C–H Bond Activation of Palladium Complexes
CNN) ppm. C25H29N3 (371.52): calcd. C 80.82, H 7.87, N 11.31;
found C 80.74, H 7.53, N 11.27.
δ = 1.14 [d, J = 6.6 Hz, 6 H, CH–(CH3)2], 1.26 [d, J = 6.6 Hz, 6
H, CH–(CH3)2], 2.21 [s, 3 H, O–C(=O)CH3], 3.25 [sept, J = 6.6 Hz,
2 H, CH–(CH3)2], 4.52 (br., 2 H, CH2Py), 6.83 (s, 1 H, NH), 6.87
(br., 1 H, CH–Ar), 7.12 (br., 1 H, CH–Ar), 7.17 (m, 2 H, CH–Ar),
7.24 (m, 3 H, CH–Ar), 7.42 (t, J = 7.8 Hz, 1 H, CH–Ar), 7.59 (t,
J = 7.2 Hz, 1 H, CH–Ar), 8.35 (d, J = 5.4 Hz, 1 H, CH–Ar) ppm.
13C{1H} NMR (150 MHz): δ = 22.9 [br., CH–(CH3)2], 24.1 [br.,
CH–(CH3)2], 24.4 [s, O–C(=O)CH3], 28.6 [s, CH–(CH3)2], 55.7 (s,
CH2–Py), 120.9, 122.7, 123.2, 123.9, 124.4, 129.5, 130.7, 133.7,
137.8, 149.0 (CH–Ar), 132.0, 145.1, 147.0, 148.8, 152.9, 162.0 [three
Cipso–Ar, one metalated C–Ph, one C–CH–(CH3)2 and one NCN],
177.8 [s, O–C(=O)CH3] ppm. C27H39N3O4Pd (576.02): calcd. C
60.50, H 5.83, N 7.84; found C 60.55, H 6.19, N 7.37.
Complex 1: CH2Cl2 (15 mL) was added at room temperature to a
flask that contained {Ph–C[=N–(2,6-di-iPr–C6H3)][NH(CH2)2-
NMe2]} (0.35 g, 1 mmol) and Pd(OAc)2(0.22 g, 1 mmol). After 1 h
of stirring, the volatile compounds were removed under reduced
pressure to afford a brown solid. The resulting solid was purified
by THF/hexane solution to afford a pale yellow solid; yield 0.44 g,
76%. 1H NMR (600 MHz): δ = 1.12 [d, J = 6.6 Hz, 6 H, CH–
(CH3)2], 1.18 [d, J = 6.6 Hz, 6 H, CH–(CH3)2], 1.82 [s, 3 H, O–
C(=O)CH3], 1.99 [s, 3 H, O–C(=O)CH3], 2.34 (t, J = 6.0 Hz, 2 H,
CH2), 2.71 [s, 6 H, N(CH3)2], 3.07 (t, J = 6.0 Hz, 2 H, CH2), 3.24
[sept, J = 6.6 Hz, 2 H, CH–(CH3)2], 6.91 (d, J = 7.8 Hz, 2 H, CH–
Ar), 6.94 (m, 2 H, CH–Ar), 7.07 (t, J = 7.2 Hz, 1 H, CH–Ar), 7.19–
7.26 (m, 3 H, CH–Ar), 9.99 (s, 1 H, NH) ppm. 13C{1H} NMR
(150 MHz): δ = 21.7 [s, CH–(CH3)2], 23.5 [s, O–C(=O)CH3], 23.6
[s, O–C(=O)CH3], 25.6 [s, CH–(CH3)2], 28.6 [s, CH–(CH3)2], 50.7
[s, N(CH3)2], 53.0 (s, CH2), 65.8 (s, CH2), 123.0, 127.0, 128.3, 128.4,
130.1 (CH–Ar), 129.9, 131.8, 146.6, 168.6 [two Cipso–Ar, one CNN
and one C–CH–(CH3)2], 178.1 [s, O–C(=O)CH3] ppm.
