Copper immobilized ferromagnetic nanoparticle triazine dendrimer (FMNP@TD-Cu(ii))-catalyzed regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles

Article abstract of DOI:10.1039/c5nj03219a

A copper immobilized ferromagnetic nanoparticle triazine dendrimer (FMNP@TD-Cu(ii)) has been demonstrated for the first time as a recoverable and reusable heterogeneous nanocatalyst in the click synthesis of 1,4-disubstituted 1,2,3-triazoles by a one-pot three component reaction of halides, sodium azides and alkynes under mild conditions. The catalyst is very easy to handle and is environmentally safe and economical. FMNP@TD-Cu(ii) was characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR and EDX methods.

Full text of DOI:10.1039/c5nj03219a

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ARTICLE TYPE
Copper immobilized on ferromagnetic nanoparticles triazine dendrimer
(FMNPs@TD-Cu(II))‑catalyzed regioselective synthesis of 1,4-
disubstituted 1,2,3-triazoles
Kiumars Bahrami,*a,band Mehdi Sheikh Arabia
5
Received (in XXX, XXX) XthXXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
Copper immobilized on ferromagnetic nanoparticles triazine
40 However, the active sites in heterogeneous catalysts are not as
accessible as in a homogeneous catalysts, and so the activity of
the catalyst is usually decreased. Consequently, we need a
catalyst system that not only demonstrates high activity and
selectivity (such as a homogeneous system) but also possesses the
45 ease of catalyst separation and recovery (such as a heterogeneous
system). These objectives can be obtained by nanocatalysis.
Nanocatalysts bridge the gap between homogeneous and
heterogeneous systems, keeping the desirable attributes of both
systems.4
dendrimer (FMNPs@TD-Cu(II)) has been demonstrated for
the first time as a recoverable and reusable heterogeneous
10 nanocatalyst in the click synthesis of 1,4-disubstituted 1,2,3-
triazoles by a one-pot three component reaction of halides,
sodium azide and alkynes under mild conditions. The catalyst
is very easy to handle and is environmentally safe and
economical. FMNPs@TD-Cu(II) was characterized by
15 transmission electron microscopy (TEM), scanning electron
microscopy (SEM), X-ray diffraction (XRD), FT-IR and EDX
methods.
50 Thus, nanocatalysts enjoy several advantages over conventional
catalyst systems; however, separation and recovery of these tiny
nanocatalysts from the reaction mixture is difficult. To overcome
this problem, the use of magnetic nanoparticles has appeared as a
viable solution; their insoluble and paramagnetic nature enables
55 easy and effective separation of these catalysts from the reaction
mixture with an external magnet.4
1 Introduction
During the last few decades, a central focus of modern synthetic
20 organic chemistry is the design of new reactions and synthesis
strategies that make easy the synthesis of biologically active
compounds with potential application in the pharmaceutical or
agrochemical industries.
Ferromagnetic nanoparticles (FMNPs) have included an
increasing attention in the fields of nanoscience and
nanotechnology because of their incomparable and novel
60 physicochemical properties that can be achieved in the light of
their particle size and morphology. FMNPs improved with
organic compounds have been widely employed for biomedical,
biotechnological, and environmental applications, because their
properties can be magnetically managed by applying an external
65 magnetic field.5 In general, it makes accessible high potential
applications, like DNA extraction, cell separation, gene directing,
drug delivery, magnetic resonance imaging and heavy metal ion
removal.6
Dendrimers are considered as the fourth generation of
25 macromolecule building which have potential applications in
biology, chemistry, and material science.1 Generally, dendrimer
synthesis is performed in solution phase. Incomplete and side
reactions are two distinctive problems associated with dendrimer
preparation and magnitude of these problems increases when
30 dendrimer synthesis is carried out on solid phase. It requires great
efforts to optimize reaction conditions to remove these problems
and because of this, there are only few reports on solid phase
dendrimer synthesis.2
By immobilizing homogeneous catalysts on insoluble supports,
35 the benefits of both homogeneous as well as heterogeneous
catalysts are obtained. These catalysts can be separated simply
from the products by a simple filtration. In the past years, some
dendrimers covalently-bonded to the inorganic or polymeric
supports have been competently prepared.3
Triazoles are an important class of heterocyclic organic
70 compounds and have a large spectrum of biological activities like
antiallergenic,7 anti-infective agents,8 anti-HIV,9 and anti-
bacterial.10 In addition, compounds belonging to this class are
also useful as dyes, corrosion inhibitors, photographic materials,
and photosensitizers.11
a Department of Organic Chemistry, Faculty of Chemistry, Razi
University, Kermanshah 67149-67346, Iran.
bNanoscience and Nanotechnology Research Center (NNRC), Razi
University, Kermanshah, 67149-67346, Iran. E-mail:
kbahrami2@hotmail.com; Fax: +98(833)4274559; Tel:
+98(833)4274559.
75 For the synthesis of 1,2,3-triazoles several synthetic methods
using various catalysts12-14 are accessible. Although, some of the
reported methods are satisfactory, from the synthetic efficiency
point of view, many of these methods suffer drawbacks such as
† Electronic Supplementary Information (ESI) available: Experimental
details, including 1H and 13C NMR spectra for products. See
DOI: 10.1039/b000000x/
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tedious work-up procedures, long reaction times, low yields, 55 corresponding Cu(II) supported on magnetic nanoparticles
drastic reaction conditions, co-occurrence of several side
reactions, or the use of organic solvents remain problematic.
Another drawbacks of some of the existing methods is that the
catalysts are destroyed during the work-up procedure and cannot
be recovered and reused. Therefore, the introduction of efficient
and green approaches using recoverable and reusable catalysts for
the preparation of titled compounds is highly desirable.
(FMNPs@TD-Cu(II)). The characterization of the catalyst was
carried out by FT-IR, TGA, XRD, EDX, SEM, and TEM.
