Anchoring Cu nanoparticles on functionalized multi-walled carbon nanotube for regioselective synthesis of 1,2,3-triazoles via click reaction

Article abstract of DOI:10.1002/aoc.6281

Unique properties of 1,2,3-triazoles on the one hand and necessity of usage of an efficient catalyst with fidelity in principles of green chemistry on the other hand impelled us to design and synthesis of a novel heterogeneous nanocatalyst (Cu@Arg-MWCNTs)

Full text of DOI:10.1002/aoc.6281

Received: 5 February 2021
DOI: 10.1002/aoc.6281
Revised: 26 March 2021
Accepted: 19 April 2021
F U L L P A P E R
Anchoring Cu nanoparticles on functionalized multi-walled
carbon nanotube for regioselective synthesis of
1,2,3-triazoles via click reaction
Mahsa Khoshnevis
| Hossein Eshghi
Department of Chemistry, Faculty of
Unique properties of 1,2,3-triazoles on the one hand and necessity of usage of
an efficient catalyst with fidelity in principles of green chemistry on the other
hand impelled us to design and synthesis of a novel heterogeneous
nanocatalyst (Cu@Arg-MWCNTs) with simple synthesis, immense power,
high regioselectivity, and easy separation and recyclability. The Cu@Arg-
MWCNT structure is characterized by different analyses and used for the syn-
thesis of various triazoles. Its high catalytic activity is confirmed by high yields
and short reaction times under mild conditions in click reaction.
Science, Ferdowsi University of Mashhad,
Mashhad, Iran
Correspondence
Hossein Eshghi, Department of
Chemistry, Faculty of Science, Ferdowsi
University of Mashhad, Mashhad
91775-1436, Iran.
Email: heshghi@um.ac.ir
Funding information
Ferdowsi University of Mashhad, Grant/
Award Number: 3/47784
K E Y W O R D S
click, Cu@MWCNT, heterogeneous nanocatalyst, Huisgen, triazole
1 | INTRODUCTION
regioselectivity, and yield enhancement,[20,21] but still
demands more revision. Direct use of Cu(I) salts as
A wide range of benefits in medicinal chemistry,[1]
organic chemistry and synthesis as building blocks,[2]
catalysis and material science,[3–5] polymer science,[6]
bioconjugation,[7,8] drug discovery,[9,10] industry,[11] and
agrochemical[12] are the main reasons of inconsiderable
interest to the 1,2,3-triazole family. According to this
extensive utility, development of various synthetic
methods is obvious.
Huisgen's 1,3-dipolar cycloaddition reaction of azides
and alkynes[13] as classical process for synthesis of
1,2,3-triazoles[9,14] has high applicability and adaptability
potentials. Simultaneously, deficiencies such as long reac-
tion times at high temperature and low reaction rate and
selectivity had restricted their use.[15] In 2002, Tornøe
et al.[16] and Rostovtsev et al.[17] independently used
Cu(I) salts as a homogeneous catalyst in this reaction,
which resulted in enormous transformation in this click
reaction.[18]
homogeneous catalyst has been restricted not only for
difficulty of their separation which results in contamina-
tion of product and recovery[22] but also because of their
instability and formation of alkyne homocoupling by-
product.[23] Furthermore, it would be better to do the
reaction via an in situ multicomponent one-pot azidation
in the presence of alkynes, sodium azide, and epoxide/
alkyl or aryl halides, instead of utilization of hazardous
and toxic alky/aryl azides.[24]
Inevitable interest of scientists to the synthesis of tri-
azole derivatives has resulted in the emersion of vast and
variable Cu catalysts,[25] and as it was mentioned before,
direct utilization of Cu(I) salt is not an intellectual
choice. Instead, in situ preparation of active Cu(I) by
reduction and oxidation of Cu(II) salts and Cu(0) metal,
respectively, or combination of Cu (II)/Cu(0) seems to be
much better elections.[26] Wide range of ligands
[27,28]
[29]
containing N, P, and S
or mixed of NN/NO/NS
The copper(I)-catalyzed azide–alkyne cycloaddition
(CuAAC) version of Huisgen reaction rectified most
deficiencies of non-catalyzed version,[18,19] among which
are improvement of reaction conditions, promotion of
and various supporting matrices such as zeolites,[20,30]
charcoals,[24] montmorillonite,[31] activated carbon
nanotubes,[32,33] graphene oxides,[34,35] silica,[36] and
polymers[37] have been used for preparation of an
Appl Organomet Chem. 2021;e6281.
wileyonlinelibrary.com/journal/aoc
© 2021 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.6281

