Pd–S-methylisothiourea supported on magnetic nanoparticles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions

Article abstract of DOI:10.1016/j.crci.2016.06.010

Supported Pd–S-methylisothiourea on magnetic nanoparticles (Pd–SMU-MNPs) as an efficient and magnetically reusable nanocatalyst was prepared and applied for the Heck and Suzuki cross-coupling reactions. All coupling reactions proceeded in short reaction times with good to excellent yields. After completion of reactions, the catalyst was easily separated from the reaction mixture using an external magnetic field and reused for several consecutive runs without significant loss of its catalytic efficiency and activity. This nanomagnetic catalyst was characterized by FT-IR spectroscopy, XRD, VSM, ICP-OES, TEM and SEM techniques. The leaching of the catalyst has been examined by a hot filtration test and ICP-OES analysis.

Full text of DOI:10.1016/j.crci.2016.06.010

C. R. Chimie xxx (2016) 1e8
Contents lists available at ScienceDirect
Comptes Rendus Chimie
www.sciencedirect.com
Full paper/M eꢀ moire
PdeS-methylisothiourea supported on magnetic
nanoparticles as an efficient and reusable nanocatalyst for
Heck and Suzuki reactions
*
Arash Ghorbani-Choghamarani , Bahman Tahmasbi, Nourolah Noori,
Sara Faryadi
Department of Chemistry, Faculty of Science, Ilam University, P.O. Box 69315516, Ilam, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
Supported PdeS-methylisothiourea on magnetic nanoparticles (PdeSMU-MNPs) as an
efficient and magnetically reusable nanocatalyst was prepared and applied for the Heck
and Suzuki cross-coupling reactions. All coupling reactions proceeded in short reaction
times with good to excellent yields. After completion of reactions, the catalyst was easily
separated from the reaction mixture using an external magnetic field and reused for
several consecutive runs without significant loss of its catalytic efficiency and activity. This
nanomagnetic catalyst was characterized by FT-IR spectroscopy, XRD, VSM, ICP-OES, TEM
and SEM techniques. The leaching of the catalyst has been examined by a hot filtration test
and ICP-OES analysis.
Received 15 March 2016
Accepted 28 June 2016
Available online xxxx
Keywords:
Magnetic nanoparticle
Heck reaction
Suzuki reaction
CeC coupling
Palladium
©
2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.
1. Introduction
demands for sustainability [9e11]. Therefore, nano-
particles (NPs) have recently emerged as efficient alter-
Palladium commonly has been applied as one of the
natives for the immobilization of homogeneous catalysts
[12,13]. Because, by decreasing the support size, the sur-
powerful metals for CeC coupling reactions [1e3]. Cross-
coupling reactions such as Heck and Suzuki reactions
were used as significant procedures in modern synthetic
organic chemistry for the preparation of natural products,
pharmaceuticals, agrochemicals, herbicides, biologically
active compounds, UV screens, polymers, hydrocarbons,
liquid crystal materials and advanced materials [4e7].
Homogeneous Pd-catalysts have been widely reported in
carbonecarbon coupling reactions because of their high
catalytic activity [8], while, in the catalytic reactions, sep-
aration and reusability of the catalyst is an important
factor because of stringent ecological and economical
face area is increased and consequently
a semi-
homogeneous media is obtained, which can be used as a
bridge to improve the gap between homogeneous and
heterogeneous catalysts [14]. However, in order to simplify
catalyst recovery and reusability of the particles, magnetic
nanoparticles (MNPs) have recently emerged in catalyst
science, and they can be rapidly isolated from the reaction
mixture using an external magnet [15]. More importantly,
magnetic separation is more effective and easier than
filtration or centrifugation [16]. Among the various mag-
netic nanoparticles, Fe
such as easy preparation, having a high surface-area, low
3 4
toxicity, and easy availability [17,18]. Therefore, Fe O
3 4
O MNPs have many advantages
*
Corresponding author. Department of Chemistry, Faculty of Science,
MNPs are considered as ideal support for the hetero-
genization of homogeneous catalysts [10e13].
Ilam University, P.O. Box 69315516, Ilam, Iran.
