Synthesis of the first nanomagnetic particles with semicarbazide-based acidic ionic liquid tag: an efficient catalyst for the synthesis of 3,3′-(arylmethylene)bis(4-hydroxycoumarin) and 1-carbamato-alkyl-2-naphthol derivatives under mild and green conditi

Article abstract of DOI:10.1002/aoc.3461

Semicarbazide functionalized with chlorosulfonic acid on the surface of silica-coated magnetic nanoparticles, {Fe₃O₄@SiO₂@(CH₂)₃Semicarbazide-SO₃H/HCl}, as a novel magnetic Br?nsted acid ca

Full text of DOI:10.1002/aoc.3461

Full paper
Received: 15 December 2015
Revised: 25 January 2016
Accepted: 26 January 2016
Published online in Wiley Online Library: 26 April 2016
(wileyonlinelibrary.com) DOI 10.1002/aoc.3461
Synthesis of the first nanomagnetic particles
with semicarbazide-based acidic ionic liquid
tag: an efficient catalyst for the synthesis of
3,3′-(arylmethylene)bis(4-hydroxycoumarin)
and 1-carbamato-alkyl-2-naphthol derivatives
under mild and green conditions
Mohammad Ali Zolfigol*, Roya Ayazi-Nasrabadi and Saeed Baghery
Semicarbazide functionalized with chlorosulfonic acid on the surface of silica-coated magnetic nanoparticles, {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl}, as a novel magnetic Brønsted acid catalyst according to the aims of green chemistry was synthesized
and fully characterized using Fourier transform infrared, UV–visible and energy-dispersive X-ray spectroscopies, X-ray diffraction,
scanning electron, transmission electron and atomic force microscopies and thermogravimetric analysis. The capability and excel-
lent activity of this nanoparticle catalyst were exhibited in the synthesis of two series of compounds with important biological ac-
tivities, namely 3,3′-(arylmethylene)bis(4-hydroxycoumarin) and 1-carbamato-alkyl-2-naphthol derivatives, under mild, green and
solvent-free conditions. To the best of our knowledge, this is the first study of the synthesis and application of {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl} as Brønsted acid solid magnetic nanoparticles. Consequently the present study can open up a novel
and promising intuition in the sequence of logical design, synthesis and applications of task-specific Brønsted acid magnetic nano-
particle catalyst with favourable properties as a full-fledged efficient material for sustainable approaches. Copyright © 2016 John
Wiley & Sons, Ltd.
Additional supporting information may be found in the online version of this article at the publisher’s web site.
Keywords: semicrabazie-based ionic liquid; nanomagnetic silica-coated Fe3O4 functionalized with ionic liquid; {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl}; 3,3′-(arylmethylene)bis(4-hydroxycoumarin); 1-carbamato-alkyl-2-naphthol; solvent-free
catalysts are benefits over homogeneous ones.[4] One method is the
immobilization of a catalytic homogeneous tag on a nanomagnetic
Introduction
Nowadays knowledge-based and rational design and synthesis of
task-specific and biological-based catalysts are more in demand
because catalytic systems have played an excellent role in pollution
prevention in our environment.[1] In this regard, a wide range of
solid catalysts and their supported forms have been reported in
the last few years for various chemical processes and have been
reviewed extensively. Among the reported solid catalysts, solid
acids have been also used widely for various organic functional
group transformations.[2]
hybrid solid material, to convert it to a heterogeneous catalyst with
homogeneous action in chemical-based processes.
Among the four types of magnetic nanoparticles (MNPs), i.e.
metals, alloys, metal oxides and ferrites, iron oxides have attracted
the most attention, because they can be produced easily via sedi-
mentation and also they have stronger magnetic properties. While
several improvements have been realized in the synthesis and
application of MNPs, their consistency in the long term without
aggregation or surface oxidation is still a concern.[5–8]
The study of solid acid catalysis has been carried out broadly
and it has had much influence on the improvement of both basic
investigation and chemical industry, principally in the field of
chemistry-based processes. More wide and quantitative investiga-
tion of the acidic property of solid materials is nowadays preferred
to correlate this property with stability, catalytic activity, selectivity
and high turnover number and frequency, and to clarify the nature
of acid–base bifunctional catalysis.[3] Heterogeneous catalysts have
the advantage of easy separation from products without the neces-
sity of washing. Also, recyclability and reusability of heterogeneous
In the well-known class of coumarin derivatives, dimeric coumarins
(also named biscoumarins) are of particular interest. Biscoumarin
derivatives occur naturally in a great number of plants and
*
Correspondence to: M. A. Zolfigol, Department of Organic Chemistry, Faculty
of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran. E-mail:
zolfi@basu.ac.ir
Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University,
Hamedan 6517838683, Iran
Appl. Organometal. Chem. 2016, 30, 500–509
Copyright © 2016 John Wiley & Sons, Ltd.

