Ligand-free Suzuki-Miyaura Cross-Coupling Reactions of Aryltriazenes with Arylboronic Acids
2-Methyl-4-nitrobiphenyl17
chilled solution of 11 mmol of pyrrolidine in 10 mL of 1
mol•L -
KOH solution. The reaction mixture was
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Pale yellow oil; 1H NMR (CDCl3, 400 MHz) δ: 2.36
(s, 3H), 7.29—7.32 (m, 2H), 7.36—7.48 (m, 4H), 8.09
(d, J=8.4, 1H), 8.14 (s, 1H); 13C NMR (CDCl3, 100
MHz) δ: 148.58, 139.80, 139.74, 137.30, 135.37, 130.66,
129.08, 128.71, 128.48, 128.01, 125.16, 123.87, 21.26.
stirred for 30 min in the cold and then the precipitate
was isolated by filtration. The damp solid was then re-
crystallized from about 10 mL of absolute EtOH or
chromatographed on silica gel with 20∶1 petrol ether/
ethyl acetate and dried.
General procedure for the Suzuki cross-couplings of
aryltriazenes and arylboronic acids catalyzed by
Pd(OAc)2 catalyst
3-Nitro-4'-methyl-biphenyl18
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Yellow solid, m.p. 75—76 ℃; H NMR (CDCl3,
600 MHz) δ: 2.42 (s, 3H), 7.30 (d, J=8.0 Hz, 2H),
7.51—7.62 (m, 3H), 7.90 (d, J=15.5 Hz, 1H), 8.17 (d,
J=16.0 Hz, 1H), 8.44 (s, 1H); 13C NMR (CDCl3, 150
MHz) δ: 148.73, 142.80, 138.59, 135.76, 132.83, 129.90,
129.67, 129.46, 126.99, 126.81, 121.75, 121.69, 21.20.
5 mol% Pd(OAc)2 (0.025 mmol), aryltriazenes (0.5
mmol), arylboronic acid (1 mmol) were mixed in diox-
ane (5 mL). The mixture was stirred and added
BF3•OEt2 (65 µL, 0.50 mmol) dropwise at room tem-
perature under an argon atmosphere. When the reaction
was completed, solvent was evaporated under reduced
pressure. The product was purified by silica gel column
chromatography.
4'-Methoxy-4-methylbiphenyl15
White solid, m.p. 108— 109 ℃; 1H NMR (CDCl3,
400 MHz) δ: 2.38 (s, 3H), 3.84 (s, 3H), 6.95 (d, J=8.6
Hz, 2H), 7.21 (d, J=8.0 Hz, 2H), 7.43 (d, J=8 Hz, 2H),
7.50 (d, J=8.6 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ:
158.94, 137.98, 136.39, 133.76, 129.47, 127.99, 126.62,
114.18, 55.37, 21.10.
Analytical data
3-Nitrobiphenyl13
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Yellow solid, m.p. 59—60 ℃; H NMR (CDCl3,
4'-Methoxy-3-nitro-biphenyl16
400 MHz) δ: 7.41—7.51 (m, 3H), 7.59—7.63 (m, 3H),
7.91 (d, J=8.0 Hz, 1H), 8.18— 8.20 (m, 1H), 8.45 (s,
1H); 13C NMR (CDCl3, 100 MHz) δ: 148.73, 142.88,
138.66, 133.08, 129.74, 129.20, 128.78, 128.58, 127.18,
122.06, 121.96.
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Yellow solid, m.p. 79—80 ℃; H NMR (CDCl3,
400 MHz) δ: 3.87 (s, 3H), 7.02 (d, J=8.8 Hz, 2H),
7.56—7.60 (m, 3H), 7.86 (d, J=7.2 Hz, 1H), 8.13—
8.16 (m, 1H), 8.41 (t, J=2.0 Hz, 1H); 13C NMR (CDCl3,
100 MHz) δ: 160.07, 148.75, 142.48, 132.54, 131.09,
129.65, 128.29, 121.42, 121.40, 114.58, 55.43.
