456
K. Song et al. / Journal of Organometallic Chemistry 751 (2014) 453e457
Table 4
isolated by re-crystallization as a red solid (0.10 g, 52.7%). Mp:
>250 ꢀC. FT-IR (KBr, cmꢁ1): 3055 (w), 2920 (s), 2852 (s), 1728 (s),
1621 (s), 1579 (m), 1356 (s), 1306 (s), 1262 (s), 1707 (s), 836 (s), 762
Heck reaction of aryl bromides and styrene using complex C1.a
4×
10-3 mol% [Pd]
(s), 705 (vs). 1H NMR (400 MHz, CDCl3, TMS):
d
8.13 (d, J ¼ 8.0, 2H,
1.1 mol% Na2CO3
DMA
Ar
+
ArBr
Ph
Pyrene H), 7.84 (s, 2H, Pyrene H), 7.45 (d, J ¼ 8.0, 2H, Pyrene H), 7.33-
7.27 (m, 6H, Pyrene H, Ph H), 7.25e7.23 (m, 2H, Ph H), 2.36 (s, 12H,
Ph
PheCH3). 13C NMR (100 MHz, CDCl3, TMS):
d 166.8, 147.4, 136.5,
132.6, 130.4, 129.5, 128.9, 128.4, 128.2, 128.1, 127.1, 124.8, 18.7. Anal.
Calcd for C32H26Cl2N2Pd: C, 62.40; H, 4.26; N, 4.55. Found: C, 62.15;
H, 4.43; N, 4.22.
c
Entry
ArBr
Conversion (%)b
TOF (hꢁ1
)
Complex C2: Using the same procedure as for the synthesis of
C1, the red powder C2 was produced in 17.2% yield. Mp: >250 ꢀC.
FT-IR (KBr, cmꢁ1): 3058 (w), 2964 (s), 2869 (s), 2361 (s), 1623 (s),
1583 (m), 1460 (s), 1356 (s), 1302 (s), 1223 (s), 833 (s), 754 (s), 705
1
2
99
86
2100
Br
1800
H3C
Br
(vs). 1H NMR (400 MHz, CDCl3, TMS):
d
8.13 (d, J ¼ 8.00, 2H, Pyrene
H), 7.86 (s, 2H, Pyrene H), 7.47e7.43 (m, 4H, Pyrene H), 7.37e7.30
(m, 6H, Ph H), 3.12e3.07 (m, 4H, PheCH2e), 2.59e2.54 (m, 4H, Phe
CH2e), 1.28 (t, J ¼ 7.6, 12H, PheCH3). 13C NMR (100 MHz, CDCl3,
Br
3
4
75
58
1600
1200
TMS):
d 166.9, 146.6, 136.1, 133.1, 132.5, 131.1, 128.7, 128.2, 128.0,
CH3
127.3, 126.9, 125.1, 24.8, 13.1. Anal. Calcd for C36H34Cl2N2Pd: C,
64.34; H, 5.10; N, 4.17. Found: C, 64.18; H, 5.28; N, 4.04.
Complex C3: Using the same procedure as for the synthesis of C1,
the red powder C3 was produced in 54.3% yield. Mp: >250 ꢀC. FT-IR
(KBr, cmꢁ1): 3056 (w), 2963 (s), 2902 (m), 2371 (s), 1971 (m), 1624
(s),1617 (s),1575 (s),1472 (vs),1302 (vs),1033 (s), 838 (vs), 709 (vs).1H
S
Br
5
6
70
73
1500
1500
MeO
Br
NMR (400 MHz, CDCl3, TMS):
d
8.14 (d, J ¼ 6.8, 2H, Pyrene H), 7.86 (s,
2H, Pyrene H), 7.54 (d, J ¼ 7.2, 2H, Pyrene H), 7.08 (s, 4H, Pyrene H, Ph
H), 2.33 (s, 6H, PheCH3), 2.23 (s, 12H, PheCH3). 13C NMR (100 MHz,
CDCl3, TMS): d 167.1, 145.4, 138.1, 136.0, 132.5, 130.4, 130.3, 128.2, 128.1,
127.8, 127.2, 125.0, 21.5, 18.7. Anal. Calcd for C34H30Cl2N2Pd: C, 63.42;
H, 4.70; N, 4.35. Found: C, 63.35; H, 4.77; N, 4.13.
