14
C.-M. Hsiao et al. / Journal of Organometallic Chemistry 861 (2018) 10e16
Table 2
spectra were recorded using a Bruker Avance 300 spectrometer and
the chemical shifts were recorded in ppm relative to the residual
Calculated and experimental 1H NMR chemical shift of the aromatic protons of
cymene for compounds 1e5.
protons of CDCl
performed using a Heraeus CHN-OS Rapid Elemental Analyzer at
3
(
d
¼ 7.24, 77.0 ppm). Elemental analyses were
compound
Calculated H1, H2, H3, H4
4.69, 5.20, 5.08, 2.98
experimental
5.32 (d, 1H)
6
the Instrument Center of the NCHU. [(
h
-cymene)RuCl
2 2
] (cym-
5
5
3
.14 (d, 1H)
.03 (d, 1H)
.64 (d, 1H)
ene ¼ 4-isopropyltoluene) [13] and L
H ~ L H [26] were prepared
1
5
accordingly.
4
4
.2. Synthesis
.2.1. Synthesis of [Ru(
A Schenk flask charged with L
h
6-cymene)(L
1
)Cl] (1)
1
H (0.30 g, 1.3 mmol) and 15 mL of
5.80, 5.75, 3.70, 5.70
5.34 (d, 1H)
ꢁ
5
3
.16 (t, 2H)
.58 (d, 1H)
THF was cooled to 0 C and added n-BuLi (0.51 mL, 1.3 mmol). The
resulting solution was added dropwise to a THF (15 mL) solution of
6
ꢁ
[Ru(h -cymene)Cl ] (0.39 g, 0.63 mmol) at 0 C. After stirring 3 h,
2 2
all the volatiles were removed under vaccum and the resulting
residue was extracted with methylene chloride (3 ꢂ 10 mL) and
filtered through Celite. The filtrate was vaccum dried and residue
was recrstallized from a saturated toluene solution to yield 0.24 g of
5.73, 4.42, 3.29, 4.85
5.35 (s, 2H)
1
red crystals (37.7%). H NMR (CDCl
3
): 7.82e7.72 (m, 3H, Ph),
4
4
.92 (d, 1H)
.18 (d, 1H)
3
7
C
3
.39e7.21 (m, 7H, Ph), 5.40 (s, 1H, CCHC), 5.32 (d, JHH ¼ 8 Hz, 1H,
3
3
6
H
4
), 5.14 (d, JHH ¼ 8 Hz, 1H, C
6
H
4
), 5.03 (d, JHH ¼ 8 Hz, 1H, C
6
H
4
),
),
C
3
3
.64 (d, JHH ¼ 8 Hz, 1H, C
6
H
4
), 2.66 (sept, JHH ¼ 7 Hz, 1H, CHMe
2
1
3
1
.99 (s, 3H, cymene Me), 1.76 (s, 3H, Me), 1.17 (m, 6H, CHMe
2
).
NMR (CDCl
3
): 171.8 (C¼O), 164.7 (C¼N), 157.4 (Ph), 139.7 (Ph), 129.7
(
(
(
Ph), 129.4 (Ph), 127.9 (Ph), 127.8 (Ph), 127.0 (Ph), 126.2 (Ph), 125.5
Ph), 123.5 (Ph), 100.8 (Cipso), 96.3 (Cipso), 94.6 (CH), 87.3 (CH), 84.7
CH), 84.5 (CH), 79.4 (CH), 30.6 (CH), 24.8 (Me), 23.5 (Me), 21.0 (Me),
4.75, 5.59, 4.77, 3.84
5.33 (d, 1H)
5
4
4
.07 (d, 1H)
.65 (d, 1H)
.47 (d, 1H)
1
8.5 (Me). Anal. Calcd. for C26
H28ClNORu (507.04): C, 61.59; H, 5.57;
N, 2.76. Found: C, 60.96; H, 5.49; N, 2.97%.
4
.2.2. Synthesis of {Ru(
h
6-cymene)(L
Similar procedure as for synthesizing compound 1 was adopted.
