Polystyrene-supported ionic liquid copper complex: A reusable catalyst for one-pot three-component click reaction

Article abstract of DOI:10.1016/j.apcata.2015.07.015

Copper(II) complex of 1,2-bis(4-pyridylthio)ethane immobilized on polystyrene was a used as a highly stable, active, reusable and green catalyst for click synthesis of 1,2,3-triazoles via one-pot three-component reaction of organic halides, sodium azide a

Full text of DOI:10.1016/j.apcata.2015.07.015

Accepted Manuscript
Title: Polystyrene-supported ionic liquid copper complex: A
reusable catalyst for one-pot three-component click reaction
Author: Mahnaz Tavassoli Amir Landarani-Isfahani Majid
Moghadam Shahram Tangestaninejad Valliolah Mirkhani Iraj
Mohammadpoor-Baltork
PII:
S0926-860X(15)30067-3
DOI:
Reference:
http://dx.doi.org/doi:10.1016/j.apcata.2015.07.015
APCATA 15462
To appear in:
Applied Catalysis A: General
Received date:
Revised date:
Accepted date:
16-4-2015
5-7-2015
6-7-2015
Please cite this article as: Mahnaz Tavassoli, Amir Landarani-Isfahani, Majid
Moghadam, Shahram Tangestaninejad, Valliolah Mirkhani, Iraj Mohammadpoor-
Baltork, Polystyrene-supported ionic liquid copper complex: A reusable catalyst
for one-pot three-component click reaction, Applied Catalysis A, General
http://dx.doi.org/10.1016/j.apcata.2015.07.015
This is a PDF file of an unedited manuscript that has been accepted for publication.
As a service to our customers we are providing this early version of the manuscript.
The manuscript will undergo copyediting, typesetting, and review of the resulting proof
before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that
apply to the journal pertain.

Polystyrene-supported ionic liquid copper complex: A reusable catalyst for one-pot
three-component click reaction
Mahnaz Tavassoli, Amir Landarani-Isfahani, Majid Moghadam, Shahram Tangestaninejad,* Valliolah
Mirkhani, Iraj Mohammadpoor-Baltork
Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441, Iran
Highlights
u A copper complex was attached to chloromethylated polystyrene u A heterogeneous catalyst was
prepared u The catalyst was used for click reaction of alkynes and arylhalide u The catalyst was reusable
Abstract- Copper(II) complex of 1,2-bis(4-pyridylthio)ethane immobilized on polystyrene was a used
as a highly stable, active, reusable and green catalyst for click synthesis of 1,2,3-triazoles via one-pot
three-component reaction of organic halides, sodium azide and alkynes. The catalyst was characterized
by FT-IR spectroscopy, thermogravimetric analysis, elemental analysis, field emission scanning
electron microscopy, energy dispersive X-ray, transmissiondiversity of organic halides or α-
bromoketones and alkyl/aryl terminal alkynes, and excellent yields of the products were obtained using
0.2 mol% of catalyst. This catalytic system also showed excellent activity in the synthesis of bis-1,4-
disubsitituted 1,2,3-triazoles. Moreover, the catalyst could be recycled and reused for seven cycles
without any decrease in its catalytic activity.
Keywords: Copper complex; Click reaction; Polystyrene; Triazole; Ionic liquid.
1. Introduction
The use of transition metal complexes as catalyst has rapidly increased in recent years because of their
ability to catalyze a wide range of chemical transformations [1]. Among them, Cu(II) complexes have
long been found as effective catalysts in a variety of organic synthesis [2]. Due to their low cost, high
Corresponding authors: Tel: +98-31-37934920; fax: +98-31-36689732: E-mails: moghadamm@sci.ui.ac.ir (M.
Moghadam); stanges@sci.ui.ac.ir (S. Tangestaninejad).

activity and selectivity, these complexes have also found numerous industrial such as dehydrogenation
of alcohols [3], methanol synthesis [4], production of hydrogen in fuel cells [5].
In last decade, the copper complexes have attracted much attention in click chemistry. Click chemistry,
first introduced by the groups of Meldal [6] and Sharpless [7], describes a new concept for conducting
organic reactions. Based upon the premise, organic synthesis should take advantages such as being
modular, stereospecific, high-yielding and involving simple and green protocols [8]. Preparation of
1,2,3-triazoles by copper-catalysed alkyne-azide cycloaddition (CuAAC) has emerged as a prominent
"Click" chemistry [9-11]. 1,2,3-Triazoles have received considerable attention in synthetic organic
chemistry due to their numerous biological and pharmaceutical activities such as anti-HIV [12-14],
antibacterial [15-17], and antiallergic [18] properties.
The typical procedure for synthesis of 1,2,3-triazoles is Huisgen [3+2] cycloaddition of organic azides
and terminal alkynes in the presence of copper catalysts [19]. However, the early Huisgen
cycloaddition process required a strong electron-withdrawing substituent on either azide or alkyne and
high temperature for a prolonged period of time, and often afforded a mixture of 1,4-and 1,5-
disubstituted isomers. [20, 21] During the past decades, alternative copper-catalysed processes have
represented a significant advance in regioselective synthesis of 1,2,3-triazoles [22-25]. In the first
report of this reaction, the active Cu(I) species (CuI, CuBr) were directly formed from Cu(I) salts in the
presence of ligands [26]. Because of the instability of Cu(I) salts, Cu(I) was prepared in situ via
reduction of different Cu(II) salts (CuCl2,CuBr2 or CuSO4) [27-30] with ascorbate or by comproportion
of Cu(0) nano size clusters and Cu(II) [31, 32]. Nevertheless, the preparation of copper immobilized on
supports such silica [33], Zeolite [34] and magnetic nanoparticles have become increasingly more
profitable from easy recovery and economical viewpoints [35].
However, long reaction times, high temperature, formation of homocoupling products of alkynes
(Glaser coupling) and the use of large amounts of copper are the limitations and drawbacks of many of
the previously reported methods [36, 37]. Therefore, the development of a reusable, eco-friendly and

