Ruthenium complexes of chelating amido-functionalized N-heterocyclic carbene ligands
793
83.0
(p-CH3C6H4CH(CH3)2),
81.9
(p- cm−1. Anal. calcd. for C25H32RuN3OCl•0.5CH2Cl2: C,
CH3C6H4CH(CH3)2), 55.5 (COCH2), 55.4 (CH2NH), 53.78; H, 5.84; N, 7.38. Found: C, 53.54; H, 6.23; N,
37.8 (CH3), 31.5 (p-CH3C6H4CH(CH3)2), 24.9 (p- 6.87.
CH3C6H4CH(CH3)2), 20.1 (p-CH3C6H4CH(CH3)2),
18.7 (p-CH3C6H4CH(CH3)2). IR (KBr Pellet): 1686
(νCO) cm−1. Anal. calcd. for C23H28RuN3OCl: C,
55.36; H, 5.66; N, 8.42. Found: C, 55.35; H, 6.02; N,
8.34.
2.5 Synthesis of [1-(benzyl)-3-N-(benzylacetamido)
imidazol-2-ylidene]Ru(p-cymene)Cl (3c)
A mixture of {[1-(benzyl)-3-{N-(benzylacetamido)
imidazol-2-ylidene}]2Ag}+Cl− (3b) (0.421 g, 0.557 mmol)
and [Ru(p-cymene)Cl2]2 (0.170 g, 0.278 mmol) was
dissolved in dichloromethane (ca. 40 mL) and was
stirred at room temperature for 6 h, when the forma-
tion of an off-white AgCl precipitate was observed.
The reaction mixture was then filtered and the sol-
vent was removed under vacuum to yield the crude
product as a brown solid. The crude product 3c
was purified by column chromatography on a sil-
ica gel by elution with a CHCl3/CH3OH (v/v 10:1)
mixed medium to give the product 3c as brown solid
2.4 Synthesis of [1-(i-propyl)-3-N-(benzylacetamido)
imidazol-2-ylidene]Ru(p-cymene)Cl (2c)
A mixture of {[1-(i-propyl)-3-{N-(benzylacetamido)
imidazol-2-ylidene}]2Ag}+Cl− (2b) (0.331 g, 0.505 mmol)
and [Ru(p-cymene)Cl2]2 (0.308 g, 0.505 mmol) was
dissolved in dichloromethane (ca. 40 mL) and was
stirred at room temperature for 6 h, when the forma-
tion of an off-white AgCl precipitate was observed.
The reaction mixture was then filtered and the solvent
was removed under vacuum to yield the product 2c
as a brown solid. The crude product 2c was purified
by column chromatography on a silica gel by elution
with a CHCl3/CH3OH (v/v 10:1) mixed medium to
1
(0.208 g, 65%). H NMR (CDCl3, 400 MHz, 25◦C):
δ 7.50 (br, 1H, C6 H5), 7.48 (br, 1H, C6 H5), 7.41–
7.39 (br, 2H, C6 H5), 7.36–7.34 (br, 3H, C6 H5),
7.32 (br, 2H, C6 H5), 7.29 (br, 1H, C6 H5), 7.03 (br,
1H, NCHCHN), 6.91 (br, 1H, NCHCHN), 5.67
1
give the product 2c as brown solid (0.202 g, 76%). H
NMR (CDCl3, 400 MHz, 25◦C): δ 7.47 (d, 2H, 3JHH
=
2
2
7 Hz, o-C6 H5), 7.32 (br, 2H, m-C6 H5), 7.29 (br, 1H,
(d, 1H, JHH = 16 Hz, CH2), 5.55 (d, 1H, JHH
=
3
3