Nano magnetic with semicarbazide-based acidic ionic liquid tag
microorganisms.[9,10] They are frequently biologically active[11–14] and
many of them have been confirmed in view of therapeutic usage,[15]
as anti-inflammatory,[16] anticoagulant,[17,18] cardiovascular,[19]
antimicrobial[20] and anti-proliferative factors.[21–23] Lately, numerous
approaches have been studied for the preparation of biscoumarin
derivatives via reactions between 4-hydroxycoumarin and numerous
aldehydes.[24–29]
Correspondingly, amidoalkylnaphthol derivatives are of signifi-
cance as they can be effortlessly converted to biologically active
compounds, through amide hydrolysis reaction. Hypotensive and
bradycardiac properties have been reported for this type of
compounds.[30–32] Amidoalkylnaphthols can also be changed to
1,3-oxazine derivatives.[33] 1,3-Oxazines have potentially different bi-
ological activities including antihypertensive, antimalarial, antitumor,
anticonvulsant, antianginal, antipsychotic, analgesic, antibiotic and
antirheumatic properties.[34–42] Several Lewis and Brønsted acids
have been applied to catalyse this transformation, such as [Msim]Cl,
[Dsim]Cl, [Msim]AlCl4,[43] [Et3N–SO3H]Cl,[44] nano-S (S8-NP),[45] saccha-
rin sulfonic acid,[46] [2-MPyH]OTf,[47] {[HMIM]C(CN)3},[48] cation-
exchanged resins,[49] sulfamic acid/ultrasound,[50] HClO4/SiO2[51] and
H3PW12O40.[52]
Scheme 1. The synthesis of 3,3′-(arylmethylene)bis(4-hydroxycoumarin)
and 1-carbamato-alkyl-2-naphthol derivatives using novel semicarbazide
functionalized with chlorosulfonic acid on the surface of silica-coated MNPs,
i.e. {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}, as a green and mild
catalyst.
In continuation of our studies of the synthesis and application of
solid acids,[53] inorganic acidic salts,[54] nanomagnetic catalysts[55]
and knowledge-based improvement of task-specific ionic liquids,[56]
it was found that favourable structural diversity of ionic liquids with
outstanding properties could be attained via design, synthesis and
application of novel cationic cores with appropriate anionic counter-
parts. With this target, it was decided to join all of these investigation
areas to the design, synthesis and applications of semicarbazide
functionalized with chlorosulfonic acid on the surface of silica-coated
MNPs, namely {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}, as a
green and mild heterogeneous catalyst for the synthesis of
3,3′-(arylmethylene)bis(4-hydroxycoumarin) and 1-carbamato-alkyl-
2-naphthol derivatives under solvent-free conditions (Scheme 1).
Figure 1. FT-IR spectra: (a) Fe3O4; (b) Fe3O4@SiO2; (c) Fe3O4@SiO2@(CH2)3-Cl;
(d) Fe3O4@SiO2@(CH2)3Semicarbazide; (e) {Fe3O4@SiO2@(CH2)3Semicarbazide-
SO3H/HCl}.
Results and discussion
Characterization of novel {Fe3O4@SiO2@(CH2)3Semicarbazide-
SO3H/HCl} catalyst
the bare Fe3O4 MNPs shows a characteristic absorption peak of
Fe O bond at about 580 cmÀ1. The absorption peaks of the silica
shell in the Fe3O4@SiO2 core–shell MNPs at about 1100 and 798
cmÀ1 are related to the antisymmetric and symmetric stretching vi-
brations of Si O Si bond in oxygen–silica tetrahedra, respectively.
Correspondingly, the absorption peak of the Fe3O4@SiO2@(CH2)3
core–shell MNPs at 2930 cmÀ1 is linked to the stretching vibration
of C H groups. The absorption peak at 1632 cmÀ1 is also linked to
the stretching vibration of C O bond of semicarbazide group. Fur-
thermore, the absorption band at 3320 cmÀ1 corresponds to
stretching vibration of O H in the SO3H group and the peak at
1177 cmÀ1 is related to vibrational modes of O SO2 bonds. The ab-
Recently, Gu and co-workers reported a sulfonyl-containing
ammonium-based Brønsted acid ionic liquid as an efficient liquid
heterogeneous catalyst for the synthesis of a wide range of organic
[57]
compounds under solvent-free conditions
In this way,
nanospherical silica with imidazole linker and sulfonic acid tag for
various multicomponent reactions[58] has also been reported by
our research group. Herein, we report novel core–shell
nanomagnetic silica coated with semicarbazide spacer and sulfonic
acid tag.
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as a novel, green
and task-specific catalyst was synthesized and fully characterized
using Fourier transform infrared (FT-IR), UV–visible and energy-
dispersive X-ray (EDX) spectroscopies, thermogravimetric analysis
(TGA), X-ray diffraction (XRD), scanning electron microscopy
(SEM), transmission electron microscopy (TEM) and atomic force
microscopy (AFM). Generally, with the addition of substance in each
synthesis step, FT-IR, EDX and UV–visible spectra, TGA and XRD pat-
terns confirm the synthesis of pro-catalyst. Changes in any of these
analyses indicate that the material is added in each synthesis step.
FT-IR spectroscopy was employed to compare the synthesized
blank Fe3O4 MNPs, Fe3O4@SiO2 core–shell MNPs and the other
core–shell surface-modified models (Fig. 1). The FT-IR spectrum of
sorption associated with S O bond vibration appears at 1059 cmÀ1
.