NH2
5
Cl
O
O
O
N
N
60
65
70
75
N
TEOS
(EtO)3SiCH2CH2CH2NH2
EtOH-H2O, 25 °C, 8 h
Cl
Cl
Among the various procedures for the regioselective synthesis of
Fe3O4
SiO2
Fe3O4
SiO2
Fe3O4
THF, 25 °C, 10 h
EtOH, 60 °C, 14h
10 triazoles, development of copper catalysed azide alkyne
cycloaddition (CuAAC) proved to be an important milestone in
the synthesis of 1,2,3-triazoles.15-20
FMNPs
FMNPs-PA
MW= 58.1
Cl
N
N
Cl
N
N
Cl
Nanocatalysis has become an active area of research, because
these materials exhibit better catalytic activity due to the
15 enhanced surface area towards organic transformations.21 Copper-
supported magnetic nanoparticles have been investigated for the
preparation of 1,4-disubstituted 1,2,3-triazoles.22
Cl
N
H2N
N
NH2
HN
NH
HN
N
NH
HN
N
NH
Cl
N
Cl
N
N
N
N
N
N
NH
NH
NH
In order to further improve the practicality of the CuAAC
reaction and as a part of our ongoing research on the development
20 of useful synthetic protocols,23 herein, we describe a convenient
and efficient one-pot method for the synthesis of 1,4-disubstituted
Cl
N
O
O
O
O
O
O
O
O
O
N
N
H2NCH2CH2NH2
DMF, 60 °C, 12 h
Cl
Cl
H2NCH2CH2NH2
DMF, 60 °C, 14 h
Fe3O4
SiO2
Fe3O4
SiO2
Fe3O4
SiO2
THF, 25 °C, 14 h
1,2,3-triazoles compounds using FMNPs@TD-Cu(II) as
a
FMNPs-CC1
MW= 206.0
FMNPs-TD (G1)
MW= 253.3
FMNPs-CC2
MW= 543.3
recoverable and reusable nanocatalyst under mild conditions
(Scheme 1).
NH2
HN
N
25
30
35
N
H
N
N
N
N
H
NH2
NH2
R2
O
R1
R2
H
N
H
Cu(OAc)2
N
FMNPs@TD-Cu(II)
H
N
N
Fe3O4
O
Si (CH2
)
N
3
NaN3
N
H
N
DMF, 25 °C, 6 h
N
N
O
NH
SiO2
EtOH-H2O/Na2CO3, 25 C
X
R1
N
H
N
N
FMNPs-TD (G2)
MW= 637.8
HN
NH2
NH2
HN
N
Cu
(II)
HN
N
Cu
(II)
N
H2N
N
H
N
HN
H
N
N
HN
(II)Cu
N
N
NH2
NH2
N
H
NH2
NH2
O
O
N
N
H
(II)Cu
N
H
H
Fe3O4
SiO2
FMNPs
SiO2
Si (CH2)3
N
N
O
O
Si (CH2)3
N
N
H
N
H
N
N
N
O
HN
(II)Cu
N
N
O
HN
N
H
N
H
FMNPs@TD-Cu(II)
N
(II)Cu
N
N
HN
(II)Cu
HN
(II)Cu
FMNPs@TD-Cu(II)
N
H2
N
H2
Scheme 2 Synthetic route of FMNPs@TD-Cu(II) catalyst.
40 Scheme 1 FMNPs@TD-Cu(II) catalyzed one-pot synthesis of
1,4-disubstituted 1,2,3-triazoles.
The FT-IR spectrum for the FMNPs–PA (Fig. 1a) shows a
stretching vibration at ~3464 cm−1 which includes the
2 Results and discussion
80 contributions from both symmetrical and asymmetrical modes of
the O-H bonds attached to the surface iron atoms. The presence
of an adsorbed water layer is confirmed by a stretch for the
vibrational mode of water found at 1653 cm−1. The band
formation between FMNPs and 3-aminopropyltriethoxysilane
85 group is confirmed by Fe–O–Si absorption band that appears at
~985 cm−1.24 Also, the characteristic bands for C-H aliphatic
bond appear at ~1460 and ~2921 cm.−1 Moreover, the bands at
~1642 cm−1of the C=N is a good reason for the presence of
triazine moiety on the Fe3O4 MNPs.
2.1 Catalyst characterization
45 The FMNPs@TD-Cu(II) was prepared by the route outlined in
Scheme 2. Naked magnetic Fe3O4 nanoparticles were synthesized
through chemical precipitation procedure, and subsequently were
coated with 3-aminopropyltriethoxysilane (APTS). The reaction
of cyanuric chloride (CC) with FMNPs-PA was performed at 25
50 C to substitute one chlorine atom of cyanuric chloride to produce
FMNPs-CC1 which upon treatment with ethylenediamine gave
FMNPs-TD (G1). The same procedure was applied to increase
the dendrimer generation, FMNPs–CC2 and FMNPs-TD (G2). In
the end, the reaction of G2 group with Cu(OAc)2 was led to the
90
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Table 1 Thermogravimetric analysis (TGA) results
Sample
Organic
(wt%)
7.02
Organic
(mmol/g MNPs)
1.20
Yield
(%)
-
Entry
FMNPs-PA
FMNPs-CC1
G1
1
2
3
4
5
10.43
11.21
13.10
15.32
0.50
0.44
0.24
0.23
41
88
54
95
FMNPs-CC2
G2
5
60 A summary of the elemental analysisand TGA data is presented
in Table 2, indicating a good agreement between the two
methods.
Fig. 1 FT-IR spectrum of a: FMNPs-PA; b: G1; c: FMNPs-CC2;
10 d: G2.