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KHOSHNEVIS AND ESHGHI
effective, easily recoverable, and reusable heterogeneous
catalysts.[12]
bath. The PTFE MEMBRANES 0.22 μm (MF047PT022,
filtraTECH, France) was used for filtration. UNIVERSAL
320 centrifuge from (Pole Ideal Tajhiz Co., Iran) was used
for centrifugation. Melting points of the products
were determined with a Thermo Scientific IA9200
(Electrothermal Engineering) melting point apparatus.
Analytical thin-layer chromatography (TLC) was per-
formed on Merck 60 F254 precoated silica gel plate
(0.2 mm thickness) and examined under ultraviolet
(UV) light. Fourier transform infrared (FT-IR) spectra
were recorded on a Nicolet Fourier spectrophotometer
(USA) using KBr discs. The mass spectra of compounds
were recorded on a 5973Network Mass Selective Detec-
tor. The LC/MS/MS system AB SCIEX 3200 QTRAP was
used for identification of the product (Table 2, Entry 7).
Morphology studies of the prepared samples were carried
out using a LEO-1450VP microscope (Germany) scanning
electron microscope (SEM). Field emission scanning elec-
tron microscope (FE-SEM) images and energy-dispersive
X-ray spectroscopy (EDX) were recorded using a TES-
CAN BRNO-Mira3 LMU with gold coating equipped to
determine the elemental compositions. The Zeiss Leo
912 OMEGA (120 kV) transmission electron microscope
(TEM) (Germany) was used to record TEM images and
determine the shape and morphology of the synthesized
Cu@Arg-MWCNT nanocatalyst. 1H and 13C NMR spectra
were measured, respectively, at 300 and 75 MHz with tet-
ramethylsilane (TMS) as internal reference (CDCl3 and
acetone-d6) on Bruker DRX300 AVANCE spectrometer.
The content of the metal cations was recorded by induc-
tively coupled plasma optical atomic emission spectrome-
ter (ICP-AES) analysis with a Varian Vista-PRO CCD
(Australia). Powder X-ray diffraction (XRD) patterns
were obtained by use of X-ray diffractometer (Bruker D4
Endeavor) with Ni-filtered Cu Kα radiation in the angle
2θ ranging from 20 to 80ꢁ (40 kV, 30 mA). Nanoparticle
size dispersion was determined by applying a particle size
analyzer (Vasco3, Cordouan, France), which can measure
the dispersion between 0.5 nm and 6 μm. Ther-
mogravimetric analysis (TGA) measurements were car-
ried out on a Shimadzu TGA-50 under air atmosphere at
a heating rate of 10ꢁC/min.
In recent decades, chemists' endeavor is fidelity in
principles of green chemistry and utilization of them
in reactions like click chemistry,[38] so design and synthe-
sis of a heterogeneous nanocatalyst as heart of the reaction
is the most important factor to achieve this goal.[39] Based
on the investigations, supported copper nanoparticles
(CuNPs) are considered to be much more effective cata-
lysts for CuAAC reaction.[40,41] According to these points,
we became interested in design and synthesis of an effi-
cient, eco-friendly, and novel heterogeneous nanocatalyst
by means of a simple and inexpensive material and
method in the presence of multi-walled carbon nanotubes
(MWCNTs) and arginine and reduction of copper acetate
monohydrate by using sodium borohydride in ethanol.
After synthesis and detection of the catalyst (Cu@Arg-
MWCNT), its catalytic activity, regioselectivity, stability,
easy recoverability, reusability, and alignment with green
chemistry in click reaction (in the presence of sodium
azide, phenylacetylene, and epoxide/alkyl or aryl halides
in water medium and under mild condition) (Scheme 1)
was evaluated, and acceptable results were obtained.
2 | EXPERIMENTAL
2.1 | Materials
MWCNTs (>95%, OD: 20–30) were obtained from US
Research Nanomaterials, Inc. (3302 Twig Leaf Lane,
Houston, TX 77084, USA). FeSO4ꢀ7H2O, H2O2, K2CO3,
Cu(OAc)2ꢀH2O, sodium borohydride, arginine, alkyl
halides, epoxides, sodium azide, and EtOH and other sol-
vents were manufactured by Merck and Sigma-Aldrich,
and no more purification was needed.
2.2 | Equipment
The ultrasound energy was employed by using
PARSONIC 15S (Pars Nahand Engg. Co., Iran) ultrasonic
SCHEME 1 Synthesis of
1,4-disubstituted-1,2,3-triazoles in the
presence of Cu@Arg-MWCNT

KHOSHNEVIS AND ESHGHI
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2.3 | Preparation of catalyst
2 mol% Cu) in water (0.5 mL) was sonicated for 2 min,
and the suspension was stirred at 70ꢁC for appropriate
time. Upon the completion of the reaction, which was
defined by TLC, catalyst simply was removed from the
reaction mixture by centrifugation. The separated catalyst
was washed with hot methanol (3 ꢂ 10 mL) and dried in
the oven (50ꢁC) to be ready for the next run. The
resulting mixture was diluted with distilled water
(10 mL) and extracted with EtOAc (3 ꢂ 10 mL), and
then, the organic layer was washed with saturated brine
and finally dried over anhydrous Na2SO4. The solvent
removal in the following and recrystallization of the
crude product with EtOH:H2O (3:1) resulted in pure
β-hydroxy-1,4-disubstituted 1,2,3-triazole derivatives
2.3.1 | Functionalization of MWCNT-OH
with epibromohydrin (EP-MWCNT)
At the first step, synthesis of hydroxylated MWCNTs
(MWCNT-OH) was performed according to method dis-
cussed in previously reported article.[42]
MWCNT-OH (0.5 g) and epibromohydrin (2.5 mL) in
the presence of absolute EtOH (50 mL) were sonicated
for 20 min at room temperature; then, the mixture
was stirred at 60ꢁC, and after 24 h, the produced EP-
MWCNTs were centrifuged and washed truly with abso-
lute EtOH and dried in the oven at 50ꢁC.
1
(Table 2, Entries 1–10). Melting point, FT-IR, mass, H
NMR, and 13C NMR spectroscopies were used for identi-
fication and characterization of the products. The synthe-
sized new compound (4 g) was also characterized
2.3.2 | Functionalization of MWCNTs with
L-arginine (Arg-MWCNT)
1
successfully by use of H NMR, 13C NMR, FT-IR, and
A mixture of EP-MWCNT (0.5 g), K2CO3 (4 mmol), and
L-arginine (5 mmol) in the presence of absolute EtOH
(250 mL) in a round-bottom flask was first sonicated
20 min for better dispersion, and then, the flask content
was refluxed for about 40 h. Finally, Arg-MWCNT was
separated by centrifugation, washed exactly with EtOH,
and dried under vacuum at 50ꢁC.
LC/MS/MS studies, which are readily available in
Figures S1–S6
3.1.1 | Spectral data of representative
compounds
2-(4-Phenyl-1H-1,2,3-triazol-1-yl)cyclohexan-1-ol
(Table 2, Entry 1) (4a)
2.3.3 | Synthesis of Cu@Arg-MWCNT
In a two-neck round-bottom flask, Arg-MWCNT (0.5 g)
in the presence of absolute EtOH (70 mL) was dispersed
via sonication for 20 min. Then, Cu(OAc)2ꢀH2O
(1.5 mmol) was added, and the mixture was stirred under
argon atmosphere at room temperature for 4 h; in follow-
up, NaBH4 (0.5 g) suspension in ethanol (10 mL) was
injected drop by drop to the flask content and let it mag-
netically stirred under argon atmosphere for 48 h.
Finally, the residue was centrifuged and washed with
EtOH to remove excess NaBH4; then, the produced
Cu@Arg-MWCNT was dried under vacuum at 50ꢁC.
White solid, m.p.: 177–179ꢁC (Lit.[32] 179–180ꢁC). FT-
IR (KBr, ν, cmꢃ1): 698 (s), 769 (s), 978 (w), 1055 (s), 1080
(s), 1236 (s), 1463 (s), 1609, 1579 (s), 2864 (w), 2942 (s),
1
3122 (m), 3309 (br). H NMR (300 MHz, CDCl3) δ ppm:
7.82 (s, 1H), 7.79 (d, 2H, J = 7.2), 7.46–7.41 (m, 2H),
7.38–7.33 (m, 1H), 4.27–4.08 (m, 2H), 3.19 (s, 1H, OH),
2.30–2.26 (m, 2H), 2.04–1.93 (m, 2H), 1.61–1.44 (m, 4H).
13C NMR (75 MHz, CDCl3) δ ppm: 146.9, 130.2, 128.7,
128.0, 125.5, 119.7, 72.6, 67.2, 33.7, 31.5, 24.8, 24.0. MS
(m/z): 243 (M+).
3 | GENERAL PROCEDURE FOR
SYNTHESIS OF 1,4-DISUBSTITUTED
1,2,3-TRIAZOLES
1-(4-Phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (Table 2,
3.1 | General procedure for synthesis of
Entry 2) (4b)
triazoles in the presence of epoxides
In a model reaction, a mixture of phenylacetylene
(1 mmol), sodium azide (1.1 mmol), and epoxides
(1 mmol) in the presence of Cu@Arg-MWCNT (0.01 g or