more convenient catalyst for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles is still in
demand.
Accordingly, various procedures for the preparation of 1,4-disubstituted 1,2,3-triazoles through the in
situ generation of organic azides have been developed. [38, 39] But, only a few reports are available
dealing with the synthesis of bis-1,4-disubstituted 1,2,3-triazoles [40].
Ionic liquids are able to dissolve and stabilize copper salts for regioselective click reaction [41]. But
they have some disadvantages such as difficulties in reusability of catalyst and product isolation, which
make them economically and environmentally unfavorable. Thus, the ionic liquid supported species
can solve this serious drawback [42].
Polystyrene as a solid support has gained substantial popularity, due to its low cost, ready availability,
chemical inertness, and facile functionalization [43].
These results in combination with our efforts on the development of efficient copper catalysts for
organic transformations [44-46], prompted us to report a green, convenient and regioselective method
for synthesis of mono- and bis-1,4-disubstituted 1,2,3-triazoles in the presence of Cu(II) immobilized
on polystyrene supported ionic liquid as a reusable catalyst (Scheme 1).
R2
N
Br
R1
R1
N
N
or
or
or
N
O
O
N
N
R2
Cu(II)-PsIL
Br
R2
R2 = alkyl or aryl
+ NaN3
+
R1
Sodium ascorbate
PEG-400
R1
or
N N
Br
N
R2
N
R2
N
Br
N
Scheme 1.Click reaction catalysed by Cu(II)-PsIL
2. Experimental Section
2.1. General Remarks

The chemicals were purchased from Fluka and Merck chemical companies. FT-IR spectra were
1
13
recorded on a JASCO 6300D spectrophotometer. H and C NMR (400 and 100 MHz) spectra were
recorded on a Bruker Avance 400 MHz spectrometer using CDCl3 as solvent. Elemental analysis was
performed on a LECO CHNS-932 analyzer. Thermogravimetric analysis (TGA) was carried out on a
Mettler TG50 instrument under air flow at a uniform heating rate of 10 oCmin-1 in the range 30-600 oC.
The scanning electron micrographs were taken on a Hitachi S-4700 field emission-scanning electron
microscope (FE-SEM). The transmission electron microscopy (TEM) was carried out on a Philips
CM10 transmission electron microscope operating at 100 kV. The copper content of the catalyst was
determined by a Jarrell-Ash 1100 ICP analysis. The CV measurements were carried out on Autolab
Potentiostat/Galvanostat101 instrument controlled by Nova 1.8 Software (Eco Chemie, Utrecht, the
Netherlands).
2.2. Synthesis of 1,2-bis(4-pyridylthio)ethane, (1)
A mixture of 4-bromopyridinium chloride (5.1 mmol, 1 g), 1,2-ethanedithiol (0.3 mL, 3.5 mmol) and
sodium hydroxide (7.7 mmol, 0.3 g) in 10 mL of DMF was stirred at 80 ˚C for 24 h. The reaction
progress was monitored by TLC (eluent diethyl ether/ methanol, 2:1). The mixture was diluted with
water and EtOAc. The aqueous layer was extracted, and evaporated under reduced pressure. Then,
residue was purified by recrystallization from ethanol to afford the pure product.
2.3. Immobilization of 1,2-bis(4-pyridylthio)ethane on polystyrene, (2)
In a round-bottomed flask equipped with a condenser and a magnetic stirrer bar, a mixture of
chloromethylated polystyrene (1), (1 g) and 1,2-bis(pyridylthio)ethane, (0.1 g, 0.4 mmol) in DMF (10
mL) was stirred at 80 ˚C for 24 h. Then, the reaction mixture was filtered and the resulting solid
washed with ethanol (2 × 20 mL) and dried in a vacuum oven at 50 oC.
2.4. Synthesis of polystyrene supported ionic liquid (PsIL), (3)