Table 2 Elemental analysis results
Entry
Sample
FMNP-PA
FMNPs-CC1
G1
C
H
N
Total
7.02
7.54
The amount of organic moieties attached to FMNPs was
measured by using TGA and elemental analysis. The TGA plots
of FMNPs-PA, FMNPs-CC1, G1, FMNPs-CC2 and G2 show that
thermal decomposition occurred in two steps (Fig. 2). Weight
15 loss first occurred in the temperature range of 150 to 250 °C; and
next above 250 °C. The first step weight loss corresponds to
elimination of physically adsorbed water. The second-step weight
loss is due to removal of organic moieties on the surface. The
TGA results are summarized in Table 1. The observed total
20 weight loss for FMNPs-PA, FMNPs-CC1, G1, FMNPs-CC2, and
G2 are 7%, 10.4%, 11.2%, 13.1% and 15.3%, respectively. The
weight loss of G1 and G2 appears about 11.2% and 15.3% at
250-550 °C is contributed to the thermal decomposition of 3-
aminopropyltrimethoxysilane, triazine, and diamines groups and
25 shows an irreversible process (Fig. 2c,e). On the basis of these
values, the theoretical conversion at each stage is 41% (FMNPs-
PA→ FMNPs-CC1), 88% (FMNPs-CC1→G1), 54% (G1 →
FMNPs-CC2) and 95% (FMNPs-CC2 → G2).
TGA(Wt%)
EA(wt%)
TGA(Wt%)
EA(wt%)
TGA(Wt%)
EA(wt%)
TGA(Wt%)
EA(wt%)
4.35
4.68
3.64
3.66
5.31
5.52
6.37
6.46
8.65
8.83
0.97
1.04
0.35
0.36
0.94
0.97
0.60
0.61
1.28
1.31
1.69
1.69
2.83
2.84
4.95
5.15
2.70
2.74
5.38
5.49
1
2
3
4
5
10.43
10.48
11.21
11.66
13.10
13.29
15.32
15.64
FMNPs-CC2
G2
TGA(Wt%)
EA(wt%)
70 The XRD patterns of magnetite and FMNPs@TD-Cu(II) are
depicted in Figure 3. The magnetite XRD peaks clearly seen in
XRD profile such as 220, 311, 400, 422, 511 and 440 (JCPDS
file, no. 901-3024).
The crystallite size of the catalysts was determined by
75 Debye−Scherrer equation was found to be 23.5 nm, which is an
agreement with the result obtained from the TEM which shows a
size distribution between 20 and 35 nm (Fig.5b).
The copper content of FMNPs@TD-Cu(II), measured by ICP
analysis, was obtained to be 0.41 mmol per gram of
80 FMNPs@TD-Cu(II) catalyst. The EDX results in Fig. 4 shows
that Cu exists in the nanoparticles.
30
70
35
40
Fig. 3 The XRD pattern of (a) FMNPs and (b) FMNPs@TD-
80 Cu(II).
Fig. 2 TGA curve of: (a) MNPs-PA, (b) MNPs-CC1, (c) G1, (d)
MNPs-CC2, (e) G2.
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30 nanoparticles are well dispersed and uniform in shape and size.
35
40
Fig. 4 EDX pattern of FMNPs@TD-Cu(II).
The FMNPs (Fig. 5a) and FMNPs@TD-Cu(II) (Figure 5b) was
also characterized by TEM. The dark colored regions or black
spots in the photograph correspond to the Fe3O4 species while the
colorless parts being that of silica.
40
5
10
45
Fig. 6 SEM images of a: FMNPs-SiO2; b: FMNPs@TD-Cu(II).
Figure
7 shows the magnetization curves of Fe3O4 and
15
FMNPs@TD-Cu(II). As can be observed from the figure, the
saturation magnetization was decreased. The lower saturation
75 magnetization of the FMNPs@TD-Cu(II) relative to that of bare
Fe3O4 nanoparticles, can be attributed to the formation of a silica
shell around the Fe3O4 core.
55
20
20 Fig. 5 TEM images of a:FMNPs-SiO2; b: FMNPs@TD-Cu(II).
SEM image is shown in Figure 6. The SEM image shows that
FMNPs (Figure 6a) and FMNPs@TD-Cu(II) (Figure 6b) have a
mean diameter of about 35 nm and a nearly spherical shape,
which is consistent with XRD, SEM and TEM image shows the
60 Fig. 7 Magnetization curves of Fe3O4 and FMNPs@TD-Cu(II).
4
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Table 4 FMNPs@TD-Cu(II) Catalyzed click synthesis of 1,4-
2.2 Catalytic studies
disubstituted 1,2,3-triazolesa
Initially, for screening experiments, three-component reaction
between phenylacetylene (1 mmol), benzyl choloride (1 mmol),
and sodium azide (1.1 mmol) was selected as a model reaction
(Table 3). The model reaction was first carried out in the absence
of FMNPs@TD-Cu(II). Stirring was continued in H2O-EtOH
(1:1) as solvent at 25 C. Timely analysis of the reaction mixture
(TLC) did not indicate any appreciable progress of the reaction.
(Table 3, entry 1). In the presence of FMNPs@TD-Cu(II) (8 mg),
10 the corresponding product was obtained in 99% yield (Table 3,
entry 2). Then, the same reaction was carried out in the presence
of FMNPs@TD-Cu(II) (8 mg) in different single and mixed
solvents at room temperature (Table 3, entries 3−8). As shown,
the maximum yields were obtained in both H2O-EtOH (1:1) and
15 H2O-MeOH (1:1) mixed solvent systems (Table 3, entries 2 and
8). However, H2O-EtOH (Table 3, entry 12) was preferred
because of safety problems. Next, we examined the catalyst
loading (5-10 mg), and 8 mg was found to be the optimum
catalyst loading for completion of this reaction. However, upon
20 decreasing the loading of catalyst to 5 mg and 6 mg reduced the
yields to 55 and 68 respectively (Table 3, entries 9 and 10). When
a catalyst loading of 10 mg was used, the yield of the product was
98%, but the reaction rate increased, so that the reaction was
complete within 10 min (Table 3, entry 11).
R1
N
40
N
FMNPs@TD-Cu(II)
R1
R2
N
NaN3
R2 CH2X
Entry
+
EtOH-H2O/Na2CO3, 25 C
5
Yield %b/t
(min)
Ref.