E-mail addresses: arashghch58@yahoo.com, a.ghorbani@mail.ilam.ac.
ir (A. Ghorbani-Choghamarani).
http://dx.doi.org/10.1016/j.crci.2016.06.010
1631-0748/© 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

2
A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
2
. Result and discussion
2
.1. Catalyst preparation
In continuation of our studies about the application of
new catalysts in organic functional group transformations
16,19], herein we report a simple and efficient method for
[
the carbonecarbon cross-coupling reaction in the presence
of catalytic amounts of PdeSMU-MNPs. The PdeSMU-
MNPs were prepared by the concise route that has been
3 4
outlined in Scheme 1. Initially, naked Fe O MNPs were
prepared by coprecipitation of iron(II) and iron(III) ions in
ꢀ
basic solution at 80 C [16], followed by modification using
(
3-chloropropyl)trimethoxysilane (CPTES). Subsequently,
S-methylisothiourea immobilized on Fe magnetic
nanoparticles (SMU-MNPs) via the reaction of ClePre-
SieFe with a S-methylisothiourea hemisulfate salt.
3 4
O
Fig. 1. SEM image of PdeSMU-MNPs.
3 4
O
Finally, PdeSMU-MNPs were prepared via coordination of
palladium(II) with SMU-MNPs followed by reduction of
Pd(II) to Pd(0) by NaBH . The catalyst has been character-
4
ized by scanning electron microscopy (SEM), transmission
electron microscopy (TEM), vibrating sample magnetom-
etry (VSM), inductively coupled plasma atomic emission
spectroscopy (ICP-OES), X-ray diffraction (XRD) and Fourier
transform infrared spectroscopy (FT-IR).
The amount of loaded palladium on the PdeSMU-MNPs
ꢂ3
ꢂ1
was found to be 1.54 ꢁ 10 mol g based on inductively
coupled plasma atomic emission spectroscopy (ICP-OES).
The XRD patterns of the Fe
3 4
O nanoparticles and cata-
ꢀ
ꢀ
ꢀ
lyst showed several peaks at 2
q
values of 30.5 , 35.8 , 43.6 ,
4.3 , 57.5 and 63.2 related to crystal planes in the Fe
cubic lattice (Fig. 3). Also the XRD pattern of PdeSMU-
ꢀ
ꢀ
ꢀ
5
3 4
O
ꢀ
ꢀ
ꢀ
MNPs shows a series of peaks (40.0 , 46.4 and 67.4 ), and
these results revealed that the surface modification of the
3 4
Fe O nanoparticles didn't destroy their cubic lattice
structures [20].
2
.2. Catalyst characterization
3 4
Successful functionalization of the Fe O NPs can be
The morphology and particle size of PdeSMU-MNPs
inferred from the FT-IR technique. Fig. 4 shows FT-IR
spectra of Fe , Cl-MNPs, SMU-MNPs and PdeSMU-
were evaluated by SEM and TEM analysis. The SEM image
shows that these nanoparticles are spherical in shape with
an average diameter of 24 ± 3 nm (Fig. 1). Also, TEM images
reveal that the diameter of the PdeSMU-MNPs is 15 ± 3 nm
Fig. 2).
In order to determine the exact amount of palladium in
PdeSMU-MNPs, the ICP-OES technique was performed.
3 4
O
MNPs. The FT-IR spectrum for bare Fe
ing vibration at 3390e3440 cm from both symmetrical
and asymmetrical modes of OeH bonds, which are
3
O
4
shows a stretch-
ꢂ1
(
attached to the surface of MNPs. The presence of Fe
3 4
O was
shown in FT-IR by two strong absorption bands around 582
Scheme 1. Preparation process of PdeSMU-MNPs.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
3
Fig. 2. TEM images of PdeSMU-MNPs.
1500
1300
1100
b
Pd
Pd
900
700
500
300
Pd
a
10
20
30
40
50
60
70
80
3 4
Fig. 3. XRD patterns of Fe O nanoparticles (a) and PdeSMU-MNPs (b).
ꢂ1
and 443 cm , which corresponds to the FeeO bond of
Fe
3
O
4
MNPs is due to the coating of the Fe
3
O
4
MNPs by
ꢂ1
3
Fe O
4
[13]. The stretching vibrations at 990 cm (corre-
sponding to FeeOeSi bonds) and 1057 and 780 cm
organic layers and a palladium complex.
ꢂ1
(
related to OeSi bonds) indicate that the silica organic
2.3. Catalytic study
group was successfully coated on the surface of Fe
3 4
O
nanocrystals [16,21]. Furthermore, the presence of the
anchored organic groups including propyl silane is
confirmed by CeH stretching vibrations that appear at
In order to study the catalytic activity of PdeSMU-
MNPs, Suzuki reaction has been performed using sodium
tetraphenyl borate (NaBPh
4
) and phenylboronic acid
2
885 and 2973. Also, in the FT-IR spectrum of SMU-MNPs,
(PhB(OH) ) in the presence of this nanostructural com-
pound (Scheme 2).
In order to optimize the reaction conditions, the effect of
various parameters such as temperature, solvent (DMF,
2
ꢂ1
the located bands around 1629 cm correspond to the
C]N stretching vibrations, indicating that Cl of Cl-MNPs
has been successfully replaced by S-methylisothiourea.
