330
M. Feuerstein et al. / Journal of Organometallic Chemistry 687 (2003) 327Á336
/
Table 2
Palladium catalysed Suzuki cross-coupling reactions with haloquinolines
Entry Aryl halide
Arylboronic acid
Ligand Product Ratio substrate/catalyst
Yield (%)
TON
1
2
3
4
5
6
7
8
9
3-Bromoquinoline
Benzeneboronic acid
Benzeneboronic acid
1
dppe
14
14
15
16
17
17
18
19
19
1 000 000
100 000
100 000
10 000
10 000
100 000
1000
82
83
820 000
83 000
60 000
6800
3-Bromoquinoline
3-Bromoquinoline
4-Bromoisoquinoline
2-Chloroquinoline
2-Chloroquinoline
2-Chloroquinoline
2-Chloroquinoline
2-Chloroquinoline
2-Methylphenylboronic acid
Benzeneboronic acid
Benzeneboronic acid
1
1
1
1
1
1
1
60
68
88
8800
Benzeneboronic acid
30 a
90
30 000
900
910
1-Naphthaleneboronic acid
2-Methylphenylboronic acid
2-Methylphenylboronic acid
1000
10 000
91
37 a
3700
Conditions: catalyst [Pd(C3H5)Cl]2/ligand 1/2, see Ref. [7a], ArX (one equivalent), ArB(OH)2 (two equivalents), K2CO3 (two equivalents), xylene,
130 8C, 20 h, isolated yields.
GC yield.
a
mmol) and benzeneboronic acid (2.44 g, 20 mmol). The
Hz, 2H), 7.96 (m, 2H), 7.86 (d, Jꢁ
/
8.3 Hz, 1H), 7.77 (m,
7.48 (m, 4H).
2H), 7.68 (d, Jꢁ8.5 Hz, 1H), 7.64Á
/
/
residue was purified by column chromatography (etherÁ
/
2-(2-Methylphenyl)quinoline (19): (Table 2, entry 8),
2-chloroquinoline (1.31 ml, 10 mmol), Pd complex (10
mmol) and 2-methylphenylboronic acid (2.72 g, 20
mmol). The residue was purified by column chromato-
pentane: 3/7) to give 3-phenylquinoline in 82% (1.68 g)
isolated yield. 1H-NMR (300 MHz, CDCl3): dꢁ
9.18 (s,
1H), 8.27 (d, Jꢁ2.2 Hz, 1H), 8.14 (d, Jꢁ8.5 Hz, 1H),
7.85 (d, Jꢁ8.2 Hz, 1H), 7.70 (m, 3H), 7.58-7.49 (m,
/
/
/
/
graphy (etherÁ
nyl)quinoline in 91% (2.00 g) isolated yield. H-NMR
(300 MHz, CDCl3): dꢁ8.18 (d, Jꢁ8.4 Hz, 2H), 7.84 (d,
Jꢁ7.4 Hz, 1H), 7.73 (dd, Jꢁ7.7 and 7.0 Hz, 1H), 7.54
(m, 3H), 7.34 (m, 3H), 2.43 (s, 3H).
/
pentane: 3/7) to give 2-(2-methylphe-
3H), 7.42 (m, 1H).
1
3-(2-Methylphenyl)quinoline (15): (Table 2, entry 3),
3-bromoquinoline (1.36 ml, 10 mmol), Pd complex (0.1
mmol) and 2-methylphenylboronic acid (2.72 g, 20
mmol). The residue was purified by column chromato-
/
/
/
/
graphy (etherÁ
nyl)quinoline in 60% (1.31 g) isolated yield. H-NMR
(300 MHz, CDCl3): dꢁ8.91 (s, 1H), 8.15 (d, Jꢁ8.3 Hz,
1H), 8.09 (s, 1H), 7.85 (d, Jꢁ8.3 Hz, 1H), 7.73 (m, 1H),
7.58 (m, 2H), 7.32 (m, 3H), 2.31 (s, 3H).
