Supporting Information
Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2013
Chemoselective Hydrogenation of Functionalized Nitroarenes and Imines by
Using Carbon Nanofiber-Supported Iridium Nanoparticles
Yukihiro Motoyama,*[a] Masahiro Taguchi,[b] Nelfa Desmira,[a] Seong-Ho Yoon,[c]
Isao Mochida,[c] and Hideo Nagashima[c]
asia_201301184_sm_miscellaneous_information.pdf
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Contents
1. General Methods
P-S2
2. Synthesis and Characterization of Ir/CNFs and Ir/AC
P-S2
3. Synthesis and Spectral Data of Imines
P-S4
4. General Procedure for the Hydrogenation of Nitroarenes and Imines
P-S5
5. Spectral Data of Amines
P-S5
6. References
P-S8
S
1
1. General Methods.
Activated carbon, anhydrous toluene, ether and ethyl acetate, and 4-nitrophenyl glycidyl ether (1g)
were purchased from Kanto Chemical Co., Ltd. p-Tolaldehyde, aniline, p-chloroaniline, p-bromoaniline,
p-acetylaniline, nitroarenes 1a–d, 1f, 1h, and 1i were purchased from Tokyo Chemical Industry Co., Ltd.
Ir4(CO)12 and 3-chloro-4-benzyloxynitrobenzene (1e) was purchased from Aldrich Chemical Company, Inc.
1
H and
13
C NMR spectra were measured on JEOL ECA 270 (270 MHz) and ECA 400 (396 MHz)
spectrometers. Chemical shifts for 1H NMR were described in parts per million downfield from
tetramethylsilane as an internal standard (δ = 0) in CDCl3, unless otherwise noted. Chemical shifts for 13C
NMR were expressed in parts per million in CDCl3 as an internal standard (δ = 77.1), unless otherwise
noted. IR spectra were measured on JASCO FT/IR-4200 spectrometer. GC analyses were performed on a
Shimadzu GC-17A gas chromatograph equipped with TC-17 (30 m) column. ICP-MS and HRMS analyses
were performed at the Analytical Center in Institute for Materials Chemistry and Engineering, Kyushu
University. Analytical thin-layer chromatography (TLC) was performed on aluminum sheets pre-coated
with aluminum oxide (Merck, aluminum oxide 150 F254, neutral) and glass plates pre-coated with silica gel
(Merck, Kieselgel 60 F254). Visualization was accomplished by UV light (254 nm), anisaldehyde, and
phosphomolybdic acid. CNFs were prepared by the method reported previously.1
2. Synthesis and Characterization of Ir/CNFs and Ir/AC.
To a suspension of carbon materials (CNFs or activated carbon: AC) (100 mg) in mesitylene (17 mL)
was added Ir4(CO)12 (7.2 mg, [Ir] = 5.0 mg) under an argon atmosphere. After it was stirred at 165 °C for
24 h, the insoluble carbon materials were isolated by filtrating using membrane filters (Durapore®; 0.45
µm HV). The solids were washed with toluene (50 mL) and ether (50 mL) and then dried under vacuum
(0.04 Torr) at room temperature for 3 h to afford Ir/CNFs and Ir/AC.
ICP-MS Analysis: The Ir catalyst prepared as above (10 mg) was added to an aqueous HCl solution
(12 mol/L, 10 mL). After the resultant suspension was heated at 75 °C for 12 h, the insoluble carbon
materials were removed by filtration using membrane filters (Durapore®; 0.45 mm HV). The obtained
supernatant was diluted with an aqueous solution of HCl, and the concentration of HCl was adjusted to 1.2
x 10-4 mol/L. The iridium contents on CNFs were calibrated with a commercially available standard
reagent (ACROS: Ir atomic absorption standard solution, 1 mg/mL Ir in 5% HCl); five standard solutions,
of which Pd concentration is in a rage from 5 ppb to 200 ppb, were used for calibration.
TEM Studies: A few drops of a suspension of each sample in n-butanol were deposited on the TEM
grid (STEM 150 Cu grid, 150 mm), and the solvent was removed at room temperature under reduced
pressure (0.04 Torr). TEM observations were carried out with a JEOL JEM 2010F transmission electron
microscope operating at 200 kV. The particle size distributions were obtained from the TEM images using
a digital camera.
