J. Quirante et al. / Journal of Organometallic Chemistry 696 (2011) 1011e1017
1015
(d, J ¼ 2 Hz, 1H, H-4), 6.86 (dd, J ¼ 8.8 and 2.4 Hz, 1H, H-6), 6.76 (d,
J ¼ 2 Hz, 1H, H-3), 3.87 (s, 3 H, OCH3). 13C NMR (gHSQC, gHMBC)
154.5, (C-5), 138.6 (C-2), 132.5 (C-10), 132.0 (C-7a), 129.7 (C-3a),
129.0 (C-30 and C-50), 127.6 (C-40), 125.0 (C-20 and C-60), 112.6 (C-6),
111.6 (C-7), 102.3 (C-4), 99.8 (C-3), 55.8 (CH3).
4.1.2.2. 2-(4-Chlorophenyl)-3-ferrocenylmethyl-1H-indole (9). Dark
yellow solid, mp 179e181 ꢃC. Yield 92%. Anal. Calc. For
C25H20ClFeN: C, 70.52; H, 4.70; N, 3.29. Found: C, 70.16; H, 4.73; N,
3.30%. MS (ESIþ): m/z ¼ 425 [Mþ]. IR: 3540, 3413, 3397, 1483, 1455,
1435, 1335, 1311, 1105, 1089, 1010, 997, 832, 738, 495. 1H NMR
(gCOSY) 7.94 (b s, 1H, NH-indol), 7.63 (d, J ¼ 8 Hz, 1H, H-4), 7.53 (d,
J ¼ 8 Hz, 2H, H-20 and H-60), 7.46 (d, J ¼ 8 Hz, 2H, H-30 and H-50), 7.33
(d, J ¼ 7.6 Hz, 1H, H-7), 7.19 (t, J ¼ 7.4 Hz, 1H, H-6), 7.12 (dd, J ¼ 7.4
and 8 Hz, 1H, H-5), 4.06 (s, 5 H, C5H5), 4.12 (s, 2H, H2 and H5, C5H4),
4.00 (s, 2H, H3 and H4, C5H4), 3.94 (s, 2H, CH2). 13C NMR (gHSQC,
gHMBC) 135.9 (C-7a), 133.6 (C-40), 133.0 (C-2), 131.7 (C-10), 129.4
(C-20 and C-60), 129.0 (C-30 and C-50), 128.9 (C-3a), 122.5 (C-6), 119.8
(C-4), 119.6 (C-5), 113.6 (C-3), 110.8 (C-7), 88.9 (C1), 68.8 (C2 and C5),
68.7 (C5H5), 67.0 (C3 and C4), 24.6 (CH2).
4.1.1.5. 5-Nitro-2-phenyl-1H-indole (5). 1H NMR (gCOSY) 8.78 (b s,
1H, NH-indol), 8.59(d, J ¼ 2 Hz, 1H, H-4), 8.12 (dd, J ¼ 9.2 and 2 Hz,
1H, H-6), 7.70 (m, 2H, H-20 and H-60), 7.50 (td, J ¼ 7.6 and 1.4 Hz, 2H,
H-30 and H-50), 7.44 (d, J ¼ 9.2 Hz, 1H, H-7), 7.41 (tt, J ¼ 7.4 and
1.6 Hz, 1H, H-40), 6.98 (s, 1H, H-3). 13C NMR (gHSQC, gHMBC) 142.3,
(C-3a), 141.2 (C-2), 139.7 (C-7a), 131.1 (C-10), 129.3 (C-30 and C-50),
128.8 (C-40), 128.6 (C-5), 125.4 (C-20 and C-60), 118.0 (C-6), 117.7
(C-4), 110.9 (C-7), 101.6 (C-3).
4.1.1.6. 5-Chloro-2-phenyl-1H-indole (6). 1H NMR (gCOSY) 8.37 (b s,
1H, NH-indol), 7.64 (dt, J ¼ 7.2 and 1.2 Hz, 2H, H-20 and H-60), 7.58
(d, J ¼ 2 Hz, 1H, H-4), 7.44 (td, J ¼ 7.4 and 1.4 Hz, 2H, H-30 and H-50),
7.34 (tt, J ¼ 7.4 and 1.2 Hz, 1H, H-40), 7.29 (d, J ¼ 8.8 Hz,1H, H-7), 7.13
(dd, J ¼ 9 and 2 Hz, 1H, H-6), 6.75 (s, 1H, H-3). 13C NMR (gHSQC,
gHMBC) 139.3 (C-2), 135.1 (C-7a), 131.8 (C-10), 130.3 (C-3a), 129.1
(C-30 and C-50), 128.1 (C-40), 125.8 (C-5), 125.2 (C-20 and C-60), 122.5
(C-6), 120.0 (C-4), 111.9 (C-7), 99.5 (C-3).