C27H39N3O4Pd (576.02): calcd. C 56.30, H 6.82, N 7.29; found C
56.36, H 6.71, N 7.25.
General Procedure for the Suzuki-Type Coupling Reaction: Pre-
scribed amounts of catalyst, aryl halide (1.0 equiv.), phenylboronic
acid (1.5 equiv.), base (3.0 equiv.) and a magnetic stir bar were
placed in a Schlenk tube under nitrogen. Toluene (3 mL) was added
by syringe, and the reaction mixture was heated in an oil bath at
the prescribed temperature for the prescribed time. After removal
of the volatile compounds, the residue was diluted with ethyl acet-
ate, then filtered through a pad of silica gel. A sample in [D]chloro-
form was taken for determination of conversion. The crude mate-
rial was further purified by flash chromatography on silica gel.
Complex 2: The procedure for preparation of 2 was similar to that
used for 1 but with {Ph–C(NHCH2Py)[=NH–(2,6-di-iPr–C6H3)]}
(0.37 g, 1 mmol) and Pd(OAc)2 (0.25 g, 1.1 mmol). A yellow solid
was obtained; yield 0.57 g, 96%. 1H NMR (600 MHz): δ = 1.10 [d,
J = 7.2 Hz, 6 H, CH–(CH3)2], 1.20 [d, J = 6.6 Hz, 6 H, CH–
(CH3)2], 1.91 [s, 3 H, O–C(=O)CH3], 2.09 [s, 3 H, O–C(=O)CH3],
3.25 [sept, J = 6.6 Hz, 2 H, CH–(CH3)2], 4.53 (s, 2 H, CH2Py), 6.93
(d, J = 7.8 Hz, 2 H, CH–Ar), 7.00 (m, 2 H, CH–Ar), 7.06–7.10
(overlap, 2 H, CH–Ar), 7.25–7.32 (overlap, 4 H, CH–Ar), 7.78 (m,
1 H, CH–Ar), 8.19 (d, J = 6 Hz, 1 H, CH–Ar), 10.20 (s, 1 H, NH)
ppm. 13C{1H} NMR (150 MHz): δ = 21.6 [s, CH–(CH3)2], 23.4 [s,
O–C(=O)CH3], 25.6 [s, CH–(CH3)2], 28.5 [s, CH–(CH3)2], 62.6 (s,
CH2Py), 119.6, 123.06, 123.12, 127.1, 128.46, 128.54, 130.4, 138.8,
148.9 (CH–Ar), 129.1, 131.5, 146.6, 162.1, 168.9 [three Cipso–Ar,
one NCN and one C–CH–(CH3)2], 178.2, 178.9 [O–C(=O)CH3]
ppm. C27H39N3O4Pd (576.02): calcd. C 58.44, H 5.92, N 7.05;
found C 58.59, H 5.49, N 6.99.
Crystal Structure Data: The crystals were grown from a solution of
1 in dichloromethane/hexane or a solution of 4 in concentrated
chloroform, then isolated by filtration. Suitable crystals of 1 were
sealed in thin-walled glass capillaries under a nitrogen atmosphere
at 293 K and mounted on a Bruker AXS SMART 1000 dif-
fractometer. A crystal of 4 was mounted onto a glass fibre by using
a perfluoropolyether oil “oil-drop” method and cooled rapidly in
a stream of cold nitrogen gas with an Oxford Cryosystems Cryos-
tream unit. Diffraction data were collected at 100 K with an Oxford
Gemini S diffractometer. The absorption correction was carried out
on the basis of symmetry-equivalent reflections by using SADABS
for 1, and semiempirical absorption correction was based on the
spherical harmonics implemented in the SCALE3 ABSPACK scal-
ing algorithm from Crysalis RED, Oxford Diffraction Ltd for 4.[14]
Table 2. Summary of crystal data for compounds 1 and 4.
