Preparation of carbon supported CuPd nanoparticles as novel heterogeneous catalysts for the reduction of nitroarenes and the phosphine-free Suzuki-Miyaura coupling reaction

Article abstract of DOI:10.1039/c4nj01788a

This paper reports on the synthesis and use of CuPd nanoparticles supported on carbon, as highly active catalysts for the reduction of nitroarenes and Suzuki-Miyaura coupling reactions. The catalyst was characterized using the powder XRD, SEM, ICP-AES and EDS techniques. This method has the advantages of high yields, elimination of homogeneous catalysts, simple methodology and easy work up. Catalytic efficiency remains unaltered even after several repeated cycles.

Full text of DOI:10.1039/c4nj01788a

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Preparation of carbon supported CuPd nanoparticles as a novel
heterogeneous catalyst for reduction of nitroarenes and phosphine-free
Suzuki-Miyaura coupling reaction
Mahmoud Nasrollahzadeh,* Babak Jaleh and Ali Ehsani
This paper reports on the synthesis and use of C/CuPd bimetallic NPs as heterogeneous catalysts for the phosphine-free Suzuki-
Miyaura coupling and reduction of nitroarenes.

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DOI: 10.1039/C4NJ01788A
www.rsc.org/xxxxxx | XXXXXXXX
ARTICLE TYPE
Preparation of carbon supported CuPd nanoparticles as a novel
heterogeneous catalyst for reduction of nitroarenes and phosphine-free
Suzuki-Miyaura coupling reaction
5
Mahmoud Nasrollahzadeh,a* Babak Jalehb and Ali Ehsania
aDepartment of Chemistry, Faculty of Science, University of Qom, PO Box 37185-359, Qom, Iran. E-mail: mahmoudnasr81@gmail.com; Fax: +98 25
32103595; Tel: +98 25 32850953
bPhysics Department, Bu-Ali Sina University, Hamedan, Iran
10
Received (in XXX, XXX) Xth XXXXXXXXX 200X, Accepted Xth XXXXXXXXX 200X
First published on the web Xth XXXXXXXXX 200X
DOI: 10.1039/b000000x
15
This paper reports on the synthesis and use of CuPd
nanoparticles supported on carbon, as a highly active catalyst for
reduction of nitroarenes and SuzukiꢀMiyaura coupling reactions.
The catalyst was characterized using the powder XRD, SEM,
ICPꢀAES and EDS techniques. This method has the advantages
agglomeration. The use of carbon (C) as support for transition
metal catalysts has recently been demonstrated.6
In the course of our studies on the development of
60 heterogeneous catalysts,7 herein, we report a simple and efficient
synthesis of a carbon supported CuPd bimetallic NPs and their
application as a recoverable catalyst in ligandꢀfree Suzukiꢀ
Miyaura coupling reaction and reduction of nitroarenes. More
importantly, the synthesized catalyst presented good catalytic
65 property, and could be easily separated from the reaction mixture
and reused many times with no loss of activity, indicative of a
potential application in industry.
20 of high yields, elimination of homogeneous catalysts, simple
methodology and easy work up. Catalytic efficiency remains
unaltered even after several repeated cycles.
Introduction
The palladiumꢀcatalyzed SuzukiꢀMiyaura coupling reaction
25 constitutes a powerful, versatile and popular methodology for Cꢀ
C bond formation.1ꢀ3 This reaction has become one of the most
influential synthetic methods for the synthesis of biaryl
compounds, which constitute a wide range of natural products,
biologically active molecules and pharmaceuticals.1ꢀ3
Results and Discussion
Carbon was prepared via pyrolysis of tar at 110 ºC and was
characterized with XRD and SEM methods.
Typical SEM image of carbon powder is shown in Figure 1.
As it is clear, the obtained carbon powder has a porous structure
and nonuniform morphology, comprising differently shaped
70
30
These reactions are generally catalyzed by soluble palladium
(Pd) complexes with phosphine various ligands in toxic organic
solvents.1ꢀ3 However, transitionꢀmetal palladium and phosphine
ligands are expensive owing to the cost of chemical
transformation in synthetic procedures and were limited in
75 structures.
