Synlett 2008(7): 1096-1100  
DOI: 10.1055/s-2008-1042917
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Novel InCl3/SiO2-Catalyzed Hydroarylation of Arenes with Styrenes under Solvent-Free Conditions

Gaojun Suna, Huayin Suna, Zhiyong Wang*a, Ming-Ming Zhou*b
a Hefei National Laboratory for Physical Science at Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. of China
Fax: +86(551)3603185; e-Mail: zwang3@ustc.edu.cn;
b Department of Physiology and Biophysics, Mount Sinai School of Medicine, New York University, One Gustave L. Levy Place, New York, NY 10029-6574, USA
Further Information

Publication History

Received 24 December 2007
Publication Date:
17 March 2008 (online)

Abstract

A novel InCl3/SiO2-catalyzed hydroarylation of various styrenes with arenes has been developed. The reaction can be carried out under solvent-free conditions to afford a series of 1,1-di­arylalkanes in high yields and with good regioselectivities. The catalyst can be reused six times without obvious loss of catalytic activity.

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The catalyst (InCl3/SiO2) was prepared by adding SiO2 (500 mg, 200-300 mesh) to a stirred solution of InCl3×4H2O (1 mmol) in CHCl3 (10 mL) followed by evaporation of the solvent in vacuo.

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The catalyst can be recovered by washing the mixture with petroleum ether, followed by the removal of the solvent.

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Typical Procedure for the FC-Arylation of Styrenes
In a typical experiment, InCl3/SiO2 (0.025 mmol, 5 mol%), styrene (0.5 mmol, 1 equiv), and anisole (0.55 mmol, 1.1 equiv) were mixed. The solution was heated at 80 °C for 2 h, cooled down, and gently evaporated under vacuo. The resulting crude mixture was purified by column chromatography on SiO2 (gradient hexane to hexane-
EtOAc = 100:1) to afford 97 mg (91%) of a colorless oily product.