The superparamagnetic properties of particles were
measured using the VSM technique. The magnetization
DMSO, toluene, water or PEG), bases (Et
CO ) and amount of catalyst were examined for the
cross-coupling of iodobenzene with PhB(OH) (Table 1). We
3
N, KOH, NaOEt or
K
2
3
curves of Fe
3
O
4
MNPs and PdeSMU-MNPs are shown in
2
Fig. 5. The magnetic measurements show that PdeSMU-
MNPs have a saturated magnetization value of 42 emu g
found that the reaction did not proceed in the absence of
PdeSMU-MNPs (Table 1, entry 9). As shown in Table 1, the
best results were observed in the presence of 0.006 gr,
0.92 mol % of PdeSMU-MNPs (Table 1, entry 4). Also,
different bases and various solvents have been examined
ꢂ1
and Fe
3 4
O MNPs have a saturated magnetization value of
ꢂ1
74 emu g . Decreasing the magnetic properties of the
ꢂ1
PdeSMU-MNPs (74 / 42 emu g ), compared with the
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

4
A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
Scheme 2. PdeSMU-MNPs catalyzed the Suzuki reaction.
the results are summarized in Table 2. In this study, various
aryl iodides (Table 2, entries 1e3), bromides (Table 2, en-
tries 4e10) and chlorides (Table 2, entries 11e13) were
reacted with phenylboronic acid efficiently. All products
were obtained in good yields. Therefore, this methodology
is an efficient protocol for the cross-coupling a wide range
of aryl halide including Cl, Br and I.
Also, the same reaction conditions have been applied for
the cross-coupling of aryl halides with NaBPh
4
in the
presence of PdeSMU-MNPs (Table 2, entries 14e24). Aryl
halides including electron-neutral, electron-rich and
electron-poor substituents reacted with NaBPh
4
to produce
the corresponding biphenyl in good to excellent yields
(88e99% yield of products).
Also, we examined the catalytic activity of PdeSMU-
MNPs in the Heck reaction (Scheme 3). In order to find out
the best reaction conditions, the coupling reaction of
iodobenzene with butyl acrylate was selected as the model
reaction (Table 3). The reaction conditions, such as the
solvent (Table 3, entries 1e5), base (Table 3, entries 6e9),
and amount of catalyst (Table 3, entries 9e13), were opti-
mized in this model reaction (Table 3). Also, the effect of
3 4
Fig. 4. FT-IR spectra of Fe O (a), Cl-MNPs (b), SMU-MNPs (c) and PdeSMU-
MNPs (d).
and the best results were obtained in H
2
O as solvent using
ꢀ
3
mmol of K
2
CO
3
at 50 C.
After optimization conditions, we examined the cata-
lytic activity of PdeSMU-MNPs for various aryl halides and
Scheme 3. PdeSMU-MNPs catalyzed the Heck reaction.
100
a
80
60
40
20
0
7
4.09438
42.16083
b
-10000
-5000
0
5000
10000
-
-
-
-
20
40
60
80
-100
H (Oe)
Fig. 5. Magnetization curves of Fe
3
O
4
(a) and PdeSMU-MNPs (b) at room temperature.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
5
Table 1
Optimization of reaction conditions for the CeC coupling reaction of iodobenzene (1 mmol) with phenylboronic acid (1 mmol) in the presence of PdeSMU-
MNPs.
ꢀ
Yield %a
Entry
Solvent (2 mL)
Base (3 mmol)
Catalyst (g)
Temperature ( C)
Time (min)
1
2
3
4
5
6
7
8
9
DMSO
DMF
Toluene
H O
2
PEG
K
K
K
K
K
2
2
2
2
2
CO
CO
CO
CO
CO
3
3
3
3
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
e
50
50
50
50
50
50
50
50
50
50
50
50
40
r.t.
25
25
30
30
30
30
30
30
600
30
30
30
30
100
91
95
43
96
97
56
61
18
3
2
H O
2
H O
2
H O
2
H O
2
H O
2
H O
2
H O
2
H O
2
H O
(Et)
KOH
NaOEt
K
K
K
K
K
K
3
N
b
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
3
3
3
3
3
3
e
10
11
12
13
14
0.002 (0.31 mol %)
0.003 (0.46 mol %)
0.005 (0.75 mol %)
0.006 (0.92 mol %)
0.006 (0.92 mol %)
37
49
68
55
34
a
Isolated yields.