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KHOSHNEVIS AND ESHGHI
White solid, m.p.: 114–116ꢁC (Lit.[43] 114–116ꢁC).
1-Butoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol
(Table 2, Entry 5) (4e)
FT-IR (KBr, ν, cmꢃ1): 517 (m), 697 (s), 762 (s), 819 (m),
981 (m), 1088 (s), 1139 (s), 1230 (m), 1370 (w), 1429 (m),
1
1465 (m), 1612 (w), 2964 (m), 3145 (m), 3263 (b). H
NMR (300 MHz, CDCl3) δ ppm: 7.90 (s, 1H), 7.83 (d, 2H,
J = 6.9 Hz), 7.47–7.42 (m, 2H), 7.38–7.34 (m, 1H), 4.52
1
2
(dd, 1H, J = 13.3, J = 2.1), 4.43–4.27 (m, 2H), 2.11 (s,
broad, OH), 1.35 (d, 3H, J = 6.3 Hz). 13C NMR (75 MHz,
CDCl3) δ ppm: 147.0, 130.3, 128.8, 128.2, 125.7, 121.1,
66.7, 57.2, 30.9. MS (m/z): 203 (M+).
White solid, m.p.: 64–66ꢁC (Lit.[43] 66–68ꢁC). FT-IR
(KBr, ν, cmꢃ1): 697 (s), 766 (s), 826 (m), 981 (m), 1089 (s),
1115 (s), 1229 (m), 1467 (m), 1611 (w), 2866 (s), 2929 (m),
2953 (s), 3139 (m), 3257 (b). 1H NMR (300 MHz, acetone-
d6) δ ppm: 8.34 (s, 1H), 7.94–7.91 (m, 2H), 7.48–7.31
1-(4-Phenyl-1H-1,2,3-triazol-1-yl)butan-2-ol (Table 2,
Entry 3) (4c)
1
2
(m, 3H), 4.66 (dd, 1H, J = 13.8 Hz, J = 3.6 Hz), 4.46
(dd, 1H, 1J = 13.8 Hz, 2J = 7.5 Hz), 4.21 (broad, 1H),
3.54–3.44 (m, 4H), 1.63–1.53 (m, 2H), 1.48–1.36 (m, 2H),
0.94 (t, 3H). 13C NMR (75 MHz, CDCl3) δ ppm: 147.4,
130.4, 128.8, 128.1, 125.7, 121.2, 71.5, 71.4, 69.2, 53.0,
31.6, 19.2, 13.8. MS (m/z): 275 (M+).
White powder m.p.: 111–113ꢁC (Lit.[34] 110–112ꢁC).
FT-IR (KBr, ν, cmꢃ1): 695 (s), 764 (s), 826 (w), 981 (m),
1091 (s), 1137 (s), 1229 (m), 1467 (m), 1633 (m), 2872 (m),
2933 (m), 2960 (m), 3140 (m), 3255 (s), 3411 (b). 1H NMR
(300 MHz, CDCl3) δ ppm: 7.88 (s, 1H), 7.81–7.78 (m, 2H),
7.45–7.35 (m, 3H), 4.55 (dd, 1H, 1J = 13.8 Hz,
2J = 2.7 Hz), 4.34–4.27 (m, 1H), 4.14–4.08 (m, 1H), 3.03
(broad, 1H, OH), 1.68–1.57 (m, 2H), 1.1 (t, 3H,
J = 7.41 Hz). 13C NMR (75 MHz, CDCl3) δ ppm: 147.3,
130.3, 129.2, 128.8, 128.2, 125.6, 71.8, 55.8, 27.5, 9.8. MS
(m/z): 217 (M+).
1-Isopropoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-
2-ol (Table 2, Entry 6) (4f)
1-(Allyloxy)-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-
2-ol (Table 2, Entry 4) (4d)
White powder, m.p.: 62–64ꢁC (Lit.[44] 62–64ꢁC). FT-IR
(KBr, ν, cmꢃ1): 695(w), 766 (m), 1086 (s), 1125 (s), 1383
1
(m), 1466 (m), 1647 (w), 2971 (w), 3411 (b). H NMR
(300 MHz, CDCl3) δ ppm: 7.95 (s, 1H), 7.89–7.86 (m, 2H),
7.49–7.44 (m, 2H), 7.39–7.36 (m, 1H), 4.63 (dd, 1H,
2
1
1J = 14.1 Hz, J = 3.9 Hz), 4.50 (dd, 1H, J = 14.1 Hz,
2J = 6.6 Hz), 4.27–4.20 (m, 1H), 3.68–3.60 (m, 1H), 3.55
(dd, 1H, 1J = 9.4 Hz, 2J = 4.8 Hz), 3.38 (dd, 1H,
1J = 9.4 Hz, J = 6.3 Hz), 2.20 (s, broad, 1H, OH), 1.20
2
White solid, m.p.: 70–72ꢁC (Lit.[32] 70–72ꢁC). FT-IR
(KBr, ν, cmꢃ1): 696 (s), 767 (s), 827 (m), 921 (m), 1090 (s),
1110 (s), 1364 (m), 1433 (m), 1647 (w), 2930 (m), 3140 (m),
3239 (b). 1H NMR (300 MHz, CDCl3) δ ppm: 7.94 (s, 1H),
7.85 (dd, 2H, 1J = 8.4, 2J = 1.5), 7.48–7.43 (m, 2H),
7.39–7.35 (m, 1H), 6.00–5.87 (m, 1H), 5.35–5.24
(dd, 6H, 1J = 6 Hz, 2J = 1.8 Hz). 13C NMR (75 MHz,
CDCl3) δ ppm: 146.9, 130.4, 128.8, 128.1, 125.7, 72.5, 69.4,
68.8, 53.1, 22.0. MS: m/z (%): 261 (M+).
1-(tert-Butoxy)-3-(4-phenyl-1H-1,2,3-triazol-1-yl)
propan-2-ol (Table 2, Entry 7) (4g)
1
2
(m, 2H), 4.64 (dd, 1H, J = 14.1 Hz, J = 3.6 Hz), 4.49
1
2
(dd, 1H, J = 14.1 Hz, J = 8.4 Hz), 4.34–4.25 (m, 1H),
4.06 (td, 2H, 1J = 5.7 Hz, 2J = 1.2 Hz), 3.57 (dd, 1H,
1J = 9.6 Hz, 2J = 4.8 Hz), 3.45 (dd, 1H, 1J = 9.6 Hz,
2J = 6 Hz), 2.14 (s, broad, 1H, OH). 13C NMR (75 MHz,
CDCl3) δ ppm: 147.7, 139.9, 130.3, 128.8, 128.2, 125.7,
121.2, 117.8, 72.4, 70.8, 69.3, 53.0. MS (m/z): 259 (M+).