2-Nitrobipheyl14
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Pale yellow oil; H NMR (CDCl3, 400 MHz) δ:
4-Brom-biphenyl18
7.31— 7.34 (m, 2H), 7.40—7.51 (m, 5H) 7.62 (t, J=7.5
Hz, 1H), 7.86 (d, J=8.0 Hz, 1H); 13C NMR (CDCl3,
100 MHz) δ: 149.32, 137.41, 136.35, 132.35, 132.00,
128.73, 128.27, 128.21, 127.91, 124.11.
White solid, m.p. 89—90 ℃; 1H NMR (CDCl3, 400
MHz) δ: 7.35—7.47 (m, 5H), 7.53—7.61 (m, 4H); 13C
NMR (CDCl3, 100 MHz) δ: 140.24, 140.11, 131.98,
129.02, 128.86, 127.77, 127.06, 121.67.
4-Nitrobipheyl14
4-Iodo-biphenyl18
1
Yellow solid, m.p. 114 ℃; H NMR (CDCl3, 400
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White solid, m.p. 112—113 ℃; H NMR (CDCl3,
MHz) δ: 7.43— 7.52 (m, 3H), 7.61— 7.64 (m, 2H),
7.72— 7.76 (m, 2H), 8.29— 8.32 (m, 2H); 13C NMR
(CDCl3, 100 MHz) δ: 147.64, 147.08, 138.76, 129.19,
128.96, 127.82, 127.41, 124.13.
400 MHz) δ: 7.27—7.38 (m, 3H), 7.44 (t, J=7.4 Hz,
2H), 7.55 (d, J=7.6 Hz, 2H), 7.76 (d, J=8.4 Hz, 2H);
13C NMR (CDCl3, 100 MHz) δ: 140.74, 140.07, 137.85,
129.02, 128.92, 127.71, 126.91, 93.04.
4-Methoxybiphenyl15
4'-Methoxy-4-nitro-biphenyl15
White solid, m.p. 89—90 ℃; 1H NMR (CDCl3, 600
MHz) δ: 3.85 (s, 3H), 6.97 (d, J=8.5 Hz, 2H), 7.30 (t,
J=7.4 Hz, 1H), 7.41 (t, J=7.6 Hz, 2H), 7.52—7.55 (m,
4H); 13C NMR (CDCl3, 150 MHz) δ: 159.13, 140.83,
133.78, 128.74, 128.18, 127.75, 126.75, 126.67, 114.20,
114.16, 55.37
1
Yellow solid, m.p. 107—108 ℃; H NMR (CDCl3,
400 MHz) δ: 3.88 (s, 3H), 7.02 (d, J=8.8 Hz, 2H), 7.58
(d, J=8.4 Hz, 2H), 7.69 (d, J=8.8 Hz, 2H), 8.27 (d,
J=8.8 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ: 160.59,
147.34, 146.68, 131.21, 128.70, 127.20, 124.28, 114.75,
55.56.
1-Phenylnaphthalene16
4'-Methyl-4-nitrobiphenyl19
Yellow oil; 1H NMR (CDCl3, 600 MHz) δ: 7.38 (t,
J=6.9, 3H), 7.45—7.51 (m, 6H), 7.84 (d, J=8.2 Hz,
1H), 7.87 (t, J=9.7 Hz, 2H); 13C NMR (CDCl3, 150
MHz) δ: 154.77, 134.51, 130.09, 128.28, 127.42, 126.33,
125.92, 125.75, 125.72, 125.45,125.40, 125.06, 122.11,
120.01, 104.58.
Colorless solid, m.p. 139—140 ℃; 1H NMR (CDCl3,
400 MHz) δ: 2.43 (s, 3H), 7.31 (d, J=8.0 Hz, 2H), 7.53
(d, J=8.4 Hz, 2H), 7.72 (d, J=8.4 Hz, 2H), 8.28—8.30
(d, J=8.8 Hz, 2H); 13C NMR (CDCl3, 100 MHz) δ:
147.56, 146.85, 139.12, 135.83, 129.91, 127.46, 127.22,
Chin. J. Chem. 2011, 29, 72— 78
© 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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