Complex 3: A solution of 1 (0.58 g, 1 mmol) in toluene (15 mL)
was heated at 80 °C for 48 h. The volatile compounds were re-
moved under reduced pressure and the residue was purified by
THF/hexane solution to obtain a white precipitate. The crude prod-
uct was washed hexane (30 mL three times) to afford white solid;
1·CH2Cl2
4·CHCl3·H2O
Formula
Mr
C28H39Cl2N3O4Pd
658.92
C28H34Cl3N3O3Pd
673.33
T [K]
297(2)
100(2)
1
Crystal system
Space group
monoclinic
P21/n
monoclinic
P21/n
yield 0.46 g, 90%. H NMR (600 MHz): δ = 1.16 [d, J = 6.6 Hz, 6
H, CH–(CH3)2], 1.27 [d, J = 6.6 Hz, 6 H, CH–(CH3)2], 2.11 [s, 3
H, O–C(=O)CH3], 2.56 [overlap, 8 H, CH2 and N(CH3)2], 2.84 (br.,
2 H, CH2), 3.21 [sept, J = 6.6 Hz, 2 H, CH–(CH3)2], 6.67 (br., 1
H, NH), 6.80 (br., 1 H, CH–Ar), 6.96 (br., 1 H, CH–Ar), 7.12 (t,
J = 7.2 Hz, 1 H, CH–Ar), 7.20 (d, J = 7.8 Hz, 2 H, CH–Ar), 7.21
(t, J = 8.4 Hz, 1 H, CH–Ar), 7.38 (t, J = 7.8 Hz, 1 H, CH–Ar)
ppm. 13C{1H} NMR (150 MHz): δ = 22.6 [s, CH–(CH3)2], 24.15
[s, O–C(=O)CH3], 24.24 [s, CH–(CH3)2], 28.6 [s, CH–(CH3)2], 46.6
(s, CH2), 47.4 [s, N(CH3)2], 63.6 (s, CH2), 123.3, 123.8, 129.4, 130.4,
a [Å]
b [Å]
c [Å]
a [°]
10.3443(14)
22.158(3)
14.4909(18)
90
9.9600(3)
18.5872(5)
16.5409(5)
90
β [°]
107.768(2)
90
3163.0(7)
4
1.384
0.791
17578
356
6182 (0.0269)
0.0408, 0.1139
0.0517, 0.1215
1.041
101.862(2)
90
2996.80(15)
4
1.492
0.920
28387
363
7152 (0.0385)
0.0356, 0.0889
0.0505, 0.0927
1.019
γ [°]
V [Å3]
Z
ρcalcd. [Mgm–3]
μ(Mo-Kα) [mm–1]
Reflections collected
Parameters
Indep. reflections (Rint
133.9 (CH–Ar), 122.7, 132.2, 144.9, 146.8, 152.5, 161.8 [two Cipso
–
Ar, one NCN, two C–CH–(CH3)2 and one metalated C–Ph], 177.5
[s, O–C(=O)CH3] ppm. C25H35N3O2Pd (515.97): calcd. C 58.19, H
6.84, N 8.14; found C 57.69, H 6.25, N 8.04.
)
Final R indices R1[a], wR2
R indices (all data)
GoF[b]
[a]
Complex 4: A solution of 2 (0.57 g, 0.96 mmol) in THF (3 mL) was
heated at 80 °C for 3 h. The brown suspension was cooled to room
temperature and filtered. The brown residue was washed with THF
[a] R1 = [(Σ|Fo| – |Fc|)/Σ|Fo|], wR2 = [Σw(F2o – Fc2)2/Σw(F2o)2]1/2, w =
to afford a pale grey solid; yield 0.57 g, 59%. 1H NMR (600 MHz): 0.10. [b] GoF = [Σw(F2o – Fc2)2/(Nrflns – Nparams)]1/2
.
Eur. J. Inorg. Chem. 2012, 720–726
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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