/
pentane: 3/7) to give 3-(2-methylphe-
1
2.5. Coupling products with a bromoindole,
bromopyrimidines and a bromothiazole (Table 3)
/
/
/
5-Phenylindole (20): (Table 3, entry 2), 5-bromoindole
(1.96 g, 10 mmol), Pd complex (0.1 mmol) and benzene-
boronic acid (2.44 g, 20 mmol). The residue was purified
4-Phenylisoquinoline (16): (Table 2, entry 4), 4-
bromoisoquinoline (2.08 g, 10 mmol), Pd complex (1
mmol) and benzeneboronic acid (2.44 g, 20 mmol). The
by column chromatography (etherÁ
5-phenylindole in 90% (1.74 g) isolated yield. H-NMR
(300 MHz, CDCl3): dꢁ8.06 (brs, 1H), 7.96 (s, 1H), 7.76
(d, Jꢁ8.5 Hz, 2H), 7.52 (m, 3H), 7.45Á7.35 (m, 2H),
7.20 (t, Jꢁ3.1 Hz, 1H), 6.67 (m, Jꢁ3.1 Hz, 1H).
/
pentane: 3/7) to give
1
residue was purified by column chromatography (etherÁ
pentane: 3/7) to give 4-phenylisoquinoline in 68% (1.39
g) isolated yield. 1H-NMR (300 MHz, CDCl3): dꢁ
9.28
(s, 1H), 8.50 (s, 1H), 8.04 (d, Jꢁ7.9 Hz, 1H), 7.90 (d,
Jꢁ7.9 Hz, 1H), 7.69-7.62 (m, 2H), 7.52-7.35 (m, 5H).
/
/
/
/
/
/
/
/
5-(2-Methylphenyl)indole (21): (Table 3, entry 3), 5-
bromoindole (1.96 g, 10 mmol), Pd complex (0.1 mmol)
and 2-methylphenylboronic acid (2.72 g, 20 mmol). The
residue was purified by column chromatography (etherÁ
pentane: 3/7) to give 5-(2-methylphenlyl)indole as a red
liquide in 70% (1.45 g) isolated yield. 1H-NMR (300
/
2-Phenylquinoline (17): (Table 2, entry 5), 2-chloro-
quinoline (1.31 ml, 10 mmol), Pd complex (1 mmol) and
benzeneboronic acid (2.44 g, 20 mmol). The residue was
/
purified by column chromatography (etherÁ/pentane: 3/
7) to give 2-phenylquinoline in 88% (1.81 g) isolated
MHz, CDCl3): dꢁ
Jꢁ8.4 Hz, 1H), 7.38Á
(s, 1H), 2.27 (s, 3H). 13C-NMR (50 MHz, CDCl3): dꢁ
/
8.00 (brs, 1H), 7.64 (s, 1H), 7.41 (d,
1
yield. H-NMR (300 MHz, CDCl3): dꢁ
7.82 (dd, Jꢁ8.6 and 8.9 Hz, 1H), 7.63Á
7.36Á7.27 (m, 4H).
/
8.00 (m, 3H),
7.48 (m, 3H),
/
/7.29 (m, 4H), 7.24 (m, 2H), 6.62
/
/
/
/
140.0, 135.7, 134.7, 133.7, 130.3, 130.2, 127.7, 126.7,
125.6, 124.7, 123.7, 121.0, 110.5, 102.6, 20.7. MS (70 ev);
m/z (%): 207 (100) [Mꢀ], 207 (87), 204 (19), 179 (20),
178 (16), 103 (13), 89 (15), 63 (11), 50 (13).
5-Phenylpyrimidine (22): (Table 3, entry 5), 5-bromo-
pyrimidine (1.59 g, 10 mmol), Pd complex (0.1 mmol)
and benzeneboronic acid (2.44 g, 20 mmol). The residue
2-(1-Naphthyl)quinoline (18): (Table 2, entry 7), 2-
chloroquinoline (1.31 ml, 10 mmol), Pd complex (10
mmol) and 1-naphthaleneboronic acid (3.44 g, 20 mmol).
The residue was purified by column chromatography
(etherÁ
90% (2.30 g) isolated yield. 1H-NMR (300 MHz,
CDCl3): dꢁ8.31 (d, Jꢁ8.5 Hz, 1H), 8.21 (d, Jꢁ8.5
/
pentane: 3/7) to give 2-(1-naphthyl)quinoline in
/
/
/
was purified by column chromatography (etherÁpen-
/