Functionalized polytriazoles on graphene oxide-supported copper(I) complex as an effective reusable catalyst for sonochemical click synthesis of triazoles in aqueous media

Article abstract of DOI:10.1016/j.ica.2017.06.057

In the present study, a copper complex immobilized on graphene oxide was synthesized as a novel, green, highly efficient and reusable heterogeneous catalyst. Then, the synthesis of β-hydroxy-1,2,3-triazole derivatives were performed by the employment of G

Full text of DOI:10.1016/j.ica.2017.06.057

ꢀꢁꢁꢂꢃꢄꢂꢅꢆ ꢇꢈꢉꢊꢁꢋꢌꢃꢄ

Functionalized polytriazoles on graphene oxide-supported copper (I) complex
as an effective reusable catalyst for sonochemical click synthesis of triazoles in
aqueous media
Hossein Naeimi*, Zahra Ansarian
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, 87317-
51167, I.R. Iran; Fax: +98-03155912397; Tel: +98-03155912388;
E-mail: naeimi@kashanu.ac.ir
Abstract
In the present study, a copper complex immobilized on graphene oxide was synthesized as a
novel, green, highly efficient and reusable heterogeneous catalyst. Then, the synthesis of β-
hydroxy-1,2,3-triazole derivatives were performed by the employment of GO@polytriazole-Cu
as catalyst under ultrasound irradiation to afford the desired products in high yields and short
reaction times. Also, in this protocol the catalyst could be easily recovered and reused several
times without any significant loss of its catalytic activity.
Keywords: Ultrasound, Graphene oxide, Triazole, Catalyst, Click reaction, Complex.
1

1. Introduction
One of the key benefits of green chemistry is the replacement of the conventional heating
techniques with environmentally safe process such as the use of ultrasound. It has been used to
increase the reaction rates and give higher yields in a lot of organic reactions [1]. On the other
hand, catalysis is one of the substantial bases of green chemistry [2]. Elimination of trace
amounts of catalyst from the end product is necessary since metal contamination is highly
regulated, especially by the pharmaceutical industry. To overcome these problems, scientists
have investigated a numerous range of strategies and the use of heterogeneous catalyst systems
appears to be the best logical solution [3]. Recycling of organocatalysts is a significant aspect in
green chemistry. Thus, recent attainments in chemical performance have focused on use of
heterogeneous catalysts in organic reactions.
1,2,3-Triazole derivatives are usually acquired via the Huisgen’s azide–alkyne cycloaddition
(CuAAC reaction). Several copper sources have been demonstrated for the CuAAC, containing
simple halide salts and coordination complexes in homogeneous or heterogeneous form [4-7].
One-pot synthesis of 1,2,3-triazoles has been reported through heterogeneous catalytic systems
such as aminopropyl-silica-supported Cu nanoparticles [8], chitosan stabilized copper iron oxide
nanocomposite [9], CuFe2O4 nanoparticles [10], carbon-supported copper nanomaterials [11],
Cu[N2,N6-bis(2-hydroxyphenyl) pyridine-2,6-dicarboxamidate] [12].
A more generally suitable strategy that prevents the contamination of the metals in the reaction
products is the immobilization of the catalyst to a support such as mesoporous silica [13, 14],
zeolites [15, 16], polymers [17, 18], and activated carbons [19], which can be easily removed
from the final product, and ideally be reused for subsequent reactions. Among these support
systems, graphene oxide is a special support used in the preparation of heterogeneous catalysts
2

[20, 21]. Graphene, a two dimensional (2D) structure of sp2-bonded carbon atoms, has been
widely used in organic synthesis, materials chemistry, and biomedicine because of its high
specific surface area, chemical and thermal stability, very high electrical conductivity, non-
toxicity, flexibility.[22, 23] Graphene oxide surface contains polar functional groups including
alcohols, epoxides, and carboxylic acids [23-26]. Moreover, these functional groups have been
shown to be reactive toward some reactive groups such as isocyanate [27], chlorosulfonic acid as
the sulfonating reagent [28] and amine groups [29]. Functionalization of graphene oxide is the
important route to gain well interfacial bonding between graphene oxide sheets and functional
active site.
The various ligands have been employed in the preparation of copper complex as catalysts in
CuAAC reactions including (substituted) bipyridines [30, 31], (substituted) 1,10-
phenanthroline[30], tris(2-dioctadecylaminoethyl) amine[32], tris(1-benzyl-1H-1,2,3-triazol-4-
yl)-methanol[33]. Due to the interesting properties of GO as a support for the preparation of
heterogeneous catalytic system, herein, we report a preparation of GO-supported copper catalyst,
include 1,2,3-triazoles as copper (I)-stabilizing ligands in catalysis to prepare the β-hydroxy-
1,2,3-triazoles under ultrasound irradiation in water at room temperature.
2. Results and discussion
2.1. Preparation and characterization of the catalyst
The structures of heterogeneous Cu(I) complex and the intermediate steps were characterized by
Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDX),
X-ray diffraction(XRD), Field emission scanning electron microscopy (FE-SEM), Atomic-force
microscopy(AFM) andInductively coupled plasma (ICP) analyses.
3