4.1.2.3. 3-Ferrocenylmethyl-2-(4-fluorophenyl)-1H-indole (10). Yellow
solid, mp 146e148 ꢃC. Yield 94%. Anal. Calc. For C25H20FFeN: C,
73.37; H, 4.89; N, 3.42. Found: C, 73.28; H, 4.99; N, 3.50%. MS
(ESIþ): m/z ¼ 409 [M]þH.þ IR: 3418, 1502, 1457, 1436, 1227, 1216,
1156, 1101, 841, 815, 735, 489. 1H NMR (gCOSY) 7.94 (b s, 1H, NH-
indol), 7.62 (d, J ¼ 8 Hz, 1H, H-4), 7.54e7.60 (m, 2H, H-20 and H-60),
7.35 (d, J ¼ 8 Hz, 1H, H-7), 7.15e7.22 (m, 3 H, H-6, H-30 and H-50),
7.12 (m, 1H, H-5), 4.12 (s, 2H, H2 and H5, C5H4), 4.04 (s, 5 H, C5H5),
4.00 (s, 2H, H3 and H4, C5H4), 3.93 (s, 2H, CH2). 13C NMR (gHSQC,
gHMBC) 163.6, 161.2 (C-40), 135.8 (C-7a), 133.3 (C-2), 130.0, 129.9
(C-20 and C-60), 129.4 (C-10), 129.1 (C-3a), 122.3 (C-6), 119.7 (C-5),
119.6 (C-4), 115.9, 115.8 (C-30 and C-50), 113.1 (C-3), 110.7 (C-7), 88.9
4.1.1.7. 2-(2pyiridyl)-1H-indole (7). 1H NMR (gCOSY) 9.86 (b s, 1H,
NH-indol), 8.57 (dm, J ¼ 4.8 Hz, 1H, H-30), 7.80 (m, 1H, H-60), 7.70
(td, J ¼ 7.6 and 1.6 Hz, 1H, H-50), 7.65 (d, J ¼ 7.6 Hz, 1H, H-4), 7.37
(dm, J ¼ 8 Hz, 1H, H-7), 7.21 (ddd, J ¼ 8.2, 7 and 1.2 Hz, 1H, H-6), 7.16
(ddd, J ¼ 7.4, 4.8 and 1 Hz, 1H, H-40), 7.11 (ddd,, J ¼ 7.8, 7.1 and
0.9 Hz, 1H, H-5), 7.02 (m, 1H, H-3). 13C NMR (gHSQC, gHMBC) 150.4
(C-10), 149.1 (C-30), 136.7 (C-2), 136.62 (C-50), 136.59 (C-7a), 129.1
(C-3a), 123.1 (C-6), 122.0 (C-40), 121.1 (C-4), 120.1 (C-5), 119.9 (C-60),
111.4 (C-7), 100.6 (C-3).
(C1), 68.8 (C2 and C5), 68.7 (C5H5), 67.1 (C3 and C4), 24.6 (CH2). 19
NMR -114.37.
F
4.1.2.4. 3-Ferrocenylmethyl-5-methoxy-2-phenyl-1H-indole (11). Grey
solid, mp 141e143 ꢃC. Yield 90%. Anal. Calc. For C26H22FeNO: C,
74.12; H, 5.50; N, 3.32. Found: C, 73.78; H, 5.67; N, 3.31%. MS (ESIþ):
m/z ¼ 421 [M]þHþ. IR: 3386, 1481, 1449, 1214, 1021, 828, 770, 698,
510, 496. 1H NMR (gCOSY) 7.87 (b s, 1H, NH-indol), 7.60 (dd, J ¼ 7.8
and 1.2 Hz, 2H, H-20 and H-60), 7.49 (t, J ¼ 7.8 Hz, 2H, H-30 and H-50),
7.38 (tt, J ¼ 7.6 and 1.2 Hz,1H, H-40), 7.24 (d, J ¼ 8.8 Hz,1H, H-7), 7.04
(d, J ¼ 2.6 Hz, 1H, H-4), 6.84 (dd, J ¼ 8.6 and 2.6 Hz, 1H, H-6), 4.16 (s,
2H, H2 and H5, C5H4), 4.05 (s, 5 H, C5H5), 4.02 (s, 2H, H3 and H4,
C5H4), 3.94 (s, 2H, CH2), 3.85 (s, 3 H, OCH3). 13C NMR (gHSQC,
gHMBC) 154.2 (C-5), 135.2 (C-2), 133.3 (C-10), 131.0 (C-7a) 129.6 (C-
3a),128.8 (C-30 and C-50),128.1 (C-20 and C-60),127.7 (C-40),112.7 (C-
3), 112.2 (C-6), 111.4 (C-7), 101.7 (C-4), 90.0 (C1), 69.4 (C2, C5 and
C5H5), 67.7 (C3 and C4), 55.9 (OCH3), 24.6 (CH2).
4.1.2. General synthetic procedure for the preparation of
3-ferrocenylmethyl-2-pheylindoles (8e14)
A slightly modified procedure of Boev and coworkers [17] was
followed for the synthesis of the 3-ferrocenylmethyl-2-phenyl-
indoles. To a stirred solution of the parent 2-phenylindole deriva-
tive (1e7, 1 mmoL) and ferrocenemethanol (216 mg, 1 mmoL) in
dichloromethane (25 mL), 10 mL of an aqueous solution of HBF4
(6 mL of 50% commercial acid þ 4 mL H2O) was added dropwise.