No reaction.
b
Table 2
CeC Coupling reaction of aryl halides (1 mmol) using PhB(OH)
2
4
(1 mmol) or NaBPh (0.5 mmol) in the presence of PdeSMU-MNPs (0.006 g, 0.92 mol %).
Entry
Aryl halide
Phenylating reagent
Time (min)
Yield (%)a
Melting point (ºC) [Ref.]
1
2
3
4
5
6
7
8
9
Iodobenzene
4-Iodotoluene
2-Iodotoluene
4-Bromonitrobenzene
4-Bromochlorobenzene
4-Bromobenzonitrile
Bromobenzene
4-Bromotoluene
4-Bromophenol
4-Bromobenzaldehyde
4-Chloronitrobenzene
Chlorobenzene
4-Chlorobenzonitrile
Iodobenzene
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
Phenylboronic acid
30
60
300
20
90
60
40
40
40
96
94
90
99
95
96
91
92
92
88
62e65 [22]
42e44 [22]
Oil [23]
115e117 [24]
70e72 [23]
82e84 [23]
64e66 [22]
42e44 [22]
161e163 [23]
55e57 [25]
115e116 [24]
63e66 [22]
82e84 [23]
64e66 [22]
43e44 [22]
Oil [23]
116e117 [24]
70e72 [23]
82e85 [23]
161e163 [23]
56e58 [25]
115e117 [24]
62e65 [22]
82e85 [23]
b
b
b
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
70
b,c
100
125
140
30
45
280
40
20
60
60
100
90
90
89
92
b,c
b,c
Phenylboronic acid
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
Sodium tetraphenyl borate
97
94
91
98
99
90
90
89
4-Iodotoluene
2-Iodotoluene
4-Bromonitrobenzene
4-Bromochlorobenzene
4-Bromobenzonitrile
4-Bromophenol
4-Bromobenzaldehyde
4-Chloronitrobenzene
Chlorobenzene
b,c
93
90
93
b,c
140
170
b,c
4-Chlorobenzonitrile
a
b
c
Isolated yield.
PEG used as the solvent.
PdeSMU-MNPs was 8 mg, 1.2 mol %.
temperature (Table 3, entries 12e15) was examined. As
2.4. Recyclability of the catalyst
shown in Table 3, the best conditions were obtained in the
presence of PdeSMU-MNPs (8 mg, 1.2 mol %) in DMF using
The reusability of catalysts is an important advantage
from an industrial point of view. Therefore, the recovery
and recyclability of PdeSMU-MNPs were examined in the
coupling reaction of iodobenzene with phenylboronic acid.
After completion of the reaction, the catalyst was rapidly
isolated from the reaction mixture by magnetic decanta-
tion and washed with diethyl ether to remove residual
organic materials. Then, the reaction vessel was charged
with fresh substrates and subjected to the next run. As
shown in Fig. 6, the catalyst can be reused over eight times
without any significant loss of its catalytic activity or
ꢀ
K
2
CO
3
at 120 C (Table 3, entry 2).
This optimized reaction conditions was then applied for
the cross-coupling of different aryl halides including io-
dides (Table 4, entries 1e5), bromides (Table 4, entries 6e9)
and chlorides (Table 4, entries 10e12) in the presence of
PdeSMU-MNPs and all products were obtained in good
yield (91e97%). The reaction of various aryl halides
(
including electron-donating and electron-withdrawing
groups) with butyl acrylate was investigated to confirm
the generality of the present methodology.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

6
A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
Table 3
Optimization of reaction conditions for the CeC coupling reaction of iodobenzene (1 mmol) with butyl acrylate (1.2 mmol) in the presence of PdeSMU-MNPs.
ꢀ
Yield %a
Entry
Solvent (2 mL)
Base (3 mmol)
Catalyst (g)
Temperature ( C)
Time (min)
1
2
3
4
5
6
7
8
9
DMSO
DMF
Toluene
DMSO:H
PEG
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
K
K
K
K
K
2
2
2
2
2
CO
CO
CO
CO
CO
3
3
3
3
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
e
120
120
120
120
120
120
120
120
120
120
120
120
60
90
90
90
90
90
90
90
90
1200
90
90
90
90
90
90
30
95
15
45
60
65
30
2
O
3
(Et)
KOH
NaOEt
K
K
K
K
K
K
K
3
N
Trace
b
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
2
CO
3
3
3
3
3
3
3
e
10
11
12
13
14
15
0.004 (0.6 mol %)
0.005 (0.75 mol %)
0.007 (1.05 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
0.008 (1.2 mol %)
35
60
70
25
55
70
80
100
a
Isolated yield.