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2
Ir/CNF-H
0
Ir/CNF-P
1
2
3 (nm)
0
Ir/CNF-H
2
3 (nm)
Ir/CNF-P
Ir/AC
Ir/CNF-T
0
1
1
2
3 (nm)
Ir/CNF-T
0
1
2
3 (nm)
Ir/AC
Figure S1. TEM images and histgrams of the Ir particles of Ir/CNFs and Ir/AC.
S
3
3. Synthesis and Spectral Data of Imines.
N-Phenyl-4-methylbenzaldimine (3a).2 This compound was prepared from p-tolaldehyde and aniline in
benzene in the presence of MgSO4; White solids; Mp. 45-47 °C; IR (KBr): ν
N
3064, 3031, 2884, 1621, 1586, 1568, 1482, 1447, 1190, 1169, 980, 909, 815,
742, 692 cm-1; H NMR (396 MHz, CDCl3): δ 2.43 (s, 3H), 7.18-7.25 (m, 3H),
7.29 (d, J = 7.7 Hz, 2H), 7.39 (t, J = 7.7 Hz, 2H), 7.80 (d, J = 7.7 Hz, 2H), 8.43 (s, 1H); 13C NMR (99.5
MHz, CDCl3): δ 21.9, 121.0, 125.9, 128.9, 129.2, 129.6, 133.8, 142.0, 152.4, 150.4; GLC (TC-17, 30 m,
detection FID, column temp. 250 °C, tR = 7.5 min.
N-4-Chlorophenyl-4-methylbenzaldimine (3b). This compound was prepared from p-tolaldehyde and
p-chloroaniline in benzene in the presence of MgSO4; White solids; Mp.
N
Cl
117-119 °C; IR (KBr): ν 2854, 1621, 1607, 1567, 1475, 1164, 1096, 1078,
1006, 835, 818, 717, 676 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.43 (s,
3H), 7.14 (d, J = 8.7 Hz, 2H), 7.28 (d, J = 7.7 Hz, 2H), 7.35 (d, J = 8.7 Hz, 2H), 7.79 (d, J = 7.7 Hz, 2H),
8.40 (s, 1H); 13C NMR (99.5 MHz, C6D6): δ 21.8, 122.3, 129.0, 129.3, 129.6, 131.3, 133.5, 142.3, 150.8,
160.8; HRMS (EI) calcd for C14H12ClN 229.0658, found 229.0659; GLC (TC-17, 30 m, detection FID,
column temp. 250 °C, tR = 10.6 min.
N-4-Bromophenyl-4-methylbenzaldimine (3c). This compound was prepared from p-tolaldehyde and
p-bromoaniline in benzene in the presence of MgSO4; White solids; Mp.
N
Br
131-133 °C; IR (KBr): ν 2855, 1620, 1604, 1565, 1473, 1164, 1066, 1003,
833, 820, 716 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.43 (s, 3H), 7.08 (d, J
= 8.7 Hz, 2H), 7.28 (d, J = 7.7 Hz, 2H), 7.49 (d, J = 8.7 Hz, 2H), 7.78 (d, J = 7.7 Hz, 2H), 8.39 (s, 1H); 13C
NMR (99.5 MHz, C6D6): δ 21.9, 122.3, 128.9, 129.3, 129.7, 131.4, 133.5, 142.2, 150.8, 160.7; HRMS (EI)
calcd for C14H12BrN 273.0153, found 273.0155; GLC (TC-17, 30 m, detection FID, column temp. 250 °C,
tR = 13.8 min.
N-4-Acetylphenyl-4-methylbenzaldimine (3d). This compound was prepared from p-tolaldehyde and
p-acetylaniline in benzene in the presence of MgSO4; White solids; Mp.