2
)]Cl} (2)
6
L
2
H (0.30 g, 1.1 mmol), n-BuLi (0.45 mL, 1.1 mmol), and [Ru(
cymene)Cl (0.34 g, 0.56 mmol) were used. Compound 2 was
isolated in 31.9% yield (0.28 g). H NMR (CDCl
Ph), 7.30e7.18 (m, 4H, Ph), 6.99 (m, 2H, Ph), 5.41 (s, 1H, CCHC), 5.34
h -
4.51, 5.57, 4.60, 2.94
5.33 (d, 1H)
2 2
]
5
4
3
.00 (d, 1H)
.49 (d, 1H)
.78 (d, 1H)
1
3
): 7.83e7.74 (m, 3H,
3
(
(
(
(
1
1
8
1
5
d, JHH ¼ 8 Hz, 1H, C
6
H
4
), 5.16 (m, 2H, C
6
H
4
), 3.93 (s, 3H, OMe), 3.58
3
3
d, JHH ¼ 8 Hz, 1H, C
6
H
4
), 2.66 (sept, JHH ¼ 7 Hz, 1H, CHMe ), 1.97
2
13
s, 3H, Me), 1.72 (s, 3H, cymene Me), 1.16 (m, 6H, CHMe
CDCl
): 171.7 (C¼O), 165.7 (C¼N), 151.4 (Ph), 146.6 (Ph), 139.9 (Ph),
29.3 (Ph), 127.8 (Ph), 127.5 (Ph), 126.9 (Ph), 126.6 (Ph), 121.5 (Ph),
10.3 (Ph), 101.0 (Cipso), 95.4 (Cipso), 94.4 (CH), 87.5 (CH), 85.9 (CH),
4.6 (CH), 55.2 (OMe), 30.5 (CH), 23.9 (Me), 23.7 (Me), 20.6 (Me),
30ClNO Ru (537.06): C, 60.38; H,
.63; N, 2.61. Found: C, 59.28; H, 5.88; N, 2.75%.
2
). C NMR
3
8.4 (Me). Anal. Calcd. for C27
H
2
4
.2.3. Synthesis of {Ru(
h
6-cymene)[L
Similar procedure as for synthesizing compound 1 was adopted.
3
)]Cl} (3)
6
L
3
H (0.30 g, 0.93 mmol), n-BuLi (0.41 mL, 1.0 mmol), and [Ru(
cymene)Cl (0.23 g, 0.47 mmol) were used. Compound 3 was
isolated in 52.4% yield (0.29 g). H NMR (CDCl
Ph), 7.32e7.14 (m, 6H, Ph), 5.48 (s, 1H, CCHC), 5.35 (br, 2H, C
h -
Scheme 3. Amination of benzyl alcohol with primary amines catalyzed by ruthenium
compounds.
2 2
]
1
3
): 7.86e7.85 (m, 2H,
),
), 3.89
),
6 4
H
3
3
4
.92 (d,
JHH ¼ 8 Hz,1H, C
6
H
4
), 4.18 (d,
), 3.24 (sept, JHH ¼ 7 Hz, 1H, CHMe
J
HH ¼ 8 Hz, 1H, C
6 4
H
bidentate ligands also allowed a spin-saturation transfer mecha-
nism in our cymene-ruthenium system. Further explorations are
being conducted with Ru derivatives prepared from these ruthe-
nium compounds and their different catalytic approaches, as well
as their potential efficacy in inhibiting cancer cells.
3
3
(
2
sept, JHH ¼ 7 Hz, 1H, CHMe
2
2
3
.89 (sept, JHH ¼ 7 Hz, 1H, CHMe
2
), 1.77 (s, 3H, cymene Me), 1.71 (s,
13
3
H, Me), 1.37 (m, 12H, CHMe
2
2
), 1.07 (m, 6H, CHMe ). C NMR
(
1
CDCl
3
): 172.4 (C¼O), 167.2 (C¼N), 151.3 (Ph), 143.8 (Ph), 141.8 (Ph),
29.2 (Ph), 138.0 (Ph), 129.5 (Ph), 129.1 (Ph), 128.3 (Ph), 127.9 (Ph),
127.0 (Ph), 126.5 (Ph), 125.4 (Ph), 125.1 (Ph), 123.5 (Ph), 104.3 (Cipso),
4
. Experimental
96.0 (CH), 95.3 (Cipso), 86.8 (CH), 84.2 (CH), 82.1 (CH), 30.5 (CH), 28.1
(
Me), 27.5 (Me), 26.0 (Me), 25.4 (Me), 25.3 (Me), 25.1 (Me), 23.3 (Me),
21.8 (Me), 17.8 (Me). Anal. Calcd. for 40ClNORu
591.20)þ(C 0.2: C, 65.81; H, 6.88; N, 2.30. Found: C, 66.19; H,
6.93; N, 2.35%. Small amount of solvent in the molecules.
4
.1. General procedure
32
C H
(
7 8
H )
All starting materials were used as purchased. H and 13C NMR
1