Job/Unit: O43233
/KAP1
Date: 14-11-14 14:05:27
Pages: 10
Iron-Catalyzed C–H Bond Functionalization
7.59–7.71 (m, 3 H), 7.81 (d, J = 7.6 Hz, 1 H), 8.03 (d, J = 8 Hz, 1
H), 8.53 (d, J = 8.4 Hz, 1 H), 8.62 (d, J = 8.4 Hz, 1 H) ppm. 13C
NMR (100 MHz, CDCl3): δ = 114.5, 115.7, 118.3, 120.0, 122.3,
122.4, 123.1, 124.4, 124.9, 126.6, 128.4, 128.9, 129.0, 130.1, 130.2,
12-Phenylbenzo[e]pyrido[1,2-a]indole (14l): Dark green oil; Rf = 0.53
(hexanes/ethyl acetate, 95:5 v/v). H NMR (400 MHz, CDCl3): δ =
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6.52 (t, J = 6.8 Hz, 1 H), 6.75 (dd, J = 8.8 Hz, J = 2 Hz, 1 H),
7.19–7.30 (m, 1 H), 7.30–7.40 (m, 3 H), 7.46 (t, J = 7.6 Hz, 2 H),
7.51–7.61 (m, 3 H), 7.82–7.91 (m, 2 H), 8.10 (d, J = 8 Hz, 1 H),
8.30 (d, J = 7.2 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3): δ =
109.2, 109.6, 110.9, 118.2, 120.7, 121.6, 122.5, 123.0, 124.6, 124.7,
125.3, 125.5, 125.9, 127.0, 128.5, 128.8, 128.9, 131.5, 133.6,
132.6, 132.9, 133.2, 134.5, 137.1 ppm. IR (neat): ν = 703, 734, 751,
˜
797, 1444, 1600, 1725, 2853, 2924, 2956, 3049 cm–1. HRMS: calcd.
for C22H16N [M + H]+ 294.1283; found 294.1291.
3-Chloro-7-phenylindolo[1,2-a]quinoline (14g): Fluorescent solid;
136.4 ppm. IR (neat): ν = 737, 793, 1370, 1600, 2920, 2954,
˜
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m.p. (121–122 °C). Rf = 0.53 (hexanes/ethyl acetate, 95:5 v/v). H
3050 cm–1. HRMS: calcd. for C22H16N [M + H]+ 294.1283; found
294.1295.
NMR (400 MHz, CDCl3): δ = 6.98 (dd, J = 7.6 Hz, J = 2 Hz, 1
H), 7.38–7.59 (m, 8 H), 7.61–7.67 (m, 2 H), 8.02 (d, J = 6 Hz, 1
H), 8.38 (d, J = 6.8 Hz, 1 H), 8.45 (dd, J = 7.2 Hz, J = 2 Hz, 1
H) ppm. 13C NMR (100 MHz, CDCl3): δ = 111.9, 114.2, 116.8,
119.6, 120.3, 122.5, 122.8, 123.1, 126.3, 126.8, 127.9, 128.1 128.4,
General Experimental Procedure for Iron-Catalyzed Oxidation: In a
reaction tube, FeCl2 (6.3 mg, 0.05 mmol), 2-benzhydrylpyridine
(13a, 122.5 mg, 0.5 mmol), and acetic acid (143 μL, 2.5 mmol) in
DMSO (3 mL) were stirred at 125 °C for 12 h under oxygen (oxy-
gen balloon). The reaction mixture was then diluted with water,
and the resulting mixture was washed with aqueous NaHCO3. The
aqueous layer was extracted with ethyl acetate, and the combined
organic layers were dried with Na2SO4 and evaporated in vacuo.
The resulting residue was purified by chromatography on a silica
gel column (hexanes/ethyl acetate, 95:5) to give pure diphenyl(pyr-
idin-2-yl)methanol (15a).
129.0, 129.1, 130.0, 132.7, 132.8, 134.1, 135.4 ppm. IR (neat): ν =
˜
920, 1044, 1250, 1636, 1734, 2945, 2996 cm–1. HRMS: calcd. for
C22H15NCl [M + H]+ 328.0893; found 328.0889.