140-143 °C; IR (neat): ν 2918, 1671, 1620, 1588, 1565, 1406, 1353, 1263,
N
O
1161, 1109, 997, 957, 835, 820 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.43
(s, 3H), 2.62 (s, 3H), 7.22 (d, J = 8.7 Hz, 2H), 7.30 (d, J = 7.7 Hz, 2H), 7.80 (d, J = 7.7 Hz, 2H), 8.00 (d, J
= 8.7 Hz, 2H), 8.40 (s, 1H); 13C NMR (99.5 MHz, C6D6): δ 21.8, 26.6, 120.9, 129.2, 129.7, 129.8, 133.3,
134.5, 142.6, 156.6, 161.7, 197.4; HRMS (EI) calcd for C16H15NO 237.1154, found 237.1151; GLC
(TC-17, 30 m, detection FID, column temp. 250 °C, tR = 20.3 min.
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4. General Procedure for the Hydrogenation of Nitroarenes and Imines.
Hydrogenation of Nitroarenes: The hydrogenation of nitroarenes was performed in a 100 mL stainless
steel autoclave fitted with a glass inner tube in the presence of nitroarene (1; 1 mmol), ethyl acetate (3 mL)
and Ir/CNF-T [S/C = 1,700 or 500 mol(1)/mol(Ir)] at 25 or 50 °C under H2 (initial pressure = 10 atm).
After complete reaction, the insoluble catalyst was removed by using filtration, and the filtrate was
concentrated under reduced pressure to give the product, aniline 2. The purity of the product was
determined by using capillary GLC and/or 1H NMR analysis.
Hydrogenation of Imines: The hydrogenation of imines was performed in a 100 mL stainless steel
autoclave fitted with a glass inner tube in the presence of nitroarene (3; 1 mmol), ethyl acetate (3 mL) and
Ir/CNF-T [S/C = 1,200 mol(3)/mol(Ir)] at 25 °C under H2 (initial pressure = 10 atm). After complete
reaction, the insoluble catalyst was removed by using filtration, and the filtrate was concentrated under
reduced pressure to give the product, amine 4. The purity of the product was determined by using capillary
GLC and/or 1H NMR analysis.
Recycle Experiments: After the hydrogenation of 4-chloronitrobenzene 1b over Ir/CNF-T [S/C = 2,300
mol (1b)/ mol (Ir)], the recovered catalyst was dried under reduced pressure and subjected to a further run
of reduction of 1b.
5.
Spectral Data of Amines:
4-Aminoanisole (2a):3,4 This compound was identified by spectral comparison with a sample purchased
MeO
NH2
from commercially sources and literature data. Colorless solid; mp 56-57 °C; IR
(KBr) ν 3427, 3335, 3221, 3073, 3007, 2964, 2938, 2912, 1844, 1631, 1499, 1440,
1234, 1129, 1040, 829, 644 cm-1; 1H NMR (396 MHz, CDCl3) δ 3.42 (bs, 2H), 3.75 (s, 3H), 6.65 (d, J =
8.7 Hz, 2H), 6.75 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3) δ 55.7, 114.8, 116.4, 140.0,152.8;
GLC (TC-17, 30 m, detection FID, column temp. 170 °C, tR = 7.2 min (2a), 11.9 min (1a).
4-Chloroaniline (2b):3 This compound was identified by spectral comparison with a sample purchased
Cl
1
NH2
from commercially sources and literature data. Colorless solid; Mp 69-70 °C; IR
(KBr): ν 3475, 3376, 3201, 1878, 1616, 1506, 1286, 1179, 1083, 1008, 815, 639 cm-1;
H NMR (396 MHz, CDCl3): δ 3.65 (bs, 2H), 6.61 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 8.7 Hz, 2H); 13C NMR
(99.5 MHz, CDCl3): δ 116.2, 123.0, 129.1, 145.0; GLC (TC-17, 30 m, detection FID, column temp.
170 °C), tR = 4.5 min (aniline), 6.8 min (2b), 7.3 min (1b).