Due to the fascinating properties of GO as support for the preparation of heterogeneous catalytic
system, we describe a preparation of GO-supported copper catalyst, include 1,2,3-triazoles as
copper(I)-stabilizing ligands (Scheme 1).
Scheme1. Preparation of GO@PTA-Cu organocatalyst
Figures 1a–e indicates the FT-IR spectra of graphite, GO, GO@CTS, GO@N3 and 1,2,3-
triazole-functionalized GO (GO@PTA), respectively. The FT-IR spectrum of natural graphite
powder has been exhibited in Fig. 1a. Figure1b shows the FT-IR spectrum of GO powder. The
stretching vibration at 3398 cm-1 in the GO (Fig. 1b) refers to the OH groups, and the absorption
band at 1717 cm-1 corresponds to C=O groups. As indicated in Fig. 1b, the absorption peaks at
1640 cm-1 and 1056 cm-1 are assigned to carbon–carbon double bonds and C-O, respectively. The
4

presence of numerous hydroxyl groups on the GO, provide active sites for the bonding between
GO sheets and silane. Figure 1c shows the FT-IR spectrum of the CPTES coated graphene oxide.
As can be seen in this Figure, the FT-IR absorption peak at 1045 cm-1 representing the Si–O–C
bond and the vibrational bands at 2926 cm-1 and 2854 cm-1 are attributed to CH2 groups. Also, the
presence of peak at 695 cm-1 is represented the C-Cl bond, which indicated the successful
coating of CPTES onto the graphene oxide through chemical bonding. The Fig. 1d is shown the
absorption peak of azide groups at 2098 cm-1. Figure 1e shows the FT-IR spectrum of the 1,2,3-
triazole-functionalized GO. In this Figure, the disappearance of peak at 2098 cm-1 indicated the
successful azide-alkyne coupling reaction on the nanosheets. Moreover, the N=N stretching
absorption for triazole compounds appeared nearly around 1457 cm-1.
Fig. 1. FT-IR spectra of (a) graphite, (b) GO, (c) GO@CTS, (d) GO@N3 and (e) GO@PTA
XRD patterns were analyzed to realize the phase structure of GO. Figure 2a-c shows XRD
patterns of graphite, GO and GO@PTA-Cu, respectively. The graphite powder shows a sharp
5

peak at 2ϴ= 26° (Figure 2a), corresponding to the interlayer spacing (d-spacing= 0.335 nm). The
exfoliated graphene oxide shows a broad peak at about 2ϴ = 26.5° and a peak at 2ϴ = 12° (d-
spacing=0.78 nm) (Figure 2b). The enhancement in d spacing is due to the intercalation of water
molecules and the formation of oxygen-containing functional groups between the layers of the
graphite. After the surface covalent functionalization of GO with CPTMS, click coupling process
and finally production of the GO@PTA-Cu catalyst, the diffraction peak at 2ϴ=12◦ compared to
GO was disappeared that indicated the increasing of interlayer distances (Figure 2c).
Fig. 2. XRD patterns of (a) graphite, (b) GO and (c) GO@PTA-Cu
The FE-SEM images of GO, GO@PTA-Cu are shown in Figure 3. Different morphologies were
observed for GO nanosheets and prepared catalyst. This images confirmed that two dimensional
GO nanosheets can be produced via exfoliation of suspended graphite oxide.
6

Fig. 3. FE-SEM images of (a) GO and (b) GO@PTA-Cu
Atomic force microscopy (AFM) is employed to observe the morphology of GO nanosheets and
measure their thickness. The AFM images of the GO and GO@PTA-Cu easily confirm the
wrinkled 2D characteristic of the GO nanosheets. The images indicate that the thicknesses of GO
was approximately 0.9 to 1.5 nm, corresponding to structures with 1 to 2 layers (Figure 4a).
After the surface functionalization, the thickness of sheets is increased to 4.3 nm (Figure 4b).
The addition in thickness of functionalized GO nanosheets is perhaps caused by the organic
compounds grafted on the graphene oxide sheets, indicating the successful functionalization of
GO.
7

Fig. 4. AFM images of (a) GO nanosheets and (b) GO@PTA-Cu
The Cu content of GO@PTA-Cu catalyst was determined by an inductively coupled plasma (ICP)
analyzer. According to the obtained results from ICP analysis, it was revealed the presence of
1.1% copper on the catalyst. Also, to support the mentioned observation, the catalyst was
subjected to energy dispersive X-ray. The EDX analysis of GO and GO@PTA-Cu catalyst
confirmed the presence of organosilane and copper on their regions (Figure 5a,b).
Fig. 5. EDS patterns of (a) GO and (b) GO@PTA-Cu
8