No reaction.
b
Table 4
Cross-coupling of aryl halides (1 mmol) with butyl acrylate (1.2 mmol)
performed in the coupling reaction of iodobenzene with
butyl acrylate. In this study, we obtained the yield of
product in the half time of the reaction that was 63%. Then
the reaction was repeated and in half time of the reaction,
the catalyst separated and allowed the filtrate to react
further. The yield of reaction in this stage was 64% con-
firming that the PdeSMU-MNPs act heterogeneously in the
reaction media.
Also, to determine the exact leaching of palladium in the
catalyst, the amount of Pd in PdeSMU-MNPs was deter-
mined by ICP-OES after six times recycling. The amount of
Pd in the recovered catalyst was found to be
(
(
Heck reaction) in the presence of catalytic amounts of PdeSMU-MNPs
8 mg, 1.2 mol %).
ꢀ
Entry Aryl halide
Time
min)
Yield
(%)
Melting point ( C)
[Ref.]
a
(
1
2
3
4
5
6
Iodobenzene
4-Iodotoluene
2-Iodotoluene
4-Iodoanisole
2-Iodoanisole
4-
90
96
95
91
93
92
97
Oil [23]
Oil [23]
Oil [23]
Oil [23]
Oil [26]
60e62 [23]
120
350
90
450
90
Bromonitrobenzene
4-
7
720
91
Oil [27]
ꢂ3
ꢂ1
1.49 ꢁ 10
mol g
based on ICP-OES. Therefore the
Bromochlorobenzene
amount of Pd in the catalyst after six times recovery is
8
9
1
1
1
4-Bromobenzonitrile 75
95
95
93
90
91
40e42 [27]
Oil [23]
Oil [23]
39e42 [27]
60e63 [23]
ꢂ3
ꢂ1
comparable with the fresh catalyst (1.54 ꢁ 10 mol g for
fresh PdeSMU-MNPs). Therefore, only 3% leaching of
palladium from the catalyst was observed after six runs.
The results from the hot filtration test and ICP-OES tech-
nique showed that leaching of palladium during the reac-
tion is negligible.
Bromobenzene
Chlorobenzene
80
300
0
1
2
4-Chlorobenzonitrile 420
4-
330
Chloronitrobenzene
a
Isolated yields.
Also, in order to determine leaching of palladium in the
reaction mixture, the Suzuki reaction through the coupling
of iodobenzene with phenylboronic acid was performed
and the obtained biphenyl has been characterized by ICP-
OES to detect amounts of palladium in products. Interest-
ingly, in this analysis even trace amounts of palladium
weren't observed in the biphenyl product.
palladium leaching. The average isolated yield for eight
runs was 94.5%, which clearly proved the practical recy-
clability of this catalyst.
In order to show that PdeSMU-MNPs act heteroge-
neously in the reaction media, a hot filtration test was
1
00
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
2.5. Comparison of the catalyst with previously reported ones
In order to examine the efficiency of the described
procedure, we compared the results of the coupling of
iodobenzene with phenylboronic acid with those of the
previously reported procedures in the literature (Table 5).
This catalyst showed a shorter reaction time and higher
reaction yield than the other catalysts. Also PdeSMU-MNPs
are superior in terms of price, bio-compatibility, stability
and easy separation than the previously reported works. In
addition, the recoverability and recyclability of PdeSMU-
MNPs is more rapid and easier than the other catalysts. As
is evident PdeSMU-MNPs (in this work) have many
1
2
3
4
5
6
7
8
Run number
Fig. 6. Recyclability of PdeSMU-MNPs in the coupling of iodobenzene with
phenylboronic acid.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
7
Table 5
Comparison results of PdeSMU-MNPs with other catalysts for the coupling of iodobenzene with phenylboronic acid.
Entry Catalyst (mol % of Pd)
Size of
catalyst (nm)
Condition
Temperature Time
( C)
Yield TON TOF
Ref.