4-Bromoaniline (2c):3 This compound was identified by spectral comparison with a sample purchased
Br
NH2
from commercially sources and literature data. Colorless solid; mp 60-61 °C; IR
(KBr): ν 3476, 3384, 3184, 1877, 1607, 1488, 1288, 1180, 1121, 1061, 829 cm-1; 1H
NMR (396 MHz, CDCl3): δ 3.66 (bs, 2H), 6.56 (d, J = 8.7 Hz 2H), 7.23 (d, J = 8.7 Hz, 2H); 13C NMR
(99.5 MHz, CDCl3): δ 110.1, 116.7, 132.0, 145.5; GLC (TC-17, 30 m, detection FID, column temp. 170 °C,
tR = 4.5 min (aniline), 9.0 min (2c), 9.8 min (1c).
S
5
4-Iodoaniline (2d):3 This compound was identified by spectral comparison with a sample purchased from
I
NH2
commercially sources and literature data. Colorless solid; Mp 61-62 °C; IR (KBr): ν
3406, 3300, 3203, 3058, 3028, 1871, 1629, 1581, 1482, 1274, 1176, 997, 682 cm-1; 1H
NMR (396 MHz, CDCl3): δ 3.67(bs, 2H), 6.47 (d, J = 8.2 Hz, 2H), 7.41 (d, J = 8.2 Hz, 2H); 13C NMR
(99.5 MHz, CDCl3): δ 79.4, 117.3, 137.9, 146.1; GLC (TC-17, 30 m, detection FID, column temp. 170 °C,
tR = 4.5 min (aniline), 14.0 min (2d), 15.8 min (1d).
4-Benzyloxy-3-chloroaniline (2e): This compound was identified by spectral comparison with a literature
BnO
NH2
data. Colorless liquid; IR (KBr): ν 3406, 3299, 3199, 3062, 3032, 2908, 2861, 1628,
1504, 1375, 1269, 1224, 1051, 1010, 915, 852, 739, 693 cm-1; 1H NMR (396 MHz,
CDCl3): δ 3.48 (bs, 2H), 5.05 (s, 2H), 6.50 (dd, J = 8.7, 2.9 Hz, 1H), 6.76 (d, J = 2.9
Cl
Hz, 1H), 6.80 (d, J = 8.7 Hz, 1H), 7.31 (t, J = 7.2 Hz, 1H), 7.38 (t, J = 7.2 Hz, 2H), 7.45 (d, J = 7.2 Hz,
2H); 13C NMR (99.5 MHz, CDCl3): δ 72.2, 114.2, 117.0, 117.2, 124.4, 127.4, 127.9, 128.5, 137.1, 141.4,
147.1; GLC (TC-17, 30 m, detection FID, column temp. 250 °C, tR = 16.3 min (2e), 18.3 min (1e).
4-Aminoacetophenone (2f):3 This compound was identified by spectral comparison with a sample
purchased from commercially sources and literature data. Colorless solid; Mp
NH2
O
102-104 °C; IR (KBr): ν 3399, 3341, 3301, 2970, 2927, 2884, 1614, 1516, 1363, 1260,
1083, 998, 897, 780, 732 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.50 (s, 3H), 4.11 (bs,
2H), 6.65 (d, J = 8.7 Hz, 2H), 7.80 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ 26.1, 113.7, 127.8,
130.8, 151.3, 196.6; GLC (TC-17, 30 m, detection FID, column temp. 170 °C, tR = 15.3 min (1f), 20.4 min
(2f).
4-Aminophenyl glycidyl ether (2g).5 This compound was identified by spectral comparison with a
literature data. Red liquid; IR (neat): ν 3351, 3005, 2922, 1508, 1230, 1035,
O
O
NH2
912, 824 cm-1; 1H NMR (396 MHz, C6D6): δ 2.19 (dd, J = 4.8, 2.9 Hz, 1H),
2.30 (dd, J = 4.8, 3.9 Hz, 1H), 2.82 (bs, 2H), 2.94 (ddt, J = 5.8, 3.9, 2.9 Hz, 1H),
3.51 (dd, J = 10.6, 5.8 Hz, 1H), 3.71 (dd, J = 10.6, 2.9 Hz, 1H), 6.33 (d, J = 8.7 Hz, 2H), 6.72 (d, J = 8.7
Hz, 2H); 13C NMR (99.5 MHz, C6D6): δ 44.0, 50.2, 69.9, 116.1, 116.2, 141.4, 151.9; HRMS (EI) calcd for
C9H11NO2 165.0790, found 165.0788.