KHOSHNEVIS AND ESHGHI
5 of 18
Pale yellow crystal, m.p.: 77–79ꢁC (new) FT-IR (KBr,
ν, cmꢃ1): 694 (s), 765(s), 1080 (s), 1100 (s), 1196 (s), 1227
(m), 1362 (s), 1440 (m), 1465 (m), 1484 (m), 1613 (w),
2973 (s), 3133 (w), 3344 (b). 1H NMR (300 MHz, CDCl3) δ
ppm: 7.97 (s, 1H), 7.87 (d, 2H, J = 7.2 Hz), 7.48–7.43 (m,
2H), 7.39–7.34 (m, 1H), 4.63 (dd, 1H, 1J = 13.9, Hz
7.92 (s, 1H), 7.78 (d, 2H, J = 7.2 Hz), 7.45–7.40
(m, 2H), 7.37–7.31 (m, 3H), 7.03 (t, 1H), 6.95 (d, 2H),
4.79–4.73 (m, 1H), 4.63–4.55 (m, 2H), 4.11–4.03 (m,
2H), 2.98 (broad, 1H). 13C NMR (75 MHz, CDCl3) δ
ppm: 158.09, 147.60, 129.67, 129.55, 128.87, 128.25,
125.70, 121.62, 121.40, 114.57, 68.95, 68.8, 53.13. MS
(m/z): 295 (M+).
1
2
2J = 3.9 Hz), 4.48 (dd, 1H, J = 14.1 Hz, J = 6.9 Hz),
1
2
4.24–4.16 (m, 1H), 3.49 (dd, 1H, J = 9.1, J = 4.8 Hz),
1
2
3.36 (dd, 1H, J = 9.1 Hz, J = 6 Hz), 2.55 (s, broad, 1H,
OH), 1.23 (s, 9H [3 ꢂ CH3]). 13C NMR (75 MHz, CDCl3)
δ ppm: 147.2, 130.4, 128.7, 128.0, 125.5, 121.3, 73.5, 69.5,
62.9, 53.5, 27.4. MS (m/z): 275 (M+). LC/MS/MS studies
on compound (4g) were done, and its mass spectra has
been shown in Figure S6. Compound (4g) gave [M + H]+
ion at m/z = 276.165 and [M + Na]+ adduct ion at m/
z = 298.148.
2-Phenyl-2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethan-1-ol
(Table 2, Entry 10) (4j)
1-(3-Methoxyphenoxy)-3-(4-phenyl-1H-1,2,3-triazol-1-yl)
propan-2-ol (Table 2, Entry 8) (4h)
Pale yellow solid, m.p.: 123–125ꢁC (Lit.[13] 125–
127ꢁC). FT-IR (KBr, ν, cmꢃ1): 690 (s), 763 (s), 1074 (s),
1235 (m), 1454 (m), 1482 (m), 1605 (w), 2928 (m), 3155
1
(m), 3215 (br). H NMR (300 MHz, CDCl3) δ ppm: 7.82
1
2
(d, 2H), 7.75 (s, 1H), 7.56 (dd, 1H, J = 6 Hz, J = 3 Hz),
7.46–7.36 (m, 6H), 7.31 (s, 1H), 5.73–5.71 (m, 1H), 4.67
(dd, 1H, 1J = 12 Hz, 2J = 8.1 Hz), 4.28–4.24 (m, 1H), 2.86
(broad, 1H). 13C NMR (75 MHz, CDCl3) δ ppm: 147.6,
136.0, 132.9, 129.2, 129.1, 128.8, 128.3, 127.1, 125.7, 67.3,
65.3. MS (m/z): 265 (M+).
White powder, m.p.: 97–99ꢁC (Lit.[35] 99–100ꢁC). FT-
IR (KBr, ν, cmꢃ1): 688 (m), 764 (s), 1048 (s), 1154 (s),
1201 (s), 1265 (m), 1288 (s), 1492 (s), 1602 (s), 2834 (m),
1
2871 (m), 2930 (m), 2961 (m), 3144 (w), 3382 (b). H
3.2 | General procedure for synthesis of
NMR (300 MHz, CDCl3) δ ppm: 7.91 (s, 1H), 7.76 (d, 2H,
J = 7.2 Hz), 7.44–7.32 (m, 3H), 7.25–7.20 (m, 1H), 6.60–
6.52 (m, 3H), 4.79–4.72 (m, 1H), 4.64–4.46 (m, 2H), 4.16
(s, 1H), 4.06–3.95 (m, 2H), 3.81 (s, 3H). 13C NMR
(75 MHz, CDCl3) δ ppm: 160.9, 159.5, 159.3, 147.8, 130.2,
130.1, 128.8, 128.2, 125.6, 107.1, 106.6, 101.2, 68.9, 67.8,
55.3, 53.1. MS (m/z): 325 (M+).
triazoles in the presence of alkyl halides
In a model reaction, a mixture of phenylacetylene
(1 mmol), sodium azide (1.1 mmol), and alkyl halides
(1 mmol) in the presence of Cu@Arg-MWCNT (0.01 g or
2 mol% Cu) in water medium (0.5 mL) was sonicated for
2 min, and the suspension was stirred at 70ꢁC for appro-
priate time. Upon the completion of the reaction, which
was defined by TLC, catalyst simply was removed from
the reaction mixture by centrifugation. The separated cat-
alyst was washed with hot methanol (3 ꢂ 10 mL) and
dried in the oven (50ꢁC) to be ready for the next run. The
resulting mixture was diluted with distilled water
(10 mL) and extracted with EtOAc (3 ꢂ 10 mL), and
then, the organic layer was washed with saturated brine
and finally dried over anhydrous Na2SO4. The solvent
removal in the following and recrystallization of the
crude product with EtOH:H2O (3:1) resulted in pure
1,4-disubstituted 1,2,3-triazole derivatives (Table 2,
Entries 11–16). Melting point, FT-IR, mass, 1H NMR, and
13C NMR spectroscopies were used for identification
and characterization of the products.
1-Phenoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol
(Table 2, Entry 9) (4i)
White crystal, m.p.: 124–126ꢁC (Lit.[35] 124–127ꢁC).
FT-IR (KBr, ν, cmꢃ1): 692 (s), 752 (s), 1043 (m), 1079
(m), 1173 (w), 11248 (s), 1496 (s), 1599 (s), 2933 (w),
1
3084 (w), 3397 (br). H NMR (300 MHz, CDCl3) δ ppm:

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KHOSHNEVIS AND ESHGHI
3.2.1 | Spectral data of representative
compounds
ppm: 8.28 (d, 2H, J = 8.4 Hz), 7.86 (d, 2H, J = 6.9 Hz),
7.78 (s, 1H), 7.50–7.46 (m, 3H), 7.43–7.39 (m, 2H), 5.74
(s. 2H). 13C NMR (75 MHz, CDCl3) δ ppm: 148.1, 141.7,
130.1, 128.9, 128.5, 128.5, 125.7, 124.3, 121.0, 119.7, 53.7.
MS (m/z): 280 (M+).
1-Benzyl-4-phenyl-1H-1,2,3-triazole (Table 2, Entries
11, 14) (4k)
1-(4-Chlorobenzyl)-4-phenyl-1H-1,2,3-triazole (Table 2,
Entry 16) (4n)
White crystal, m.p.: 128–130ꢁC (Lit.[44] 127–129ꢁC).
FT-IR (KBr, ν, cmꢃ1): 695 (s), 730 (s), 768 (s), 1044 (m),
1074 (m), 1223 (m), 1361 (w), 1450 (m), 2973 (w), 3141
1
(w). H NMR (300 MHz, CDCl3) δ ppm: 7.85–7.82 (m,
Pale yellow cottony solid, m.p.: 141–143ꢁC (Lit.[46]
143–144ꢁC). FT-IR (KBr, ν, cmꢃ1): 694 (s), 764 (s),
809 (s), 1018 (s), 1095 (s), 1217 (s), 1411 (m), 1460 (s),
1492 (s), 1597 (m), 1687 (w), 2998 (w), 3084 (m), 3125
(m). 1H NMR (300 MHz, CDCl3) δ ppm: 7.85 (d, 2H,
J = 7.2 Hz), 7.75 (s, 1H), 7.46–7.37 (m, 5H), 7.35–7.29 (m,
2H), 5.57 (s, 2H). 13C NMR (75 MHz, CDCl3) δ ppm:
148.2, 134.8, 133.2, 130.4, 129.3, 129.1, 128.8, 128.3, 125.7,
53.5. MS (m/z): 269 (M+).
2H), 7.69 (s, 1H), 7.46–7.39 (m, 5H), 7.37–7.33 (m, 3H),
5.6 (s, 2H). 13C NMR (75 MHz, CDCl3) δ ppm: 148.2,
134.7, 130.5, 129.1, 128.8, 128.1, 128.0, 125.7, 119.4, 54.2.
MS (m/z): 235 (M+).
1-(3-Nitrobenzyl)-4-phenyl-1H-1,2,3-triazole (Table 2,
Entry 12) (4l)
4 | RESULTS AND DISCUSSION
4.1 | Characterization of Cu@Arg-
MWCNT
White solid, m.p.: 148–150ꢁC (Lit.[45] 148–152ꢁC). FT-
IR (KBr, ν, cmꢃ1): 692 (m), 725 (s), 764 (s), 811 (w), 1075
(w), 1353 (s), 1465 (w), 1518 (s), 1612 (w), 2953 (w), 3084
Cu@Arg-MWCNT was synthesized, through the pathway
defined completely and shown in Scheme 2, as a novel,
green, powerful, recoverable, and reusable nanocatalyst.
After hydroxylation of MWCNTs via Fenton reaction
followed by reaction with epibromohydrin, utilization of
L-arginine amino acid as a natural ligand was our next
strategy in approaching to principles of green chemistry.
As the final step in the synthesis of our desired
nanocatalyst, we should immobilize Cu(0) nanoparticles
(CuNPs) on the Arg-MWCNTs by means of reduction of
Cu(II) salt in the presence of NaBH4. Results from differ-
ent characterization techniques such as FT-IR, XRD,
EDX, TGA, inductively coupled plasma (ICP), element
maps analysis (elemental mapping), a particle size analy-
sis (PSA), scanning electron microscopy (SEM), FE-SEM,
and TEM confirmed the successful synthesize of the
Cu@Arg-MWCNT catalyst.
1
(w), 3141 (w). H NMR (300 MHz, CDCl3) δ ppm: 8.27–
8.25 (m, 2H), 7.86–7.84 (m, 2H), 7.81 (s, 1H), 7.68–7.61
(m, 2H), 7.48–7.43 (m, 2H), 7.39–7.35 (m, 1H), 5.73 (s,
1H). 13C NMR (75 MHz, CDCl3) δ ppm: 145.9, 136.8,
133.8, 130.3, 128.9, 128.4, 125.7, 123.8, 122.8, 119.5, 53.2.
MS (m/z): 280 (M+).
1-(4-Nitrobenzyl)-4-phenyl-1H-1,2,3-triazole (Table 2,
Entries 13, 15) (4m)
Figure 1 shows comparative FT-IR spectral data of
pristine MWCNT (p-MWCNT), MWCNT-OH, EP-
MWCNT, Arg-MWCNT, and Cu@Arg-MWCNT, respec-
tively, from bottom to top. As it can be seen in Figure 1a,
the FT-IR spectrum of the p-MWCNT showed a band at
Yellow solid, m.p.: 154–156ꢁC (Lit.[23] 156–157ꢁC).
FT-IR (KBr, ν, cmꢃ1): 692 (m), 732 (m), 763 (m), 1045
(w), 1078 (w), 1222(w), 1351 (s), 1519 (s), 1465 (w), 1607
1
(w), 3084 (w), 3125 (w). H NMR (300 MHz, CDCl3) δ