UV–visible spectroscopy was another technique applied for prov-
ing the structure of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as a MNP catalyst. This analysis was used to compare alterations
in the various steps of catalyst synthesis. Hence, it was found that
there are differences in absorption maxima among catalyst struc-
ture {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} and other struc-
tures, and this emphasizes the synthesis of this compound. We are
able to identify the presence of an additional moiety on the chief
structure of MNPs, especially at λ = 272 nm (Fig. 2). These step-
by-step changes in the UV–visible spectra represent the prepara-
tion of the MNP catalyst. The intensity of absorption at λ = 272 nm
Appl. Organometal. Chem. 2016, 30, 500–509
Copyright © 2016 John Wiley & Sons, Ltd.
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M. A. Zolfigol et al.
Figure 4. TGA curves: (a) {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl};
(b) Fe3O4; (c) Fe3O4@SiO2; (d) Fe3O4@SiO2@(CH2)3-Cl; (e) Fe3O4@SiO2@(CH2)
3Semicarbazide.
Figure 2. UV–visible absorption curves of {Fe3O4@SiO2@(CH2)3
Semicarbazide-SO3H/HCl} as a MNP catalyst.
loss is about 7%. The weight loss (14%) between 120 and 410°C is
attributed chiefly to the thermal decomposition of semicarbazide
functionalized with chlorosulfonic acid on the surface of the silica
coating. {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} displays
three-step weight loss behaviour. A weight loss of MNP catalyst of
about 5% appears at 410–510°C, which is attributed to the thermal
decomposition of the MNP catalyst. As a result, the TGA of the MNP
catalyst shows main loss in three steps, and decomposes after
510°C. The changes in TGA spectra confirm that material is added
in each synthesis step.
The structures of Fe3O4 MNPs, Fe3O4@SiO2@(CH2)3
Semicarbazide and {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
were investigated using XRD. The XRD pattern of the bare MNPs
reveals a pattern consistent with those of spinel ferrites described
(Fig. 5). The related peaks are identified in both of the
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} XRD patterns, indi-
cating the retention of the crystalline spinel ferrite core structure
during the reaction process. The positions and relative intensities
of all peaks conform well with the standard XRD pattern of Fe3O4
MNPs (JCPDS card no. 85-1436) representing the retention of the
crystalline cubic spinel structure of MNPs. The XRD patterns of the
particles show nine characteristic peaks linked to a cubic iron oxide
phase (2θ = 14.80°, 30.10°, 35.50°, 43.10°, 53.00°, 57.00°, 62.80°,
70.50°, 73.90°). These are revealed to their corresponding indices
(1 1 0), (2 2 0), (3 1 1), (4 0 0), (3 3 1), (4 2 2), (5 1 1), (4 4 0) and
(5 3 1), respectively. It is implicit that the resultant nanoparticles
changes during the synthesis of the MNP catalyst in each stage.
Moreover, band-gap energy (Ebg) is calculated on the basis of the
maximum absorption band of the catalyst and is determined as
4.559 eV, using the equation Ebg (eV) = 1240/λ (where Ebg is the
band-gap energy and λmax is the absorption wavelength (ca 272 nm)
of the MNP catalyst. No additional peaks linked with impurities
and structural imperfections are seen in the spectrum, which
indicates that the MNP catalyst had been prepared. The samples
for of UV–visible spectral investigation were prepared in ethanol
solvent and a concentration of 0.1 g of MNP catalyst was studied
(via dispersing process).
The EDX spectrum of the attained {Fe3O4@SiO2@(CH2)3
Semicarbazide-SO3H/HCl} as MNP catalyst indicates the presence
of the anticipated elements in the structure of the catalyst, for
example carbon (C), nitrogen (N), iron (Fe), oxygen (O), silicon (Si),
sulfur (S) and chlorine (Cl) (Fig. 3). It is clearly revealed that the
synthesized MNP catalyst contains only C, N, Fe, O, Si, S and Cl ele-
ments. No extra peaks related to any impurity are identified with
SEM coupled EDX, which means that the MNP catalyst is composed
only of C (6.88), N (6.88), Fe (22.18), O (50.58), Si (46.30), S (16.52) and
Cl (0.70), which is shown by the elemental analysis.
The TGA curve of the {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/
HCl} as MNP catalyst displays a mass loss of organic material as it
decomposes upon heating (Fig. 4). The primary weight loss from
the MNP catalyst (room temperature to 120°C) is owing to the
removal of physically adsorbed water and organic solvents, which
were used in the course of the synthesis of the catalyst. The weight
Figure 5. XRD patterns: (a) {Fe3O4@SiO2}; (b) {Fe3O4@SiO2@(CH2)3
Semicarbazide}; (c) {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as MNP
catalyst.
Figure 3. EDX spectrum of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as MNP catalyst.