ꢀ
(min) (%)a
ꢂ1
)
(h
ꢀ
1
2
3
4
5
6
NHCePd(II) complex (1.0 mol %)
Pd NP (1.0 mol %)
CA/Pd(0) (0.5e2.0 mol %)
Pd/Au NPs (4.0 mol %)
e
THF, Cs
2
CO
O, KOH
O, K CO
O, K
CO
CO
3
80
C
12 h
12 h
120
24 h
24 h
180
88
95
94
88
99
97
88
95
188 47
22
99
97
7.33
7.92
[28]
[29]
[30]
[31]
[32]
ꢀ
2.5e14
3.2 ± 0.4
80
H
H
2
100
100
C
C
ꢀ
2
2
3
ꢀ
EtOH/H
DMF, Cs
O, K
2
2
CO
3
80
C
0.92
4.12
32.33 [33]
ꢀ
ꢀ
Pd(II)eNHC complex (1 mol %)
e
2
3
100
100
C
C
0
N,N -Bis(2-pyridinecarboxamide)-1,2-benzene
10e20
H
2
2
3
palladium complex (1 mol %)
Pd-MPTAT-1 (0.02 g)
ꢀ
7
8
9
1
50
NaOH, DMF: H
1:5)
CO
O (5:1)
CO , 1,4-dioxane: 95
O (1:1)
O, K CO
2
O
85
C
C
C
C
8 h
10 h
240
30
95
96
91
96
e
e
e
e
[34]
[35]
(
K
H
K
H
H
ꢀ
LDH-Pd(0) (0.3 g)
6e10
150e300
15 ± 3
2
3
, 1,4-dioxane: 80
2
ꢀ
ꢀ
PANI-Pd (2.2 mol %)
2
3
41.36 10.34 [36]
2
0
PdeSMU-MNPs (0.006 mg, 0.92 mol %)
2
2
3
50
104 208
This
work
a
Isolated yield.
ꢀ
advantages such as a low reaction time, high number of
TNO and TOF, high yield of products, reacting at low tem-
perature and use of water as the solvent.
2
stirred in H O or PEG-400 at 50 C and the progress of the
reaction was monitored by TLC. After completion of the
reaction, the catalyst was separated by an external magnet
and washed with ethylacetate. The reaction mixture was
3
. Experimental
extracted with H
was dried over anhydrous Na
2
O and ethylacetate and the organic layer
SO (1.5 g). Then the solvent
2
4
3
.1. Preparation of the catalyst
was evaporated and pure biphenyl derivatives were ob-
tained in good to excellent yields.
3 4
The Fe O MNPs were synthesized according to our
recently reported procedure via a chemical coprecipitation
3.3. General procedure for the Heck reaction
technique using FeCl
tion at 80 C [23]. The obtained Fe
3
$6H
2
O and FeCl
2
$6H
2
O in basic solu-
ꢀ
3
O
4
nanoparticles (1.5 g)
A mixture of aryl halide (1 mmol), n-butyl acrylate
(1.2 mmol), K CO (3 mmol), and PdeSMU-MNPs (0.008 g,
was dispersed in 50 mL toluene by sonication for 30 min,
then 2.5 mL of (3-choloropropyl)triethoxysilane (CPTES)
2
3
ꢀ
1.2 mol %) was stirred in DMF at 120 C (the progress of the
reaction was monitored by TLC). After completion of the
reaction, the mixture was cooled down to room tempera-
ture and the catalyst was separated by an external magnet,
washed with diethyl ether and the reaction mixture was
was added to the mixture. The reaction mixture was stirred
ꢀ
under a N
2
atmosphere at 40 C for 8 h. Then, the prepared
nanoparticles (CleMNPs) were washed with ethanol,
separated by magnetic decantation and dried at room
temperature. In the next step, the obtained Cl-MNPs (1 g)
were dispersed in 50 mL ethanol for 20 min, then S-
methylisothiourea hemisulfate salt (2.5 mmol) and potas-
extracted with H O and diethyl ether. The organic layer was
2
dried over Na SO (1.5 g); the solvent evaporated and pure
2
4
products were obtained in 81e98% yields.
sium carbonate (2.5 mmol) were added to the reaction
ꢀ
mixture and stirred for 24 h at 80 C under a N
2
atmo-
3
3
.4. Selected spectral data
sphere. Then, the resulting nanoparticles (SMU-MNPs)
were washed with ethanol and separated using magnetic
decantation and dried at room temperature. The obtained
SMU-MNPs (1 g) were dispersed in 25 mL ethanol by
0
.4.1. 1,1 -Biphenyl
1
H NMR (400 MHz, CDCl
3
):
d
H
¼ 7.66e7.64 (m, 4H),
7
.52e7.41 (m, 4H), 7.42e7.38 (tt, J ¼ 7.6, 1.2 Hz, 2H) ppm.
sonication for 20 min; subsequently, palladium acetate
ꢂ3
(
0.5 g, 1.95 ꢁ 10 mol) was added to the reaction mixture.
0
3
.4.2. [1,1 -Biphenyl]-4-carbonitrile
ꢀ
The reaction mixture was stirred at 80 C for 20 h. Then,
1
H NMR (400 MHz, CDCl
3
):
d
H
¼ 7.79e7.76 (m, 2H),
NaBH
was continued for two more hours. The final product
PdeSMU-MNPs) was separated by magnetic decantation,
washed with ethanol and dried at room temperature.
4
(0.5 mmol) was added to the reaction mixture and it
7
.74e7.71 (m, 2H), 7.65e7.62 (m, 2H), 7.55e7.51 (m, 2H),
7.49e7.45 (m, 1H) ppm.