To a slurry of polystyrene-bound 1,2-bis(4-pyridylthio)ethane (2) (1 g) in toluene (10 mL) was added
methyl iodide (5 ml) and stirred at room temperature for 6 h. Then, the mixture was filtered; the
precipitate was washed with ethanol (2 × 20 mL) and dried in a vacuum oven at 50 oC.
2.5. Immobilization of Cu(II) triflate on PsIL, (Cu(II)-PsIL), (4)
A mixture of Cu(OTf)2 (15 mg) and PsIL, (3), (1 g) in ethanol (10 mL) was refluxed for 24 h. The
reaction mixture was filtered; the solid material was washed with ethanol (2 × 20 mL) and then dried in
a vacuum oven at 40 °C to afford the Cu-PsIL catalyst.
2.6. Electrochemical studies
The cyclic voltammograms (CVs) were recorded at 25 °C using a three-electrode assembly including,
an Ag/AgCl (3 M KCl) reference electrode, a large area Pt plate as the counter electrode (70 times
larger than that of the working electrode), and the modified glassy carbon electrode (GCE) disk as the
working. Toward the study of electrochemical behavior of Cu(II)-PSIL, the catalyst was casted on the
GCE surface. CVs were recorded in acetate buffer electrolyte (pH= 5) at a potential scan rate of 10
mVs-1.
2.7. General procedure for synthesis of 1,2,3-triazoles by the reaction of benzyl bromides, alkynes and
sodium azide
A mixture of Cu(II)-PsIL (0.2 mol%, 10 mg) and sodium ascorbate (5 mg) in PEG-400 (2 mL) was
allowed to stirrer for 2 min and then, benzyl bromide (1 mmol), sodium azide (1.2 mmol) and
alkyl/phenyl acetylene were added to mixture. The reaction mixture was stirred at 65 ˚C and its
progress was monitored by TLC (eluent diethyl ether/ethyl acetate, 2:1). After completion of the
reaction, water and ethyl acetate were added; the catalyst was separated by filtration and washed with
acetone and water, and dried under vacuum. The organic layer was separated and dried over Na2SO4.
The products were purified by recrystallization from n-hexane/EtOAc.

2.8. General procedure for synthesis of 1,2,3-triazoles from α-bromo ketones, alkynes and sodium
azide
A mixture of Cu(II)-PsIL (0.2 mol%, 10 mg) and sodium ascorbate (5 mg) in PEG-400 (2 mL) was
allowed to stirrer for 2 min and then α-bromo ketones (1 mmol), sodium azide (1.2 mmol) and
alkyl/phenyl acetylene were added to mixture. The reaction mixture was stirred at 65 ˚C. After
completion of the reaction (as monitored by TLC, elutent diethyl ether/ethyl acetate, 1:1), water and
ethyl acetate was added to mixture and catalyst was filtered and washed with acetone and water. The
organic layer was dried over Na2SO4. If necessary, purification of product was performed by
recrystallization from n-hexane/EtOAc.
2.9. General procedure synthesis of bis 1,2,3-triazoles
A mixture of Cu(II)-PsIL (0.4 mol%, 20 mg) and sodium ascorbate (10 mg) in PEG-400 (3 mL) was
allowed to stirrer for 2 min and then 1,4 /1,2-bis(bromomethyl)benzene (1 mmol), sodium azide (2.4
mmol) and alkyl/phenyl acetylene were added to mixture. The reaction mixture was stirred at 65 ˚C.
The reaction progress was monitored by TLC. The workup of the desired product was as described
above.
3. Results and Discussion
3.1. Synthesis and characterization of Cu(II)-PsIL-
The preparation route for catalyst is shown in Scheme 2. The ligand, 1,2-bis(4-pyridylthio)ethane (A)
was prepared by the reaction of 4-bromopyridinium chloride with 1,2-ethandithiol. Reaction of this
ligand with chloromethylated polystyrene, PS, afforded the supported ligand, B. Then, B was reacted
with methyl iodide in to prepare the polystyrene supported ionic liquid (PsIL). These processes were
monitored by elemental analysis, FT-IR and thermogravimetric analysis (TGA). The nitrogen content
of the PsIL, measured by CHNS analysis, showed a value of about 1.5%. Based on this value, the
amount of IL supported on the polystyrene is about 0.53 mmolg-1.

N
N
Br
Ps
CH2Cl
SH
S
S
NaOH
S
S
+
DMF, 80 oC, 24 h
DMF, 80 oC, 24 h
HS
N+
H
Cl-
N+
N
Cl-
1
CH2
Ps
Me
N+
Me
I-
I-
N+
2
Cu(OTf)2
OTf
S
S
MeI
S
S
Cu
Toluene, rt, 12 h
EtOH, reflux, 24 h
OTf
N+
N+
Cl-
Cl-
CH2
CH2
Ps
Ps
PsIL
3
Cu(II)-PsIL
4
Scheme 2. The preparation route for catalyst
The FT-IR spectrum of the PsIL showed characteristic band of pyridinium ring at 1645 cm-1 (C=N). In
addition, the characteristic band at 1160 cm-1 (C-S) was observed, while the FT-IR spectrum of
polystyrene showed no band in this region (Fig. 1).
The thermal decomposition behaviour of polystyrene supported ionic liquid (PsIL) was also compared
with chloromethylated polystyrene (Ps) by thermogravimetric analysis (TGA). As can be seen in Fig. 2,
o
the curves show main weight loss from 350 to 450 C, attributed to the main chain pyrolysis,
o
commencing at about 350 C with the evolution of aromatics from the degradation of the styrene.
o
However, the weight loss curve of PsIL shows two steps. The second step from 450 to 550 C is

