Extremely Efficient Cross-Coupling of Benzylic Halides with Aryltitanium Tris(isopropoxide)
NMR (100 MHz, CDCl3): d=159.6, 142.6, 140.8, 129.3,
128.8, 128.4, 126.0, 121.3, 114.7, 111.2, 54.9, 41.8.
3H), 7.12–7.08 (m, 2H), 6.84–6.81 (m, 2H), 3.92 (s, 2H),
3.77 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3): d=157.9,
141.5, 133.1, 129.7, 128.7, 128.3, 125.9, 113.8, 55.0, 40.9.
1-Benzyl-4-fluorobenzene (2p):[40] Eluent: hexane/ethyl
acetate=100/1; colorless liquid; yield: 0.173 g (93%).
1H NMR (400 MHz, CDCl3): d=7.31–7.25 (m, 2H), 7.18–
7.10 (m, 5H), 6.99–6.94 (m, 2H), 3.95 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): d=162.6, 160.2, 140.9, 136.8, 136.7,
130.3, 130.2, 128.8, 128.5, 126.2, 115.3, 115.1, 41.0.
4-Benzylthioanisole (2f):[34] Eluent: hexane/ethyl ace-
1
tate=100/1; colorless liquid; yield: 0.210 g (98%). H NMR
(400 MHz, CDCl3): d=7.29–7.25 (m, 2H), 7.22–7.16 (m,
5H), 7.12–7.10 (m, 2H), 3.94 (s, 2H), 2.46 (s, 3H); 13C{1H}
NMR (100 MHz, CDCl3): d=140.9, 138.1, 135.7, 129.4,
128.8, 128.4, 127.0, 126.1, 41.3, 16.1.
1-Benzyl-4-tert-butylbenzene (2g):[35] Eluent: hexane/ethyl
acetate=100/1; colorless liquid; yield: 0.219 g (96%).
1H NMR (400 MHz, CDCl3): d=7.31–7.28 (m, 4H), 7.22–
7.18 (m, 3H), 7.13–7.10 (m, 2H), 3.95 (s, 2H), 1.29 (s, 9H);
13C{1H} NMR (100 MHz, CDCl3): d=148.7, 141.2, 138.0,
128.9, 128.5, 128.4, 126.0, 125.3, 41.4, 34.3, 31.4.
1-Benzyl-4-vinylbenzene (2q):[41] Eluent: hexane/ethyl
acetate=100/1; colorless liquid; yield: 0.186 g (98%).
1H NMR (400 MHz, CDCl3): d=7.35–7.25 (m, 4H), 7.21–
7.13 (m, 5H), 6.69 (dd, J=17.6, 11.2 Hz, 1H), 5.72 (dd, J=
17.6, 0.8 Hz, 1H), 5.20 (dd, J=11.2, 0.8 Hz, 1H), 3.96 (s,
2H); 13C{1H} NMR (100 MHz, CDCl3): d=140.9, 140.7,
136.5, 135.4, 129.1, 128.8, 128.4, 126.3, 126.1, 113.2, 41.6.
4-Benzylphenol (2r):[30] Eluent: hexane/ethyl acetate=
100/1; colorless liquid; yield: 0.175 g (95%). 1H NMR
(400 MHz, CDCl3): d=7.28–7.24 (m, 2H), 7.21–7.14 (m,
3H), 7.04–7.01 (m, 2H), 6.74–6.71 (m, 2H), 4.92 (br, 1H),
3.89 (s, 2H). 13C{1H} NMR (100 MHz, CDCl3): d=153.4,
141.4, 133.4, 130.0, 128.7, 128.4, 125.9, 115.3, 40.9.
2-Benzylbiphenyl (2h):[34] Eluent: hexane/ethyl acetate=
100/1; colorless liquid; yield: 0.241 g (99%). 1H NMR
(400 MHz, CDCl3): d=7.37–7.14 (m, 12H), 6.99–6.97 (m,
2H), 3.96 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): d=
142.2, 141.6, 141.4, 138.1, 130.3, 130.1, 129.2, 128.8, 128.2,
128.0, 127.4, 126.8, 126.1, 125.7, 39.0.
3-Benzylbiphenyl (2i):[36] Eluent: hexane/ethyl acetate=
100/1; colorless liquid; yield: 0.241 g (99%). 1H NMR
(400 MHz, CDCl3): d=7.56–7.53 (m, 2H), 7.41–7.36 (m,
4H), 7.35–7.24 (m, 4H), 7.21–7.14 (m, 4H), 4.02 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): d=141.6, 141.4, 141.2,
141.0, 128.91, 128.85, 128.7, 128.5, 127.9, 127.8, 127.19,
127.15, 126.1, 125.0, 42.0.
(4-Trimethylsilylbenzyl)benzene (2s):[42] Eluent: hexane/
ethyl acetate=100/1; colorless liquid; yield: 0.225 g (94%);
1H NMR (400 MHz, CDCl3): d=7.46–7.43 (m, 2H), 7.31–
7.24 (m, 2H), 7.21–7.17 (m, 5H), 3.97 (s, 2H), 0.24 (s, 9H);
13C{1H} NMR (100 MHz, CDCl3): d=141.7, 140.9, 137.7,
133.5, 129.0, 128.4, 128.3, 126.1, 41.9, À1.1.