TGA was further employed to confirm the successful anchoring of organic groups on the surface
of GO. As shown in Figure 6, Below 260 °C, there was a mass loss (42%) that was attributable
to the removal of adsorbed water firstly and oxygen-containing functional groups on the GO
surface. Around 260–610 °C, a reduction occurred (24%), which is attributed to the covalency of
organic groups.
Fig. 6. TGA curve of GO@PTA-Cu
Thermogravimetric analysis can evaluate the amount of functional groups per carbon
atoms.[34] To estimate the amount of functionalization, weight loss values were used
together with the molecular weight of the different groups and equation (1) was applied.
(1)
where X stands for the number of carbon atoms in GO@PTA per covalent functional group,
R (%) is the residual mass at 610 °C in the TGA plot, L (%) is the weight loss between 260–
610 °C, and Mw is the molecular weight of the organic groups on the surface of GO.
9

According to equation 1, organic groups on the surface of GO measurements indicated that
there is one functional group every approximately 70 carbon atoms.
2.2. Investigation of catalyst activity
Initially, the reaction parameters such as catalyst amount (%), solvent and sonication time (min)
were optimized in the reaction of styrene oxide (1 mmol), phenylacetylene (1 mmol), NaN3 (1.1
mmol) as the model reaction (Scheme 2).
Scheme 2. Synthesis of 2-phenyl-2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethanol (3a).
To choose the medium of the reaction, different solvents were screened in the model reaction. It
was found that the reaction with using H2O after 7 min resulted in higher yield (Table 1).
Moreover, the reactions were clean in water compared to those in organic solvents. The results
are shown in Table 1.
Table 1. Solvent optimization for the synthesis of 3a in the model reactiona
Entry
Solvent
H2O
Time (min) Yieldb (%)
1
2
3
4
7
7
95
70
85
35
EtOH
H2O: MeOH
(50:50)
9
PhCH3
13
10

5
6
CH2Cl2
13
12
27
15
n-Hexane
a Reaction conditions: styrene oxide (1 mmol), phenylacetylene (1 mmol),
NaN3 (1.1 mmol), GO@PTA-Cu (10mg, 0.017 mol%), under ultrasound conditions,
b Isolated yields.
The amount of GO@PTA-Cu as a catalyst for this reaction was also evaluated. (Table 2) The
model reaction was carried out in the presence of different mole amounts of catalyst. The best
result was observed with 10 mg (Cu, 0.0017mmol) of the catalyst and the catalyst afforded 95%
yield of the product 3a at 7 min in water under ultrasound irradiation. No product was observed
in the absence of the catalyst Table 2, entry 1).
Table 2. The optimization of GO@PTA-Cu catalyst amount in the model reactiona
Entry Catalyst (mg)
Cu(mmol)
-
Time (min)
Yieldb (%)
1
2
3
4
5
0
2
30
10
7
-
0.00034
0.00086
0.0017
0.0034
73
92
95
90
5
10
20
7
8
aReaction conditions: styrene oxide (1 mmol), phenylacetylene (1 mmol), NaN3 (1.1 mmol), H2O, GO@PTA-Cu
(0.017%), under ultrasound conditions, b Isolated yields.
The effect of ultrasonic irradiation frequency on this reaction was also investigated. In this
regard, the sample model reaction was carried out at different irradiation powers in the range of
20–55 W and without ultrasound (Table 3).
11

As can be seen, without exposing the reaction to ultrasound irradiation, the product was not
obtained at room temperature for 120 min. (Table 3, entry 1). Moreover, the effect of ultrasonic
irradiation of different powers was examined. It was observed that reaction in the presence of
GO@PTA-Cu and ultrasonic irradiation at power of 45 W acquired the best yield of product, with
95 % isolated yield after 7 min (Table 3, entry 4). It means that the ultrasound can be accelerated
the rate of reaction and formation of pure products in high yields. The effects of ultrasound on
chemical reactions is related to the formation, growth and collapse of the hole in a liquid leading
to localized hot spots with high temperature, high pressure. Therefore, ultrasonic irradiation can
be employed as an alternative energy source for organic reactions ordinarily accomplished by
heating.
Table 3. The influence of ultrasonic irradiation on the synthesis of 3a in the model reactiona
Entry
Power
Silent
20
Time (min) Yieldb (%)
1
2
3
4
5
120
20
13
7
-
55
70
95
95
30
45
55
7
a Reaction conditions: styrene oxide (1 mmol), phenylacetylene (1 mmol),
NaN3 (1.1 mmol), GO@PTA-Cu (10mg, 0.017 mol%), under various ultrasound irradiation power at room
temperature,b Isolated yields.
After optimization of the reaction conditions, we performed these conditions for a series of
different aryl and alkyl-substituted oxiranes (1a-j) and terminal alkynes (2a,b) to probe the
12