3-Methyl-10-p-tolylpyrido[1,2-a]indole (14h): Dark green semisolid;
Rf = 0.53 (hexanes/ethyl acetate, 95:5 v/v). 1H NMR (400 MHz,
CDCl3): δ = 2.35 (s, 3 H), 2.51 (s, 3 H), 6.36 (td, J = 6.8 Hz, J =
0.8 Hz, 1 H), 6.75 (ddd, J = 9.4 Hz, J = 3 Hz, J = 1.2 Hz, 1 H),
7.16 (dd, J = 8.4 Hz, J = 0.8 Hz, 1 H), 7.24 (d, J = 8 Hz, 2 H),
7.50 (d, J = 8.4 Hz, 2 H), 7.54–7.62 (m, 2 H), 7.82 (d, J = 8.4 Hz,
1 H), 8.17 (d, J = 7.2 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3):
δ = 21.4, 22.1, 105.8, 108.2, 110.1, 118.4, 119.2, 122.1, 124.3, 125.3,
Diphenyl(pyridin-2-yl)methanol (15a): White solid, m.p. 106–
107 °C; ref.[33] m.p. 107–108 °C. Rf = 0.48 (hexanes/ethyl acetate,
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95:5 v/v). H NMR (400 MHz, CDCl3): δ = 6.22 (br. s, 1 H), 7.03
(d, J = 8 Hz, 1 H), 7.11–7.26 (m, 11 H), 7.54 (td, J = 7.6 Hz, J =
1.6 Hz, 1 H), 8.50 (d, J = 4.8 Hz, 1 H) ppm. 13C NMR (100 MHz,
CDCl3): δ = 81.0, 122.5, 123.0, 127.5, 128.1, 128.3, 136.5, 146.2,
125.7, 129.0, 129.7, 130.2, 132.5, 132.8, 135.2 ppm. IR (neat): ν =
˜
731, 1347, 1457, 1540, 1614, 2857, 2919, 3029 cm–1. HRMS: calcd.
for C20H18N [M + H]+ 272.1439; found 272.1451.
147.9, 163.3 ppm. IR (neat): ν = 762, 1035, 2924, 3020, 3064,
˜
3407 cm–1. HRMS: calcd. for C18H15NONa [M + Na]+ 284.1051;
found 284.1060.
1-Methyl-10-o-tolylpyrido[1,2-a]indole (14i): Dark green semisolid;
Rf = 0.53 (hexanes/ethyl acetate, 95:5 v/v). 1H NMR (400 MHz,
CDCl3): δ = 1.98 (s, 3 H), 2.09 (s, 3 H), 6.33 (t, J = 6.8 Hz, 1 H),
6.61–6.70 (m, 1 H), 6.88–7.02 (m, 2 H), 7.06–7.28 (m, 5 H), 7.65
(d, J = 8 Hz, 1 H), 8.18 (d, J = 7.2 Hz, 1 H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 19.9, 20.4, 106.0, 107.9, 108.0, 118.3, 119.8,
121.7, 123.8, 124.1, 125.3, 127.2, 127.4, 129.1, 129.6, 131.2, 132.7,
(4-Fluorophenyl)(phenyl)(pyridin-2-yl)methanol (15b): White solid;
m.p. 76–77 °C. Rf = 0.48 (hexanes/ethyl acetate, 95:5 v/v). 1H NMR
(400 MHz, CDCl3): δ = 6.18 (s, 1 H), 6.85–6.93 (m, 2 H), 7.00 (d,
J = 8 Hz, 1 H), 7.10–7.25 (m, 8 H), 7.55 (td, J = 7.6 Hz, J = 1.6 Hz,
1 H), 8.50 (d, J = 4.8 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3):
δ = 80.6, 114.8, 115.0, 122.6, 122.9, 127.6, 128.2, 130.1 (d, J =
8 Hz), 136.7, 142.2, 146.1, 148.0, 162.2 (d, J = 245 Hz), 163.2 ppm.
133.5, 135.7, 139.2 ppm. IR (neat): ν = 723, 754, 1598, 1627, 2854,
˜
2923, 3438 cm–1. HRMS: calcd. for C20H18N [M + H]+ 272.1439;
found 272.1450.
IR (neat): ν = 701, 834, 1040, 1157, 1220, 1351, 1504, 1592, 2927,
˜
3023, 3058, 3389 cm–1. HRMS: calcd. for C18H15NOF [M + H]+
280.1138; found 280.1134.