35 industrial applications. Therefore, the development of mild,
highly efficient and environmentally benign method for the
ligandꢀfree SuzukiꢀMiyaura coupling reactions still remains as an
active research area. Additionally, the recovery and reusability of
the catalyst represents
a key issue for the sustainable
40 development of any catalytic process. Catalyst separation is a
critically important issue, and catalysts that are active but difficult
to recycle/recover from the reaction mixture are generally not
preferred in the chemical industry. This shift has been driven by
the need to develop improved and more efficient processes that
45 are also economically viable. Thus, we decided to concentrate on
developing an efficient heterogeneous catalyst that is air and
moisture stable and highly active.
In recent years, metal nanoparticles (NPs) have attracted a
great attention as heterogeneous catalysts due to their interesting
50 structure and high catalytic activities.4 It is wellꢀknown that nanoꢀ
sized metal particles have a high surfaceꢀtoꢀvolume ratio that can
dramatically enhance the interaction between reactants and
catalysts.5 Additionally, nanocatalysis can make the products
easily removable from the reaction mixtures and make the
55 catalysts recyclable. The agglomeration of metal nanoparticles is
inevitable. An ideal support is needed to decrease nanoparticles
Figure 1. SEM image of carbon.
In Figure 2, the diffraction peaks at 26.4° and 43.5° can be
80 attributed to the graphite structures (002) and (100). The broad
band near (002) peak is also observed, implying presence of
amorphous carbon in the sample. By combining SEM and XRD
results, it can be therefore inferred that this sample is contained of
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a highly disordered materials in the form of amorphous carbon
that accompanied with a mount of crystalline structures in
graphite form. Therefore, the crystallites in the C samples have
intermediate structures between graphite and amorphous state.
100
(a)
90
80
70
60
50
40
30
20
10
0
10
15
20
25
30
35
40
45
50
2 Theta (degree)
5
Figure 2. XRD pattern of carbon.
40 Figure 4. SEM image of C/Cu NPs.
Cu NPs were synthesized through arc discharge of copper
electrodes under inert atmosphere (Ar as carrier gas). In this
method, a 20 V DC voltage and 90 A current are applied between
10 two metallic copper electrodes. Both the anode and cathode were
Cu, 1.5 cm in diameter and 1.0 cm in length. Then Cu NPs were
supported on carbon powder particles and collected in powder
form on a surface filter element by a vacuum pump. The
schematic of the experimental setup is shown in Figure 3. C/Cu
15 NPs were characterized using the powder XRD, SEM and EDS.
Figure 5. EDS spectrum of C/Cu NPs.
3000
(b)
Figure 3. Schematic of the experimental setup.
Cu
2500
2000
1500
1000
500
SEM was recorded to understand the morphological changes
occurring on the surface of the carbon. Figure 4 shows an SEM
20 image of C/Cu NPs. As expected, after copper loading on the
surface of the carbon, a change in morphology of the carbon
surface is observed.
The elemental composition of C/Cu NPs was also analyzed by
the Energy Dispersive Xꢀray Spectroscopy (EDS). This technique
25 further confirmed that C/Cu NPs was composed of copper and
carbon which suggests the immobilization of the metal on the
surface of the carbon (Figure 5).
Cu
50
Cu
0
10
20
30
40
60
70
80
In Figure 6, three diffraction peaks at 2θ values of 43.4°, 50.5°
and 74.1° corresponding to (111), (200) and (220) planes of
30 copper were observed that can be indexed to standard XRD data
for copper (JCPDS 04ꢀ0836). The results showed that the copper
nanopowder consisted of a faceꢀcentered cubic (fcc) structure.
Also, in the XRD pattern of C/Cu NPs, copper nanoparticle
diffraction peaks are so intense that those peaks related to carbon
35 structures are not observable. Moreover, no diffraction peaks
were observed for copper oxide indicating the formation of pure
copper nanoparticles. EDS result (Figure 5) was proved this
result.