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Nano magnetic with semicarbazide-based acidic ionic liquid tag
are pure Fe3O4 with a spinel structure and that the grafting method
does not induce any phase change of Fe3O4. The size, shape and
morphology of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as
MNP catalyst were investigated using XRD, SEM, TEM and AFM ana-
lyses. The XRD pattern of the MNP catalyst was studied in the range
10–90° (Fig. 5). As revealed in Fig. 5, the XRD pattern shows diffrac-
tion lines of highly crystalline nature at 2θ = 18.80°, 26.20°, 26.70°,
28.70°, 29.20°, 29.80°, 35.40°, 35.90°, 51.40°, 57.40°, 62.50° and
63.00°. The peak width (FWHM), size and interplanar distance from
the XRD pattern of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
in the range 18.80–63.00° were obtained and the results are
summarized in Table 1. For example, assignments for the highest
diffraction line, 35.90°, reveal a FWHM of 0.13 and a crystalline size
for the catalyst of ca 64.24 nm through the Debye–Scherrer equa-
tion: D = Kλ/(βcos θ) (where D is the crystalline size, K is the shape
factor, corresponding to 0.9, λ is the X-ray wavelength, β is the
FWHM of the diffraction peak and θ is the Bragg diffraction angle
in degrees). An interplanar distance of 0.249848 nm (from the
highest diffraction line at 35.90°) is found via the Bragg equation:
dhkl = λ/(2sin θ), where λ is Cu radiation wavelength (0.154178
nm). Crystallite sizes obtained from numerous diffraction lines
using the Debye–Scherrer equation are found to be in the
nanometre range (18.97–64.24 nm), which is chiefly in good agree-
ment with the results obtained from SEM and TEM (Fig. 6). In ge-
neral, with addition of reactants in each stage, XRD patterns
confirm the synthesis of the catalyst in each step. Changes in XRD
patterns indicate that the materials are attached as a tag in each
synthesis step (nevertheless the general structure of XRD patterns
is kept).
AFM is a method that allows the determination and analysis of
surfaces with high resolution. AFM has abundant advantages, and
practically any typical surface can be imaged: for example hard sur-
faces such as the surface of a ceramic material, or the dispersal of a
metallic nanocomposite; or very soft, for example molecules of
proteins or plastic materials. Figure 7 displays the two- and three-
dimensional AFM images of {Fe3O4@SiO2@(CH2)3Semicarbazide-
SO3H/HCl} as MNP catalyst. No important partition area in size
is identified in the images. After studying the three-dimensional
2.1 μm2 × 2.1 μm2 frameworks, we can understand that the obtained
MNP catalyst has an interrupted structure with a desirable external
planarity. The surface of the coat on the MNP catalyst is visibly
revealed to be less than 65 nm.
Figure 6. (a, b) SEM images and (c, d) TEM images of {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl} as MNP catalyst.
Magnetic measurements of the Fe3O4 nanoparticles and the
MNP catalyst were conducted at room temperature using a vibrat-
ing sample magnetometer. Based on the magnetization curves
(Fig. 8), the saturation magnetization of the obtained MNP catalyst
decreases from 52 emu gÀ1 (Fe3O4) to 11 emu gÀ1. This reduction
in saturation magnetization is due to the surface coating on the
Fe3O4 nanoparticles.
Table 1. XRD data for {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as MNP catalyst
Entry
2θ
Peak width
(FWHM) (°)
Size (nm)
Interplaner
distance (nm)
1
18.80
26.20
26.70
28.70
29.20
29.80
35.40
35.90
51.40
57.40
62.50
63.00
0.20
0.43
0.26
0.17
0.16
0.41
0.23
0.13
0.15
0.18
0.33
0.38
40.27
18.97
31.40
48.23
51.32
20.05
36.26
64.24
58.78
50.32
28.16
24.52
0.471450
0.339729
0.333479
0.310678
0.305472
0.299456
0.253262
0.249848
0.177559
0.160409
0.148427
0.147369
2
3
4
5
Application of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as MNP catalyst in synthesis of 3,3′-(Arylmethylene)bis(4-
hydroxycoumarin) derivatives
6
7
8
Initially, to optimize the reaction conditions, the condensation
reaction of 4-chlorobenzaldehyde with 4-hydroxycoumarin was
selected as a model and various amounts of {Fe3O4@SiO2@(CH2)3
Semicarbazide-SO3H/HCl} as MNP catalyst were used from room
temperature to 100°C under solvent-free conditions (Table 2). As
9
10
11
12
Appl. Organometal. Chem. 2016, 30, 500–509
Copyright © 2016 John Wiley & Sons, Ltd.
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M. A. Zolfigol et al.
Figure 8. Vibrating sample magnetometry curves: (a) Fe3O4; (b) Fe3O4@SiO2;
(c) Fe3O4@SiO2@(CH2)3-Cl; (d) Fe3O4@SiO2@(CH2)3Semicarbazide; (e)
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}.
Table 2. Result of amount of catalyst and temperature in synthesis of
3,3′-(arylmethylene)bis(4-hydroxycoumarin) derivatives under solvent-
free conditionsa
Entry
Catalyst
Reaction
Reaction
Yield (%)b
loading (mg) temperature (°C) time (min)
1
Catalyst-free
80
80
80
80
80
180
90
No reaction
2
1
3
40
3
90
55
4
5
90
86
5
7
70
90
6
10
10
10
10
10
10
15
20
r.t.