attributed to the degradation of ionic liquid unit. These results clearly indicate that the ionic liquid or
ligand have been covalently linked to polystyrene.
After preparation and characterization of PsIL, copper was immobilized on the polystyrene via
complexation of copper(II) triflate with ligand to produce the polystyrene supported ionic liquid copper
complex, Cu(II)-PsIL, (Scheme 2). The copper content of this catalyst, measured by ICP analysis, was
obtained to be 0.2 mmol per gram of Cu(II)-PsIL.
The SEM images of the polystyrene and the Cu(II)-PsIL catalyst showed that the surface morphology
of the two samples is different. The surface of the catalyst is rough due to the presence of ionic liquid
ligand (Fig. 3). EDX analysis confirmed the presence of copper in the catalyst (Fig. 3c). The EDX
analysis clearly showed the presence of chloride and iodide ions in the catalyst matrix.
As a further indication for the presence of iodide and chloride ions, the supported complex was used as
an ion exchange resin in a column through which aqueous NaNO3 solution was passed. After elution
with H2O, the eluate was analyzed for its halide ions content by the potentiometric titration. As can be
seen in Fig. 4, the titration curve has two equivalence points for iodide and chloride which shows
values about 0.59 and 0.53 mmolg-1 for iodide and chloride ion, respectively. On the other hand, the
amount of iodide ions clearly shows that all nitrogen pyridines have been quaternerized.
The Cu(II)-PsIL catalyst was also characterized by TEM (Fig. 5). The dark regions or black spots in the
photograph demonstrate the copper species while the colourless parts belong to polystyrene, this is due
to the higher electron density of copper compared to polystyrene supported ionic liquid.
3.2. Cyclic voltammetry of Cu(II)-PsIL
The redox behavior of Cu species with different oxidation states could be studied via some
electrochemical techniques such as cyclic voltammetry (CV). According to the ability of ligand to
stabilize the certain oxidation states of the metal, the distinct peaks are observed [47]. In the case of Cu,
the two anodic peaks could be attributed to the conversion of Cu(0) to Cu (I) and Cu (I) to Cu (II) [47].
Fig. 6 represents the CVs of the Cu(II)-PSIL casted GCE in acetate buffer (0.1 M, pH= 5) solution
before and after the treatment with sodium ascorbate as a reducing agent. The voltammogram in Fig. 6a

depicts the electrochemical behavior of Cu(II)-PSIL in its non-reduced form. The first anodic peak at
approximate potential of -0.07 V, could be attributed to the conversion of Cu(0) to Cu(I) [48]. The
second peak positioned at approximate potential of 0.21 V was also resulted from the conversion of Cu
species to Cu(II) on GCE surface [49]. In reverse direction, the cathodic peak at -0.04 V was belonged
to the reduction of Cu species [49]. The voltammogram in Fig. 6b belongs to the catalyst after
reduction with sodium ascorbate. To obtain this species, the catalyst was stirred with sodium ascorbate
for 30 min and then filtered. As can be seen, the peak corresponds to Cu(II) has been disappeared and
only the peak attributed to the conversion of Cu(0) to Cu(I) presents. These observations clearly
confirm the oxidation state of the copper species and also the reduction of Cu(II) to Cu(I) in the
presence of sodium ascorbate.
3. 2. Investigation of catalytic activity of Cu(II)-PsIL in the synthesis of 1,2,3-triazole derivatives
First, the copper complex using CuCl2 as the copper source was prepared and its catalytic activity was
investigated in the model reaction. In this case only 15% of the corresponding triazole was produced.
To increase the electron-deficiency of the copper centre, we decided to use the copper triflate as copper
source. In the presence of triflates the interaction of copper centre and phenylacetylene will be
increased. Therefore, the catalytic activity of Cu(II)-PsIL catalyst was investigated in click reaction. In
this manner, the three-component reaction between phenyl acetylene (1 mmol), 4-bromobenzyl
bromide (1 mmol) and sodium azide (1.2 mmol) in the presence of Cu(II)-PsIL was chosen as model
reaction. The reaction conditions such as sodium ascorbate, amount of catalyst, the type of solvent and
temperaturewere optimized and a summary of the optimization results is provided in Table 1.
When the model reaction was carried out in the absence of sodium ascorbate and catalyst at 65 ˚C; no
product was formed under these conditions (Table 1, entry 1). In order to check the ability iodide ions
in the reduction of Cu(II) to Cu(I), the model reaction was carried out in the presence of Cu(II)-PsIL
(0.2 mol%) and in the absence of sodium ascorbate, in which only a trace amount of the desired
product was obtained (Table 1, entry 2). For further investigation on effect of iodide ions on catalyst
activity, the model reaction was performed in the presence of NaI instead of sodium ascorbate for