versatility of the protocols under GO@PTA-Cu catalysis. The results are summarized in Table 4.
We first investigated the reaction of aryl-substituted epoxides with phenylacetylene (Table 4,
entries 1,2). The aryl-substituted epoxides 1a and 1b reacted rapidly, affording triazoles 3a and
3b, respectively, in high yields and short reaction times and with reverse regioselectivity to that
displayed by the alkyl-substituted epoxides. Subsequently, we examined the reaction between
aliphatic epoxides and phenylacetylene (Table 4, entries 3-10). In these cases, it was observed a
decrease in yield and increase in reaction time than the aryl-substituted epoxides. The formation
of bis-triazoles 3h from 1h and 1i in this reactions can be due to the existence of good leaving
groups (OTs, Cl) in the primary epoxides (Table 4, entries 8,9). The consumption of the internal
alkynes in this procedure led to the formation of product which resulted from the ring opening of
epoxide, without forming any triazole product (Table 4, entry 12). Furthermore, the structures of
these products were confirmed by 1H NMR and 13C NMR spectra.
Table 4. Synthesis of β-hydroxy-triazoles catalyzed by GO@PTA-Cu
Entry
1
Alkyne
(R2)
Epoxide
Product
T
Yieldb( TONc TOFd
(h-1)
549 4692
(min)
%)
7
95
(1a)
(1b)
(3a)
(3b)
2
7
95
549 4692
3
13
92
531 2447
13

(1c)
(1d)
(3c)
(3d)
4
14
93
537 2304
5
17
92
531 1876
(1e)
(3e)
6
12
90
520 2600
(1f)
(3f)
7
20
85
491 1474
(1g)
(1h)
(3g)
(3h)
8e
10
90
520 3113
14

9 e
17
16
82
90
473 1671
(1i)
(1j)
(3h)
10
520 1947
(3i)
11
12
10
30
90
520 3114
(1a)
(3j)
-
-
-
_
a General reaction conditions: 1 (1 mmol), 2 (1 mmol), NaN3 (1.1 mmol), GO@PTA-Cu (0.017 mol%, 10mg), H2O,
under ultrasound conditions,b Isolated yields. cTON: mole of formed β-hydroxy-1,2,3-triazole per mole of catalyst. d
TOF (h-1): (mmol of product/mmol of active site of catalyst)/ time of the reaction (h). e The reaction was done with
1 : 2 : 2 mol ratio of epoxide, alkyne and NaN3, respectively.
The recovery and reusability of catalysts are highly preferable for the green process. The
possibility of recycling the catalyst was investigated through the model reaction under optimized
conditions. Upon completion of the reaction, the catalyst was separated by filtration, washed
with methanol and drying at 80°C in an oven for 8h. The recycled catalyst could be reused five
times with no loss of catalytic activity so that the yields were ranged from 95 to 87 % (Figure 7).
15

Fig. 7. The reusability of the catalyst GO@PTA-Cu in the synthesis of (3a)
2.3. The proposed mechanism
The suggested mechanism for the formation of β-hydroxy-1,2,3-triazoles includes two routes
[35], in which GO@PTA-Cu has a two-fold catalytic impress as a bifunctional catalyst, which
incorporates one-pot ring opening and 1,3-dipolar cycloaddition. Firstly, GO@PTA-Cu catalyze
the formation of organoazide (II) from epoxide and sodium azide (Scheme 3).
16

Scheme 3. Proposed mechanism for synthesis of β-hydroxy-1,2,3-triazoles
Also, a π-complex is formed between phenylacetylene and GO@PTA-Cu to obtain the copper (I)
acetylide intermediate (III) the generation and disappearance of the organoazide intermediate
being monitored by TLC. Coordination of the organoazide to the copper center of the acetylide
enhances the nucleophilicity of the triple bond and initiates a sequence of steps which finally
results in the formation of the new C-N bond between the nucleophilic β-carbon atom of the
acetylide and the terminal, electrophilic nitrogen atom of the azide.[36]
Ultimately, after protonation of intermediate (IV), β-hydroxy-1,2,3-triazole is obtained in high
yield and short reaction time.
17

3. Conclusion
In conclusion, we have successfully demonstrated that a straightforward, clean, eco-friendly,
efficient and cost-effective synthesis of 1,2,3-triazoles in an aqueous medium water under
ultrasound irradiation. Furthermore, in this research we have designed a heterogeneous catalyst
based on GO@polytriazole-Cu. These polytriazole ligands on the surface of GO not only
stabilize Cu(I) intermediates but also advance the catalytic process. The prepared catalyst was
characterized using various techniques such as; FT-IR, FE-SEM, ICP, EDS, AFM and XRD
techniques. These results confirmed that the functionalization of GO was performed.
4. Experimental section
4.1 Materials and Apparatus
The chemicals used in this work were purchased from Fluka and Merck Chemical Companies
and used without purification. IR spectra were obtained as KBr pellets on a Perkin-Elmer 781
1
13
spectrophotometer and on an impact 400 Nicolet FT-IR spectrophotometer. H NMR and C
NMR were recorded in CDCl3 and DMSO solvents on a Bruker DRX-400 MHz spectrometer
with tetramethylsilane as internal reference. A Bandelin ultrasonic HD 3200 with 6 mm diameter
model KE 76 probe was used to generate ultrasonic irradiation and homogenize the reaction
mixture. The piezoelectric crystals in this kind of probe normally work at approximately 700
kHz; by use of appropriate clamps. However, the output frequency of piezoelectric crystals was
controlled and reduced to 20 kHz in the reaction mixture. XRD patterns were recorded by an
X'PertPro (Philips) instrument with 1.54 °A wavelengths of X-ray beam and Cu anode material,
at a scanning speed of 2° min-1 from 10° to 80° (2ϴ). The SEM images of prepared catalysts
18