25
1
2
99 (15)
99 (22)
25
-
3
4
95 (20)
98 (16)
CHO
O
-
5
6
95 (25)
95 (40)
97 (35)
94 (40)
93 (30)
95 (27)
12b
26
-
25 Table 3 Optimization of the reaction conditionsa
Ph
N
N
N
Ph
+
NaN3
Ph
7
Ph CH2Cl
Entry
FMNPs-TD@Cu(II)
Solvent
Time
(min)
Yieldb
(%)
(mg)
8
27
28
28
-
8
8
8
8
8
8
8
H2O/EtOH (1:1)
H2O/EtOH (1:1)
EtOH
1
2
3
4
5
6
7
8
9
15
15
15
15
15
15
15
15
15
15
10
-
99
80
50
68
37
73
95
55
68
98
C6H13Br
9
CH3CN
DMF
EtOAc
H2O
10
H2O/MeOH (1:1)
H2O/EtOH (1:1)
H2O/EtOH (1:1)
H2O/EtOH (1:1)
5
6
10
11
90 (37)
2b
10
11
aReaction conditions: Phenylacetylene (1 mmol), benzyl choloride (1
mmol), sodium azide (1.1 mmol), sodium carbonate (1 mmol)
FMNPs@TD-Cu(II), 25 C.
12
98 (20)
2b
bIsolated yields.
aThe purified products were characterized by mp, 1H and 13C NMR
spectroscopy.
b Yields refer to pure isolated products.
Under the optimized reaction conditions, the scope of the
methodology was investigated for the synthesis of various 1,4-
30 disubstituted 1,2,3-triazoles and the results are described in Table
4. Various benzylic, allylic and aliphatic halides afforded
excellent yields of the products under these reaction conditions
(Table 4). Aliphatic halides are usually known to be less reactive
than aromatic ones, but with this catalytic system, the reaction of
35 phenylacetylene with hexyl bromide (Table 4, entry 9) proceeded
efficiently to provide the desired 1,4-disubstituted 1,2,3-triazole
in 93% yields. In addition, α-bromoacetophenone reacted
smoothly with phenylacetylene to produce the corresponding β-
keto-1,2,3-triazole in 95% yield within 27 min (Table 4, entry
10). 2-Bromo-1-(furan-2-yl)ethanone, as
45 substrate, also worked well in this reaction under similar reaction
conditions to afford the desired product in 90% yield after 37 min
(Table 4, entry 11). Aryl acetylenes such as phenylacetylene and
2-(prop-2-ynyloxy)benzaldehyde as well as alkyl acetylenes such
as 1-hexyne reacted rapidly and smoothly to produce the
a
heteroaromatic
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corresponding 1,4-disubstituted 1,2,3-triazoles in excellent yields 40 under the reactions, and can be recycled multiple times.
(Table 4). Interestingly, the presence of aldehyde group did not
interfere with this reaction, and desired products were obtained in
excellent yields (Table 4, entries 3 and 4). It is noteworthy that
3 Conclusions
5
the reactions were completed within 15-40 minutes at 25 C, and
the products were produced in excellent yields with high purity
and excellent regioselectivity, in which only 1,4-regioisomeric
products were formed.
In conclusion, the synthesis and characterization of a new stable
and heterogeneous catalyst, Cu(II) containing Fe3O4 triazine
dendrimer (FMNPs@TD-Cu(II)), is reported. FMNPs@TD-
45 Cu(II) catalyzes three-component reaction for the construction of
1,4-disubstituted1,2,3-triazole from phenylacetylenes, sodium
azide and aromatic, heteroaromatic, allylic and aliphatic halides.
The reaction has good substrate scope and furnishes the products
in excellent yields and regioselectivity. Furthermore, the catalyst
50 is stable under the reaction conditions and can be recycled and
reused several times without a significant loss in activity.
Importantly, recovery of the catalyst can be accomplished easily
using a simple external magnet. Therefore, this synthetic
methodology can be considered as a useful practical achievement
55 in the preparation of these important heterocyclic compounds.
Further studies are on going in our laboratory to understand other
applications of the catalyst in various organic reactions.
A comparison of the efficiency of this method with selected
10 previously methods29-31 is collected in Table 5. As can be seen,
the present protocol is indeed superior to several of the other
protocols.
Table 5 Comparison of click synthesis of 1,4-disubstituted 1,2,3-
triazoles by the FMNPs@TD-Cu(II) catalytic system with some
15 of those reported in the literature
Product
ConditionsRef.
Yield%b/Time
this work
99 (15 min)
98 (6 h)
94 (25 h)
C/Cu NPs/H2O/70 C29
5 mol%/Cu/H2O/55 C30
4 Experimental
this work
97 (30 min)
80 (7 h)
82 (7 h)
C/Cu NPs/H2O/70 C29
0.5 mol% Cu NPs/C/H2O-
EtOH/70 C31
4.1 Material and physical measurements
60 The materials were purchased from Merck and Fluka and were
used without any additional purification. All reactions were
monitored by thin layer chromatography (TLC). Melting points
were determined using a Stuart Scientific SMP2 apparatus. FT-
IR spectra were determined on a Perkin-Elmer 683 instrument. 1H
65 and 13C NMR spectra were recorded on a Bruker (200, 500 MHz)
spectrometer in CDCl3 as solvent. X-ray powder diffraction
The reusability of the catalyst for the cycloaddition reaction of
phenyl acetylene, sodium azide and benzyl chloride, was
subsequently investigated. When the reaction was completed, the
mixture was separated catalyst by an external magnet then diluted
20 with water and EtOAc. The catalyst was separated by simple
filtration, dried, and used for subsequent runs. Thus, after
recovery the catalyst was subjected to a second reaction from
which it gave the desired product in 97% yield; the average
chemical yield for six consecutive runs was 96%, which clearly
25 demonstrates the practical recyclability of this catalyst (Fig. 8).