reducing of Cu(II) to Cu(I) (Table 1, entry 16). But, the result showed that the trace amount of the
corresponding triazole was produced.
While, in the presence of Cu(II)-PsIL (0.2 mol%) and in the absence of sodium ascorbate, only a trace
amount of the desired product was obtained (Table 1, entry 2). These results show that the Cu(II)
species have low ability in catalysing this reaction. When, the same reaction was performed in the
presence of Cu(II)-PsIL (0.2 mol%) and sodium ascorbate (5 mg), the highest yield was obtained.
Then, the effect of different solvents was studied in the model reaction (Table 1, entries 3-11). It was
found that, the solubility of sodium azide is an efficient parameter on the yield of the desired product.
In aprotic polar and nonpolar solvents, the reaction gives very low yield probably because of poor
solubility of sodium azide; while, in polar protic solvents, higher yield of the corresponding triazole
was obtained (70%). Among the solvents examined, PEG-400 was found to be the best reaction
medium. The effects of amount of the catalyst and temperature were also investigated; on increasing
them, the yield of the desired product did not increase further (Table 1, entries 12 and 14), but the yield
decreased on lowering these parameters (Table 1, entries 13 and 15).
Consequently, from the observations summarized in Table 1, we concluded that 0.2 mol% of the
o
catalyst and 5 mg sodium ascorbate in PEG-400 at 65 C, are the most appropriate reaction conditions
for this transformation.
Using the optimized reaction conditions, the scope and applicability of the copper catalysed synthesis
of 1,4-disubstituted 1,2,3-triazoles by the reaction of different alkynes and substituted benzyl bromides
was explored. As can be seen in Table 2, both aromatic and aliphatic terminal acetylenes gave the
corresponding triazoles in excellent yields, high purity, and excellent regioselectivity, in which only
1,4-regioisomeric products were formed. However, aryl alkynes required shorter reaction times
compared to their aliphatic counterparts. It was also found that the benzyl bromides containing
electron-donating and electron-withdrawing substituents reacted efficiently to afford the desired
products in high yields.

Encouraged by the obtained results with benzyl bromides, the potential of this catalytic system in the
synthesis of 1,4-disubstituted 1,2,3-triazoles using α-bromo ketones was also investigated. A variety of
structurally divergent α-bromo ketones having different functional groups on the aromatic ring were
reacted with terminal alkynes and sodium azide in thepresence of Cu(II)-PsIL/sodium ascorbate to
generate the corresponding β-keto-1,2,3-triazoles in 87-98% yields at 65 °C within 10-25 min (Table 3,
entries 1-5). Moreover, hetereocyclic α-bromo ketone such as 2-(bromoacetyl)furan participated well in
this reaction under similar conditions to afford the desired product in 90% yield after 25 min (Table 3,
entry 6).
In order to further widen the applicability of this catalytic system and due to the various applications of
bis-triazoles in the field of coordination chemistry [50, 51], and as precursors for ionic liquids [52,53],
the preparation of bis-triazoles was also studied. The results are summarized in Table 4. As the data
demonstrate, the "bis-click" reaction of 1,2-bis(bromomethyl)benzene or 1,4-bis(bromomethyl)benzene
with terminal alkynes and sodium azide was performed efficiently in the presence of Cu(II)-PsIL
catalyst at 65 oC and the corresponding bis-1,2,3-triazoles were obtained in high yields.
Compared to most of the previously reported methods, the yield with the Cu(II)-PsIL catalyst is higher,
the reaction time is shorter and the turn over frequency (TOF) is higher, indicating the efficiency of this
method (Table 5).
3.3. Recycling of the Cu(II)-PsIL catalyst
The recycling and reusability of a catalyst are key roles in economical and environmental
aspects. Therefore, the reusability of Cu(II)-PsIL was examined in the reaction of 4-
bromobenzyl bromide with phenyl acetylene and in the presence of sodium azide under the
optimized conditions. After completion of reaction, the mixture was first cooled to room
temperature, diluted with water and ethyl acetate and the catalyst was separated by simple
filtration and reused. The results showed that the catalyst could be reused seven consecutive
times without significant loss of its catalytic activity (Fig. 7). The amount of copper leached

was determined by ICP which indicated that only a trace amount of copper (less than 2%) was
leached in the first run.
4. Conclusions
In conclusion, we demonstrated a novel and eco-friendly strategy for regioselective synthesis of 1,4-
disubstituted-1,2,3-triazoles via one pot three-component reaction of substituted benzyl bromides,
sodium azide and terminal alkyne in the presences of catalytic amounts of Cu(II) immobilized on
polystyrene supported ionic liquid (Cu(II)-PsIL). This method is appropriate to both aromatic/aliphatic
acetylenes and benzyl bromide/α-bromo ketones, and generates a diverse range of triazoles in excellent
yields. This catalytic system was also used efficiently for the synthesis of bis1,4-disubstituted-1,2,3-
triazoles. Ease of recovery and reuse of the catalyst, short reaction times, wide scope and simple work-
up procedure make this method a valid contribution to the existing methodologies.
Acknowledgments. The authors are grateful to the Research Council of the University of Isfahan
for financial support of this work.
Appendix A. Supplementary material
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/.
Abbreviations:
<xps:span class=deft>Ps, Polystyrene; PsIL, Polystyrene supported ionic liquid; Cu(II)</xps:span>
<xps:span class=defd>PsIL, Polystyrene supported ionic liquid copper complex.</xps:span>
References
[1] C. P. Vinod, K. Wilson, A. F. Lee, J. Chem. Technol. Biotechnol. 86 (2011) 161–171.
[2] A. E. Wendlandt, A. M. Suess, S. S. Stahl, Angew. Chem. Int. Ed. 50 (2011) 11062–11087.
[3] M. E. Crivello, C. F. Pérez, S. N. Mendieta, S. G. Casuscelli, G. A. Eimer, V. R. Elías, E. R.
Herrero, Catal. Today 133-135 (2008) 787–792.
[4] B. Hu, Y. Yamaguchi, K. Fujimoto, Catal. Commun. 10 (2009) 1620–1624.