were taken on a FE-SEM Hitachi S4160 instrument. The AFM image of GO nanosheets and
functionalized graphene oxide were measured using scanning probe microscopy (SPM-9600,
Shimadzu). Melting points obtained with a Yanagimoto micro melting point apparatus. The
purity determination of the substrates and reaction monitoring were accomplished by TLC on
silica-gel polygram SILG/UV 254 plates (from Merck Company).
4.1.Preparation of catalyst
Catalyst preparation involves several steps as followed:
4.1.1 Preparation of graphene oxide
Graphene oxide was synthesized by Hummers method.[37] Graphite powder (5.0 g) was stirred
in the presence of sodium nitrate (2.5 g) and sulfuric acid (115 mL) placed in an ice bath. Then,
potassium permanganate (15 g) was slowly added to mixture and stirred for 2 h. The mixture
solution was transferred to a water bath (35 °C) and stirred for 30 min. Afterward of deionized
water (230 mL) was added into the solution slowly and the solution temperature monitored was
about 98 °C and stirred for 15 min. Then deionized water (700 mL) and H2O2 (50 mL, 30%) was
added to the solution respectively. The obtained suspension was filtered and washed by diluted
HCl (5%) and deionized water several times and dried at 60°C under vacuum. The graphite oxide
was dispersed in distilled water to get a concentration of 0.5 mg mL-1 and exfoliated by
ultrasound to obtain GO nanosheets.
4.1.2 Synthesis of 3-chloropropyltrimethoxysilane functionalized GO (GO@CTS)
Graphene oxide (1g) was dispersed in 250 mL anhydrous toluene by using an ultrasonic probe.
Subsequently, 3.0 mL of CTS was diluted in 20 mL dry toluene that followed by drop wise
19

addition to the graphene oxide dispersion. The reaction mixture was stirred and heated to reflux
for 48 h under nitrogen atmosphere. After completion of the reaction, functionalized graphene
oxide nanosheets were washed with toluene and ethanol to remove excess CTS and then dried
under in an oven at 70 °C [38, 39].
4.1.3 Preparation of GO@N3
In a 1000 mL round-bottom flask, 1.0 g of the GO@CTS was added into deionized water (150
mL), followed by sonication (35 W) for 5min. Then, 2g of NaN3 and 0.2 g KI were added into
the reaction vessel, heating at 60°C for 48 h. After this step, the resulted product was washed
with water several times and dried at 50 °C in vacuum.
4.1.4 Huisgen 1,3-dipolar cycloaddition between azide functionalized GO (GO@N3) and
tripropargylamine
The azide functional GO, was attached to the alkyne groups by a copper catalyzed azide/alkyne
“click” reaction (Scheme 1). The azide-functionalized GO (1g) was dispersed in 250 mL
deionized water by using an ultrasonic probe. Subsequently, tripropargylamine(0.6 g) and copper
catalyst based CuSO4 and sodium ascorbate (0.05 and 0.1 equiv, respectively) were added into
the reaction vessel. The reaction was performed for 48 h at room temperature. After this step, the
resulted product was washed with water several times and dried under vacuum overnight.
4.1.5 Preparation of copper complex catalyst immobilized on GO(GO@PTA-Cu)
1,2,3-triazole-functionalized GO (1g) was dispersed in 250 mL dry acetonitrile by using
ultrasonication. In the subsequent step, CuI (0.26 mmol, 0.05 g) was added to the stirring
20

