Organometallics
Article
The residue was filtered through a plug of silica gel, evaporated, and
redissolved in a 10% solution of hydrochloric acid in methanol. The
reaction was then stirred at 75 °C for an hour and cooled to room
temperature. Neutralization with a diluted solution of NaOH followed.
The mixture was poured onto 10 mL of water and extracted with
DCM (2 × 10 mL). Combined organic phases were dried over MgSO4
and evaporated. The residue was purified by column chromatography,
providing the corresponding product 64−83%.
11a, (N-methyl)-2-vinylaniline. Light yellow oil (0.5 mmol, 67 mg,
50% yield). H NMR (500 MHz, CDCl3): δ 2.86 (s, 3H), 3.92 (s,
1
1H), 5.26−5.32 (m, 1H), 5.56−5.64 (m, 1H), 6.63 (d, J = 8.0 Hz,
1H), 6.69−6.79 (m, 2H), 7.16−7.28 (m, 2H) ppm. 13C NMR (500
MHz, CDCl3): δ 30.8, 110.1, 116.2, 117.2, 124.2, 127.3, 129.0, 132.9,
146.2 ppm. IR (CH2Cl2 film): ν 3430, 3083, 3044, 2985, 2917, 2870,
2815, 2581, 1889, 1704, 1622, 1602, 1577, 1511, 1478, 1461, 1426,
1318, 1307, 1292, 1262, 1186, 1166, 1125, 1106, 1063, 1018, 993, 910,
823, 745, 694, 661, 472, 434 cm−1. MS (EI; m/z): 51 (7), 65 (7), 77
(11), 91 (28), 117 (30), 118 (100), 119 (7), 130 (10), 132 (10), 133
(50, M+•). Anal. Calcd for C9H11N (133.19): C, 81.16; N, 10.52; H,
8.32. Found: C, 80.95; N, 10.43; H, 8.15.
11b, (N-iso-propyl)-2-vinylaniline. Light yellow oil (0.1 mmol,
62 mg, 62% yield). 1H NMR (400 MHz, CDCl3): δ 1.24 (d, J = 6.4 Hz,
6H), 3.50−3.75 (m, 2H), 5.30 (dd, J = 11.2, 2.0 Hz, 1H), 5.59 (dd, J =
17.2, 1.6 Hz, 1H), 6.63−6.79 (m, 3H), 7.15−7.20 (m, 1H), 7.24−7.28
(m, 1H) ppm. 13C NMR (400 MHz, CDCl3): δ 22.6, 23.1, 43.9, 44.2,
111.3, 116.0, 116.4, 116.8, 119.0, 124.2, 126.5, 127.6, 128.9, 129.0, 129.2,
130.1, 133.1, 144.4 ppm. IR (CH2Cl2 film): ν 3418, 3081, 3037, 2966,
2929, 2870, 2623, 1891, 1816, 1623, 1601, 1576, 1506, 1456, 1438,
1383, 1314, 1281, 1256, 1176, 1156, 1123, 1058, 1026, 996, 909, 861,
744, 696, 658, 619, 501 cm−1. MS (EI; m/z): 77 (13), 91 (14), 117
(15), 118 (100), 119 (11), 130 (21), 131 (29), 144 (11), 146 (77), 161
(38, M+•). Anal. Calcd for C9H12BrN (161.25): C, 81.94; H, 9.38; N,
8.69. Found: C, 81.68; H, 9.24; N, 8.76.
10a, (N-methyl)-2-bromoaniline. Colorless oil (1.6 mmol, 300 mg,
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64% yield). H NMR (500 MHz, CDCl3): δ 2.89 (s, 3H), 4.42 (s,
1H), 6.54−6.66 (m, 2H), 7.17−7.23 (m, 1H), 7.38−7.44 (m, 1H)
ppm. 13C NMR (500 MHz, CDCl3): δ 30.6, 109.6, 110.6, 117.6, 128.5,
132.2, 145.9 ppm. IR (CH2Cl2 film): ν 3426, 2913, 2874, 2821, 2583,
1889, 1761, 1599, 1513, 1461, 1431, 1421, 1320, 1292, 1169, 1155,
1106, 1073, 1019, 926, 893, 836, 662, 541, 434 cm−1, MS (EI; m/z):
51 (23), 52 (22), 63 (18), 77 (54), 91 (19), 104 (18), 105 (54), 184
(91), 185 (100), 186 (97, M+•). Anal. Calcd for C7H8BrN (186.05):
C, 45.19; H, 4.33; N, 7.53; Br, 42.95. Found: C, 44.97; H, 4.43; N,
7.39; Br, 43.06.
