Palladium-Schiff Base Complex Immobilized Covalently on Magnetic Nanoparticles…
2
4 h. The resulting Schiff base immobilized on c-Fe O
(100 MHz, CDCl ): d 14.1, 52.0, 127.9, 129.6, 135.8,
2
3
3
was separated by an external magnet, washed with ace-
138.9, 169.1.
tone (3 9 10 mL) and dried under vacuum. The loading
-
1
amount of Schiff base was 0.28 mmol g catalyst based
on elemental analysis.
2.5.4 (E)-Ethyl cinnamate (1d)
1
3
H NMR (400 MHz, CDCl ): d 1.43 (t, 3H, J = 8.0 Hz),
3
3
.19 (q, 2H, J = 8.0 Hz), 6.35 (d, 1H, J = 16 Hz),
3
4
2
.4 Synthesis of Palladium-Schiff Base Complex
Immobilized on c-Fe O (Pd-Imino-Py-c-Fe O )
7.27–7.28 (m, 3H), 7.41–7.42 (m, 2H), 7.63 (d, 1H,
3
13
J = 16.0 Hz); C NMR (100 MHz, CDCl ): d 14.2, 60.0,
2
3
2
3
3
118.2, 127.9, 128.7, 130.1, 134.3, 144.3, 166.6.
The synthesized Schiff base immobilized on c-Fe O
2
3
(
1.7 g) was added to a solution of palladium acetate
2.5.5 (E)-1,2-Diphenylethene (1e)
(
0.12 g) in dry acetone (5 mL). The reaction mixture was
1
stirred at room temperature for 24 h. The solid was sepa-
rated by an external magnet, and washed with acetone
H NMR (400 MHz, CDCl ): d 7.18 (s, 2H), 7.33 (t, 2H,
3
3
3
3
J = 6.8 Hz), 7.42 (t, 4H, J = 7.0 Hz), 7.58 (d, 4H,
13
J = 7.2 Hz); C NMR (100 MHz, CDCl ): d 126.7,
(
3 9 10 mL) and dried under vacuum to afford Pd-imino-
3
Py-c-Fe O .
127.8, 128.8, 137.4.
2
3
2
.5 General Procedure for Heck Coupling Reaction
2.5.6 (E)-n-Butyl 3-(4-methoxyphenyl)acrylate (1f)
1
3
A mixture of aryl halide (1 mmol), olefin (1.5 mmol), Et N
3
H NMR (400 MHz, CDCl ): d 0.91 (t, 3H, J = 7.0 Hz),
3
(
2 mmol) and Pd-imino-Py-c-Fe O (0.25 mol%, 0.009 g)
1.35–1.40 (m, 2H), 1.60–1.62 (m, 2H), 3.72 (s, 3H), 4.13
2
3
3
3
(m, 2H, J = 7.0 Hz), 6.24 (d, 1H, J = 16.0 Hz), 6.81 (d,
was stirred at 100 °C in DMF (2 mL) for an appropriate
time (Table 2). The catalyst was separated by an external
magnet, washed with EtOH, dried and reused for a con-
secutive run under the same reaction conditions. Evapo-
ration of the solvent of the filtrate under reduced pressure
gave the crude products. The pure products were isolated
by chromatography on silica gel eluted with n-hex-
ane:EtOAc (50:1).
3
3H, J = 4.8 Hz), 7.39 (d, 3H, J = 4.2 Hz), 7.58 (d, 1H,
3
3
13
J = 16.0 Hz); C NMR (100 MHz, CDCl ): d 13.6, 19.1,
30.7, 55.0, 64.0, 114.1, 115.5, 127.0, 129.5, 144.0, 161.2,
3
167.1.
2.5.7 (E)-1-Methoxy-4-styrylbenzene (1g)
1
H NMR (400 MHz, CDCl ): d 3.89 (s, 3H), 6.92 (d, 2H,
3
3
3
3
J = 8.4 Hz), 6.99 (d, 2H, J = 16.4 Hz), 7.09 (d, 2H,
2
.5.1 (E)-n-Butyl Cinnamate (1a)
3
J = 16.0 Hz), 7.36 (t, 2H, J = 7.6 Hz), 7.46–7.52 (m,
1
3
13
3H); C NMR (100 MHz, CDCl ): d 55.3, 114.1, 126.3,
126.6, 127.2, 127.8, 128.2, 128.7, 130.1, 137.7, 159.3.
H NMR (400 MHz, CDCl ): d 0.88 (t, 3H, J = 7.6 Hz),
3
3
1
3
.34–1.36 (m, 2H), 1.59–1.62 (m, 2H), 4.13 (t, 2H,
3
J = 6.8 Hz), 6.36 (d, 1H, J = 16.0 Hz), 7.29–7.30 (m,
3
H), 7.43–7.45 (m, 2H), 7.60 (d, 1H, J = 16.4 Hz);
13
3
C
2.5.8 (E)-n-Butyl 3-(4-chlorophenyl)acrylate (1h)
NMR (100 MHz, CDCl ): d 13.7, 19.2, 30.8, 64.3, 118.2,
3
1
3
1
28.0, 128.8, 130.1, 134.4, 144.4, 166.8.
H NMR (400 MHz, CDCl ): d 0.90 (t, 3H, J = 7.2 Hz),
3
1
.33–1.39 (m, 2H), 1.57–1.64 (m, 2H), 4.13 (t, 2H,
3
3
J = 6.8 Hz), 6.64 (d, 1H, J = 16.0 Hz), 7.45 (d, 2H,
2
.5.2 (E)-Methyl Cinnamate (1b)
3
3
3
J = 8.0 Hz), 7.63 (d, 1H, J = 16.0 Hz), 7.74 (d, 2H,
13
J = 8.0 Hz); C NMR (100 MHz, CDCl ): d 13.7, 19.2,
1
H NMR (400 MHz, CDCl ): d 3.74 (s, 3H), 6.38 (d, 1H,
J = 16.4 Hz), 7.31–7.33 (m, 3H), 7.45–7.47 (m, 2H), 7.63
3
3
3
3
30.7, 64.4, 118.8, 129.1, 129.4, 132.9, 136.0, 143.0, 166.7.
13
d, 1H, J = 16.4 Hz); C NMR (100 MHz, CDCl ): d
(
3
5
1.6, 117.7, 128.1, 128.9, 130.3, 134.3, 144.8, 167.3.
2.5.9 (E)-1-Chloro-4-styrylbenzene (1i)
1
2
.5.3 (E)-Methyl 2-Methyl-3-phenylacrylate (1c)
H NMR (400 MHz, CDCl ): d 7.07 (s, 2H), 7.28–7.39 (m,
3
1
H), 7.43–7.46 (m, 2H), 7.50–7.52 (m, 2H); C NMR
3
5
1
H NMR (400 MHz, CDCl ): d 2.15 (s, 3H), 3.83 (s, 3H),
(100 MHz, CDCl ): d 127.7, 128.5, 128.8, 129.0, 129.9,
130.0, 130.4, 134.3, 136.9, 138.1.
3
3
3 13
.21–7.41 (m, 5H), 7.92 (d, 1H, J = 16.0 Hz); C NMR
7
123