[5] K. Faungnawakij, Y. Tanaka, N. Shimoda, T. Fukunaga, R. Kikuchi, K. Eguchi, Appl. Catal.
B: Enzym. 74 (2007) 144–151.
[6] M. Meldal, C. W. Tornøe, Chem. Rev. 108 (2002) 2952–3015.
[7] H. C. Kolb, M. G. Finn, K. B. Sharpless, Angew. Chem. Int. Ed. 40 (2001) 2004–2021.
[8] D. Pasini, Molecules 18 (2013) 9512–9530.
[9] C. W. Tornøe, C. Christensen, M. Meldal, J. Org. Chem. 67 (2002) 3057−3064.
[10] S. Sommer, N. D. Weikart, A. Brockmeyer, P. Janning, H. D. Mootz, Angew. Chem. Int. Ed.
50 (2011) 9888−9892.
[11] E. Lallana, R. Riguera, E. Fernandez-Megia, Angew. Chem. Int. Ed. 50 (2011) 8794−8804.
[12] R. Alvarez, S. V. Elazquez, F. San, De. S. C. Aquaro, C. F. Perno, A. Karlesson, J. Balzarini,
M. J. Camarasa, J. Med. Chem. 37 (1994) 4185–4194.
[13] M. Ouellet, S. Mercier, I. Pelletier, S. Bounou, J. Roy, J. Hirabayashi, S. Sato, M. J.
Tremblay, J. Immunol. 174 (2005) 4120−4126.
[14] S. Velazquez, R. Alvarez, C. Perez, F. Gago, E. De Clercq, J. Balzarini, M. J. Camarasa,
Antiviral Chem. Chemother. 9 (1998) 481−489.
[15] K. Dabak, O. Sezer, A. Akar, O. Anac, Eur. J. Med. Chem. 38 (2003) 215–218.
[16] P. Shanmugavelan, S. Nagarajan, M. Sathish kumar, A. Ponnusamy, P. Yogeeswari, D,
Sriram, Bioorg. Med. Chem. Lett. 21 (2011) 7273–7276.
[17] M. J. Genin, D. A. Allwine, D. J. Anderson, M. R. Barbachyn, D. E. Emmert, S. A. Garmon,
D. R. Graber, K. C. Grega, J. B. Hester, D. K. Hutchinson, J. Morris, R. J. Reischer, C. W. Ford,
G. E. Zurenco, J. C. Hamel, R. D. Schaadt, D. Stapert, B. H. Yagi, J. Med. Chem. 43 (2000)
953−970.
[18] D. R. Buckle, C. J. M. Rockell, H. Smith, B. A. Spicer, J. Med. Chem. 29 (1986) 2262−2267.
[19] C. Hartmuth. M. C. Kolb, K Barry Sharpless, Drug Discov. Today 8 (2003) 1128–1137.
[20] R. Huisgen, Angew. Chem. 75 (1963) 604–637.
[21] R. Huisgen, G. Szeimies, L. Möbius, Chem. Ber. 100 (1967) 2494–2507.

[22] P. Zhao, M. Grillaud, L. Salmon, J. Ruiz, D. Astruc, Adv. Synth. Catal. 354 (2012) 1001–
1011.
[23] Z. Gonda, Z. Novak, Dalton Trans. 39 (2010) 726–729.
[24] T. R. Chan, R. Hilgraf, K. B. Sharpless, V. V. Fokin, Org. Lett. 6 (2004) 2853–2855.
[25] V. O. Rodionov, S. I. Presolski, D. D. Diaz, V. V. Fokin, M. G. Finn, J. Am. Chem. Soc. 129
(2007) 12705–12712.
[26] H. V. Rostovtsev, L. G. Green, V. V. Fokin, K. B. Sharpless, Angew. Chem. Int. Ed. 41
(2002) 2596−2599.
[27] P. Appukkuttan, W. Dehaen, V. V. Fokin, E. Van der Eycken Org. Lett. 6 (2004) 4223–4225.
[28] L. S Campbell-Verduyn, L. Mirfeizi, R. A. Dierckx, P. H. Elsinga, B. L. Feringa, Chem.
Commun. 16 (2009) 2139−2141.
[29] V. D. Bock, H. Hiemstra, J. H.-V. Maarseveen, Eur. J. Org. Chem. 2006 (2006) 51–68.
[30] H. A. Orgueria, D. Fokas, Y. Isome, P. C. -M. Chane, C. M. Baldino, Tetrahedron Lett. 46
(2005) 2911–2914.
[31] Q. Wang, T. R. Chan, R. Hilgraf, V. V. Fokin, K. B. Sharpless, M. G. Finn, J. Am. Chem.
Soc. 125 (2003) 3192−3193.
[32] F. Himo, T. Lovell, R. Hilgraf, V. V. Rostovtsev, L. Noodleman, K. B. Sharpless, V. V.
Fokin, J. Am. Chem. Soc. 127 (2005) 210−216.9
[33] T. Miaoa, L. Wang, Synthesis 3 (2008) 363–368.
[34] S. Chassaing, M. Kumarraja, A. S.-S. Sido, P. Pale, J. Sommer, Org. Lett. 9 (2007) 883–886.
[35] R. Hudson, Chao-Jun Li, A. Moores, Green Chem. 14 (2012) 622–624.
[36] G. Eglinton, A. R. Galbraith, Cyclic diynes. Chem. Ind. 1956 (1956) 737–738.
[37] P. Siemsen, R. C. Livingston, F. Diederich, Angew.Chem. Int. Ed. 39 (2000) 2632–2657.
[38] A. K. Feldman, B. Colasson, V. V. Fokin, Org. Lett. 6 (2004) 3897–3899.
[39] W. S. Brotherton, R. J. Clark, L. Zhu, J. Org. Chem. 77 (2012) 6443–6455.
[40] I. Juan, S. Sánchez, A. O. Terán, I. A. Rivero, Arkivok 4 (2011) 177–188.