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Spectroscopic Data for Products 1-Methyl-4-(1-phenylethyl)benzene (1a): 1H NMR (300 MHz, CDCl3): δ = 7.36-7.10 (m, 9 H), 4.11 (q, J = 7.2 Hz, 1 H), 2.30 (s, 4 H), 1.60 (d, J = 7.5 Hz, 3 H). 1,4-Dimethyl-2-(1-phenylethyl)benzene (1b): 1H NMR (300 MHz, CDCl3): δ = 7.23-6.95 (m, 9 H), 4.29 (q, J = 6.9 Hz, 1 H), 2.32 (s, 3 H), 2.18 (s, 2 H), 1.60 (d, J = 7.2 Hz, 3 H). 1,2-Dimethyl-4-(1-phenylethyl)benzene (1c): 1H NMR (300 MHz, CDCl3): δ = 7.20-6.93 (m, 8 H), 4.07 (q, J = 7.2 Hz, 1 H), 2.20 (s, 6 H), 1.60 (d, J = 7.2 Hz, 3 H). 2,4-Dimethyl-1-(1-phenylethyl)benzene (1d): 1H NMR (300 MHz, CDCl3): δ = 7.27-6.95 (m, 8 H), 4.28 (q, J = 7.2 Hz, 1 H), 2.29 (s, 3 H), 2.19 (s, 3 H), 1.59 (d, J = 7.5 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 146.6, 141.1, 136.0, 135.6, 131.4, 128.4, 127.8, 126.8, 125.9, 40.8, 22.3, 21.0, 19.8. IR (film): ν = 3024, 2966, 2926, 2872, 1601, 1493, 1451, 1374, 1307, 1192, 1028, 822, 762, 747, 700 cm-1. HRMS: m/z calcd for C16H18: 210.3142; found: 210.3133. 1,2,3,4-Tetrahydro-6-(1-phenylethyl)naphthalene (1e): 1H NMR (300 MHz, CDCl3): δ = 7.24-6.92 (m, 8 H), 4.08 (q, J = 7.2 Hz, 1 H), 2.72 (s, 4 H), 1.76 (s, 4 H), 1.61 (d, J = 7.5 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 146.8, 143.6, 137.1, 134.9, 129.2, 128.4, 128.3, 127.7, 126.0, 124.9, 44.6, 29.6, 29.1, 23.4, 22.1. IR (film): 3025, 2928, 2857, 1735, 1601, 1496, 1451, 1373, 1284, 1028, 910, 829, 766, 699 cm-1. HRMS: m/z calcd for C22H28: 292.2191; found: 292.2181. 1-Methoxy-4-(1-phenylethyl)benzene (1f): 1H NMR (300 MHz, CDCl3): δ = 7.30-7.12 (m, 7 H), 6.82 (d, J = 8.6 Hz, 2 H), 4.10 (q, J = 6.9 Hz, 1 H), 3.77 (s, 3 H), 1.76, (d, J = 7.2 Hz, 3 H). 1,2-Dimethoxy-4-(1-phenylethyl)benzene (1g): 1H NMR (300 MHz, CDCl3): δ = 7.28-7.15 (m, 5 H), 6.79 (s, 2 H), 6.72 (s, 1 H), 4.09 (q, J = 7.5 Hz, 1 H), 3.85 (s, 3 H), 3.82 (s, 3 H), 1.62 (d, J = 7.2 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 148.9, 146.7, 139.1, 128.4, 128.3, 127.65, 127.55, 127.5, 126.1, 119.4, 111.3, 111.2, 55.94, 55.87, 44.4, 22.1. IR (film): 3440, 3059, 3025, 2964, 2932, 2872, 2833, 1727, 1602, 1591, 1516, 1451, 1416, 1252, 1236, 1143, 1029, 908, 855, 810, 764, 701 cm-1. HRMS: m/z calcd for C16H18O2: 242.1307; found: 242.1295.
1,5-Dimethoxy-2,4-bis(1-phenylethyl)benzene (1h): 1H NMR (300 MHz, CDCl3): δ = 7.24-7.11 (m, 10 H), 7.00 (s, 1 H), 6.39 (s, 1 H), 4.45 (q, J = 7.2 Hz, 1 H), 3.73 (s, 1 H), 1.53 (d, J = 7.2 Hz, 3 H), 1.51 (d, J = 7.2 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 156.0, 147.1, 132.2, 128.2, 128.1, 127.68, 127.66, 127.0, 126.8, 126.5, 125.6, 96.0, 55.9, 37.4, 21.3. IR (KBr): 3447, 3024, 2961, 2920, 1610, 1583, 1505, 1491, 1464, 1448, 1293, 1205, 1120, 1033, 839, 821, 757, 744, 697 cm-1. HRMS: m/z calcd for C24H26O2: 346.1933; found: 346.1922. 2-(1-Phenylethyl)phenol (1i): 1H NMR (300 MHz, CDCl3): δ = 7.32-6.73 (s, 8 H), 4.69 (s, 1 H), 4.37 (q, J = 7.2 Hz, 1 H), 1.63 (d, J = 7.2 Hz, 3 H). 4-Methyl-2-(1-phenylethyl)phenol (1j): 1H NMR (300 MHz, CDCl3): δ = 7.26-7.19 (m, 5 H), 7.03 (s, 3 H), 6.91 (d, J = 7.8 Hz, 1 H), 6.65 (d, J = 8.1 Hz, 1 H), 4.33 (q, J = 7.2 Hz, 1 H), 2.29 (s, 3 H), 1.62 (d, J = 7.2 Hz, 3 H). Phenethyl(p-tolyl)sulfane (1k): 1H NMR (300 MHz, CDCl3): δ = 7.29-7.10 (m, 9 H), 3.13 (t, J = 7.5 Hz, 2 H), 2.90 (t, J = 7.8 Hz, 2 H), 2.33 (s, 3 H). 