2 Theta (degree)
45
Figure 6. XRD pattern of C/Cu NPs.
C/CuPd bimetallic NPs were fabricated in twoꢀsteps using a
simple process. Palladium nanoparticles were overlaid on the
surface of C/Cu NPs via a simple dropꢀdrying process by
50 dropping PdCl2 solution onto C/Cu NPs films and drying them at
room temperature. C/CuPd bimetallic NPs were characterized
using the powder XRD, SEM and EDS.
Typical SEM image of the CuꢀPd bimetallic nanoparticles is
shown in Figure 7. As it is clear, bimetallic nanoparticles show
55 morphology like rectangular structures.
2
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20 Figure 9. XRD pattern of C/CuPd bimetallic NPs.
Evaluation of the catalytic activity of C/CuPd bimetallic NPs
through the reduction of nitroarenes
Amines and their derivates act as important synthones in
organic chemistry. They are widely used as key intermediates in
25 dye, pharmaceutical and pesticide industry.9 Thus, the catalytic
behaviour of the C/CuPd bimetallic NPs was studied for the
reduction of nitroarenes with NaBH4.
Initial studies were performed upon the reduction of pꢀ
nitrophenol with NaBH4 as a model reactions using C/CuPd
30 bimetallic NPs (10 mg) as the catalyst in EtOH:H2O (v/v = 1:2, 3
mL) at 60 ºC for 1.5 h (Table 1). As shown in Table 1, no product
was obtained in the absence of the catalyst (Table 1, entry 1),
indicating that the catalyst was necessary for the reaction. Then
the reaction was carried out with different catalysts and the
35 results are shown in Table 1. Among the catalysts tested, C/CuPd
bimetallic NPs was found to be the most effective catalyst since it
gave the highest yield of product (Table 1, entry 2).
Figure 7. The Scanning electron microscope image of samples after
deposition of Pd.
Table 1. Reduction of pꢀnitrophenol with different catalysts.a
Entry
Catalyst
Yieldb (%)
5
We used EDS to determine chemical composition of C/CuPd
bimetallic NPs. In the EDS spectrum of C/CuPd bimetallic NPs
(Figure 8), peaks related to C, Cu and Pd were observed.
1
2
3
4
ꢀ
0.0
93
70
75
C/CuPd bimetallic NPs
C/Cu NPs
RGO/Cu NPs7g
40 aReaction condition: 1.0 equiv of 4ꢀnitrophenol, 2.0 equiv of terminal
NaBH4, 10 mg of catalyst and EtOH:H2O (v/v = 1:2, 3 mL), 60 °C, 1.5 h.
bIsolated yield.
In an attempt to extend the application of C/CuPd bimetallic
45 NPs, we studied the reduction of structurally diverse nitro
compounds. Table 2 confirmed that the catalyst exhibited
excellent activities for the reduction of nitroarenes containing
various electronꢀdonating or electronꢀwithdrawing groups. The
present method was highly chemoselective in the presence of
50 sensitive functional groups such as halogens and ꢀCOOH. The
halogen functional groups remained intact under the reaction
conditions (Table 2, entries 11 and 12). In all cases, amines were
found to be the only product of the reactions and the usual side
products of nitro reduction were not observed in the final product
55 mixtures. In addition, the steric hindrance of the substituent did
not influence the product yield in the reduction of nitroarenes
using C/CuPd bimetallic NPs (Table 2, entries 6 and 9).
Unfortunately we observed that the present method is not
amenable for aliphatic nitro compounds.
Figure 8. EDS spectrum of C/CuPd bimetallic NPs.