After vigorous stirring for 1 h, the mixture was quenched with
water (40 mL). The phases were separated, and the aqueous phase
extracted with dichloromethane (2 ꢂ 20 mL) [20]. The combined
organic extracts were washed with water (2 ꢂ 10 mL), dried over
Na2SO4 and evaporated under reduced pressure. The crude product
was purified by column chromatography on a short pad of silica gel
using diethylether as eluent. The ether was evaporated under
reduced pressure to yield the desired 3-ferrocenylmethyl deriva-
tives (8e14) in very high yield.
4.1.2.5. 3-Ferrocenylmethyl-5-nitro-2-phenyl-1H-indole (12). Yellow-
orange solid, mp 185 ꢃC. Yield 93%. Anal. Calc. For C25H20FeN2O2: C,
68.82; H, 4.62; N, 6.42. Found: C, 68.94; H, 4.61; N, 6.37%. MS (ESIþ):
m/z ¼ 436.4 [Mþ]. IR: 3470, 3450, 3382, 3325, 1515, 1473, 1328,
1300, 815, 737, 699, 480. 1H NMR (gCOSY) 8.60 (d, J ¼ 2 Hz,1H, H-4),
8.34 (b s, 1H, NH-indol), 8.10 (dd, J ¼ 8.6 and 2.2 Hz, 1H, H-6), 7.63
(m, 2H, H-20 and H-60), 7.55 (t, J ¼ 7.6 Hz, 2H, H-30 and H-50), 7.47 (t,
J ¼ 7.4 Hz, 1H, H-40), 7.37 (d, J ¼ 8.8 Hz, 1H, H-7), 4.11 (t, J ¼ 1.6 Hz,
2H, H2 and H5, C5H4), 4.07 (s, 5 H, C5H5), 4.03 (t, J ¼ 1.8 Hz, 2H, H3
and H4, C5H4), 4.01 (s, 2H, CH2). 13C NMR (gHSQC, gHMBC) 141.7
(C-3a), 138.7 (C-7a), 133.3 (C-10), 137.3 (C-2) 131.9 (C-10), 129.1 (C-30
and C-50), 128.7 (C-5), 128.6 (C-40), 128.3 (C-20 and C-60), 117.9 (C-6),
116.8 (C-4), 115.2 (C-3), 110.7 (C-7), 88.1 (C1), 68.81 (C2 and C5),
68.80 (C5H5), 67.4 (C3 and C4), 24.5 (CH2).
4.1.2.1. 3-Ferrocenylmethyl-2-phenyl-1H-indole (8). Yellow solid,
mp 128e130 ꢃC. Yield 92%. Anal. Calc. For C25H21FeN: C, 76.92; H,
5.37; N, 3.58. Found: C, 76.59; H, 5.31; N, 3.78%. MS (ESIþ): m/
z ¼ 391.11 [Mþ]. IR: 3500, 3403, 3383, 1456, 765, 746, 699, 501, 484.
1H NMR (gCOSY) 8.00 (b s, 1H, NH-indol), 7.60e7.70 (m, 3 H, H-6, H-
20 and H-60), 7.51 (t, J ¼ 7.6 Hz, 1H, H-30 and H-50), 7.41 (d, J ¼ 7.6 Hz,
1H, H-7), 7.36 (m, 1H, H-4), 7.18 (td, J ¼ 7.4 and 1.2 Hz, 1H, H-5), 7.12
(m, 1H, H-40), 4.13 (s, 2H, H2 and H5, C5H4), 4.02 (s, 7 H, H3, H4, C5H4
and C5H5), 3.99 (s, 2H, CH2). 13C NMR (gHSQC, gHMBC) 136.0 (C-7a),
134.3 (C-3a), 133.5 (C-10), 128.8 (C-20 and C-60), 128.2 (C-30 and C-50),
127.7 (C-40), 125.0 (C-2), 122.2 (C-6), 119.60 (C-4), 119.57 (C-5), 113.0
(C-3), 110.7 (C-7), 89.0 (C1), 68.8 (C2, C5), 68.6 (C5H5), 66.9 (C3, C4),
24.6 (CH2).
4.1.2.6. 5-Chloro-3-ferrocenylmethyl-2-phenyl-1H-indole (13). Orange
solid, mp 140e143 ꢃC. Yield 96%. Anal. Calc. For C25H20FeClN: C,
70.53; H, 4.74; N, 3.29. Found: C, 70.42; H, 4.97; N, 3.45%. MS (ESIþ):
m/z ¼ 425.07 [Mþ]. IR: 3500, 3407, 1638, 1580, 1463, 1450, 1425,
1307, 1104, 1000, 815, 797, 763, 699, 484. 1H NMR (gCOSY) 8.01 (b s,