mixture. This mixture was refluxed for 24 h. After completion of the reaction, the immobilized
catalyst was filtered and washed with CH3CN and dried under vacuum overnight.
4.2 Typical procedure for the preparation of β-hydroxy-1,2,3-triazoles catalyzed by
GO@PTA-Cu under ultrasound irradiation
A mixture of NaN3 (72mg, 1.1mmol), epoxide (1mmol), alkyne (1mmol) and GO@PTA-Cu
(10mg, 0.017mol%) in water (5mL) was sonicated at 45 kHz at room temperature for 7 min.
After completion of the reaction, the solid product was dissolved in hot methanol and was
filtered under reduced pressure using a vacuum pump over sintered glass. The solvent was
eliminated under vacuum to give product 3a in 95% yield.
2-Phenyl-2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethanol (3a). Pale yellow solid: mp. 125.0–127.0
°C, Lit.[40] (mp. 125.5–127.0 °C). IR (KBr): ν= 690, 758, 1047, 1080, 1241, 1438, 1463, 1493,
1
1593, 2928, 3065, 3089, 3140, 3345. H NMR (400 MHz, CDCl3) δ= 3.21 (t, J(H, H) = 6.8 Hz;
3
3
3
1H, OH), 4.22-4.27 (dd, 1H, J(H–H) = 14.4 Hz, J(H–H) = 3.6), 4.60-4.67 (dd, 1H, J(H–H) =
12.4 Hz, 3J(H–H) = 7.6), 5.69 (dd, 3J(H–H) = 8 Hz, 3J= 3.9 Hz, 1H), 7.33 (s, 1H), 7.38-7.42 (m,
6H), 7.70 (s, 1H), 7.79-7.80 (m, 3H).
2-(4-Phenyl-1H-1,2,3-triazol-1-yl)-2-p-tolylethanol (3b). Yellow solid: mp. 125.0–127.0 °C,
Lit.[41] (mp. 124.0–126.0 °C). IR (KBr): ν= 697, 726, 757, 1047, 1075, 1008, 1185, 1221, 1380,
1
1457, 1497, 2927, 3028, 3092, 3417. H NMR (400 MHz, CDCl3) δ= 2.37 (t, J(H, H) = 2.8 Hz;
3
3
3
1H), 2.38 (s, 3H), 4.20-4.25 (dd, 1H, J (H–H) = 9 Hz, J (H–H) = 3.6), 4.61-4.65 (dd, 1H, J
3
3
3
(H–H) = 12.6 Hz, J (H–H) = 8.4), 5.65-5.68 (dd, J (H,H) = 8 Hz, J= 3.2 Hz, 1H), 7.20-7.27
(m, 3H), 7.39 (m, 3H), 7.65-7.69(m, 3H).
21

1-(4-Phenyl-1H-1,2,3-triazol-1-yl)butan-2-ol (3c). White solid: mp. 110.0–112.0 °C, Lit.[35]
(mp. 110.0–111.0 °C) IR (KBr): ν= 697, 763, 981, 1079, 1136, 1228, 1456, 1617, 2926, 2962,
1
3138, 3254, 3419. H NMR(400 MHz, CDCl3) δ= 1.05-1.09 (t, 3H), 1.53-1.66 (m, 2H), 2.65-
2.66(d, 3J(H–H) = 4.4, 1H), 4.1-4.27(m, 1H), 4.28-4.33 (dd, 1H, J(H–H) = 13.8 Hz, 2J(H–H) =
3
7.6), 4.50-4.55 (dd, 1H, 3J(H–H) = 14 Hz), 7.34 (m, 1H), 7.40-7.43 (m, 2H), 7.79-7.80 (m, 2H),
7.87 (s, 1H).
1-Phenoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (3d). Pale yellow solid: mp. 125.0–
127.0 °C, Lit.[42] (mp. 125.5–126.0 °C). IR(KBr): ν= 692, 756, 981, 1043, 1245, 1494, 1595,
1
2866, 2927, 3087,3429. H NMR (400 MHz, CDCl3) δ= 3.76-3.94 (m, 1H), 4.04-4.22 (m, 2H),
4.54-4.56 (m, 2H), 4.73-4.75 (m, 1H), 6.91-6.93(m, 2H), 6.94-7.02 (m, 1H), 7.27-7.31 (m, 3H),
7.38-7.40 (m, 2H), 7.73-7.75 (m, 2H), 7.89 (s, 1H).
1-isopropoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (3e). Yellow solid: mp. 62.0–64.0
°C, Lit.[35] (mp. 61.0–63.0) R (KBr): ν= 697, 765, 923, 975,1078, 1127, 1228, 1373, 1466,
2867, 2973, 3062, 3137, 3425.1H NMR (400 MHz, CDCl3) δ= 1.15–1.17 (d, 6H), 3.36-3.41 (dd,
1H, 3J(H–H) =10 Hz, J(H–H) = 4), 3.51-3.53 (dd, 1H,3J(H–H) = 8 Hz, J(H–H) = 4.4), 3.57-
3.64 (m, 1H), 4.21 (m, 1H), 4.40-4.64 (dd, 1H, 3J(H–H) = 14 Hz, 2J(H–H) = 4), 4.57-4.60 (dd,
1H, 3J(H–H) =12 Hz, 2J(H–H) = 2.8), 7.31-7.34 (m, 1H), 7.37-7.42 (m, 2H), 7.78-7.79 (m, 2H),
7.91 (s, 1H).
3
3
2-(4-Phenyl-1H-1,2,3-triazol-1-yl)cyclohexanol (3f). Yellow solid: mp. 168.0–172.0 °C, Lit.
[40] (mp. 168.0–171.0 °C). IR (KBr): ν = 698, 768, 713, 1052, 1083, 1234, 1441, 2858, 2938,
3118, 3307. 1H NMR (400 MHz, CDCl3) δ= 0.9 (m, 2H), 1.26-1.51 (m, 4H), 1.91-2.01 (m, 2H),
4.09-4.11 (m, 1H), 4.16-4.19 (m, 1H), 7.3 (d, 1H), 7.72-7.74 (m, 2H), 7.79 (s, 1H).
22