(
0
3
.4.3. 4-Chloro-1,1 -biphenyl
1
H NMR (400 MHz, CDCl
3
):
d
H
¼ 7.61e7.59 (m, 2H),
3
.2. General procedure for the Suzuki reaction
7.58e7.55 (m, 2H), 7.51e7.44 (m, 4H), 7.43e7.39 (tt, J ¼ 6,
.6 Hz, 1H) ppm.
1
A mixture of aryl halide (1 mmol), phenylboronic acid
(
(
1 mmol) or sodium tetraphenyl borate (0.5 mmol), K
3 mmol), and PdeSMU-MNPs (0.006 g, 0.92 mol %) was
2
CO
3
3.4.4. Butyl cinnamate
1
H NMR (400 MHz, CDCl
3
):
d
H
¼ 7.75e7.71 (d, J ¼ 16 Hz,
added to a reaction vessel. The resulting mixture was
1H), 7.58e7.56 (m, 2H), 7.44e7.41 (m, 3H), 6.55e6.47 (d,
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010

8
A. Ghorbani-Choghamarani et al. / C. R. Chimie xxx (2016) 1e8
J ¼ 16 Hz, 1H), 4.27e4.24 (t, J ¼ 6.4 Hz, 2H), 1.77e1.71 (m,
H), 1.51e1.46 (m, 2H), 1.03e0.99 (t, J ¼ 7.6 Hz, 3H) ppm.
[5] S.M. Islam, A.S. Roy, P. Mondal, N. Salam, Appl. Organometal. Chem.
6 (2012) 625.
6] S. Pasa, Y.S. Ocak, H. Temel, T. Kilicoglu, Inorg. Chim. Acta 405 (2013)
93.
2
2
[
4
3
.4.5. Butyl 3-(p-tolyl)acrylate
[7] S. Nadri, M. Joshaghani, E. Rafiee, Appl. Catal. A Gen. 362 (2009) 163.
[8] G. Herve, G. Sartori, G. Enderlin, G. Mackenzie, C. Len, RSC Adv. 4
1
H NMR (400 MHz, CDCl
3
):
d
H
¼ 7.72e7.68 (d, J ¼ 16 Hz,
(2014) 18558.
1
6
2
H), 7.48e7.46 (d, J ¼ 8 Hz, 2H), 7.24e7.22 (d, J ¼ 8 Hz, 2H),
.46e6.42 (d, J ¼ 16 Hz, 1H), 4.26e4.23 (t, J ¼ 13.2 Hz, 2H),
.42 (s, 3H), 1.77e1.70 (quint, J ¼ 6.4 Hz, 2H), 1.51e1.45
[9] A. Ghorbani-Choghamarani, B. Tahmasbi, F. Arghand, S. Faryadi, RSC
Adv. 5 (2015) 92174.
[
[
[
[
[
10] C. Woo Lim, I.S. Lee, Nano Today 5 (2010) 412.
11] J. Govan, Y.K. Gun'ko, Nanomaterials 4 (2014) 222.
12] V. Polshettiwar, R.S. Varma, Green Chem. 12 (2010) 743.
13] M. Hajjami, B. Tahmasbi, RSC Adv. 5 (2015) 59194.
14] M. Hajjami, A. Ghorbani-Choghamarani, R. Ghafouri-Nejad,
B. Tahmasbi, New J. Chem. 40 (2016) 3066.
15] S. Shylesh, V. Schunemann, W.R. Thiel, Angew. Chem. Int. Ed. 49
(2010) 3428.
16] A. Ghorbani-Choghamarani, Z. Darvishnejad, B. Tahmasbi, Inorg.
Chim. Acta. 435 (2015) 223.
(
sixt, J ¼ 7.6 Hz, 2H), 1.03e0.99 (t, J ¼ 7.6 Hz, 3H) ppm.
3
.4.6. Butyl 3-(4-methoxyphenyl)acrylate
1
H
NMR (400 MHz, CDCl
3
):
d
H
¼
7.69e7.65 (d,
[
[
[
J ¼ 15.6 Hz, 1H), 7.52e7.50 (d, J ¼ 6.8 Hz, 2H), 6.94e6.93 (d,
J ¼ 7.2 Hz, 2H), 6.37e6.33 (d, J ¼ 16 Hz, 1H), 4.25e4.22 (t,
J ¼ 6.4 Hz, 2H), 3.86 (s, 3H), 1.74e1.68 (quint, J ¼ 6.8 Hz, 2H),
17] V. Polshettiwar, R. Luque, A. Fihri, H. Zhu, M. Bouhrara, J.M. Basset,
Chem. Rev. 111 (2011) 3036.