[41] A. Marra, A. Vecchi, C. Chiappe, B. Melai, A. Dondoni, J. Org. Chem. 73 (2008) 2458-2461.
[42] S. Rostamizadeh, N. Zekri, L. Tahershamsi, Polycyclic Aromat. Compd. 34 (2014) 542–560
[43] A. Catherine, Mc. Namara, M. J. Dixon, M. Bradley, Chem. Rev. 102 (2002) 3275–3300.
[44] M. Nasr-Esfahani, I. Mohammadpoor-Baltork, A. R. Khosropour, M. Moghadam, V. Mirkhani, S.
Tangestaninejad, J. Molecuar Catal. A: 379 (2013) 243-254.
[45] M. Nasr-Esfahani, I. Mohammadpoor-Baltork, A. R. Khosropour, M. Moghadam, V. Mirkhani, S.
Tangestaninejad, H. Amiri Rudbari, J. Org. Chem. 79 (2014) 1437-1443.
[46] S .Safaei, I. Mohammadpoor-Baltork, A. R. Khosropour, M. Moghadam, S. Tangestaninejad, S.,
V. Mirkhani, New J. Chem. 37(2013) 2037–2042.
[47] R. D. Braun, Anal. Chim. Acta 120 (1980) 111–120.
[48] T. R. Chan, R. Hilgraf, K. B. Sharpless, V. V. Fokin, Org. Lett. 6 (2004) 2853–2855.
[49] F. Haque, M. S. Rahman, E.Ahmed, P. K. Bakshi, and A. A. Shaikh, Dhaka Univ. J. Sci. 61
(2013) 161–166.
[50] P. Zhao, N. Li, L. Salmon, N. Liu, J. Ruiz, D. Astruc, Chem. Commun. 49 (2013) 3218–3220.
[51] W. Yan, X. Ye, N. G. Akhmedov, J. L. Petersen, X. Shi, Org. Lett. 14 (2012), 2358–2361.
[52] J. W. Choi, B. K. Cho, Soft Matter. 7 (2011) 4045–4049.
[53] Y. Yoshida, S. Takizawa, H. Sasai, Tetrahedron Lett. 52 (2011) 6877–6879.
[54] B. S. P. Anil Kumar, K. Harsha Vardhan Reddy, B. Madhav, K. Ramesh, Y. V. D. Nageswar,
Tetrahedron Lett. 53 (2012) 4595–4599.
[55] M. Keshavarz, N. Iravani, A. Ghaedi, A. Zarei Ahmady, M. Vafaei-Nezhad, S. Karimi,
Springer Plus 2 (2013) 64.
[56] J. Albadi, M. Keshavarz, M. Abedini, M. Vafaie-nezhad, Chin. Chem. Lett. 23 (2012) 797–800.

Fig. 1. The FT-IR spectrum of: (a) chloromethylatedpolystyrene and (b) polystyrene-supported ionic liquid
(PsIL).
Fig. 2. Thermogram of: (a) chloromethylatedpolystyrene (Ps), (b) polystyrene supported ionic liquid
(PsIL).
Fig. 3. SEM image of: (a) chloromethylated polystyrene, (b) Cu(II)-PsIL and (c) SEM-EDX spectrum
of Cu(II)-PsIL.
Fig. 4. Potentiometric titration curve for iodide and chloride ions.
Fig. 5. TEM image of Cu(II)-PsIL.
Fig. 6. CVs of Cu(II)-PSIL modified GCE a) before and b)after treatment with sodium ascorbate in 0.1
M acetate buffer (pH= 5) and scan rate of 10 mVs-1.
Fig. 7. Reusability of the Cu(II)-PsIL catalyst in the 1,4-disubstituted 1,2,3-triazole of benzyl bromide,
phenyl acetylene and sodium azide.