2-Hydroxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propyl acrylate (3g). Livid solid: mp. 102.0–
104.0 °C, Lit.[35] (mp. 101.0–103.0 °C) IR (KBr): ν= 695, 756, 1044, 1245, 1494, 1596, 2925,
3087, 3426. 1H NMR (400 MHz,CDCl3) δ= 3.37-3.38 (dd, 1H), 3.95-4.07 (m, 2H), 4.55-4.65 (m,
2H), 4.73-4.79 (m, 1H), 6.91-6.92 (m, 2H), 6.98-7.02 (t, 1H), 7.31-7.35 (m, 2H), 7.40-7.43 (m,
2H), 7.77-7.79 (m, 1H), 7.91 (s, 1H).
1,3-Bis(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (3h). Green solid: mp. 233.0–236.0 °C,
Lit.[43] (mp. 233.0–236.0 °C).IR (KBr): ν= 687, 724, 763, 1074, 1126, 1278, 1464, 1729,
1
2861,2928, 2959. H NMR (400 MHz, DMSO) δ= 4.40 (m, 2H), 4.56-4.61 (d, 1H), 5.81 (m,
13
1H), 7.30-7.32 (m, 1H), 7.42-7.44 (m, 2H), 7.84 (m, 2H), 8.55 (s, 1H). C NMR (400) MHz,
DMSO) δ= 54.84, 69.91, 124.12, 126.72, 127.11, 129.41, 129.68, 130.51, 132.42, 147.71.
1-(4-Phenyl-1H-1,2,3-triazol)hexan-2-ol (3i). Cream solid: mp. 92.0–94.0 °C, Lit.[41] (mp.
91.0–93.0 °C). IR (KBr): ν= 693, 764, 1087, 1138, 1228, 1463, 2862, 2925, 2959, 3142, 3248,
1
3407. H NMR (400 MHz, CDCl3) δ= 0.91-0.95 (t, 3H), 1.37-1.45 (m, 3H), 1.50-1.57 (m, 3H),
4.13-4.15 (m, 1H), 4.23-4.29 (m, 1H), 4.49-4.52 (m, 2H), 7.32-7.35 (m, 1H), 7.41-7.42 (m, 2H),
13
7.75-7.78 (m, 2H), 7.85 (s, 1H). C NMR (400 MHz, CDCl3) δ= 13.99, 22.59, 28.01, 34.17,
56.34, 70.44, 121.16, 125.53, 128.06, 128.78, 130.33, 147.27.
2-Phenyl-2-(4-propyl-1H-1,2,3-triazol-1-yl)ethanol (3j). Pale yellow solid: mp. 62.0–64.0 °C.
1
IR (KBr): ν= 697, 761, 1070, 1280, 1455, 1726, 2853, 2925, 3061, 3367. H NMR (400 MHz,
CDCl3) δ= 0.94 (m, 3H), 1.25-1.32 (m, 4H), 1.40-1.44 (m, 1H), 1.68–1.8 (t, 1H), 4.17-4.24 (m,
2H), 7.33-7.46 (m, 3H), 7.53-7.55 (m, 1H), 7.72 (m, 1H), 7.80 (s, 1H).
Acknowledgements
The authors are grateful to the University of Kashan for supporting this work by grant number
159148/77.
23

References
[1]
[2]
[3]
P. Cintas, J.-L. Luche, Green Chem. 1 (1999) 115-125.
V. Polshettiwar, R.S. Varma, Green Chem. 12 (2010) 743-754.
C. Copéret, M. Chabanas, R. Petroff Saint‐Arroman, J.M. Basset, Angew. Chem. Int. Ed. 42
(2003) 156-181.
[4]
[5]
[6]
M. Meldal, C.W. Tornøe, Chem. Rev. 108 (2008) 2952-3015.
T. Jin, M. Yan, Y. Yamamoto, ChemCatChem 4 (2012) 1217-1229.
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.
X. Xiong, L. Cai, Y. Jiang, Q. Han, Eng 2 (2014) 765-771.
R.P. Jumde, C. Evangelisti, A. Mandoli, N. Scotti, R. Psaro, J. Catal. 324 (2015) 25-31.
M. Chetia, A.A. Ali, D. Bhuyan, L. Saikia, D. Sarma, New J. Chem. 39 (2015) 5902-5907.
A.S. Kumar, M.A. Reddy, M. Knorn, O. Reiser, B. Sreedhar, Eur. J. Org. Chem. 2013 (2013)
4674-4680.
[7]
[8]
[9]
[10]
[11]
[12]
[13]
A. Shaygan Nia, S. Rana, D. Döhler, F. Jirsa, A. Meister, L. Guadagno, E. Koslowski, M. Bron,
W.H. Binder, Chem. Eur. J. 21 (2015) 10763-10770.
H. Sharghi, M. Hosseini‐Sarvari, F. Moeini, R. Khalifeh, A.S. Beni, Helv. Chim. Acta 93 (2010)
435-449.
Q. Yue, Y. Zhang, C. Wang, X. Wang, Z. Sun, X.-F. Hou, D. Zhao, Y. Deng, J. Mater. Chem. A
3 (2015) 4586-4594.
[14]
[15]
Z. Wang, X. Yang, J. Yang, Y. Jiang, N. He, Anal. Chim. Acta 862 (2015) 53-63.
W. Zhang, J. Chen, R. Liu, S. Wang, L. Chen, K. Li, ACS Sustainable Chem. Eng. 2 (2014) 683-
691.
[16]
[17]
Y. Tonbul, M. Zahmakiran, S. Özkar, Appl. Catal., B 148 (2014) 466-472.
N. Salam, B. Banerjee, A.S. Roy, P. Mondal, S. Roy, A. Bhaumik, S.M. Islam, Appl. Catal., A
477 (2014) 184-194.
[18]
[19]
J. Mondal, A. Biswas, S. Chiba, Y. Zhao, Sci. Rep. 5 (2015).
W. Chen, J. Ji, X. Duan, G. Qian, P. Li, X. Zhou, D. Chen, W. Yuan, Chem. Commun. 50 (2014)
2142-2144.
[20]
[21]
[22]
[23]
N.M. Julkapli, S. Bagheri, Int. J. Hydrogen Energy 40 (2015) 948-979.
R.H. Fath, S.J. Hoseini, J. Organomet. Chem. 828 (2017) 16-23.
O.C. Compton, S.T. Nguyen, small 6 (2010) 711-723.
D.R. Dreyer, S. Park, C.W. Bielawski, R.S. Ruoff, Chem. Soc. Rev. 39 (2010) 228-240.
24