1-Methoxy-10-(2-methoxyphenyl)pyrido[1,2-a]indole (14j): Pale yel-
low solid; m.p. 149–150 °C. Rf = 0.50 (hexanes/ethyl acetate, 95:5
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v/v). H NMR (400 MHz, CDCl3): δ = 3.81 (s, 6 H), 6.51 (t, J =
Phenyl(pyridin-2-yl)(m-tolyl)methanol (15c): Yellow oil; Rf = 0.41
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6.8 Hz, 1 H), 6.78 (d, J = 7.6 Hz, 1 H), 6.85 (t, J = 6.8 Hz, 1 H),
7.04–7.15 (m, 2 H), 7.27 (t, J = 6 Hz, 1 H), 7.32–7.44 (m, 2 H),
7.51 (dd, J = 7.6 Hz, J = 1.6 Hz, 1 H), 7.55 (d, J = 8.4 Hz, 1 H),
8.29 (d, J = 6.8 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3): δ =
55.5, 101.5, 102.6, 103.4, 108.4, 110.7, 119.1, 119.3, 119.9, 120.6,
121.4, 124.0, 124.8, 127.6, 130.7, 133.1, 154.8, 158.2 ppm. IR
(hexanes/ethyl acetate, 95:5 v/v). H NMR (400 MHz, CDCl3): δ =
2.22 (s, 3 H), 6.18 (s, 1 H), 6.93 (d, J = 7.6 Hz, 1 H), 7.00 (d, J =
7.2 Hz, 1 H), 7.04 (d, J = 8 Hz, 1 H), 7.06–7.25 (m, 8 H), 7.55 (td,
J = 7.6 Hz, J = 1.6 Hz, 1 H), 8.50 (d, J = 4.8 Hz, 1 H) ppm. 13C
NMR (100 MHz, CDCl3): δ = 21.7, 81.0, 122.4, 123.1, 125.5, 127.4,
127.8, 128.0, 128.2, 128.3, 128.9, 136.5, 137.7, 146.2, 146.3, 147.8,
(neat): ν = 743, 909, 1265, 1460, 1570, 2835, 2933, 3050 cm–1.
˜
163.5 ppm. IR (neat): ν = 703, 764, 1038, 1378, 1439, 1594, 2858,
˜
HRMS: calcd. for C20H18NO2 [M + H]+ 304.1338; found 304.1343.
2923, 3056, 3383 cm–1. HRMS: calcd. for C19H17NONa [M + Na]+
298.1208; found 298.1194.
3-Fluoro-10-(4-fluorophenyl)pyrido[1,2-a]indole (14k): Yellow solid;
m.p. 155–156 °C. Rf = 0.54 (hexanes/ethyl acetate, 95:5 v/v). 1H Naphthalen-1-yl(phenyl)(pyridin-2-yl)methanol (15d): Brown solid;
NMR (400 MHz, CDCl3): δ = 6.51 (t, J = 6.8 Hz, 1 H), 6.88 (ddd,
m.p 131–132 °C. Rf = 0.43 (hexanes/ethyl acetate, 95:05 v/v). 1H
J = 9.6 Hz, J = 6.4 Hz, J = 0.8 Hz, 1 H), 7.16–7.25 (m, 3 H), 7.54– NMR (400 MHz, CDCl3): δ = 6.52–6.63 (m, 2 H) 6.92 (d, J =
7.63 (m, 4 H), 7.87 (dd, J = 7.2 Hz, J = 5.2 Hz, 1 H), 8.18 (d, J = 8 Hz, 1 H), 7.08–7.23 (m, 6 H), 7.24–7.34 (m, 3 H), 7.48 (td, J =
7.2 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 96.7 (d, J = 7.6 Hz, J = 1.6 Hz, 1 H), 7.65–7.75 (m, 2 H), 8.00 (d, J = 8.4 Hz,
26 Hz), 105.1, 108.8, 112.7 (d, J = 25 Hz), 116.0 (d, J = 21 Hz), 1 H), 8.56 (d, J = 4.8 Hz, 1 H) ppm. 13C NMR (100 MHz, CDCl3):
118.2, 120.2 (d, J = 9 Hz), 122.6, 124.2, 124.3, 130.5, 130.6, 130.9
(d, J = 4 Hz), 133.6, 158.6 (d, J = 238 Hz), 161.4 (d, J =
δ = 81.9, 122.5, 123.7, 124.1, 125.4, 126.3, 127.2, 127.3, 127.8,
128.3, 128.5, 128.6, 129.3, 132.0, 135.1, 136.6, 141.7, 146.6, 148.0,
244 Hz) ppm. IR (neat): ν = 718, 743, 1093, 1160, 1223, 1488, 1541,
163.4 ppm. IR (neat): ν = 736, 908, 1028, 1386, 1439, 1591, 2925,
˜
˜
1629, 2852, 2925, 2962 cm–1. HRMS: calcd. for C18H12NF2 [M +
H]+ 280.0938; found 280.0948.
3055, 3377 cm–1. HRMS: calcd. for C22H17NONa [M + Na]+
334.1208; found 334.1217.
Eur. J. Org. Chem. 0000, 0–0
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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