Fig. 1. FT-IR spectrum of: (a) chloromethylated polystyrene and (b) polystyrene-supported ionic liquid
(PsIL)

Fig. 2. Thermogram of: (a) chloromethylated polystyrene (Ps), (b) polystyrene supported ionic liquid
(PsIL)
Fig. 3. SEM image of: (a) chloromethylated polystyrene, (b) Cu(II)-PsIL and (c) SEM-EDX spectrum
of Cu(II)-PsIL

Fig. 4. Potentiometric titration curve for iodide and chloride ions

Fig. 5.TEM image of Cu(II)-PsIL

Fig. 6. CVs of Cu(II)-PSIL modified GCE a) before and b)after treatment with sodium ascorbate in 0.1
M acetate buffer (pH 5) and scan rate of 10 mVs-1
Fig. 7. Reusability of the Cu(II)-PsIL catalyst in the synthesis of 1,4-disubstituted 1,2,3-triazole from
benzyl bromide, phenyl acetylene and sodium azide
Table 1. Optimization of conditions in the reaction of 4-bromobenzyl bromide with phenylacetylene
N
N
N
Br
+
Cu(II)-PsIL
+
NaN3
Ph
Ph
Sodium ascorbate
Solvent, D
Br
1 mmol
1.2 mmol
1 mmol
Br

Entry
Catalyst Amount
Solvent
T [˚C]
Time
[min]
15
Yield
[%]a
-
[mol%]
-
1
2b
3
PEG-400
PEG-400
65
65
65
65
65
65
65
65
65
65
65
65
65
85
45
65
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.1
0.2
0.2
0.2
15
15
30
15
15
25
15
15
15
30
15
30
15
30
30
Trace
70
Methanol
Toluene
4
40
5
H2O
78
6
Ethanol
72
7
DMF
65
8
PEG-400/H2O (1:1)
Ethanol/H2O (1:1)
PEG-400
89
9
75
10
11
12
13
14
15
99
Acetonitrile
PEG-400
38
99
PEG-400
71
PEG-400
99
PEG-400
73
16c
PEG-400
Trace
aIsolated yield.
bWithout sodium ascorbate.
cThe reaction was performed in the presence of sodium iodide instead of sodium ascorbate.
Table 2. Three-component synthesis of 1,4-disubstituted 1,2,3-triazoles from benzyl bromides
catalyzed by Cu(II)-PsIL.
N
N
N
Cu(II)-PsIL(0.2 mol%)
+
Br
R
Ar
+
NaN3
Ar
R
Sodium ascorbate (5 mg)
PEG-400, 65 oC
1 mmol
1.2 mmol
1 mmol

Entry
1
Benzyl bromide
R
Product
Time [min]
15
Yield [%]a
99
Br
N
N
Ph
N
Ph
Ph
Br
Br
N
N
Br
2
3
Ph
Ph
15
12
95
99
N
O2N
NO2
N
N
Br
N
Ph
N
Br
Br
N
N
4
5
C6H13
C6H13
15
20
94
95
N
N
N
Br
Br
N
Br
N
6
C6H13
23
97
N
O2N
NO2
N
Br
7
8
C5H11
C5H11
20
22
93
94
N
N
N
N
Br
N
Br
Br
N
Br
9
C5H11
23
98
N
N
O2N
NO2
aIsolated yield.
Table 3. Three-component synthesis of 1,4-disubstituted 1,2,3-triazoles from α-bromo ketones
catalyzed by Cu(II)-PsIL.

O
N
N
Cu(II)-PsIL(0.2 mol%)
Br
+
R
+
N
NaN3
Ar
Sodium ascorbate (5 mg)
PEG-400, 65 oC
Ar
R
O
Entry α-Bromoketones
R
Product
Time [min]
10
Yield[%]a
N
O
Br
Br
N
1
Ph
98
N
Br
O
Br
O2N
F
N
O
N
2
Ph
Ph
12
10
10
87
97
96
N
NO2
O
N
O
O
Br
Br
N
3
4
N
F
O
N
N
N
C5H11
O
OMe
OMe
Br
O
5
6
C5H11
25
15
92
90
N
N
N
O
N
O
Br
N
Ph
N
O
O
O
aIsolated yield.
Table 4. Three-component synthesis of 1,4-disubstituted 1,2,3-triazoles from 1,2-bis(bromomethyl)
and 1,4-bis(bromomethyl)benzene catalyzed by Cu(II)-PsIL.a
Organic halide
Alkyne
Product
Br
N
N
N
N
N
N
Br
45 min, 84%b

Br
N
N
N
N
N
N
Br
60 min, 68%
Br
N
N
N
Br
N
N
N
45 min, 88%
aReaction conditions: Organic halide (1 mmol), alkyne (2 mmol), sodium azide (2.4 mmol), Cu(II)-
PsIL (0.4 mol%), sodium ascorbate (10 mg) in PEG-400 (3 ml) at 65 ˚C.
bIsolated yield.
Table 5. Comparison of conventional protocols used for 1,4-disubstituted 1,2,3-triazoles.
N
N
N
Br
[Cu]
+ NaN3
Ph
Ph
+
Br
Br
TOF
Catalyst
Conditions
Time [min]
Yield [%]a
Ref.
This work
[45]
Cu(II)-PsIL
PEG-400, 65 ˚C
15
17
99
99
93
92
89
1980
1166
6.2
b
Cu(II)-TD@nSiO2
CuFe2O4
Ethanol/H2O (2:1), r.t
H2O, 70 ˚C
180
60
[51]
Nano copper (I)
P4VPy-CuI c
Ethanol, reflux
H2O, reflux
92
[52]
20
215
[53]
aIsolated yield.
bCopper immobilized on nanosilica triazine dendrimer.
cCopper iodide nanoparticles on poly(4-vinyl pyridine).