[24]
K. Haubner, J. Murawski, P. Olk, L.M. Eng, C. Ziegler, B. Adolphi, E. Jaehne, Chemphyschem
11 (2010) 2131-2139.
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
K.P. Loh, Q. Bao, P.K. Ang, J. Yang, J. Mater. Chem. 20 (2010) 2277-2289.
S. Park, R.S. Ruoff, Nat. Nanotechnol. 4 (2009) 217-224.
S. Stankovich, R.D. Piner, S.T. Nguyen, R.S. Ruoff, Carbon 44 (2006) 3342-3347.
L. Wang, D. Wang, S. Zhang, H. Tian, Catal. Sci. Technol. 3 (2013) 1194-1197.
Y. Yang, J. Wang, J. Zhang, J. Liu, X. Yang, H. Zhao, Langmuir 25 (2009) 11808-11814.
W.G. Lewis, F.G. Magallon, V.V. Fokin, M. Finn, J. Am. Chem. Soc. 126 (2004) 9152-9153.
T.R. Chan, R. Hilgraf, K.B. Sharpless, V.V. Fokin, Org. Lett. 6 (2004) 2853-2855.
N. Candelon, D. Lastécouères, A.K. Diallo, J.R. Aranzaes, D. Astruc, J.-M. Vincent, Chem.
Commun. (2008) 741-743.
[33]
[34]
S. z ubuk u , E. Ozkal, C. Jimeno, M.A. Pericas, Org. Lett. 11 (2009) 4680-4683.
J.M. Gónzalez-Dominguez, M. Gonzalez, A. Anson-Casaos, A. Diez-Pascual, M. Gomez, M.
Martinez, J. Phys. Chem. C 115 (2011) 7238-7248.
[35]
[36]
H. Naeimi, V. Nejadshafiee, New J. Chem. 38 (2014) 5429-5435.
J.E. Hein, J.C. Tripp, L.B. Krasnova, K.e.B. Sharpless, V.V. Fokin, Angew. Chem. 121 (2009)
8162-8165.
[37]
[38]
[39]
[40]
[41]
[42]
S. William, J. Hummers, R.E. Offeman, J. Am. Chem. Soc. 80 (1958) 1339.
M.A. Nasseri, A. Allahresani, H. Raissi, RSC Adv. 4 (2014) 26087-26093.
H.P. Mungse, S. Verma, N. Kumar, B. Sain, O.P. Khatri, J. Mater. Chem. 22 (2012) 5427-5433.
F. Alonso, Y. Moglie, G. Radivoy, M. Yus, J. Org. Chem. 76 (2011) 8394-8405.
J. Yadav, B.S. Reddy, G.M. Reddy, D.N. Chary, Tetrahedron Lett. 48 (2007) 8773-8776.
H. Sharghi, M.H. Beyzavi, A. Safavi, M.M. Doroodmand, R. Khalifeh, Adv. Synth. Catal. 351
(2009) 2391-2410.
[43]
T. Boningari, A. Olmos, B.M. Reddy, J. Sommer, P. Pale, Eur. J. Org. Chem. 2010 (2010) 6338-
6347.
25

Graphical Abstract
In the present study, a copper complex immobilized on graphene oxide was synthesized as a
novel, green, highly efficient and heterogeneous reusable catalyst. Then, the synthesis of β-
hydroxy-1,2,3-triazole derivatives were performed by the employment of GO@polytriazole-Cu
as catalyst under ultrasound irradiation to afford the desired products in high yields and short
reaction time.
26