NCHCHN), 7.21 (t, 1 H, JHH = 7 Hz, p-C6 H5), 6.95
16 Hz, CH2), 5.29 (d, 1H, JHH = 16 Hz, CH2), 4.91
2
3
(s, 1H, NCHCHN), 5.23 (d, 1H, JHH = 15 Hz, CH2),
(d, 1H, JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.75
3
3
5.10 (d, 1H, JHH = 6 Hz, p-CH3C6 H4CH(CH3)2),
(d, 1H, JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.67
3
3
5.10 (sept, 1H, JHH = 7 Hz, CH(CH3)2), 4.84 (d, 1H,
(d, 1H, JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.48
3JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.81 (d, 1H,
3JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.70 (d, 1H,
3JHH = 6 Hz, p-CH3C6 H4CH(CH3)2), 4.43 (s, 2H,
(s, 2H, CH2), 4.44 (br, 1H, p-CH3C6 H4CH(CH3)2),
3
4.33 (d, 1H, JHH = 16 Hz, CH2), 2.46 (sept,
3
1H, JHH = 6 Hz, p-CH3C6H4CH(CH3)2), 1.98
2
CH2), 4.37 (d, 1H, JHH = 15 Hz, CH2), 2.45 (sept,
(s, 3H, p-CH3C6H4CH(CH3)2), 1.11 (d, 3H,
3JHH = 6 Hz, p-CH3C6H4CH(CH3)2), 0.88 (d, 3H,
3
1H, JHH = 6 Hz, p-CH3C6H4CH(CH3)2) 1.97 (s, 3H,
3
3JHH
=
6 Hz, p-CH3C6H4CH(CH3)2). 13C{1H}
p-CH3C6H4CH(CH3)2), 1.55 (d, 3H, JHH = 7 Hz,
3
NMR (CDCl3, 100 MHz, 25◦C): δ 175.9 (NCN-
Ru), 169.8 (CO), 143.0 (ipso-C6H5), 136.90
(ipso-C6H5), 128.9 (m-C6H5), 128.2 (m-C6H5),
128.1 (o-C6H5), 128.0 (o-C6H5), 127.9 (p-
C6H5), 127.1 (p-C6H5), 122.1 (NCHCHN), 121.9
(NCHCHN), 107.8 (ipso-p-CH3C6H4CH(CH3)2),
CH(CH3)2), 1.50 (d, 3H, JHH = 7 Hz, CH(CH3)2),
1.11 (d, 3H, 3JHH = 7 Hz, p-CH3C6H4CH(CH3)2), 0.86
(d, 3H, 3JHH = 7 Hz, p-CH3C6H4CH(CH3)2). 13C{1H}
NMR (CDCl3, 100 MHz, 25◦C): δ 175.4 (NCN-Ru),
169.9 (CO), 143.8 (ipso-C6H5), 128.8 (m-C6H5), 128.2
(o-C6H5), 126.3 (p-C6H5), 122.9 (NCHCHN), 122.2
(NCHCHN), 107.6 (ipso-p-CH3C6H4CH(CH3)2),
99.4
CH3C6H4CH(CH3)2), 84.1 (p-CH3C6H4CH(CH3)2),
83.5 (p-CH3C6H4CH(CH3)2), 82.3 (p-
(ipso-p-CH3C6H4CH(CH3)2),
87.6
(p-
100.3
CH3C6H4CH(CH3)2), 85.4 (p-CH3C6H4CH(CH3)2),
83.2 (p-CH3C6H4CH(CH3)2), 82.1 (p-
(ipso-p-CH3C6H4CH(CH3)2),
88.8
(p-
CH3C6H4CH(CH3)2), 55.2 (COCH2), 53.5 (CH2NH),
51.6 (CH2Ph), 31.1 (p-CH3C6H4CH(CH3)2), 24.4 (p-
CH3C6H4CH(CH3)2), 20.1 (p-CH3C6H4CH(CH3)2),
18.5 (p-CH3C6H4CH(CH3)2). Anal. calcd. for
C29H32RuN3OCl C, 60.56; H, 5.61; N, 7.31. Found: C,
60.35; H, 5.85; N, 7.60.
CH3C6H4CH(CH3)2), 56.7 (COCH2), 55.6 (CH2NH),
52.8 (CH(CH3)2), 52.5 (CH(CH3)2), 31.6 (p-
CH3C6H4CH(CH3)2), 25.1 (p-CH3C6H4CH(CH3)2),
23.4 (CH(CH3)2), 23.2 (CH(CH3)2), 20.3 (p-
CH3C6H4CH(CH3)2). IR (KBr Pellet): 1686 (νCO
)