1-Benzyl-3,5-dimethoxybenzene (2j):[37] Eluent: hexane/
ethyl acetate=100/1; colorless liquid; yield: 0.212 g (93%).
1H NMR (400 MHz, CDCl3): d=7.28–7.25 (m, 2H), 7.21–
7.18 (m, 3H), 6.36–6.34 (m, 2H), 6.32–6.31 (m, 1H), 3.91 (s,
2H), 3.75 (s, 6H); 13C{1H} NMR (100 MHz, CDCl3): d=
160.7, 143.3, 140.6, 128.8, 128.3, 126.0, 107.0, 97.8, 55.0, 42.0.
1-Benzyl-4-chlorobenzene (2k):[33] Eluent: hexane/ethyl
acetate=100/1; colorless liquid; yield: 0.192 g (95%).
1H NMR (400 MHz, CDCl3): d=7.32–7.20 (m, 5H), 7.15 (d,
J=6.8 Hz, 2H), 7.10 (d, J=8.4 Hz, 2H), 3.93 (s, 2H);
13C{1H} NMR (100 MHz, CDCl3): d=140.4, 139.5, 131.8,
130.2, 128.8, 128.48, 128.46, 126.2, 41.1.
2-Benzylnaphthalene (2t):[39] Eluent: hexane/ethyl ace-
tate=20/1; white solid; yield: 0.198 g (91%). 1H NMR
(400 MHz, CDCl3): d=7.81–7.74 (m, 3H), 7.63 (s, 1H),
7.47–7.40 (m, 2H), 7.33–7.27 (m, 3H), 7.25–7.18 (m, 3H),
4.15 (s, 2H); 13C{1H} NMR (100 MHz, CDCl3): d=140.9,
138.5, 133.6, 132.0, 129.0, 128.4, 128.0, 127.6, 127.5, 127.1,
126.1, 125.9, 125.3, 42.0.
4-(1-Phenylethyl)anisole (2u):[43] Eluent: hexane/ethyl
acetate=20/1; colorless liquid; yield: 0.148 g (70%).
1H NMR (400 MHz, CDCl3): d=7.29–7.13 (m, 5H), 6.84–
6.81 (m, 2H), 4.10 (q, J=7.2 Hz, 1H), 3.77 (s, 3H), 1.60 (d,
J=7.2 Hz, 3H); 13C {1H} NMR (100 MHz, CDCl3): d=
157.8, 146.7, 138.5, 128.5, 128.3, 127.5, 125.9, 113.6, 55.1,
43.9, 22.0.
1-Benzyl-4-bromobenzene (2l):[38] Eluent: hexane/ethyl
acetate=100/1; colorless liquid; yield: 0.197 g (80%).
1H NMR (400 MHz, CDCl3): d=7.42–7.40 (m, 2H), 7.31–
7.25 (m, 2H), 7.23–7.19 (m, 1H), 7.15 (d, J=7.2 Hz, 2H),
7.05 (d, J=8.4 Hz, 2H), 3.93 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): d=140.3, 140.0, 131.4, 130.6, 128.8,
128.5, 126.2, 119.9, 41.2.
Acknowledgements
4-Benzylbenzonitrile (2m):[39] Eluent: hexane/ethyl ace-
1
tate=100/1; colorless liquid; yield: 0.162 g (84%); H NMR
Financial support from the National Science Council of
Taiwan, ROC, under the grant number of NSC 96-2113-M-
005-007-MY3, is appreciated.
(400 MHz, CDCl3): d=7.58–7.55 (m, 2H), 7.33–7.22 (m,
5H), 7.17–7.14 (m, 2H), 4.03 (s, 2H); 13C{1H} NMR
(100 MHz, CDCl3): d=146.6, 139.2, 132.1, 129.5, 128.8,
128.6, 126.5, 118.9, 109.8, 41.8.
5-Benzyl-1,3-bis(trifluoromethyl)benzene (2n):[23c] Eluent:
hexane/ethyl acetate=10/1; colorless liquid; yield: 0.097 g
References
1
(32%). H NMR (400 MHz, CDCl3): d=7.75–7.72 (m, 1H),
7.63 (s, 2H), 7.34–7.32 (m, 2H), 7.28–7.25 (m, 1H), 7.19–
7.16 (m, 2H), 4.10 (s, 2H); 13C{1H} NMR (100 MHz,
CDCl3): d=143.6, 138.8, 131.9 (q, J=32.7 Hz), 128.9 (m),
127.3, 127.2, 126.9, 123.4 (q, J=270 Hz), 120.3 (m), 41.5.
4-Benzylanisole (2o):[33] Eluent: hexane/ethyl acetate=
100/1; colorless liquid; yield: 0.178 g (90%). 1H NMR
(400 MHz, CDCl3): d=7.30–7.24 (m, 2H), 7.21–7.15 (m,
[1] Selected references on organoboron reagents: a) N.
Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457; b) J.
Hassan, M. Sꢃvignon, C. Gozzi, E. Schulz, M. Lemaire,
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ꢁ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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