Amparo Prades et al.
FULL PAPERS
(300 MHz, CDCl3): d=10.22 (s, 1H, NCHN), 7.41 (s, 2H,
Compound 5 was obtained as a yellow solid by precipitation
with diethyl ether; yield: 215 mg (50%). H NMR (CDCl3,
3
1
CHimidazole), 4.34 (t, JH,H =7.35 Hz, 4H, NCH2 n-Oct), 1.92 (m,
3
300 MHz): d=6.88 (s, 2H, CHimidazole), 3.64 (s, 6H, NCH3),
2.10 [s, 18H, (CH3)6]; 13C{1H} NMR (75 MHz, CDCl3): d=
181.9 (Ccarbene-Ru), 123.4 (CHimidazole), 92.8 [(CCH3)6], 37.2
(NCH3), 15.7 [(CCH3)6]; electrospray MS (15 V): m/z (frag-
ment)=395.4 [MÀCl]+; anal. calcd. for C17H26Cl2N2Ru (mol.
wt. 430.38): C 47.44, H 6.09, N 6.51; found: C 47.56, H 6.05,
N 6.42.
4H, CH2 n-Oct), 1.31 (m, 20H, CH2 n-Oct), 0.85 (t, JH,H
=
6.00 Hz, 6H, CH3 n-Oct); 13C{1H} NMR (75 MHz, CDCl3): d=
136.7 (NCHN), 122.7 (CHimidazole), 50.4 (NCH2 n-Oct), 31.8
(CH2 n-Oct), 30.4 (CH2 n-Oct), 29.1 (CH2 n-Oct), 29.0 (CH2 n-Oct),
26.3 (CH2 n-Oct), 22.7 (CH2 n-Oct), 14.1 (CH3 n-Oct); electrospray
MS (15 V): m/z (fragment)=293.3 [MÀI]+; anal. calcd. for
C19N2H37I (mol. wt. 420.41): C 54.28, H 8.87, N 6.66; found:
C 54.56, H 8.78, N 6.59.
Synthesis of 6: Silver oxide (76 mg, 0.33 mmol) was added
to a solution of 1,3-di-n-octylimidazolium iodide (138 mg,
0.33 mmol) in CH2Cl2. The solution was stirred at room tem-
perature for 1 h, and [RuCl2(h6-p-cymene)]2 (100 mg,
0.16 mmol) was then added. The mixture was refluxed for
3 h under the exclusion of light, the suspension was filtered
through Celite and the solvent was evaporated under reduce
pressure. The crude solid was purified by column chroma-
tography. Elution with a mixture of CH2Cl2/acetone (9:1) af-
forded the separation of an orange band that contained
compound 6. Compound 6 was obtained as an orange solid
by precipitation with ether; yield: 105 g (53%). 1H NMR
(300 MHz, CDCl3): d=7.05 (s, 2H, CHimidazole), 5.37 (d,
3JH,H =6.00 Hz, 2H, CHp-cym), 5.06 (d, 3JH,H =5.70 Hz, 2H,
CHp-cym), 4.56 (br, 2H, NCH2 n-Oct), 3.97 (br, 2H, NCH2 n-Oct),
2.91 (sept, 3JH,H =6.90 Hz, 1H, CHisop p-cym), 2.03 (s, 3H,
CH3p-cym), 1.97 (br, 2H, CH2 n-Oct), 1.67 (br, 2H, CH2 n-Oct),
Synthesis of 2: Silver oxide (58 mg, 0.25 mmol) was added
to a solution of 1,3-di-n-butylimidazolium iodide (154 mg,
0.50 mmol) in CH2Cl2. The suspension was stirred at room
temperature for 1 h, and [RuCl2ACTHNUTRGNEUNG
(h6-CMe)6]2 (167 mg,
0.25 mmol) was then added. The mixture was refluxed for
2 h under the exclusion of light. The suspension was filtered
through Celite and the solvent was evaporated under re-
duced pressure. The crude solid was purified by column
chromatography. Elution with a mixture of CH2Cl2/acetone
(4:1) afforded the separation of an orange band containing
compound 2. Compound 2 was obtained as an orange solid
by precipitation with diethyl ether; yield: 160 mg (62%).
1H NMR (500 MHz, CDCl3): d=7.04 (s, 2H, CHimidazole),
4.55 (td, 3JH,H =11.87 Hz, 2JH,H =4.83 Hz, 2H, NCH2 n-Bu),
3.66 (td, 3JH,H =11.75 Hz, 2JH,H =4.83 Hz, 2H, NCH2 n-Bu),
1.99 [s, 18H, (CH3)6], 1.63 (m, 2H, CH2 n-Bu), 1.51 (m, 2H,
3
3
1.30 (br, 20H, CH2 n-Oct), 1.25 (d, JH,H =7.20 Hz, 6H, CH3isop
CH2 n-Bu), 1.38 (m, 4H, CH2 n-Bu), 0.98 (t, JH,H =7.25 Hz, 6H,
3
p-cym), 0.87 (t, JH,H =6.60 Hz, 6H, CH3 n-Oct); 13C{1H} NMR
CH3 n-Bu); 13C{1H} NMR (75 MHz, CDCl3): d=176.1 (Ccarbene
-
(75 MHz, CDCl3): d=173.4 (Ccarbene-Ru) 121.7 (CHimidazole),
108.0 (CHisop p-cym), 99.3 (Cqp-cym), 85.3 (CHp-cym), 83.0
(CHp-cym), 51.7 (NCH2), 32.0 (CH2 n-Oct), 30.9 (CHisop p-cym),
29.6 (CH2 n-Oct), 29.3 (CH2 n-Oct), 27.1 (CH3isop p-cym), 22.8 (CH2
n-Oct), 22.7 (CH2 n-Oct), 18.8 (CH3isop p-cym), 14.2 (CH3 n-Oct);
electrospray MS (15 V): m/z (fragment)=563.3 [MÀCl]+;
anal. calcd. for RuCl2C29H50N2 (mol. wt. 598.70): C 58.18, H
8.42, N 4.68; found: C 57.96, H 8.47, N 4.67.