4-Cyanoaniline (2h):3,4 This compound was identified by spectral comparison with a sample purchased
NC
NH2
from commercially sources and literature data. Pale yellow solid; Mp 86-87 °C; IR
(KBr): ν 3477, 3370, 3212, 2213, 1625, 1601, 1514, 1317, 1175, 831, 696 cm-1; 1H
NMR (396 MHz, CDCl3): δ 4.14 (bs, 2H), 6.65 (d, J = 8.2 Hz, 2H), 7.42 (d, J = 8.2 Hz, 2H); 13C NMR
(99.5 MHz, CDCl3): δ 100.2, 114.5, 120.3, 133.8, 1580.5; GLC (TC-17, 30 m, detection FID, column temp.
170 °C, tR = 11.8 min (1h), 18.0 min (2h),
Ethyl 4-aminocinnamate (2i):3 This compound was identified by spectral comparison with a literature
data. Pale yellow solid; Mp 69-71 °C; IR (KBr): ν 3464, 3365, 3232, 2980,
NH2
EtO2C
1694, 1596, 1517, 1441, 1306, 1172, 1037, 983, 828 cm-1; 1H NMR (396
MHz, CDCl3): δ 1.32 (t, J = 7.2 Hz, 3H), 3.92 (bs, 2H), 4.24 (q, J = 7.2 Hz,
S
6
2H), 6.24 (d, J = 15.9 Hz, 1H), 6.65 (d, J = 8.7 Hz, 2H), 7.35 (d, J = 8.7 Hz, 2H), 7.60 (d, J = 15.9 Hz,
1H);
13
C NMR (99.5 MHz, CDCl3): δ 14.3, 60.2, 113.8, 114.9, 124.8, 129.9, 144.9, 148.8, 167.8; GLC
(TC-17, 30 m, detection FID, column temp. 250 °C, tR = 9.0 min (1i), 9.4 min (2i).
N-[(4-Methylphenyl)methyl]aniline (4a).6 This compound was identified by spectral comparison with a
literature data. Colorless solid; Mp. 44-45 °C; IR (KBr): ν 3409, 3050, 3019,
2918, 1600, 1509, 1324, 1269, 1178, 1096, 805, 743, 689 cm-1; 1H NMR (396
HN
MHz, CDCl3): δ 2.40 (s, 3H), 4.00 (bs, 1H), 4.33 (s, 2H), 6.68 (d, J = 7.7 Hz,
2H), 6.77 (t, J = 7.3 Hz, 1H), 7.18-7.26 (m, 4H), 7.31 (d, J = 7.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ
21.2, 48.1, 112.9, 117.5, 127.6, 129.3, 129.4, 136.4, 136.9, 148.3; GLC (TC-17, 30 m, detection FID,
column temp. 250 °C, tR = 7.5 min (3a), 8.2 min (4a).
N-[(4-Methylphenyl)methyl]-4-chloroaniline (4b).6 This compound was identified by spectral
comparison with a literature data. Pale yellow solid; Mp. 72-73 °C; IR
HN
Cl
(KBr): ν 3395, 2958, 2920, 2857, 1597, 1495, 1463, 1308, 1293, 1244,
1122, 1095, 1073, 807 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.36 (s, 3H),
4.02 (bs, 1H), 4.26 (s, 2H), 6.55 (d, J = 8.7 Hz, 2H), 7.12 (d, J = 8.7 Hz, 2H), 7.17 (d, J = 7.7 Hz, 2H), 7.25
(d, J = 7.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ 21.2, 48.1, 113.9, 122.0, 127.5, 129.1, 129.4, 135.9,
137.1, 146.8; HRMS (EI) calcd for C14H14ClN 231.0815, found 231.0811; GLC (TC-17, 30 m, detection
FID, column temp. 250 °C, tR = 10.6 min (3b), 12.5 min (4b).