The slight decrease of catalytic activity should be due to the
normal loss of the catalyst during the work-up stage.
patterns
were
obtained
on
SE1FERT-3003TT.
Thermogravimetric analysis (TGA) was carried out on a PL-
STA-1640 form heating rate of the range of 30-600 C. Scanning
70 electron microscopy measurements were performed on a VEGA
TESCAN microscope (FE-SEM). Transmission electron
microscopy (TEM) measurements were carried out on a Zeiss-
EM10C Germany operating at 80 Kv and formvar carbon coated
grid Cu Mesh 300.
75 4.2 Preparation and modification of large-scale the
ferromagnetic nanoparticles (FMNPs)
30
FMNPs modified with citrate groups were prepared according to
reported literature procedure.32 Iron (III) chloride hexahydrate
(5.40 g, 20 mmol) and iron (II) chloride tetrahydrate (2 g, 10
80 mmol) were dissolved in deionized H2O (120 mL) under N2
atmosphere. Then, 10 mL of ammonium hydroxide 25% was
quickly added into the solution under rapid mechanical stirring
(500 rpm), and the mixture was heated up to 60 °C, while stirred
vigorously by a mechanical stirrer for 1 hour under N2
85 atmosphere. After cooling to room temperature, the resultant
nanoparticles were gathered using a external magnet and the
collected magnetic solid were dispersed in a 200 mL of trisodium
citrate solution (0.3 M) and heated at 80 °C for 1 hour. Finally,
the precipitates were collected using an external magnet and
90 washed with acetone to eliminate remainder trisodium citrate.
Fig. 8 Recyclability of FMNPs@TD-Cu(II) for the preparation of
35 1-benzyl-4-phenyl-1H-1,2,3-triazole.
To test for leaching we filtered the catalyst after 8 min and the
reaction continued uninterrupted in the absence of catalyst. We
found that the reaction was not completed, even at long reaction
times. These observations showed FMNPs@TD-Cu(II) is stable
6
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4.3 Preparation of silica-coated FMNPs
To a mixture of ferromagnetic nanoparticles supported dendrimer
55 (G2) (0.5 g) in DMF (10 mL) was added Cu(OAc)2 (0.09 g, 0.5
mmol). The mixture was stirred for 6 hours at 25 C. The
resulting mixture was separated by an external magnet, the solid
material was washed sequentially with 25 mL of acetone and then
dried in a vacuum oven at 40C. Finally, FMNPs@TD-Cu(II)
60 catalyst was obtained as a dark green solid.
The surface modified FMNPs (1 g) were redispersed in deionized
H2O (50 mL) by the ultrasonic treatment for 25 min.
Subsequently, the resulting dispersion was centrifuged for 30 min
and adjusted to 2.0 wt %. Then, 2 mL of the ferro fluid was first
diluted with H2O (40 mL), the resultant suspension and NH3.H2O
(5 mL) were poured into ethanol (140 mL) with stirring at 40 °C.
A solution of TEOS (1 mL) in EtOH (10 mL) was added to the
dispersion in a dropwise manner under continuous mechanical
5
4.7 General procedure for synthesis of 1,2,3-triazoles in the
presence of FMNPs@TD-Cu(II) nanocatalyst
10 stirring. Then, the resultant dispersion was stirred mechanically
for 14 hours at 25 C. Finally, the silica-coated ferromagnetic
nanoparticles were composed by magnetic separation and washed
with EtOH and deionized H2O.
A mixture of sodium carbonate (0.1 g, 1mmol) and FMNPs@TD-
Cu(II) (0.008 g, containing 0.41 mmol Cu(II))/g in 3 mL of H2O-
65 EtOH (1:1) in a round bottom flask (25 mL) was stirred for 1
min. NaN3 (0.04 g, 0.6 mmol) was added and vigorously stirred
for few seconds. Then a halide derivative (0.5 mmol) and a
acetylene derivative (0.5 mmol) were added to the reaction
medium, and the mixture was stirred at 25 C for the indicated
70 reaction time (Table 4). The reaction progress was monitored by
TLC (eluent: n-hexane/EtOAc, 5:1). After completion of the
reaction, the mixture was diluted with water and ethyl acetate and
the catalyst was recovered using an external magnet. The organic
layer was separated, and the aqueous layer was extracted with
75 ethyl acetate (3 × 5 mL). The organic phases were combined,
dried with magnesium sulfate, filtered, and concentrated under
reduced pressure to afford the pure triazole in most cases. The
recovered catalyst was reused for further runs without removing
the catalyst from the flask. Spectral and analytical data for new
80 compounds follow.
4.4
Preparation
of
FMNPs
coated
by
3-
15 aminopropyltriethoxysilane (FMNPs-PA)
The obtained silica-coated FMNPs powder (1.5 g) was dispersed
in 250 mL H2O-EtOH (1:1) solution by sonication for 30 min,
and then APTS (2.5 mL) was added to the mixture. The reaction
resulting mixture was mechanically stirred under N2 atmosphere
20 for 8 h at room temperature. The suspension was centrifuged to
separate the precipitated material, which was then re-dispersed in
ethanol by sonication. The final product was separated by an
external magnet and washed five times with ethanol and stored in
a fridge for future use.
