR (400 MHz, CDCl3) δ (ppm) 8.70 (d, J = 5.6
Hz, 1H), 8.01 (dd, J = 7.6, 7.6 Hz, 1H), 7.85 (dd, J = 8.0 HzꢀJ =
7.2 Hz, 3H) , 7.65 (d, J = 7.6 Hz, 1H), 7.44 (t, J = 6.4 Hz, 1H),
1.43 (d, J = 2.0 Hz, 12H); 13C NMR (100 MHz, CDCl3) δ (ppm)
154.8, 143.3, 142.3, 137.5, 131.8, 130.3 (q, JCF =31.8 Hz) , 127.8
2-[2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-4-
(trifluoromethyl)phenyl]pyridine(2h). Yellow solid, 61.3 g, 88%