180
180
90
No reaction
7
40
60
60
75
98
98
98
97
98
8
9
80
20
10
11
12
13
90
20
100
80
20
30
80
27
aReaction conditions: 4-chlorobenzaldehyde (1 mmol), 4-hydroxycoumarin
(2 mmol).
bIsolated yield.
Table 3. Effect of solvent in synthesis of 3,3′-(arylmethylene)bis(4-
hydroxycoumarin) derivativesa
Entry
Solvent
Reaction time (min)
Yield (%)b
1
2
3
4
5
6
CH3CN
45
60
30
60
60
20
95
37
95
83
51
98
Figure 7. (a, b) Two-dimensional and (c, d) three-dimensional AFM images
of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as MNP catalyst.
H2O
C2H5OH
CH3CO2Et
Toluene
Solvent-free
evident from Table 2, the best results are obtained when the reac-
tion is conducted using 0.01 g of MNP catalyst at 80°C (Table 2,
entry 9). No improvement is observed in the yield through increas-
ing the amount of catalyst and temperature (Table 2, entries 10–13).
In the absence of MNP catalyst, the product is not obtained (Table 2,
entry 1).
aReaction conditions: 4-Chlorobenzaldehyde (1 mmol), 4-hydroxycoumarin
(2 mmol).
bIsolated yield.
Moreover, to compare the results of the reaction in solution with
those of solvent-free conditions, a mixture of 4-chlorobenzaldehyde
with 4-hydroxycoumarin as a typical reaction, using 10 mg of
MNP catalyst in various solvents, i.e. water, CH3CN, C2H5OH,
CH3CO2Et and toluene, was considered at 80°C (Table 3). As can
be seen, solvent-free conditions give the best results for this
reaction.
After identifying the optimum reaction conditions, the reaction
was performed with aromatic aldehydes and 4-hydroxycoumarin.
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Nano magnetic with semicarbazide-based acidic ionic liquid tag
To show the generality of the described procedure, numerous alde-
hydes were reacted with two equivalents of 4-hydroxycoumarin
under the same conditions. These results encouraged us to study
the scope, limitations and overview of this process for various alde-
hydes under optimized conditions. As evident from Table 4, a series
of aromatic aldehydes undergo electrophilic substitution reaction
with 4-hydroxycoumarin to provide a series of substituted
3,3′-(arylmethylene)bis(4-hydroxycoumarin) derivatives in high to
excellent yields. The nature and electronic properties of the substit-
uents on the aromatic ring affect the conversion rate, with aromatic
aldehydes possessing electron-withdrawing groups (Table 4,
entries 3 and 4) on the aromatic ring reacting faster than those with
electron-donating groups (Table 4, entries 10, 12 and 14).
A suggested simple and satisfactory mechanism for the synthesis
of 3,3′-(arylmethylene)bis(4-hydroxycoumarin) derivatives catalysed
by {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} is shown in
Scheme 2. According to the reaction procedure, initially the MNP cat-
alyst activates the carbonyl group of the aromatic aldehyde (by H+
from SO3H moiety-catalysed) and then completed Knoevenagel con-
densation of nucleophilic attack of activated 4-hydroxycoumarin (by
SO–3 moiety-catalysed) and via elimination of one molecule of H2O
forms intermediate 7. In the next step, the MNP catalyst activates
the carbonyl group of intermediate 7 (by H+ from SO3H moiety-
catalysed) and nucleophilic attack of a second equivalent of activated
4-hydroxycoumarin (by SO–3 moiety-catalysed) through Michael addi-
tion creates α,β-unsaturated ketone (intermediate 8). Finally, this
catalytic cycle is completed by removal of H+ in an enolization pro-
cess and thus the product is prepared in the presence of the MNP
catalyst.[59]
Scheme 2. Probable mechanism for the synthesis of 3,3′-(arylmethylene)
bis(4-hydroxycoumarin) derivatives catalysed by {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl} MNPs.
Table 4. Synthesis of 3,3′-(arylmethylene)bis(4-hydroxycoumarin) de-
rivatives using 0.01 g of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as MNP catalysta
In addition, considering the magnetic separation and isolation of
the MNP catalyst on reaction completion (reaction between
4-chlorobenzaldehyde and 4-hydroxycoumarin), recyclability and
reusability of the MNP catalyst for numerous runs were also studied.