1
.52e1.43 (sixt, J ¼ 8 Hz, 2H), 1.02e0.98 (t, J ¼ 7.6 Hz, 3H)
ppm.
[18] A. Rostami, B. Tahmasbi, A. Yari, Bull. Korean Chem. Soc. 34 (2013)
521.
19] A. Ghorbani-Choghamarani, B. Tahmasbi, New J. Chem. 40 (2016)
205.
1
[
4
. Conclusion
1
[
[
20] W. Zhang, X. Chen, T. Tang, E. Mijowska, Nanoscale 6 (2014) 12884.
21] M. Nikoorazm, A. Ghorbani-Choghamarani, N. Noori, Appl. Orga-
nometal. Chem. 29 (2015) 328.
In conclusion, an efficient heterogeneous nanocatalyst
PdeSMU-MNPs) was synthesized by immobilization of
(
[22] Y.Y. Peng, J. Liu, X. Lei, Z. Yin, Green. Chem. 12 (2010) 1072.
palladium on modified Fe nanoparticles. This catalyst
3
O
4
[23] A. Ghorbani-Choghamarani, B. Tahmasbi, P. Moradi, Appl. Organo-
metal. Chem. 30 (2016) 422.
was characterized by FT-IR, SEM, TEM, XRD, VSM and ICP-
OES techniques. The PdeSMU-MNPs exhibit an excellent
catalytic activity, high reusability and air or moisture sta-
bility for the Suzuki and Heck reactions. This methodology
is effective for a wide range of aryl halide including Cl, Br
and I. Also, the catalyst can be recovered and recycled over
eight times and used without any significant loss of its
activity or palladium leaching.
[24] A. Ghorbani-Choghamarani, F. Nikpour, F. Ghorbani, F. Havasi, RSC
Adv. 5 (2015) 33212.
[25] M. Samarasimhars eddy, G. Prabhu, T.M. Vishwanatha,
V.V. Sureshbabu, Synthesis 45 (2013) 1206.
[
[
26] Y.P. Wang, H.M. Lee, J. Organomet. Chem. 791 (2015) 90.
27] N. Iranpoor, H. Firouzabadi, A. Tarassoli, M. Fereidoonnezhad, Tet-
rahedron 66 (2010) 2415.
[
[
28] T. Chen, J. Gao, M. Shi, Tetrahedron 62 (2006) 6289.
29] M. Nasrollahzadeh, S.M. Sajadi, M. Maham, J. Mol. Catal. A Chem.
396 (2015) 297.
[
[
[
[
[
30] V.W. Faria, D.G.M. Oliveira, M.H.S. Kurz, F.F. Goncalves,
C.W. Scheeren, G.R. Rosa, RSC Adv. 4 (2014) 13446.
31] M. Nasrollahzadeh, A. Azarian, M. Maham, A. Ehsani, J. Ind. Eng.
Chem. 21 (2015) 746.
32] Q. Xu, W.L. Duan, Z.Y. Lei, Z.B. Zhu, M. Shi, Tetrahedron 61 (2005)
11225.
Acknowledgements
This work was supported by the research facilities of
Ilam University, Ilam, Iran.
33] Q. Du, W. Zhang, H. Ma, J. Zheng, B. Zhou, Y. Li, Tetrahedron 68
(
2012) 3577.
34] A. Modak, J. Mondal, M. Sasidharan, A. Bhaumik, Green Chem. 13
2011) 1317.
References
(
[
1] J.T. Guan, X.M. Song, Z.Y. Zhang, B.M. Wei, Z.Q. Dai, Appl. Organo-
[35] S. Singha, M. Sahoo, K.M. Parida, Dalton Trans. 40 (2011) 7130.
[36] H.A. Patel, A.L. Patel, A.V. Bedekar, Appl. Organometal. Chem. 29
(2015) 1.
metal. Chem. 29 (2015) 87.
[
[
[
2] C. Xu, H.-M. Li, Z.-Q. Wang, W.-J. Fu, Inorg. Chim. Acta 423 (2014) 11.
3] A.-R. Hajipour, F. Raiee, J. Iran. Chem. Soc. 12 (2015) 1177.
4] A.R. Hajipour, F. Raiee, J. Iran. Chem. Soc. 12 (2015) 1177.
Please cite this article in press as: A. Ghorbani-Choghamarani, et al., PdeS-methylisothiourea supported on magnetic nano-
particles as an efficient and reusable nanocatalyst for Heck and Suzuki reactions, Comptes Rendus Chimie (2016), http://
dx.doi.org/10.1016/j.crci.2016.06.010