10b, (N-iso-propyl)-2-bromoaniline. Colorless oil (1.6 mmol, 345 mg,
1
65% yield). H NMR (500 MHz, CDCl3): δ 1.27 (d, J = 6.2 Hz, 6H),
3.64−3.71 (m, 1H), 4.16 (s, 1H), 6.52−6.56 (m, 1H), 6.64−6.66
(m, 1H), 7.15−7.19 (m, 1H), 7.41−7.44 (dd, J = 7.8, 1.4 Hz, 1H)
ppm. 13C NMR (500 MHz, CDCl3): δ 22.8, 44.3, 109.8, 111.8,
117.2, 128.4, 132.5, 144.3 ppm. IR (CH2Cl2 film): ν 3406, 3070,
3027, 2967, 2927, 2927, 2870, 1920, 1882, 1845, 1755, 1664, 1596,
1511, 1463, 1453, 1426, 1384, 1366, 1319, 1285, 1246, 1176, 1154,
1123, 1112, 1048, 1018, 983, 944, 924, 858, 833, 739, 707, 667, 492,
434 cm−1. MS (EI; m/z): 92 (12), 118 (35), 119 (40), 171 (9), 198
(100), 199 (11), 200 (93), 201 (9), 213 (31), 215 (29, M+•). Anal.
Calcd for C9H12BrN (214.11): C, 50.49; H, 5.65; N, 6.54; Br, 37.32.
Found: C, 50.55; H, 5.54; N, 6.48; Br, 37.35.
11c, (N-benzyl)-2-vinylaniline. Light yellow oil (0.5 mmol, 105 mg,
1
50% yield). H NMR (500 MHz, CDCl3): δ 4.21 (s, 1H), 4.35 (s,
2H), 5.30 (dd, J = 11.0, 1.5 Hz, 1H), 5.62 (dd, J = 17.0, 1.5 Hz, 1H),
6.61−6.66 (d, 1H), 6.70−6.82 (m, 2H), 7.10−7.17 (m, 1H), 7.24−
7.30 (m, 2H), 7.31−7.40 (m, 4H) ppm. 13C NMR (500 MHz,
CDCl3): δ 48.4, 111.0, 116.4, 117.6, 124.3, 127.3, 127.4, 127.5, 128.5,
128.7, 129.0, 133.0, 139.2, 145.0 ppm. IR (CH2Cl2 film): ν 3453, 2928,
2854, 1624, 1601, 1577, 1508, 1453, 1416, 1361, 1321, 1298, 1185,
1162, 1121, 1061, 1028, 994, 917, 823, 589, 519, 498, 457 cm−1. MS
(EI; m/z): 65 (7), 91 (38), 117 (9), 118 (100), 119 (6), 130 (5), 132
(7), 194 (7), 208 (4), 209 (27, M+•). Anal. Calcd for C15H15N
(209.29): C, 86.08; H, 7.22; N, 6.69. Found: C, 85.79; H, 7.22; N, 6.73.
11d, (N-(p-nitrobenzyl))-2-vinylaniline. Bright yellow crystals, mp
10c, (N-benzyl)-2-bromoaniline. Colorless oil (2.1 mmol, 542 mg,
1
83% yield). H NMR (500 MHz, CDCl3): δ 4.39 (s, 2H), 4.75 (s,
1H), 6.54−6.62 (m, 2H), 7.08−715 (m, 1H), 7.22−7.38 (m, 5H),
7.41−7.45 (m, 1H) ppm. 13C NMR (500 MHz, CDCl3): δ 48.0, 56.4,
109.7, 111.6, 118.0, 124.5, 124.7, 127.0, 127.2, 127.3, 127.6, 128.2,
128.5, 128.6, 128.7, 132.4, 133.8, 138.0, 138.7, 144.8 ppm. IR (CH2Cl2
film): ν 3418, 3084, 3063, 3029, 2925, 2856, 2584, 2525, 1950, 1883,
1807, 1753, 1797, 1510, 1469, 1452, 1427, 1361, 1322, 1295, 1264,
1235, 1194, 1175, 1161, 1129, 1089, 1067, 1045, 1019, 989, 924, 832,
789, 742, 697, 669, 658, 627, 540, 515, 457, 433 cm−1. MS (EI; m/z):
65 (10), 91 (100), 92 (10), 171 (7), 180 (9), 182 (12), 260 (13), 261
(43), 262 (19) 263 (41, M+•). Anal. Calcd for C13H12BrN (262.15): C,
59.56; H, 4.61; N, 5.34; Br, 30.48. Found: C, 59.85; H, 4.73; N, 5.45;
Br, 30.20.
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57−59 °C (0.7 mmol, 178 mg, 70% yield). H NMR (500 MHz,
CD2Cl2): δ 4.38 (s, 1H), 4.50 (d, J = 3.5 Hz, 2H), 5.37 (dd, J = 11.1,
1.6 Hz, 1H), 5.66 (dd, J = 17.3, 1.4 Hz, 1H), 6.43−6.47 (m, 1H),
6.74−6.84 (m, 2H), 7.07−7.12 (m, 1H), 7.26 (dd, J = 7.5, 1.6 Hz,
1H), 7.53 (d, J = 8.8 Hz, 2H), 8.17−8.21 (m, 2H) ppm. 13C NMR
(500 MHz, CDCl3): δ 47.6, 111.0, 117.0, 118.2, 123.9, 124.7, 127.7,
128.9, 132.7, 144.2, 147.2 ppm. IR (CH2Cl2 film): ν 3415, 3075, 2852,
2451, 1925, 1726, 1597, 1516, 1457, 1428, 1345, 1319, 1285, 1235,
1162, 1130, 1110, 1083, 1046, 1019, 989, 926, 858, 842, 787, 737, 698,
656, 539, 462, 434 cm−1. MS (EI; m/z): 77 (6), 89 (10), 90 (9), 91
(17), 117 (15), 118 (100), 119 (11), 130 (5), 132 (6), 254 (15, M +•).