Results shown in Fig. 9 confirm that the magnetically separable
MNP catalyst could be reused and recycled eight times without
Entry
Aldehyde
Time Yield
(min) (%)b
M.p. (Lit.) (°C)
1
2
3
4
5
6
7
8
9
Benzaldehyde
30
15
10
20
30
20
20
40
40
95
92
97
98
93
95
96
91
95
233–235 (229–231)[59]
225–227 (214–215)[59]
230–231 (233–235)[59]
240–242 (261–263)[59]
234–236 (221–223)[59]
208–210 (201–203)[59]
217–218 (white solid)
267–269
3-Nitrobenzaldehyde
4-Nitrobenzaldehyde
4-Chlorobenzaldehyde
3-Chlorobenzaldehyde
2-Chlorobenzaldehyde
3-Fluorobenzaldehyde
Pyridine-4-carbaldehyde
3-Ethoxy-4-
218–219 (cream solid)
hydroxybenzaldehyde
10 3-Methoxybenzaldehyde
11 Terephthalaldehyde
40
90
50
50
20
35
93
89
92
95
96
96
249–250 (250–252)[59]
296–297[12]
227–229 (210.5)[59]
219–221 (193)[59]
235–237 (260–262)[59]
270–271 (266–269)[59]
12 3-Hydroxybenzaldehyde
13 4-Hydroxybenzaldehyde
14 4-Cyanobenzaldehyde
15 4-Methylbenzaldehyde
aReaction conditions: aldehyde (1 mmol), 4-hydroxycoumarin (2 mmol).
bIsolated yield.
Figure 9. Reusability of the {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
MNP catalyst for the synthesis of 3,3′-(arylmethylene)bis(4-
hydroxycoumarin) in 20 min.
Appl. Organometal. Chem. 2016, 30, 500–509
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

M. A. Zolfigol et al.
any noteworthy loss of its initial catalytic activity. The reaction was
scaled up to 10 mmol of 4-chlorobenzaldehyde and 4-
hydroxycoumarin in the presence of 0.1 g of MNP catalyst at 80°C.
The yield of the reaction is 98% in 20 min and 84% after the eighth
run. The results are summarized in Fig. 9.
Table 6. Effect of solvent in synthesis of 1-carbamato-alkyl-2-naphthol
derivativesa
Entry
Solvent
Reaction time
(min)
Yield (%)b
1
2
3
4
5
6
H2O
180
60
7
21
15
15
11
98
C2H5OH
Application of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
as MNP catalyst in synthesis of 1-Carbamato-alkyl-2-naphthol
derivatives
CH3CN
60
CH3CO2Et
Toluene
120
120
10
Solvent-free
To optimize the reaction conditions, the condensation reaction of
4-chlorobenzaldehyde with benzyl carbamate and β-naphthol
was chosen as a model and various amounts of MNP catalyst at
room temperature to 100°C were tested under solvent-free condi-
tions (Table 5). As evident from Table 5, the best results are
achieved when the reaction is conducted in the presence of 7 mg
of MNP catalyst at 70°C (Table 5, entry 8). No improvement is iden-
tified in the yield of the reaction through increasing the amount of
the MNP catalyst and the temperature (Table 5, entries 9 and 13). It
is clear that in the absence of the MNP catalyst, the product is not
obtained (Table 5, entry 1).
aReaction conditions: 4-chlorobenzaldehyde (1 mmol), β-naphthol
(1 mmol), benzyl carbamate (1.1 mmol).
bIsolated yield.
Table 7. Synthesis of 1-carbamato-alkyl-2-naphthol derivatives using
0.01
g of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as MNP
catalystab
To compare the results for solution with those for solvent-free
conditions, a mixture of 4-chlorobenzaldehyde, benzyl carbamate
and β-naphthol as a typical reaction in the presence of 7 mg of
MNP catalyst in various solvents, i.e. water, C2H5OH, CH3CN,
CH3CO2Et and toluene, was studied at 70°C (Table 6). Solvent-free
conditions give the best results for this reaction.
Following optimization of the reaction conditions, to probe the
efficacy and the scope of the process, various 1-carbamato-alkyl-
2-naphthol derivatives were synthesized via the one-pot three-
component condensation reaction between aromatic aldehydes
with benzyl carbamate and β-naphthol in the presence of catalytic
amounts of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} under
solvent-free reaction conditions. The results are summarized in
Table 7. The effect of substituents on the aromatic ring is seen to
be strong in terms of yields under these reaction conditions. Both
types of aromatic aldehydes with electron-releasing and electron-
withdrawing substituents on their aromatic ring give suitable prod-
ucts in high to excellent yields in short reaction times. The reaction
Entry
Aldehyde
Time Yield
(min) (%)b
M.p. (Lit.) (°C)
1
2
3
4
5
6
7
8
9
Pyridine-4-carbaldehyde
Benzaldehyde
20
15
10
12
8
88
96
90
92
96
98
94
97
95
97
97
205–206 (cream solid)
186–188 (179–180)[60]
204–205 (198–200)[60]
197–198 (196–197)[60]
200–202 (200)[60]
2-Nitrobenzaldehyde
3-Nitrobenzaldehyde
4-Nitrobenzaldehyde
4-Chlorobenzaldehyde
3-Chlorobenzaldehyde
2-Chlorobenzaldehyde
2,3-Dichlorobenzaldehyde
10
10
10
10
5
178–179 (176–177)[60]
185–186 (183–185)[60]
207–209 (214–216)[60]
209–210
10 2,4-Dichlorobenzaldehyde
11 4-Chloro-3-
207–209 (202–204)[60]
5
212–214 (pale
nitrobenzaldehyde
yellow solid)
Table 5. Result of amount of catalyst and temperature in synthesis of
197–198 (202–203)[60]
197–199 (185–186)[60]
177–178 (180–182)[60]
151–153 (152–154)[60]
196–198 (202–204)[60]
207–208
1-carbamato-alkyl-2-naphthol derivatives under solvent-free conditionsa
12 4-Fluorobenzaldehyde
13 3-Fluorobenzaldehyde
14 4-Bromobenzaldehyde
15 4-Methylbenzaldehyde
16 2-Methoxybenzaldehyde
17 Naphtalene-1-
5
10
5
96
91
93
90
92
91
Entry
Catalyst
Reaction
Reaction
Yield (%)b
loading (mg) temperature (°C) time (min)
30
30
20
1
Catalyst-free
80
80
80
80
180
180
60
No reaction
2
1
3
50
carbaldehyde
3
85
18 Naphtalene-2-
20
93
194–195
4
5
30
95
carbaldehyde
5
7
r.t.
