W.-Z. Zhang, R. He, R. Zhang
2 2 5 4
interaction between the ruthenium center and the ligands [RuCl (=CHPh)(H IMe)(2-Me-C H N)] (4): 2-Methylpyridine
FULL PAPER
(
6.0 mL, 60.8 mmol) was added to complex 1 (0.50 g, 0.62 mmol)
due to steric hindrance and therefore accelerate the dissoci-
ation of these ligands, which enhances the initiation of the
catalysts. Complex 4, which bears a 2-methylpyridine li-
gand, exhibits the highest catalytic activity for the RCM
reaction of diallylmalononitrile and the CM reaction of ac-
rylonitrile with terminal olefins, of complexes 2–5 and 7.
in a 150-mL Schlenk flask; no additional solvent was required. The
reaction mixture was stirred at room temperature for 12 h, during
which time a color change from red-brown to green was observed.
Hexane (100 mL) was then added at room temperature and a green
solid precipitated. The flask was sealed under nitrogen and allowed
to stand at 0 °C overnight. The green precipitate was then filtered,
washed four times with 10 mL of hexane, and dried in vacuo for
1
6
h to afford 4 as a green powder (0.33 g, 84% yield). H NMR
Experimental Section
3
(400 MHz, CDCl ): δ = 19.64 (s, 1 H, Ru=CHPh), 8.49 (br. s, 1 H,
pyridine), 8.01 (br. s, 1 H, pyridine), 7.57–7.02 (multiple peaks, 7
H, pyridine, ortho CH, para CH, meta CH), 6.82 (br. s, 4 H, 2,6-
dimethylphenyl aromatic CH), 6.55 (br. s, 2 H, 2,6-dimethylphenyl
aromatic CH), 4.16 (s, 2 H, NCH CH N), 3.95 (s, 2 H,
General Procedures: Oxygen- and/or moisture-sensitive materials
were manipulated using standard Schlenk techniques under dry ni-
trogen. NMR spectra were recorded with a Varian Inova instru-
1
31
13
ment (400 MHz for H, 160 MHz for P, 100 MHz for C). High-
resolution mass spectra were recorded with a Q-TOF mass spec-
trometer (Micromass, England) equipped with a Z-spray ionization
source. GC analyses were performed with a Hewlett–Packard
HP 6890 equipped with an FID and an HP-5 column. Pyridine, 3-
bromopyridine, 2-methylpyridine, 2,4-dimethylpyridine, and acry-
2
2
NCH
2
CH
2
3 3
N), 2.76 (br. s, 9 H, pyridine CH , ortho CH ), 2.25 (s,
1
3
6
H, ortho CH
3
) ppm. C NMR (CDCl
], 159.53, 151.74, 151.34,
40.53, 139.08, 137.94, 137.75, 137.28, 136.59, 130.91, 130.33,
29.35, 128.99, 128.76, 128.67, 128.33, 128.04, 127.80, 127.62,
3
, 100 MHz): δ = 312.64
(
m, Ru=CHPh), 218.09 [s, Ru–C(N)
2
1
1
[
9]
126.49, 125.17, 121.32, 120.93, 51.76, 50.85, 31.58, 20.34,
18.41 ppm.
lonitrile were freshly distilled before use. Ruthenium complex 1
and diallylmalononitrile[ were prepared according to literature
15]
procedures. Dichloromethane was dried with CaH , distilled, and
2
[
RuCl
idine (2.0 mL, 17.2 mmol) was added to complex 1 (0.14 g,
.17 mmol) in a 150-mL Schlenk flask; no additional solvent was
required. The reaction mixture was stirred at room temperature for
h, during which time a color change from red-brown to green was
2 2 2 5 3
(=CHPh)(H IMe)(2,4-Me -C H N)] (5): 2,4-Dimethylpyr-
stored under nitrogen, whereas thf, toluene, and hexane were dried
and distilled from Na/benzophenone. All other reagents were of
analytical grade, were purchased commercially, and used as re-
ceived, unless noted otherwise.
0
2
[
0
RuCl
2
(=CHPh)(H
2
IMe)(C
5
H
5
N)]
(2):
Pyridine
(10.0 mL,
observed. Hexane (100 mL) was then added at room temperature
and a green solid precipitated. The green precipitate was filtered,
washed four times with 10 mL of hexane, and dried in vacuo for
.124 mol) was added to complex 1 (1.10 g, 1.37 mmol) in a 150-
mL Schlenk flask; no additional solvent was required. The reaction
mixture was stirred at room temperature for 10 min, during which
time a color change from red-brown to green was observed. Hexane
1
6 h to afford 5 as a green powder (0.10 g, 89% yield). H NMR
(400 MHz, CDCl ): δ = 19.61 (s, 1 H, Ru=CHPh), 7.99 (br. s, 1 H,
3
(
120 mL) was then added at room temperature and a green solid
precipitated. This precipitate was filtered, washed four times with
0 mL of hexane, and dried in vacuo for 6 h to afford 2 as a green
pyridine), 7.57–6.38 (multiple peaks, 13 H, pyridine, ortho CH, para
CH, meta CH, 2,6-dimethylphenyl aromatic CH), 4.16 (s, 2 H,
NCH CH N), 3.95 (s, 2 H, NCH CH N), 2.75 (br. s, 9 H, pyridine
1
2
2
2
2
1
powder (0.79 g, 93% yield). H NMR (400 MHz, CDCl
s, 1 H, Ru=CHPh), 8.64 (br. s, 2 H, pyridine), 7.79–6.93 (multiple
peaks, 14 H, pyridine, ortho CH, para CH, meta CH, 2,6-dimeth-
ylphenyl aromatic CH), 4.13 (s, 4 H, NCH CH N), 2.67 (br. s, 6 H,
ortho CH ), 2.32 (br. s, 6 H, ortho CH
) ppm. 13C NMR (CDCl
00 MHz): δ = 307.32 (m, Ru=CHPh), 220.41 [s, Ru–C(N)
3
): δ = 19.12
3 3 3
CH , ortho CH ), 2.24 (s, 6 H, ortho CH ), 2.12 (s, 3 H, pyridine
1
3
(
3 3
CH ) ppm. C NMR (CDCl , 100 MHz): δ = 312.49 (m,
Ru=CHPh), 218.38 [s, Ru–C(N) ], 158.75, 151.24, 148.08, 140.46,
2
2
2
139.07, 137.86, 130.80, 130.15, 129.23, 128.89, 128.69, 128.53,
128.20, 126.01, 122.41, 51.63, 50.71, 31.51, 21.48, 20.45, 18.34 ppm.