10
Figure 9 represents the XRD patterns of C/CuPd bimetallic
NPs. Examining the area between 20ꢀ120° 2θ showed the
presence of copper and palladium. As shown in Figure 9, that the
pattern of the PdꢀCu alloy, exhibited characteristic diffraction
peaks of (110), (111), (222) and (3 2 14) at 2θ = 34.1°, 43.5°, 90°
15 and 117°, respectively (ICDD card#07ꢀ0138) and sharp peaks of
the (200), (220) and (222) at 2θ = 50°, 74.3°, 95.2° diffractions
peaks show that the Cu segment has cubic structure (ICDD card #
04ꢀ0836).8
60
65
70
75
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Table 2. Reduction of various nitroarenes using C/CuPd bimetallic NPs.a
corresponding products in high yields under ligandꢀfree and
aerobic conditions (Table 3, entries 1ꢀ8). Furthermore, in an
attempt to extend the application of the designed catalyst, we
screened the SuzukiꢀMiyaura coupling reactions of representative
40 aryl bromides with phenylboronic acid. The reaction of these aryl
bromides gave excellent yields in 5 h (Table 3, entries 9ꢀ13).
Entry
1
Substrate
Product
Yield b (%)
92
2
3
95 (92)c
80
Table 3. SuzukiꢀMiyaura coupling reaction of different aryl iodides with
phenylboronic acid.a
HO
NH2
4
5
90
88
45
Entry Aryl iodide
1
Product
Time (h)
3
Yieldb (%)
93, 90c
6
86
2
3
4
3
3
3
90
93
91
7
8
9
88
95
91
5
6
7
3
3
3
91
88
86
10
11
12
78
90
90
13
14
15
82
94
83
8
3
92
I
S
9
5
5
5
5
91
88
91
90
aReaction condition: 1.0 equiv of nitrobenzene, 2.0 equiv of NaBH4, 10
mg of catalyst and EtOH:H2O (v/v = 1:2, 3 mL), 60 °C, 1.5 h. b Yields are
after workꢀup. cYield after the 5th cycle.
10
11
12
5
The structure of the primary amines was in agreement with
their IR and spectra. The appearance of NH2 stretching bands in
the IR spectra, were evidence for the formation of primary
10 amines. All of the products are known and were identified by
comparison of their physical and spectral data with those of
authentic samples.10 All melting points were compared
satisfactorily with those reported in the literature.
13
5
90
aReaction conditions: Aryl halide (1.0 mmol), phenylboronic acid (1.5
mmol), C/CuPd bimetallic NPs (0.05 g), K2CO3 (3.0 mmol) and EtOH
(5.0 mL), reflux. bIsolated yield. cYield after the 5th cycle.
15 Evaluation of the catalytic activity of C/CuPd bimetallic NPs
through the ligand-free Suzuki-Miyaura coupling reaction
Due to the importance of SuzukiꢀMiyaura coupling reaction in
synthetic organic chemistry for the manufacture of CꢀC bond, we
next turned our attention to applying C/CuPd bimetallic NPs to
20 the SuzukiꢀMiyaura coupling reaction of aryl halides with
phenylboronic acid. The desired products are obtained in good to
excellent yields.
We initially selected iodobenzene and phenylboronic acid as a
model reaction. As expected, no target product could be detected
25 in the absence of catalyst. The reactivity of the C/CuPd bimetallic
NPs in EtOH in the presence of various bases (K2CO3, Na2CO3
and CsF) was investigated. Among the tested bases, K2CO3 was
found to be superior for the highest yield of product. The best
result was obtained with iodobenzene (1.0 mmol), phenylboronic
30 acid (1.5 mmol), catalyst (0.05 g), K2CO3 (3.0 mmol), and EtOH
(5.0 mL) under reflux conditions for 3 h, which obtained the
product in an excellent yield (93%). We have examined the
coupling reaction of phenylboronic acid with various aryl iodides
containing electronꢀwithdrawing or electronꢀdonating groups. As
35 shown in Table 3, aryl iodides were converted into the
50 Catalyst recyclability
The reusability of the catalyst is a very important theme,
especially for commercial applications. Therefore, the recovery
and reusability studies of the catalyst were done by conducting
the reaction of iodobenzene with phenylboronic acid (Suzukiꢀ
55 Miyaura reaction). To evaluate the reusability of C/CuPd
bimetallic NPs, the catalyst after completion of the reaction was
separated and was washed with ethanol and water, dried and the
recycled catalyst was saved for the next reaction. Not much
decrease in the activity of catalyst was observed even after five
60 cycles (Table 3, entry 1). The reusability of the catalyst was also
studied for the reduction of pꢀnitrophenol under the present
reaction conditions. The catalytic activity did not decrease
considerably after five catalytic cycles (Table 2, entry 2).