KHOSHNEVIS AND ESHGHI
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SCHEME 2 Preparation of Cu@Arg-
MWCNT
FIGURE 1 Comparative FT-IR spectra of
(a) p-MWCNT, (b) MWCNT-OH, (c) EP-
MWCNT, (d) Arg-MWCNT, and (e) Cu@Arg-
MWCNT

8 of 18
KHOSHNEVIS AND ESHGHI
3444 cmꢃ1, which can be assigned to the ꢃOH stretching
vibrations of adsorbed water. The bands that appeared at
2925 and 2856 cmꢃ1 can be assumed for CꢃH stretching
vibrations, and a peak at 1631 cmꢃ1 is referred to C=C
stretching vibrations due to the graphitic structure of
MWCNTs. Appearance of a broad peak at 3428 cmꢃ1 in
Figure 1b corresponds to the stretching vibrations of the
OH group, which is a confirmation on great hydroxyl-
ation of the p-MWCNTs. Comparison of the peak area of
NH or OH, as it can be seen in Figure 1, reveals logical
increase or decrease in peak area depending on their
functionalization. In Figure 1c, peaks at 2902 and
1376 cmꢃ1, respectively, belong to the C–H stretching of
methylene groups of 2-methyloxirane and C–H bending,
the peak at 1552 cmꢃ1 corresponds to C=C stretching of
the MWCNTs, and a strong peak 1022 cmꢃ1 corresponds
to C–O stretching of aliphatic ether. In Figure 1d, appear-
ance of a peak with intense absorption at 3439 cmꢃ1 is
assigned to the N–H stretching, and a peak at 2920 cmꢃ1
is referred to C–H stretching. COOꢃ asymmetric and
symmetric stretching vibrations at 1645 and 1551, respec-
tively, confirm that the L-arginine has been attached
from its guanidinium part. A peak at 1065 corresponds to
stretching vibration of secondary alcohol. Appearance of
a new peak at 586 in the spectrum of the final catalyst
(Figure 1e) that refers to Cu–N stretching vibration con-
firms the coordination of copper with organic ligand.
The X-ray diffraction patterns of the Arg-MWCNT
and Cu@Arg-MWCNT are shown in Figure 2. XRD anal-
ysis was used in order to study the crystalline structure of
Cu@Arg-MWCNT (Figure 2b). The diffraction peaks
were observed in (2θ [ꢁ]) = 43.3, 51.2, and 74.6, which
correspond to (111), (200), and (220) planes of FCC lattice
of metallic CuNPs. CuNPs' sensitivity to the oxygen in
the air results in their oxidation to the copper(I) oxide
(Cu2O). So, according to JCPDS reference no 05-0667,
weak diffraction peaks at around (2θ [ꢁ]) = 29, 36.7,
42.65, 61.35, and 73.3 could be attributed to (110), (111),
(200), (220), and (311) planes of Cu2O, respectively.[47]
MWCNT is characterized by a sharp peak with high
intensity at (2θ [ꢁ]) = 26ꢁ corresponding to (002) plane
indices of MWCNT,[48] which is clearly notified in both
XRD patterns (Figure 2a,b). The absence of peaks relates
to CuNPs and Cu2O in XRD pattern of the Arg-MWCNT
(Figure 2a), and their appearance in XRD pattern of the
Cu@Arg-MWCNT (Figure 2b) strongly confirms
the anchoring of CuNPs in the final step of catalyst
synthesis.
The EDX spectrum of the Cu@Arg-MWCNT repre-
sented existence of the C, N, O, and Cu elements
(Figure 3). It should be noted that the unassigned peaks
related to the Au element, which has been used as top-
coat for the analysis.
Thermal stability of the Cu@Arg-MWCNT was inves-
tigated by TGA technique (Figure 4a) and also its com-
parison with TGA graph of the Arg-MWCNT (Figure 4b),
and their weight difference can be attributed to the
CuNPs anchored onto the Arg-MWCNT surface. As it
can be interfered from the TGA graph (Figure 4a), weight
loss of the catalyst with gentle slope from 80 to 440ꢁC has
happened, which can be considered (ffi7% weight loss,
below 200ꢁC) for evaporation of physically adsorbed
water molecules and (ffi20.5% weight loss, 200–440ꢁC) for
decomposition of functional groups like hydroxyl, car-
boxyl, and epoxy on the surface and inside of the
MWCNTs, and a severe reduction weight loss (ffi40.1%)
at about 440–520ꢁC is considered for complete decompo-
sition of zwitterionic organic components. In Figure 4a,b,
FIGURE 2 XRD pattern of (a) Arg-MWCNT and (b) Cu@Arg-
MWCNT
FIGURE 3 EDX spectrum of Cu@Arg-MWCNT

KHOSHNEVIS AND ESHGHI
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FIGURE 4 (a) TGA analysis of Cu@Arg-MWCNT, (b) comparison TGA analysis of Arg-MWCNT and Cu@Arg-MWCNT
FIGURE 5 Elemental mapping of Cu@Arg-MWCNT
Arg-MWCNT shows just two weight losses. Its first
weight loss with gentle slope occurs at the range of 100–
440ꢁC (ffi31% weight loss), and the second one with
severe reduction weight loss (ffi50%) occurs at about 440–
520ꢁC. The approximate molar % of the CuNPs (2.1%)
were calculated by considering the weight difference of
the Arg-MWCNTs with Cu@Arg-MWCNTs in 520ꢁC and
the molecular weight of the CuNPs. TGA analysis
showed that 1.000 g of the catalyst contains 2.1 mmol of
copper (amount of Cu is reported 13.4 wt%).
The ICP-AES analysis was used to determine the cop-
per content of the Cu@Arg-MWCNT quantitatively. The
ICP analysis showed that 1.000 g of the catalyst contains
1.83 mmol of copper (amount of Cu is reported 11.6 wt
%), which can be considered as a great confirmation of
CuNPs anchored to the arginine ligand linked to
MWCNTs.
surface of MWCNT and confirms no aggregation of Cu
species.
Utilization of SEM/FE-SEM technique was done to
define the morphology of the Cu@Arg-MWCNT surface.
The FE-SEM images are shown in Figure 6, which appar-
ently confirm high length of the MWCNTs and spherical
structure of CuNPs.
The TEM images of synthesized Cu@Arg-MWCNT
nanocatalyst in Figure 7, besides representation of the
cylindrical shape and high length of the MWCNTs, obvi-
ously confirmed the presence of the CuNPs on MWCNTs.
Figure 8 shows the particle size distribution of the
Cu@Arg-MWCNT catalyst, which determines the size
ranging from 37 to 770 nm and most of the nanoparticles
ranging from 37 to 300 nm. Nanoparticles with size up to
100 nm are considered to be fragmentary MWCNTs and
CuNPs. NPs with size over 100 nm belong to MWCNTs,
which greatly confirms high length of MWCNTs, which
has been previously interfered from the FE-SEM and
TEM results.
Distribution of elements (C, N, O, and Cu) was char-
acterized by using elemental mapping data. Figure 5a–e
reveals uniform dispersion of these elements on the