180
180
30
No reaction
6
7
40
60
40
93
98
98
98
96
98
96
aReaction conditions: aldehyde (1 mmol), β-naphthol (1 mmol), benzyl
carbamate (1.1 mmol).
bIsolated yield.
7
7
8
7
70
10
9
7
80
10
10
11
12
13
7
90
10
7
100
70
10
of aromatic aldehydes possessing electron-withdrawing groups
(Table 7, entries 5 and 6) is faster than that of aldehydes with
electron-donating groups (Table 7, entries 15 and 16). Additionally,
recyclability and reusability of the catalyst were also studied for the
condensation of 4-chlorobenzaldehyde with benzyl carbamate and
β-naphthol. Correspondingly, the MNP catalyst was separated and
reused for further reaction.
10
15
10
70
8
aReaction conditions: 4-chlorobenzaldehyde (1 mmol), β-naphthol
(1 mmol), benzyl carbamate (1.1 mmol).
bIsolated yield.
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2016, 30, 500–509

Nano magnetic with semicarbazide-based acidic ionic liquid tag
Scheme 4. Synthesis of 3,3′-(arylmethylene)bis(4-hydroxycoumarin)
and 1-carbamato-alkyl-2-naphthol in the presence of semicarbazide
hydrochloride.
4-chlorobenzaldehyde, benzyl carbamate and β-naphthol (in the
synthesis of 1-carbamato-alkyl-2-naphthol) were investigated
under the same reaction conditions in the presence of 1 mmol
of semicarbazide hydrochloride. The 3,3′-(arylmethylene)bis
(4-hydroxycoumarin) is synthesized in trace yield and the
1-carbamato-alkyl-2-naphthol is not produced (Scheme 4).
Scheme 3. Plausible mechanism for the synthesis of 1-carbamato-alkyl-2-
naphthol derivatives catalysed by {Fe3O4@SiO2@(CH2)3Semicarbazide-
SO3H/Cl} MNPs.
In Scheme 3, we propose a probable mechanism for the synthe-
sis of 1-carbamato-alkyl-2-naphthol derivatives in the presence of
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} as MNP catalyst. As
regards the reaction process, firstly the MNP catalyst activates the
carbonyl group of the aromatic aldehyde (by H+ from SO3H
moiety-catalysed) and then nucleophilic attack of activated
β-naphthol (by SOÀ3 moiety-catalysed) and via elimination of
one molecule of H2O forms ortho-quinone methide intermediate
11. A practical description for this result can be given by study-
ing the nucleophilic addition of benzyl carbamate to intermedi-
ate 11. Finally the anticipated product is obtained after
aromatization.[47,48,60]
To compare the efficiency of our catalyst with that of catalysts
reported by others for the synthesis of 3,3′-(arylmethylene)bis
(4-hydroxycoumarin) derivatives, Table 8 summarizes the results
for catalysts in the condensation of 4-chlorobenzaldehyde with
4-hydroxycoumarin. As is evident, the MNP catalyst improves the
synthesis of product.
Conclusions
In summary, a novel, reusable, green and mild semicarbazide-based
ionic liquid stabilized on silica-coated Fe3O4 MNPs, namely
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}, was designed, syn-
thesized and fully characterized using FT-IR, UV–visible and EDX
spectroscopies, TGA, XRD, SEM, TEM and AFM. Application of this
catalyst was studied for the synthesis of 3,3′-(arylmethylene)bis
(4-hydroxycoumarin) and 1-carbamato-alkyl-2-naphthol derivatives
via the condensation reaction between 4-hydroxycoumarin and ar-
omatic aldehydes at 80°C under solvent-free conditions (synthesis
of 3,3′-(arylmethylene)bis(4-hydroxycoumarin) derivatives) and
one-pot three-component condensation reaction of aromatic alde-
hydes with benzyl carbamate and β-naphthol at 70°C (synthesis of
1-carbamato-alkyl-2-naphthol derivatives) under efficient, green,
mild and solvent-free conditions. Significant advantages of the cat-
alyst are relative environmental benignity, cleaner reaction profile,
simplicity of product isolation, short reaction time, high yield, recy-
clability and reusability, in close agreement with the green chemis-
try disciplines. To the best of our knowledge, this is the first report
of the synthesis of semicarbazide-based ionic liquid stabilized on
silica-coated Fe3O4 MNPs. Consequently the current study can open
up a novel and promising insight into the sequence of rational de-
sign, synthesis and applications of task-specific nanomagnetic ionic
liquids with desirable properties as full-fledged substances for
maintainable acid-catalysed chemical processes.