MeO
H2N
Br
Complex C4: Using the same procedure as for the synthesis of
C1, the red powder C4 was produced in 45.1% yield. Mp: >250 ꢀC.
FT-IR (KBr, cmꢁ1): 3058 (w), 2962 (s), 2870 (s), 2361 (s), 2336 (s),
1622 (m), 1600 (s), 1507 (s), 1452 (s), 1359 (s), 1304 (vs), 835 (s), 705
7
57
47
1200
1000
Br
Br
(vs). 1H NMR (400 MHz, CDCl3, TMS):
d
8.13 (d, J ¼ 8.0, 2H, Pyrene
8
H), 7.85 (s, 2H, Pyrene H), 7.50 (d, J ¼ 8.4, 2H, Pyrene H), 7.34 (t,
J ¼ 7.6, 2H, Pyrene H), 7.13 (s, 4H, Ph H), 3.06e2.99 (m, 4H, PheCH2e
), 2.56e2.50 (m, 4H, PheCH2e), 2.46 (s, 6H, PheCH3), 1.24 (t, J ¼ 7.6,
NH2
a
Reaction conditions: 2.0 mmol ArBr, 2.4 mmol styrene, 2.2 mmol Na2CO3, 4.0 mL
DMA, 150 ꢀC, 12 h.
12H, PheCH3). 13C NMR (100 MHz, CDCl3, TMS):
d 167.2, 144.4,
b
Determined by GC.
138.2, 135.8, 132.8, 132.5, 131.1, 128.1, 127.9, 127.7, 127.9, 125.2, 24.8,
21.9, 13.2. Anal. Calcd for C38H38Cl2N2Pd: C, 65.20; H, 5.47; N, 4.00.
Found: C, 64.96; H, 5.63; N, 3.74.
c
TOF: mol ArBr/mol Pd$h.
according to our previous procedure [53]. Melting points were
determined using a digital electrothermal apparatus without cali-
bration. NMR spectra were recorded on a Bruker DMX 400 MHz
instrument at ambient temperature using TMS as an internal
standard;
spectra were obtained on a PerkineElmer FT-IR 2000 spectropho-
tometer by using the KBr disc in the range of 4000e400 cmꢁ1
4.3. Heck reaction
General procedure for the Heck reaction of bromobenzene with
styrene in the presence of palladium complex, as a typical proce-
dure, the example uses C1 as in entry 3 of Table 2. A 50 ml oven-
dried Schlenk flask was charged under nitrogen with 2.0 mmol
d values are given in ppm and J values in Hz. The IR
.
Elemental analysis was carried out using a Flash EA 1112 micro-
analyzer. Conversions were determined by CP-3800 GC.
bromobenzene (210
ml, 313 mg), 2.4 mmol styrene (280 ml, 254 mg),
anhydrous 2.2 mmol Na2CO3 (233 mg) and 4.0 ml DMA. A 100
ml
solution of 4 mmol complex C1 in 5 ml DMA was added via syringe
to the above solution, and then the reactor was sealed and placed in
a 150 ꢀC oil bath, and the mixture was stirred for 12 h. After cooling
to room temperature, the mixture was diluted with EtOAc and
water. The organic layer was washed with brine, dried over Na2SO4,
and concentrated under reduced pressure. The residue was purified
by column chromatography on silica gel using petroleum ether.
4.2. Syntheses of palladium complexes (C1eC4)
The complexes (C1eC4) were prepared by the reaction of
(CH3CN)2PdCl2 with the corresponding ligands (L1eL4) in
dichloromethane according to the literature method [52,59].
Herein, only the synthesis of palladium complex C1 is described:
the ligand 4,5-bis(2,6-dimethylphenylimino)pyrenylidene (L1)
(0.34 mmol, 0.15 g) and (CH3CN)2PdCl2 (0.34 mmol, 0.09 g) were
added to a flame-dried Schlenk flask tube, then 10 ml dichloro-
methane was subsequently added with rapid stirring at room
temperature for 12 h. The solvent was removed in-vacuo and the
residual solid was washed with Et2O several times. Finally, C1 was
4.4. X-ray crystallographic studies
Single crystals of complexes C1 and C3 suitable for X-ray
diffraction were grown by slow diffusion of diethyl ether into
dichloromethane solutions at room temperature. X-ray studies