2-(1-Phenylethyl)thiophene (1l): 1H NMR (300 MHz, CDCl3): δ = 7.25-7.13 (m, 7 H), 6.57 (d, J = 4.8 Hz, 1 H), 4.22 (q, J = 7.2 Hz, 1 H), 1.63 (d, J = 7.2 Hz, 3 H). 1-Methoxy-4-(1-p-tolylethyl)benzene (2b): 1H NMR (300 MHz, CDCl3): δ = 7.31-6.97 (m, 6 H), 6.94-6.76 (m, 2 H), 4.06 (q, J = 7.2 Hz, 1 H), 3.76 (s, 3 H), 2.26 (s, 3 H), 1.59 (d, J = 7.2 Hz, 3 H). 1-Methoxy-4-(2-phenylpropan-2-yl)benzene (2c): 1H NMR (300 MHz, CDCl3): δ = 7.26-7.24 (m, 4 H), 7.16-7.13 (m, 3 H), 6.82-6.79 (m, 2 H), 3.78 (s, 3 H), 1.66 (s, 6 H). 1-[1-(4-Methoxyphenyl)-1-phenylethyl]benzene (2d): 1H NMR (300 MHz, CDCl3): δ = 7.28-7.19 (m, 6 H), 7.11-7.10 (m, 3 H), 7.02-6.99 (m, 2 H), 6.79-6.78 (m, 2 H), 3.79 (s, 3 H), 2.16 (s, 6 H). 1-[1-(2-Chlorophenyl)ethyl]-4-methoxybenzene (2e): 1H NMR (300 MHz, CDCl3): δ = 7.33 (d, J = 8.4 Hz, 1 H), 7.20-7.11 (m, 5 H), 6.82 (d, J = 8.4 Hz, 2 H), 4.60 (q, J = 7.2 Hz, 1 H), 3.77 (s, 3 H), 1.59 (d, J = 6.6 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 158.1, 144.2, 137.2, 133.9, 128.8, 128.6, 127.3, 127.0, 113.9, 55.3, 40.2, 21.4. IR (KBr): 3435, 3056, 3008, 2959, 2925, 2852, 1628, 1599, 1468, 1431, 1339, 1289, 1243, 1122, 1066, 1049, 1030, 931, 853, 787, 755, 729, 681 cm-1. HRMS: m/z calcd for C15H15ClO: 246.0811; found: 246.0800. 1-[1-(4-Chlorophenyl)ethyl]-4-methoxybenzene (2f): 1H NMR (300 MHz, CDCl3): δ = 7.23 (d, J = 8.1 Hz, 2 H), 7.14-7.08 (m, 4 H), 6.82 (d, J = 8.7 Hz, 2 H), 4.07 (q, J = 7.2 Hz, 1 H), 3.77 (s, 3 H), 1.58 (d, J = 7.2 Hz, 3 H). 1-[1-(4-Fluorophenyl)ethyl]-4-methoxybenzene (2g): 1H NMR (300 MHz, CDCl3): δ = 7.18-7.10 (m, 4 H), 6.99-6.91 (m, 2 H), 6.83-6.82 (m, 2 H), 4.10 (q, J = 7.2 Hz, 1 H), 3.79 (s, 3 H), 1.60 (d, J = 7.2 Hz, 3 H). 1-[1-(2,6-Dichlorophenyl)ethyl]-4-methoxybenzene (2h): 1H NMR (400 MHz, CDCl3): δ = 7.48 (d, J = 7.5 Hz, 1 H), 7.20 (d, J = 7.6 Hz, 3 H), 7.02-6.97 (m, 2 H), 6.77 (d, J = 8.1 Hz, 1 H), 5.11 (q, J = 7.3 Hz, 1 H), 1.70 (d, J = 7.4 Hz, 3 H). 13C NMR (100 MHz, CDCl3): δ = 157.6, 141.2, 135.5, 131.2, 129.3, 129.0, 127.4, 127.1, 119.8, 110.5, 55.3, 36.3, 15.7. IR (KBr): 3433, 3070, 2996, 2962, 2920, 2854, 1590, 1557, 1488, 1459, 1430, 1244, 1124, 1124, 1030, 779, 755, 726 cm-1. HRMS: m/z calcd for C15H14Cl2O: 280.0422; found: 280.00410. 4-[1-(4-Methoxyphenyl)ethyl]benzonitrile (2i): 1H NMR (300 MHz, CDCl3): δ = 7.57-7.54 (m, 2 H), 7.31-7.26 (m, 2 H), 7.09 (d, J = 5.7 Hz, 2 H), 6.84 (dd, J 1 = 2.1 Hz, J 2 = 4.5 Hz, 2 H), 4.14 (q, J = 7.2 Hz, 1 H), 3.78 (s, 3 H), 1.61 (d, J = 7.2 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 158.3, 152.5, 136.9, 132.3, 128.6, 128.4, 119.2, 114.1, 109.9, 55.4, 44.2, 21.7. IR (film): 3401, 3034, 2966, 2959, 2929, 2840, 2227, 1608, 1509, 1459, 1299, 1247, 1178, 1117, 835, 752 cm-1. HRMS: m/z calcd for C16H15NO: 237.1154; found: 237.1138. 1-Methoxy-3-(1,2-diphenylethyl)benzene (2j): 1H NMR (400 MHz, CDCl3): δ = 7.24-7.09 (m, 10 H), 7.00-6.98 (m, 2 H), 6.77 (d, J = 8.8 Hz, 2 H), 4.18 (t, J = 7.8 Hz, 1 H), 3.74 (s, 3 H), 3.3 (d, J = 7.8 Hz, 2 H). 13C NMR (100 MHz, CDCl3): δ = 158.0, 145.0, 140.5, 136.7, 129.2, 128.4, 128.1, 128.0, 126.2, 125.9, 55.3, 52.3, 42.4. IR (KBr): 3444, 3025, 2933, 1610, 1583, 1509, 1453, 1246, 1179, 1035, 833, 740, 697 cm-1. HRMS: m/z calcd for C21H20O: 288.1514; found: 288.1511.