Anal. Calcd for C15H14N2O2 (254.29): C, 70.85; H, 5.55; N, 11.02.
Found: C, 70.64; H, 5.50; N, 11.11.
10d, (N-(p-nitrobenzyl))-2-bromoaniline. Bright yellow crystals, mp
1
98−100 °C (1.9 mmol, 592 mg, 77% yield). H NMR (500 MHz,
CD2Cl2): δ 4.55 (d, J = 5.77 Hz, 2H), 4.93 (s, 1H), 6.44 (dd, J = 8.2,
1.3 Hz, 1H), 6.61 (td, J = 6.4, 1.3 Hz, 1H), 7.09−7.12 (m, 1H), 7.49
(dd, J = 7.9, 1.4 Hz, 2H), 8.18−8.22 (m, 2H) ppm, 13C NMR
(500 MHz, CDCl3): δ 47.4, 109.9, 111.6, 118.7, 124.0, 127.5, 128.5,
132.6, 144.0, 146.6, 147.3 ppm. IR (CH2Cl2 film): ν 3415, 3075, 2852,
2451, 1925, 1726, 1597, 1516, 1457, 1428, 1345, 1319, 1285, 1235,
1162, 1130, 1110, 1083, 1046, 1019, 989, 926, 858, 842, 787, 737, 698,
656, 539, 462, 434 cm−1. MS (EI; m/z): 77 (21), 78 (30), 89 (48),
90 (39), 91 (25), 106 (16), 136 (23), 184 (36), 186 (28), 306 (100,
4.1.3. Synthesis of 11e. 4.1.3.1. Wittig Reaction. Predried
methyl(triphenyl)phosphonium bromide (7 mmol, 2.5 g) was placed
in a Schlenk flask under argon and dissolved in 5 mL of THF. The
solution was cooled to −78 °C, and a 2.5 M butyllithium solution
(7 mmol, 3 mL) was added dropwise. The mixture was then warmed
to RT and stirred for an hour. Subsequently, the reaction mixture was
again cooled to −70 °C and a solution of 2-fluoro-5-nitrobenzaldehyde
(5 mmol) in 2 mL of THF was added dropwise. After that, the
reaction was warmed to RT and stirred for 4 h. When completion was
reached, the mixture was washed with a solution of saturated NH4Cl
and extracted with DCM (2 × 10 mL). Combined organic phases were
dried over MgSO4 and evaporated. The residue was purified on the
chromatography column, resulting in a colorless oil crystallizing in the
fridge (3.3 mmol, 556 mg, 72% yield).
M
+•). Anal. Calcd for C13H11BrN2O2 (307.15): C, 50.84; H, 3.61; Br,
26.01; N, 9.12. Found: C, 50.87; H, 3.65; N, 9.12; Br, 26.11.
4.1.2. Stille Couplings. Appropriate substituted amine (1 mmol)
and tetrakis(triphenylphosphine)palladium(0) (0.03 mmol, 35 mg)
were put in a Schlenk tube under argon and dissolved in 5 mL of
anhydrous toluene. Tributyl(vinyl)tin (1.1 mmol, 0.32 mL) was added,
and the reaction was stirred at 120 °C for 3 h. After that, that the
mixture was cooled to an ambient temperature and stirred with an
aqueous solution of KF for an hour. After that, it was extracted with
DCM (2 × 10 mL). Combined organic phases were washed with
10 mL of water, dried over MgSO4, and evaporated. The residue was
purified on the chromatography column, resulting in the correspond-
ing styrene (50−70%).
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13, 2-fluoro-5-nitrostyrene. H NMR (500 MHz, CDCl3): δ 5.56
(d, J = 11.2 Hz, 1H), 5.98 (d, J = 17.7, 1H), 6.58 (dd, J = 17.7, 11.2 Hz,
1H), 7.19 (t, J = 9.2 Hz, 1H), 8.42 (dd, J = 6.4, 2.8 Hz, 1H), 8.38−8.47
(m, 1H) ppm. 13C NMR (500 MHz, CDCl3): δ 122.9, 123.0, 124.4,
124.5, 126.6, 126.7, 127.3, 127.4 ppm. IR (CH2Cl2 film): ν 3096, 2926,
467
dx.doi.org/10.1021/om2011062 | Organometallics 2012, 31, 462−469