Ru) 121.8 (CHimidazole), 93.6 [(CCH3)6], 51.2 4 (NCH2 n-Bu),
34.0 (CH2 n-Bu), 20.4 (CH2 n-Bu), 15.6 [(CCH3)6], 14.1 (CH3
n-Bu); electrospray MS (15 V): m/z (fragment)=479.2
[MÀCl]+; anal. calcd. for C23H38Cl2N2Ru (mol. wt. 514.54):
C 53.69, H 7.44, N 5.44; found: C 53.75, H 7.47, N 5.41.
Synthesis of 3: Silver oxide (37.5 mg, 0.162 mmol) was
added to a solution of 1,3-di-n-butylimidazolium iodide
(100 mg, 0.324 mmol) in CH2Cl2. The suspension was stirred
at room temperature for 1 h, and [RuCl2(h6-methyl ben-
zoate)]2 (100 mg, 0.162 mmol) was then added. The mixture
was refluxed overnight under the exclusion of light. The
crude mixture was filtered through Celite and the solvent
removed under reduced pressure. Complex 3 was obtained
as a moderately unstable red solid by precipitation from
CH2Cl2/diethyl ether; yield: 99 mg (62%). 1H NMR
(300 MHz, CDCl3): d=7.06 (s, 2H, CHimidazole), 6.27 (d,
3JH,H =6.00 Hz, 2H, CHortho-benzoate), 5.84 (t, 3JH,H =5.50 Hz,
Catalytic Experiments
Arylation of 2-phenylpyridine: The ruthenium complex (1–
9) (0.025 mmol) and KOAc (0.05 mmol) were stirred in
NMP (2 mL) at room temperature in a thick-walled glass
tube for 1 h. Then 2-phenylpyridine (0.5 mmol), Ar-X
(1.25 mmol) and K2CO3 (1.50 mmol) were added. The re-
sulting mixture was stirred at 1208C. H2O and EtOAc were
added to the cold reaction mixture. The organic phase was
dried with Na2SO4 and concentrated under vacuum. The re-
maining residue was purified by column chromatography on
silica gel (hexanes/EtOAc mixture) to yield the correspond-
ing ortho-arylated products. Yields and ratios were deter-
3
1H, CHpara-benzoate), 5.71 (t, JH,H =5.80 Hz, 2H, CHmeta-benzoate),
4.40 (br, 2H, N-CH2 n-Bu), 3.98 (br, 2H, N-CH2 n-Bu), 3.89 (s,
3H, -COOCH3), 1.89 (br, 2H, CH2 n-Bu), 1.65 (br, 2H, CH2
3
n-Bu), 1.41 (m, 4H, CH2 n-Bu), 0.97 (t, JH,H =7.20 Hz, 6H, CH3
n-Bu); 13C{1H} NMR (75 MHz, CDCl3): d0168.4 (Ccarbene-Ru),
166.4 (COOCH3), 122.1 (CHimidazole), 90.9 (Cq benzoate), 88.3,
(CHbenzoate), 86.7 (CHbenzoate), 82.5 (Cq benzoate), 53.4
(COOCH3), 51.4 (NCH2 n-Bu), 34.0 (CH2 n-Bu), 20.3 (CH2 n-Bu),
14.1 (CH3 n-Bu); electrospray MS (15 V): m/z (fragment)=
1
mined by H NMR spectroscopy and by GC analyses using
anisole (0.5 mmol) as internal standard. According to previ-
ously reported spectroscopic data, products were identified
as 10a,[6] 10b,[6] 11b,[6] 12a,[28] 12b[28] 14a,[11] 14b,[11]15a[6] and
15b.[6]
453.5 [MÀCl]+; FT-IR (KBr): n=1723 cmÀ1 (n(C O)).
=
Synthesis of 5: A mixture of [RuCl2ACTHNUTRGNEUNG
(h6-CMe)6]2 (200 mg,
2-(4,4’’-Dibutyl-1,1’:3’,1’’-terphenyl-2’yl)pyridine (13b)
1
0.30 mmol), 1,3-di-n-methylimidazolium iodide (150 mg,
0.67 mmol), and Cs2CO3 (1.5 g, 4.70 mmol) in CH3CN was
refluxed for 6 h. The mixture was filtered, the solvent was
evaporated and the crude solid was purified by column chro-
matography. Elution with CH2Cl2/acetone (9:1) afforded the
separation of a yellow band that contained compound 5.
(Table 2, entry 5): H NMR (300 MHz, CDCl3): d=8.31 (d,
3JH,H =4.50 Hz, 1H), 7.44 (m, 3H), 7.29 (m, 1H), 6.97 (m,
8H), 6.88 (m, 2H), 2.53 (t, 3JH,H =7.65 Hz, 4H), 1.55 (m,
4H), 1.31 (m, 4H), 0.91 (t, 3JH,H =7.35 Hz, 6H); 13C{1H}
NMR (75 MHz, CDCl3): d=148.6 (CH), 142.1 (Cq), 141.0
(Cq), 139.1 (CH), 134.5(CH), 129.7 (CH), 129.5 (CH), 128.3
1160
ꢅ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2010, 352, 1155 – 1162