25 4.5 Preparation of triazine-based dendrimer supported on
FMNPs-PA (G2 or FMNPs-TD)
4.7.1 2-((1-Benzyl-1H-1,2,3-triazol-4-yl)methoxy)benzaldehy-
de (Table 4, entry 4)
A mixture of FMNPs-PA (2 g), cyanuric chloride (1.85 g, 10
mmol) and triethylamine (1.4 mL, 10 mmol) in THF (10 mL) was
shaken for 10 hours at 25 C. The solid material (MNPs-CC1)
30 was separated by an external magnet and washed five times with
hot THF and then dried in a vacuum oven at 50 C. Then, to a
slurry of FMNPs-CC1 (1 g) in DMF (12 mL), ethylenediamine
(0.53 mL, 8 mmol) and triethylamine (1.1 mL, 8 mmol) were
added. The resulting mixture was mechanically stirred at 60 C
35 for 12 hours. The resulting first generation (FMNPs-TD or G1)
was separated by an external magnet, washed five times with hot
Light yellow solid; M.p.: 115 °C: 1H NMR (500 MHz, CDCl3): δ
5.31 (s, 2H), 5.55 (s, 2H),7.05-7.58 (m, 9H), 7.82 (s, 1H), 10.41
85 (s, 1H); 13C NMR (125 MHz, CDCl3): δ 53.85, 62.09, 112.51,
120.82, 122.27, 124.54, 127.61, 128.18, 128.43, 128.71, 133.78,
135.50, 143.31, 159.92, 189.07; Anal. Calcd for C17H15N3O2: C,
69.61; H, 5.15; N, 14.33. Found: C, 69.47; H, 5.34; N, 14.40.
4.7.2 2-((1-(4-Methylbenzyl)-1H-1,2,3-triazol-4-yl)methoxy)b-
ethanol and dried in a vacuum oven at 50 C. The second 90 enzaldehyde (Table 4, entry 5)
generation FMNPs-TD (G2) was prepared according to the above
Light yellow solid; M.p.: 119 °C; 1H NMR (500 MHz, CDCl3): δ
procedure for the preparation of G1. A mixture of G1 (1 g),
40 cyanuric chloride (CC) (1.66 g, 9 mmol) and triethylamine (1.2
mL, 9 mmol) in THF (20 mL) was shaken for 14 hours at 25 C.
The final sample was separated by an external magnet (FMNPs-
CC2) washed with hot THF in five times and dried in a vacuum
oven at 50 C. Then, to a slurryof FMNPs-CC2 (1 g) in DMF (20
45 mL) were added ethylenediamine (0.63 mL, 9.5 mmol) and
triethylamine (1.3 mL, 9.5 mmol). The resulting mixture was
stirred at 60 C for 14 hours and then separated by an external
magnet. The resulting second generation of ferromagnetic
nanoparticles supported dendrimer (G2 or FMNPs-TD) was
50 washed with hot ethanol five times and dried in a vacuum oven at
50 C.
2.32 (s, 3H), 5.39 (s, 2H), 5.77 (s, 2H), 7.06-7.27 (m, 6H), 7.56-
7.81 (m, 2H), 7.83-8.09 (m, 1H), 10.42 (s, 1H); 13C NMR (125
MHz, CDCl3): δ 22.89, 53.08, 62.07, 112.48, 115.66, 115.83,
95 120.87, 121.01, 122.11, 128.27, 129.48, 129.54, 135.51, 143.42,
159.87, 167.39, 189.07; Anal. Calcd for C18H17N3O2:C, 70.34; H,
5.58; N, 13.67. Found: C, 70.18; H, 5.51; N, 13.55.
4.7.3 1-([1,1'-Biphenyl]-4-ylmethyl)-4-phenyl-1H-1,2,3-triazo-
le (Table 4, entry 8)
100 White solid; M.p.:185 °C; 1H NMR (200 MHz, CDCl3): δ 5.11 (s,
2H), 7.25-7.63 (m, 12H), 7.55-7.63 (m, 1H), 7.71 (s, 1H), 7.79-
7.83(m, 1H); 13C NMR (50 MHz, CDCl3): δ 52.54, 122.02,
122.32, 128.20, 128.28, 128.49, 128.62, 129.51, 129.58, 129.69,
4.6 Preparation of Cu(II) containing ferromagnetic
nanoparticles triazinedendrimer (FMNPs@TD-Cu(II))
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DOI: 10.1039/C5NJ03219A
S. Choi, J. H. Lee, S. Yoon, K. S. Kim, J. S. Shin and J. S.
Suh, J. Am. Chem. Soc., 2005, 127, 12387-12391.
D. R. Buckle, D. J. Outred, C. J. Rockell, H. Smith and B. A.
Spicer, J. Med. Chem., 1983, 26, 251-254.
M. Damodiran, D. Muralidharan and P. T. Perumal, Bioorg.
Med. Chem. Lett., 2009, 19, 3611-3614.
R. Alvarez, S. Velazquez, A. San-Felix, S. Aquaro, E. D.
Clercq, C. F. Perno, A. Karlsson, J. Balzarini and M. J.
Camarasa, J. Med. Chem., 1994, 37, 4185-4194.
130.02, 131.94, 134.72, 136.58, 137.07; Anal. Calcd for
C21H17N3: C, 80.00; H, 5.50; N, 13.49. Found: C, 80.21; H, 5.43;
N, 13.61.
7
8
9
70
75
Acknowledgements
5
The authors acknowledge the Razi University Research Council
for support of this work.
10 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 and D. K. Hutchinson, J. Med. Chem., 2000, 43, 953-
970.
11 (a) H. Dehne, Methoden der OrganischenChemie, 1994, 8,
305-405; (b) W. Q. Fan and A. R. Katritzky, Compr.
Heterocycl. Chem., 1996, 4, 1-126.
Notes and references
1
(a) R. K. Gopalakrishna Panicker and S. Krishnapillai,
Tetrahedron Lett., 2014, 55, 2352-2354; (b) S. T. Lo, A.
Kumar, J. T. Hsieh and X. Sun, Molecular pharm., 2013, 10,
793-812; (c) A. M. Caminade, A. Ouali, M. Keller and J. P.
Majoral, Chem. Soc. Rev., 2012, 41, 4113-4125; (d) M. A.
Mintzer and M. W. Grinstaff, Chem. Soc. Rev., 2011, 40, 173-
190; (e) Y. Cheng, L. Zhao, Y. Li and T. Xu, Chem. Soc. Rev.,
2011, 40, 2673-2703; (f) F. Vögtle, G. Richardt and N.
Werner, Front Matter. Wiley Online Library: 2009.