N-[(4-Methylphenyl)methyl]-4-bromoaniline (4c). Colorless solid; Mp. 81-83 °C; IR (KBr): ν 3396,
2914, 2845, 1590, 1492, 1463, 1396, 1309, 1243, 1179, 1068, 806 cm-1;
HN
Br
1
H NMR (396 MHz, CDCl3): δ 2.35 (s, 3H), 4.05 (bs, 1H), 4.25 (s, 2H),
6.50 (d, J = 8.7 Hz, 2H), 7.15 (d, J = 7.7 Hz, 2H), 7.23 (d, J = 7.7 Hz, 2H),
7.24 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3): δ 21.2, 48.1, 109.1, 114.5, 127.5, 129.5, 132.0,
135.8, 137.1, 147.1; HRMS (EI) calcd for C14H14BrN 275.0310, found 275.0307; GLC (TC-17, 30 m,
detection FID, column temp. 250 °C, tR = 13.8 min (3c), 16.2 min (4c).
N-[(4-Methylphenyl)methyl]-4-acetylaniline (4d). Colorless solid; Mp. 148-150 °C; IR (KBr): ν 3354,
2917, 2855, 1544, 1585, 1523, 1467, 1355, 1276, 1178, 1127, 1086, 951,
833, 804 cm-1; 1H NMR (396 MHz, CDCl3): δ 2.35 (s, 3H), 2.49 (s, 3H),
HN
O
4.36 (d, J = 5.8 Hz, 2H), 4.53 (t, J = 5.8 Hz, 1H), 6.59 (d, J = 8.7 Hz, 2H),
7.17 (d, J = 7.7 Hz, 2H), 7.24 (d, J = 7.7 Hz, 2H), 7.82 (d, J = 8.7 Hz, 2H); 13C NMR (99.5 MHz, CDCl3):
δ 21.1, 26.0, 47.2, 111.5, 126.6, 127.3, 129.4, 130.7, 135.2, 137.2, 152.1, 196.4; HRMS (EI) calcd for
C16H17NO 239.1310, found 239.1308; GLC (TC-17, 30 m, detection FID, column temp. 250 °C, tR = 20.3
min (3d), 29.7 min (4d).
N-4-Chlorophenyl-N-isopropylamine (5).7 This compound was identified by spectral comparison with a
literature data. Colorless liquid; IR (neat): ν 3411, 2966, 2872, 1598, 1496, 1315,
Cl
NH
1176, 1093, 812 cm-1; 1H NMR (396 MHz, CDCl3): δ 1.20 (d, J = 6.8 Hz, 6H), 3.44
(bs, 1H), 3.58 (sept, J = 6.8 Hz, 1H), 6.50 (d, J = 8.7 Hz, 2H), 7.10 (d, J = 8.7 Hz,
S
7
2H); 13C NMR (67.8 MHz, CDCl3): δ 22.9, 44.6, 114.3, 121.5, 129.2, 146.1; GLC (TC-17, 30 m, detection
FID, column temp. 170 °C, tR = 8.5 min (5).
6. References
1
a) A. Tanaka, S.-H. Yoon, I. Mochida, Carbon 2004, 42, 591-597; b) A. Tanaka, S.-H. Yoon, I.
Mochida, Carbon 2004, 42, 1291-1298.
2
a) P.Nongkunsarn, C. A. Ramsden, Tetrahedron 1997, 53, 3805-3830; b) A.Simion, C. Simion, T.
Kanda, S. Nagashima, Y. Mitoma, T. Yamada, K. Mimura, M. Tashiro, J. Chem. Soc., Perkin Trans.
1 2001, 2071-2078.
3
A. Yasuhara, A. Kasano, T. Sakamoto, J. Org. Chem. 1999, 64, 2301-2303.
4
D.-Y. Lee, J. F. Hartwig, Org. Lett. 2005, 7, 1169-1172.
5
H. Sajiki, K. Hattori, K. Hirota, Chem. Eur. J. 2000, 6, 2200-2204.
6
H. C. Maytum, J. Francos, D. J. Whatrup, J. M. J. Williams, Chem. Asian J. 2010, 5, 538-542.
7
M. Larrosa, C. Guerrero, R. Rodriguez, J. Cruces, Synlett 2010, 2101-2105.
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