3
3
3
,
1
1
1
2
],
[
RuCl
2
(=CHPh)(H
2
IMe)(C
9
H
7
N)
2
]
(7): Isoquinoline (1.0 mL,
52.23, 150.44, 136.70, 136.08, 130.64, 130.29, 129.65, 129.04,
28.41, 128.13, 124.04, 123.80, 48.32, 22.85, 18.69 ppm.
8.4 mmol) was added to complex 1 (0.30 g, 0.37 mmol) in a 150-
mL Schlenk flask, then 5 mL of toluene was added as solvent. The
reaction mixture was stirred at room temperature for 1 h, during
which time a color change from red-brown to green was observed.
Hexane (100 mL) was then added at room temperature and a green
solid precipitated. The green precipitate was filtered, washed four
times with 10 mL of hexane and dried in vacuo for 6 h to afford 7
[
(
RuCl
2
(=CHPh)(H
2
IMe)(3-Br-C
5
H
4
N)]
(3):
3-Bromopyridine
6.0 mL, 62.1 mmol) was added to complex 1 (1.90 g, 2.37 mmol)
in a 150-mL Schlenk flask; no additional solvent was required. The
reaction mixture was stirred at room temperature for 20 min, dur-
ing which time a color change from red-brown to green was ob-
served. Hexane (120 mL) was then added at room temperature and
a green solid precipitated. The flask was sealed under nitrogen and
allowed to stand at 0 °C overnight. The green precipitate was then
filtered, washed four times with 10 mL of hexane, and dried in
vacuo for 6 h to afford 3 as a green powder (1.53 g, 92% yield). H
3
NMR (400 MHz, CDCl ): δ = 19.05 (s, 1 H, Ru=CHPh), 8.74 (br.
s, 1 H, pyridine), 8.59 (br. s, 1 H, pyridine), 7.90–7.04 (multiple
peaks, 13 H, pyridine, ortho CH, para CH, meta CH, 2,6-dimeth-
1
as a green powder (0.14 g, 47% yield). H NMR (400 MHz,
CDCl
3
): δ = 19.18 (s, 1 H, Ru=CHPh), 9.32 (s, 1 H, isoquinoline),
8.92 (s, 1 H, isoquinoline), 8.59 (s, 1 H, isoquinoline), 8.50 (s, 1 H,
isoquinoline), 8.16–6.99 (multiple peaks, 21 H, isoquinoline, ortho
CH, para CH, meta CH, 2,6-dimethylphenyl aromatic CH), 4.14 (s,
1
4
H, NCH
CH ) ppm. C NMR (CDCl
Ru=CHPh), 218.31 [s, Ru–C(N)
2
CH
2
13
N), 2.63 (br. s, 6 H, ortho CH
3
), 2.35 (s, 6 H, ortho
, 100 MHz): δ = 314.44 (m,
], 155.17, 152.80, 151.31, 150.52,
48.40, 144.56, 143.12, 138.17, 136.16, 135.73, 135.40, 131.45,
3
3
2
ylphenyl aromatic CH), 4.13 (s, 4 H, NCH
ortho CH ), 2.36 (br. s, 6 H, ortho CH
) ppm. 13C NMR (CDCl
00 MHz): δ = 316.34 (m, Ru=CHPh), 216.63 [s, Ru–C(N)
2 2
CH N), 2.63 (br. s, 6 H,
1
1
1
1
3
3
3
,
30.31, 130.13, 129.56, 128.94, 128.04, 127.90, 127.41, 127.22,
26.64, 126.46, 126.17, 121.18, 120.91, 120.40, 51.80, 20.45,
8.82 ppm.
1
1
1
1
6
2
],
52.73, 151.48, 148.13, 138.80, 134.57, 132.23, 132.13, 130.33,
30.26, 128.85, 128.09, 127.04, 124.57, 120.78, 51.46, 20.58,
8.93 ppm. C31
H32BrCl
2
N
3
Ru (698.5): calcd. C 53.31, H 4.62, N
X-ray Crystallographic Studies: Crystals suitable for X-ray diffrac-
tion were mounted on glass fibers. Data collection was performed
.02; found C 53.12, H 4.59, N 6.07.
5350
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Eur. J. Inorg. Chem. 2007, 5345–5352