To check the heterogeneity of catalyst, which is an important
65 factor, the phenomenon of leaching was studied by ICPꢀAES
analysis of the resulting reaction solution mixture. Very low
palladium contamination was observed during these experiments.
It was shown that less than 0.2% of the total amount of the
4
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original palladium species was lost into solution during the
course of a reaction. Indeed, 12% of the copper (based on the
initial amount introduced) was detected in the filtered solution.
Conclusion
C/CuPd NPs were prepared by oneꢀpot process. Deposition of
Pd on surface of C/Cu NPs was accomplished via a simple dropꢀ
drying process by dropping 50 mL PdCl2 solution onto 50 mL of
aqueous solution of C/Cu NPs (0.5 g in 100 mL). In order to
5
In summary, we have established that the C/CuPd bimetallic 70 extract the dispersed nanoparticles, the solution was centrifuged
nanoparticles are as highly efficient, stable and recyclable
catalysts for the phosphineꢀfree SuzukiꢀMiyaura coupling and
reduction of nitroarenes. The advantages of this environmentally
benign and safe protocol include a simple reaction setup, and
several times, dispersed on a glass substrate and drying them at
room temperature. The PdCl2 solution was prepared by
ultrasonically solving a 0.02 g PdCl2 powder (5 N), 99.9 mL DI
water and 0.1 mL HCl.
10 easy workꢀup, elimination of toxic ligands and homogeneous
catalysts and high yields. Moreover, the catalyst could be reused
for four consecutive cycles without a noticeable loss of its
catalytic activity. These advantages make the process highly
valuable from the synthetic and environmental points of view.
15
75
General procedure for reduction of nitroarenes
The reduction of nitroarenes was carried out in a 25 roundꢀ
bottom flask. In a typical procedure, 10 mg of catalyst was added
in 3.0 mL of EtOH:H2O (v/v = 1:2). Then, nitrobenzene (1.0
80 mmol), NaBH4 (2.0 equiv.), and a small stirring bar were added
to the flask. The flask containing reaction mixture was placed in
an oil bath (60 °C) and stirred under air atmosphere. After
completion of reaction, the mixture was cooled to room
temperature and extracted with EtOAc. The combined extracts
Experimental
Apparatus and analysis
Highꢀpurity chemical reagents were purchased from the Merck
and Aldrich chemical companies. All materials were of
20 commercial reagent grade. Melting points were deterꢀmined in 85 were dried over anhydrous MgSO4 and the solvent was removed
open capillaries using a BUCHI 510 melting point apparatus and
are uncorrected. 1H NMR and 13C NMR spectra were recorded on
a Bruker Avance DRXꢀ400 spectrometer at 400 and 100 MHz,
respectively. FTꢀIR spectra were recorded on a Nicolet 370 FT/IR
25 spectrometer (Thermo Nicolet, USA) using pressed KBr pellets.
The element analyses (C, H, N) were obtained from a Carlo
ERBA Model EA 1108 analyzer carried out on PerkinꢀElmer
240c analyzer. Xꢀray diffraction (XRD) measurements were
carried out using a Philips powder diffractometer type PW 1373
under vacuum and the residue was subjected to gel permeation
chromatography to afford pure products.10
General procedure for Suzuki-Miyaura coupling reaction
In a typical reaction, a mixture of aryl halides (1.0 mmol),
phenylboronic acid (1.5 mmol), K2CO3 (3.0 mmol), EtOH (5.0
mL) and catalyst (0.05 g) was stirred under reflux conditions for
appropriate time. After completion of the reaction (as monitored
by TLC), the reaction mixture was cooled to room temperature,
90
30 goniometer (Cu Kα = 1.5406 A˚). The scanning rate was 2º/min 95 the solid was filtered out, and washed with ethanol and the filtrate
in the 2θ range from 10 to 80˚. Scanning electron microscopy
(SEM) was performed on a Cam scan MV2300. EDS using EDS
(S3700N) was utilized for chemical analysis of prepared
nanostructures. Metal content was estimated by inductively
was evaporated under reduced pressure. The residue was
extracted three times with diethyl ether and water. The organic
phase was dried over MgSO4, filtered and the solvent was
removed under reduced pressure and the residue was subjected to
35 coupled plasma atomic emission spectroscopy (ICPꢀAES) 100 gel permeation chromatography to afford pure products. All the
analysis conducted on a Perkin Elmer emission spectrometer.