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KHOSHNEVIS AND ESHGHI
FIGURE 6 FE-SEM images of Cu@Arg-MWCNT with three magnifications: (a) 200 nm, (b) 500 nm, (c) 1 μm
FIGURE 7 TEM images of Cu@Arg-
MWCNT with two magnifications: (a) 50 nm,
(b) 200 nm
and investigated under various parameters such as reac-
tion time, temperature, and amount of catalyst and sol-
vents (Table 1). As can be seen in Table 1 (Entries 1–5),
the model reaction was carried out in water medium at
various temperatures (r.t., 50, 70, 90, and 110ꢁC), which
allowed us to select 70ꢁC as the most convenient in order
to achieve maximum conversion of the reactants at
shorter time reaction. As shown in Table 1 (Entries
7, 11–14), reaction in the absence of solvent and in the
presence of different solvents such as acetone, acetoni-
trile, methanol, and water in the presence of 0.01 g
Cu@Arg-MWCNT (2 mol% Cu) was estimated, and based
on the results, polar solvents were more effective in this
reaction, and the best result was obtained in the presence
of water. Various amounts of the catalyst were tested for
the model reaction (Table 1, Entries 6–10); in the absence
of catalyst even after 24 h, no progress was observed in
the reaction, and increase in amount of catalyst from
0.005 to 0.01 g resulted in improvement of the reaction
yields. The further increase in the amount of Cu@Arg-
MWCNT catalyst to 0.035 g just had negligible effects on
the efficiency of the reaction. Thus, 0.01 g of catalyst in
water as green solvent at 70ꢁC was selected as optimized
reaction condition, and a series of commercially available
epoxides/halides with electron-donating and electron-
FIGURE 8 Particle size distribution of Cu@Arg-MWCNT
4.2 | Catalytic performance of Cu@Arg-
MWCNT
After being characterized thoroughly, Cu@Arg-MWCNT
performance as a heterogeneous catalyst was assessed for
the synthesis of 1,4-disubstituted triazole derivatives
using CuAAC reaction. In order to obtain optimum con-
dition, the reaction between phenylacetylene, benzyl bro-
mide, and sodium azide was selected as a model reaction

KHOSHNEVIS AND ESHGHI
11 of 18
TABLE 1 Optimization of the reaction conditions for synthesis of 1,2,3-triazole (4k) via click reaction
Entry
Solvent
H2Oa
H2O
Catalyst (mg, mol%)
Temp. (ꢁC)
Time (h)
Yield (%)
1
5.0, 1
5.0, 1
5.0, 1
5.0, 1
5.0, 1
-
r.t.
50
2.5
2
20
63
84
69
52
0
2
3
H2O
70
1
4
H2O
90
0.58
0.5
24
1
5
H2O
110
70
6
H2O
7
H2O
10.0, 2
15.0, 3
25.0, 5
35.0, 7
10.0, 2
10.0, 2
10.0, 2
10.0, 2
70
92
86
87
94
52
29
43
83
8
H2O
70
1
9
H2O
70
0.75
0.5
3.5
3
10
11
12
13
14
H2O
70
-
70
Acetone
Acetonitrile
Methanol
70
70
3
70
1.5
aDeionized water.
TABLE 2 Synthesis of 1,4-disubstituted-1,2,3-triazoles (4a–4n) under optimized condition
Entry
Epoxide/halide
Time (h)
Triazole
Yield (%)
TON/TOF (hꢃ1
)
1
3
88
4400/1467
(Continues)

12 of 18
KHOSHNEVIS AND ESHGHI
TABLE 2 (Continued)
Entry
Epoxide/halide
Time (h)
Triazole
Yield (%)
TON/TOF (hꢃ1
)
2
2
91
4550/2275
3
1.5
90
4500/3000
4
2
90
4500/2250
5
1.25
92
4600/3680
6
2.5
91
4550/1820

KHOSHNEVIS AND ESHGHI
13 of 18
TABLE 2 (Continued)
Entry
Epoxide/halide
Time (h)
Triazole
Yield (%)
TON/TOF (hꢃ1
)
7
3.25
88
4400/1354
8
2
81
89
92
4050/2025
4450/8900
4600/3680
9
0.5
10
1.25
11
0.5
92
4600/9200
(Continues)

14 of 18
KHOSHNEVIS AND ESHGHI
TABLE 2 (Continued)
Entry
Epoxide/halide
Time (h)
Triazole
Yield (%)
TON/TOF (hꢃ1
)
12
3
86
4300/1433
13
14
15
16
1.5
91
90
89
88
4550/3033
4500/4500
4450/1483
4400/1760
1
3
2.5

KHOSHNEVIS AND ESHGHI
15 of 18
withdrawing groups, sodium azide, and phenylacetylene
were subjected to the azidolysis–cycloaddition reaction,
which resulted in desired 1,4-disubstituted-1,2,3-triazoles
in good to excellent yields within short reaction times
(Table 2).
Based on the results, it is presumed that ring opening
occur via SN 2 mechanism. As can be seen in Scheme 3 at
first step, aliphatic epoxides connect with CuNPs of the
catalyst and then the azide as nucleophiles attack at
its less hindered position. After that, formation of a
π-complex between phenylacetylene and Cu@Arg-
MWCNT results in a copper(I) acetylide intermediate.
Nucleophilicity of the triple bond enhances the coordina-
tion of the synthesized organoazide to the copper center
of the acetylide. As a result, attack of the Cβ of the
acetylide as a nucleophile to the terminal N atom of
the synthesized organoazide as electrophile followed by a
protonation finally leads in the formation of 1,2,3-triazole
ring as final product.
4.3 | Mechanistic evaluation of the
reaction in the presence of Cu@Arg-
MWCNT
Compound (4a) with trans-β-hydroxytriazole structure
1
that has been interfered from the H NMR coupling con-
stants suggests the proposed pathway of the reaction.
SCHEME 3 Proposed mechanism of the
reaction
FIGURE 9 Recycling of the Cu@Arg-
MWCNT in the synthesis of the triazole (4k)