80
10
15
20
25
30
35
40
45
50
55
60
65
12 (a) S. R. Kale, S. S. Kahandal, M. B. Gawande and R. V.
Jayaram, RSC Adv., 2013, 3, 8184-8192; (b) P. V. Chavan, K.
S. Pandit, U. V. Desai, M. A. Kulkarni and P. P. Wadgaonkar,
RSC Adv., 2014, 4, 42137-42146; (c) A. Kamal and P.
Swapna, RSC Adv., 2013, 3, 7419-7426; (d) X. Xiong and L.
Cai, Catal. Sci. Technol., 2013, 3, 1301-1307; (e) W. Li, X.
Zhou, Y. Luan and J. Wang, RSC Adv., 2015, 5, 88816-88820;
(f) A. Ali, A. G. Correa, D. Alves, J. Zukerman-Schpector, B.
Westermann, M. A. B. Ferreira and M. W. Paixao, Chem.
Commun., 2014, 50, 11926-11929.
13 (a) B. J. Borah, D. Dutta, P. P. Saikia, N. C. Barua and D. K.
Dutta, Green Chem., 2011, 13, 3453-3460; (b) J. Kim, J. Park
and K. Park, Chem. Commun., 2010, 46, 439-441; (c) Z. Shi,
B. Li, X. Wan, J. Cheng, Z. Fang, B. Cao, C. Qin and Y.
Wang, Angew. Chem. Int. Ed., 2007, 46, 5554-5558; (d) M.
Tajbakhsh, M. Farhang, S. M. Baghbanian, R. Hosseinzadeh
and M. Tajbakhsh, New J. Chem., 2015, 39, 1827-1839; (e)
H.-W. Bai, Z.-J. Cai, S.-Y. Wang. and S.-J. Ji, Org. Lett.,
2015, 17, 2898-2901.
14 (a) S. Aerry, A. Kumar, A. Saxena, A. De and S. Mozumdar,
Green Chem. Lett. Rev., 2013, 6, 183-188; (b) A. Kumar, S.
Aerry, A. Saxena and S. Mozumdar, Green Chem., 2012, 14,
1298-1301; (c) S. L. Jain, B. S. Rana, B. Singh, A. K. Sinha,
A. Bhaumik, M. Nandi and B. Sain, Green Chem., 2010, 12,
374-377; (d) Z.-J. Cai, X.-M. Lu, Y. Zi, C. Yang, L.-J. Shen, J.
Li, S.-Y. Wang and S.-J. Ji, Org. Lett., 2014, 16, 5108–5111.
15 (a) H. C. Kolb, M. G. Finn and K. B. Sharpless, Angew.
Chem., 2001, 40, 2004-2021; (b) A. N. Prasad, B. M. Reddy,
E.-Y. Jeong and S.-E. Park, RSC Adv., 2014, 4, 29772-29781.
16 (a) A. Krasinski, Z. Radic, R. Manetsch, J. Raushel, P. Taylor,
K. B. Sharpless and H. C. Kolb, J. Am. Chem. Soc., 2005, 127,
6686-6692; (b) M. Vashist, K. Kushwaha, R. Kaushik and S.
C. Jain, RSC Adv., 2014, 4, 23679-23684.
17 (a) L. V. Lee, M. L. Mitchell, S. Huang, V. V. Fokin and K. B.
Sharpless, C. Wong, J. Am. Chem. Soc., 2003, 125, 9588-
9589; (b) Sasikala, S. K. Rani, D. Easwaramoorthy and K.
Karthikeyan, RSC Adv., 2015, 5, 56507-56517.
18 J. E. Hein, J. C. Tripp, L. B. Krasnova, K. B. Sharpless and V.
V. Fokin, Angew. Chem. Int. Ed., 2009, 48, 8018-8021.
19 P. Appukkuttan, V. P. Mehta and E. V. Eycken, Chem. Soc.
Rev., 2010, 39, 1467-1477.
20 C. O. Kappe and E. V.Eycken, Chem. Soc. Rev., 2010, 39,
1280-1290.
21 (a) J. Virkutyte and R. S. Varma, Chem. Science, 2011,2, 837-
846; (b) L. De Rogatis, M. Cargnello, V. Gombac, B.
Lorenzut, T. Montini and P. Fornasiero, Chem. Sus. Chem.,
2010, 3, 24-42.
85
2
(a) A. Y. T. Huang, C. H. Tsai, H. Y. Chen, H. T. Chen, C. Y.
Lu, Y. T. Lin and C. L. Kao, Chem. Commun., 2013, 49, 5784-
5786; (b) M. Nasr-Esfahani, I. Mohammadpoor-Baltork, A. R.
Khosropour, M. Moghadam, V. Mirkhani, S. Tangestaninejad
and H. Amiri Rudbari, J. Org. Chem., 2014, 79, 1437−1443;
(c) M. Nasr-Esfahani, I. Mohammadpoor-Baltork, A. R.
Khosropour, M. Moghadam, V. Mirkhani and S.
Tangestaninejad, J. Mol.r Catal. A: Chem., 2013, 379, 243–
254; (d) G. R. Krishnan and K. Sreekumar, Eur. J. Org.
Chem., 2008, 28, 4763-4768; (e) T. Kehat, K. Goren and M.
Portnoy, New J. Chem., 2007, 31, 1218-1242; (f) A. Dahan
and M. Portnoy, J. Poly. Sci. Part A, 2005, 43, 235-262; (g) P.
Wu, A. K. Feldman, A. K. Nugent, C. J. Hawker, A. Scheel,
B. Voit, J. Pyun, J. M. Frechet, K. B. Sharpless and V. V.
Fokin, Angew. Chem., 2004, 43, 3928-3932; (h) G.
Sanclimens, L. Crespo, E. Giralt, M. Royo and F. Albericio,
Peptide Sci., 2004,76, 283-297; (i) S. Lebreton, S. Monaghan
and M. Bradley, Aldrich. Acta., 2001, 34, 75-83; (j) A. Basso,
B. Evans, N. Pegg and M. Bradley, Chem. Commun., 2001, 8,
697-698.