products are known compounds and the spectral data and melting
points were identical to those reported in the literature.11
Preparation of amorphous carbon from tar
Carbon has been synthesized by pyrolysis of tar. The tar was
40 put in a tubular furnace at room temperature. A flow of N2 was 105
continuously passed over the furnace and the temperature was
raised until 800 °C at a rate of 15 °C minꢀ1. The sample remained
at 800 °C by 2 h. Then sample cooled slowly until room
temperature. The resulting sample becomes black and will be
45 referred to as C.
Acknowledgement
We gratefully acknowledge the Iranian Nano Council and
University of Qom for the support of this work.
References
110 1 (a) N. Miyaura, A. Suzuki, Chem. Rev., 1995, 95 (7), 2457;
(b) A. Fihri, M. Bouhrara, B. Nekoueishahraki, J. M. Basset,
Chem. Soc. Rev., 2011, 40, 5181; (c) C. C. C. Johansson
Seechurn, M. O. Kitching, T. J. Colacot and V. Snieckus, Angew.
Chem. Int. Ed., 2012, 51, 5062.
Preparation of C/Cu NPs
Carbon/Copper (C/Cu) composite powder was prepared by arc
discharge method. Ar as carrier gas with a low flow rate was
50 passed through the vessel containing carbon powder and directed 115 2 I. Favier, D. Madec, E. Teuma, M. Gomez, Curr. Org. Chem.,
carbon particles toward the discharge chamber. In this chamber,
two Cu rods (diameter: 1.5 cm and length: 1 cm) were used as
electrodes. The position of the bottom electrode was fixed,
whereas the top electrode was adjustable. The electrode gap was
2011, 15, 3127.
3 (a) R. Chinchilla, C. Nájera, Chem. Rev., 2007, 107, 874; (b)
R. H. Heck, Palladium Reagents for Organic Synthesis;
Academic Press, New York, 1985; (c) J. Hassan, M. Sévignon, C.
55 set to 2ꢀ3 mm at the beginning of the experiment and a high 120 Gozzi, E. Schulz, M. Lemaire, Chem. Rev., 2002, 102, 1359.
current (90 A) and a low voltage (20 V) was established between
the electrodes. Then, the electrode gap was decreased until
electrical discharge occurred between the electrodes resulting in
evaporation of the electrode material and formation of Cu
4 (a) S. Wei, Z. Dong, Z. Ma, J. Sun, J. Ma, Catal. Commun.,
2013, 30, 40; (b) J. Hassan, M. Sévignon, C. Gozzi, E. Schulz, M.
Lemaire, Chem. Rev., 2002, 102, 1359; (c) M. B. Gawande, P. S.
Branco and R. S. Varma, Chem. Soc. Rev., 2013, 42, 3371; (d) D.
60 nanoparticles. Therefore, when carbon powder was transmitted 125 Wang, D. Astruk, Chem. Rev., 2014, 114 (14), 6949; (e) M. B.
through the electrodes, Cu nanoparticles were supported on
carbon powder particles. Then, final products were collected in
powder form on a surface filter element by a vacuum pump.
Gawande, S. N. Shelke, R. Zboril and R. S. Varma, Acc. Chem.
Res. 2014, 47, 1338; (f) R. J. White, R. Luque, V. Budarin, J. H.