16 of 18
KHOSHNEVIS AND ESHGHI
An exception has been happened at (4j), and primary
High regioselectivity of the Cu@Arg-MWCNT was
confirmed by detect of 1,4-disubstituted 1,2,3-triazoles as
the only product of the click reaction in its presence.
Based on a research resulting to easily distinguish
1,4-disubstituted 1H-1,2,3-triazoles from the isomeric
1,5-disubstituted 1H-1,2,3-triazoles,[49] appearance of a
13C signal of at δ ≈ 120 ppm for compound 4k, which is
due to C5 of the 1,4-disubstituted 1H-1,2,3-triazoles, was
a great confirmation on the high regioselectivity of our
catalyst. No 13C signal appearance at δ ≈ 133 ppm, which
is due to C4 of 1,5-disubstituted 1H-1,2,3-triazoles, also
showed that 1,4-disubstituted 1,2,3-triazoles were the
only products.
β-hydroxytriazole has been formed as the major product
instead of secondary ones. This event can be explicated
that in these cases, the electronic factor overcomes the
steric factor, which results in nucleophilic attack of
the azide at the sterically crowded benzylic position,
instead of the less substituted β-carbon.
4.4 | The recyclability and stability of the
Cu@Arg-MWCNT
Besides the high catalytic activity and ease of separation
of this novel heterogeneous nanocatalyst (Cu@Arg-
MWCNTs), it is noteworthy to mention that it is also
reusable up to five runs without any noticeable decrease
in its catalytic activity. For this purpose, after the comple-
tion of the first reaction, the Cu@Arg-MWCNT was sepa-
rated easily from the reaction mixture by centrifugation
and washed thoroughly with ethanol (3 ꢂ 10 mL) and
dried in the oven at 50ꢁC to be used for the next run. This
FIGURE 10 The FT-IR spectrum of the (top) fresh and
(bottom) the recycled catalyst after five times
FIGURE 11 FE-SEM images of (a) fresh catalyst and (b) recycled catalyst after five runs with three magnifications (A,A0 200 nm, B,B0
500 nm, C,C0 1 μm)

KHOSHNEVIS AND ESHGHI
17 of 18
TABLE 3 Comparison of click synthesis of 1,4-disubstituted 1,2,3-triazoles catalyzed by the Cu@Arg-MWCNT heterogeneous
nanocatalyst with other catalysts reported in the literatures
Entry
Catalyst
Solvent
H2O
Temp. (ꢁC)
Time (h)
Yield (%)
Ref.
[23]
1
2
3
4
5
6
7
Cu/C
100
90
1
0.75
2
91
95
92
93
96
92
92
[50]
[51]
[52]
[45]
[53]
CuAl2O4 NPs
H2O
GO-Salen-Zn
H2O
100
r.t.
70
Cu NPs
MeOH
H2O/PEG
EtOH
H2O
8
Cu-PEI@Fe3O4 MNPs
Silica-APTS-supported copper(I)
Cu@Arg-MWCNT
3
78
24
0.5
70
This work
process was repeated for each run. The results forcefully
confirmed the recyclability of this catalyst (Figure 9).
Comparison of the FT-IR spectra of the Cu@Arg-
MWCNT before being used in reaction (fresh catalyst)
and after being used for five times in model reaction
(recycled catalyst) as can be seen in Figure 10 greatly
confirms the structure stability of the catalyst.
The FE-SEM images of the fresh Cu@Arg-MWCNT
catalyst and after recycling for five runs have been shown
in Figure 11. Analogy of the fresh catalyst (Figure 11a)
with recycled one (Figure 11b) shows that the catalyst
has preserved its long cylindrical structure, which also
confirms the catalyst's structure stability.
of this catalyst strongly confirms its high regioselectivity.
This catalyst also has the ability to be recycled and reused
for several times without any significant decrease in its
catalytic efficiency and yields.
In conclusion, we introduced a new regioselective
and highly efficient heterogeneous nanocatalyst. High
catalytic activity in water medium and its reusability and
fidelity in principles of green chemistry are among its
interesting features that bring Cu@Arg-MWCNT up as a
unique catalyst.
ACKNOWLEDGMENTS
The authors gratefully acknowledge the vice-chancellor
of the Affairs of Research of Ferdowsi University of
Mashhad for financial support (Grant No. 3/47784).
4.5 | Comparison of Cu@Arg-MWCNT
with other catalysts
AUTHOR CONTRIBUTIONS
Mahsa Khoshnevis: Data curation; investigation.
Hossein Eshghi: Conceptualization; data curation;
methodology; supervision; validation; visualization.
In order to investigate the competency of our catalyst in
comparison with other catalysts, their catalytic activity
in synthesis of 1,2,3-triazole (4k) has been compared in
Table 3. According to the results shown in Table 3, this
new heterogeneous nanocatalyst has the ability to per-
form this reaction in shorter reaction time and mild
green conditions, which is another confirmation on its
efficiency.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are avail-
able in the Supporting Information of this article.
ORCID
Mahsa Khoshnevis https://orcid.org/0000-0003-3940-
9375
Hossein Eshghi https://orcid.org/0000-0002-8417-220X
5 | CONCLUSION
REFERENCES
Cu@Arg-MWCNT catalyst was synthesized via a simple
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such as FT-IR, FE-SEM, ICP, XRD, EDS, and mapping.
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reaction in the presence of Cu@Arg-MWCNT catalyst in
mild reaction conditions and short reaction time with
high to excellent yields is great confirmation on its high
catalytic activity. Synthesis of 1,4-disubstituted triazoles
as the only product of the click reaction in the presence
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How to cite this article: M. Khoshnevis,
H. Eshghi, Appl Organomet Chem 2021, e6281.
https://doi.org/10.1002/aoc.6281