90
95
100
105
110
115
120
125
130
135
3
(a) T. Selvam, A. Machoke and W. Schwieger, Applied
Catalysis A General, 2012, 445, 92-101; (b) A.V. Biradar, A.
A. Biradar and T. Asefa, Langmuir,2011,27, 14408-14418; (c)
S. J. Dilly, S. J. Carlisle, A. J. Clark, A. R. Shepherd, S. C.
Smith, P. C. Taylor and A. Marsh, J. Poly. Sci. Part A, 2006,
44, 2248-2259; (d) J. P. Reynhardt,Y. Yang, A. Sayari and H.
Alper, Advanced Mat.,2005, 15, 1641-1646; (e) J. P.
Reynhardt,Y. Yang, A. Sayari and H. Alper, Chem. mat.,
2004, 16, 4095-4102.
4
5
V. Polshettiwar, R. Luque, A. Fihri, H. Zhu, M. Bouhrara and
J. M. Basset, Chem. Rev., 2011, 111, 3036–3075.
(a) A. S. Albuquerque, M. V. Tolentino, J. D.Ardisson, F. C.
Moura, R. Mendonça and W. A. Macedo, Ceramics
International, 2012, 38, 2225-2231; (b) M. Florea, M. Alifanti,
V. Parvulescu, D. Mihaila-Tarabasanu, L. Diamandescu, M.
Feder, C. Negrila and L. Frunza, Catalysis Today, 2009, 141,
361-366; (c) A.H. Latham and M. E. Williams, Accounts
Chem. Research, 2008, 41, 411-420; (d) P. D. Stevens, G. Li,
J. Fan, M. Yen and Y. Gao, Chem. Commun., 2005, 35, 4435-
4437; (e) T. Hyeon, Chem. Commun., 2003, 8, 927-934; (f) D.
Chiba, M. Yamanouchi, F. Matsukura and H. Ohno, Science,
2003, 301, 943-945.
22 R. Hudson, C. J. Li and A. Moores, Green Chem., 2012, 14,
622-624.
6
(a) Y. Weng, J. Zhao, S. Y. Yu and S. Y. Song, Cryst. Eng.
Commun., 2014, 16, 6257-6262; (b) J. Feng, W. Q. Fan, S. Y.
Song, Y. N. Yu, R. P. Deng and H. J. Zhang, Dalton Trans.,
2010, 39, 5166-5171; (c) L. Zhang, S. Qiao, Y. G. Jin, Z. G.
Chen, H. Gu and G. Q. Lu, Adv. Mater., 2008, 20, 805-809;
(d) Y. S. Lin, S.H. Wu, Y. Hung, Y. H. Chou, C. Chang, M. L.
Lin, C. P. Tsai and C. C. Y. Mou, Chem. Mater., 2006, 18,
5170-5172; (e) Y. M. Huh, Y. W. Jun, H. T. Song, S. Kim, J.
23 (a) K. Bahrami, M. M. Khodaei and F. Naali, J. Org. Chem.,
2008, 73, 6835-6837; (b) K. Bahrami, M. M. Khodaei and M.
Sheikh Arabi, J. Org. Chem., 2010, 75, 6208-6213; (c) K.
Bahrami, M. M. Khodaei and M. Soheilizad, J. Org.Chem.,
2009, 74, 9287-9291; (d) K. Bahrami, M. M. Khodaei and P.
Fattahpour, Catal. Sci. Technol., 2011, 1, 389-393; (e) K.
8
|Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

Page 9 of 10
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View Article Online
DOI: 10.1039/C5NJ03219A
Bahrami, M. M. Khodaei, H. Targhan and M. SheikhArabi,
Tetrahedron Lett., 2013, 54, 5064-5068; (f) K. Bahrami, M.
M. Khodaei and M. Roostaei, New J. Chem., 2014, 38, 5515-
5520; (g) K. Bahrami, M. M. Khodaei and A. Nejati, Green
Chem., 2010, 12, 1237-1241; (h) K. Bahrami, M. M. Khodaei,
P. Fattahpour and M. Sheikh Arabi, J. Porous Mater.; 2015,
22, 211-218.
75
80
5
10
15
20
25
30
35
40
45
50
55
60
65
70
24 S. Luo, X. Zheng, H. Xu, X. Mi, L. Zhang and J. P. Cheng,
Adv. Synth. Catal., 2007, 349, 2431-2434.
25 J. González, V. M. Pérez, D. O. Jiménez, G. Lopez Valdez, D.
Corona, E. Cuevas Yañez, Tetrahedron Lett., 2011, 52, 3514-
3517.
26 F. Friscourt and G.-J. Boons, Org. Lett., 2010, 12, 4936-4939.
27 S. Kamijo, T. Jin, Z. Huo and Y. Yamamoto, J. Org. Chem.,
2004, 69, 2386-2393.
28 C. Shao, X. Wang, J. Xu, J. Zhao, Q. Zhang and Y. Hu, J.
Org. Chem., 2010, 75, 7002-7005.
29 M. Nasrollahzadeh, B. Jaleh, P. Fakhri, A. Zahraei and E.
Ghadery, RSC Adv., 2015, 5, 2785-2793.
30 C. Zhang, B. Huang, Y. Chen and D.-M. Cui, New J. Chem.,
2013, 37, 2606-2609.
31 F. Alonso, Y. Moglie, G. Radivoy and M. Yus, Org. Biomol.
Chem., 2011, 9, 6385-6395.
32 D. Yang and J. Hu, S. Fu, J. Phy. Chem. C, 2009, 113, 7646-
7651.
85
90
95
100
105
110
115
120
125
130
135
140
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Graphical Abstract
The synthesis, characterisation and catalytic activity of
FMNPs@TD-Cu(II) for the synthesis of 1,4-disubstituted 1,2,3-
triazoles is reported.
5
10
15
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