Clark, D. J. Macquarrie, Chem. Soc. Rev. 2009, 38, 481; (g) J. M.
Campelo, D. Luna, R. Luque, J. M. Marinas, A. A. Romero,
130 ChemSusChem, 2009, 2, 18.
65 Preparation of C/CuPd NPs
This journal is © The Royal Society of Chemistry [year]
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Page 7 of 7
New Journal of Chemistry
View Article Online
DOI: 10.1039/C4NJ01788A
5 (a) F. Benaskar, V. Engels, N. Patil, E. V. Rebrov, J.
Meuldijk, V. Hessel, L. A. Hulshof, D. A. Jefferson, J. C.
Schouten, A. E. H. Wheatley, Tetrahedron Lett., 2010, 51, 248;
(b) Y. Isomura, T. Narushima, H. Kawasaki, T. Yonezawa and Y.
Obora, Chem. Commun., 2012, 48, 3784.
5
6 R. Narayanan, M. A. ElꢀSayed, J. Catal., 2005, 234, 348.
7 (a) M. Nasrollahzadeh, M. Maham, A. Ehsani and M. Khalaj,
RSC Adv., 2014, 4, 19731; (b) M. Nasrollahzadeh, A. Rostamiꢀ
Vartouni, A. Ehsani, M. Moghadam, J. Mol. Catal. A Chem.,
10 2014, 387, 123; (c) M. Nasrollahzadeh, A. Zahraei, A. Ehsani and
M. Khalaj, RSC Adv., 2014, 4, 20351; (d) M. Nasrollahzadeh, F.
Babaei, S. M. Sajadi, A. Ehsani, Spectrochim. Acta A, 2014, 132,
423; (e) M. Nasrollahzadeh, RSC Adv., 2014, 4, 29089; (f) M.
Nasrollahzadeh, New J. Chem., 2014, 38, 5544; (g) P. Fakhri, B.
15 Jaleh, M. Nasrollahzadeh, J. Mol. Catal. A Chem., 2014, 383-
384, 17; (h) M. Nasrollahzadeh, A. Ehsani, M. Maham, Synlett,
2014, 25, 505; (i) M. Nasrollahzadeh, S. M. Sajadi, M. Khalaj,
RSC Adv., 2014, 4, 47313; (j) M. Nasrollahzadeh, M. Maham, M.
M. Tohidi, J. Mol. Catal. A Chem., 2014, 391, 83; (k) M.
20 Nasrollahzadeh, A. Ehsani, A. RostamiꢀVartouni, Ultrason.
Sonochem., 2014, 21, 275; (l) M. Nasrollahzadeh, S. M. Sajadi,
A. RostamiꢀVartooni, M. Khalaj, RSC Adv., 2014, 4, 43477.
8 B. Jaleh, A. Omidvar Dezfuli, T. Madrakian and M. Ahmadi,
Iran. J. Phys. Res., 2012, 12, 39.
25 9 S. Suwanprasop, T. Nhujak, S. Roengsumran, A. Petsom, Ind.
Eng. Chem. Res., 2004, 43, 4973.
10 (a) A. K. Shil, D. Sharma, N. R. Guha, P. Das, Tetrahedron
Lett. 2012, 53, 4858S; (b) B. Sreedhar, D. Keerthi Devi, Deepthi
Yada, Catal. Commun., 2011, 12, 1009; (c) C. Feng, H.ꢀY.
30 Zhang, N.ꢀZ. Shang, S.ꢀT. Gao, C. Wang, Chin. Chem. Lett.,
2013, 24, 539.
11 (a) P. K. Mandali, D. K. Chand, Catal. Commun., 2013, 31,
16; (b) T. S. A. Heugebaert, S. De Corte, T. Sabbe, T. Hennebel,
W. Verstraete, N. Boon, C. V. Stevens, Tetrahedron Lett., 2012,
35 53, 1410; (c) Y.ꢀY. Peng, J. Liu, X. Lei, Z. Yin, Green Chem.,
2010, 12, 1072.
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