According to the suggested reaction mechanism, the
presence of hydrochloride salt moiety does not affect the
progress of reactions. To illustrate this issue, the reactions
between 4-hydroxycoumarin and 4-chlorobenzaldehyde (in the
synthesis of 3,3′-(arylmethylene)bis(4-hydroxycoumarin)) and
Table 8. Comparison of results for synthesis of model product by MNP
catalyst with those obtained using other reported catalysts
Entry
Reaction conditions
Catalyst Time Yield
amount (min) (%)
Ref.
Experimental
1
2
3
4
MNP catalyst, 80°C
10 mg
20
30
20
25
80 This work
[26]
TBAB, H2O, 100°C
10 mol%
10 mol%
15 mol%
95
General procedure for preparation of {Fe3O4@SiO2@(CH2)
3Semicarbazide-SO3H/HCl} catalyst
[26]
TBAB, solvent-free, 100°C
[MIM(CH2)4SO3H], solvent-
free, 80°C
87
[59]
93
Firstly, magnetite phase Fe3O4 was prepared by adding 3 ml of
FeCl3 (2 M dissolved in 2 M HCl) to 10.33 ml of double-distilled wa-
ter followed by dropwise addition of 2 ml of Na2SO3 (1 M) for 3 min
under magnetic stirring. With a change of colour from red to light
yellow in the solution, 80 ml of an NH3ÁH2O solution (0.85 M) was
added under vigorous stirring. Subsequently after 15 min, the
[59]
5
6
7
8
SBPPSP, H2O/C2H5OH, reflux 60 mg
15
25
95
[61]
RuCl3ÁnH2O, H2O, 80°C
Nano SiO2Cl, CH2Cl2, 40°C
SDS, H2O, 60°C
5 mol%
75 mg
85
[62]
180
150
92
[63]
20 mol%
93
Appl. Organometal. Chem. 2016, 30, 500–509
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

M. A. Zolfigol et al.
by recrystallization from ethanol–water (10:1), which resulted
in precipitation of the desired 1-carbamato-alkyl-2-naphthol
derivatives. All of the products were identified by comparison of
their physical data with those of known compounds (supporting
information).
Acknowledgments
We thank Bu-Ali Sina University and Iran National Science Founda-
tion (INSF) for financial support of our research group.
References
Scheme 5. Synthesis of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl}
MNPs.
[1] M. A. Zolfigol, R. Ayazi, S. Baghery, RSC Adv. 2015, 5, 71942.
[2] a) M. Kaur, S. Sharma, P. M. S. Bedi, Chin. J. Catal. 2015, 36, 520. See
reviews: b) P. Gupta, S. Paul, Catal. Today. 2014, 236, 153.
c) M. M. Heravi, Z. Faghihi, J. Iran. Chem. Soc. 2014, 11, 209.
[3] a) K. Tanabe, T. Yamagushi, T. T. Akeshita, J. Res. Inst. Catal. Hokkaido
Univ. 1968, 16, 425. b) Y. C. Sharma, B. Singh, Biofuels. Bioprod.
Biorefin. 2011, 5, 69.
[4] a) S. Rostamnia, E. Doustkhaha, Synlett 2015, 26, 1345. b) K. Zeng,
Z. Huang, J. Yang, Y. Gu, Chin. J. Catal. 2015, 36, 1606. c) X. Pan, M. Li,
Y. Gu, Chem. Asian J. 2014, 9, 268. d)M. Li, A. Taheri, M. Liu, S. Sun,
Y. Gu, Adv. Synth. Catal. 2014, 356, 537.
[5] a) B. Karimi, F. Mansouri, H. M. Mirzaei, Chem. Cat. Chem. 2015, 7, 1736.
See reviews: b) T. Cheng, D. Zhang, H. Li, G. Liu, Green Chem. 2014, 16,
3401. c) M. B. Gawande, R. Luque, R. Zboril, Chem. Cat. Chem. 2014, 6,
3312. d) D. Zhang, C. Zhou, Z. Sun, L. Wu, C. Tunga, T. Zhang,
Nanoscale 2012, 4, 6244.
[6] a) A. Schatz, O. Reiser, W. J. Stark, Chem. Eur. J. 2010, 16, 8950.
b) D. Astruc, F. Lu, J. R. Aranzaes, Angew. Chem. Int. Ed. 2005, 44, 7852.
[7] A. H. Lu, E. L. Salabas, F. Schìth, Angew. Chem. Int. Ed. 2007, 46, 1222.
[8] S. Laurent, D. Forge, M. Port, A. Roch, C. Robic, L. V. Elst, R. N. Muller,
Chem. Rev. 2008, 108, 2064.
magnetite precipitate (Fe3O4) was washed to pH < 7.5 with distilled
water and separated with a magnet.[64]
A mixture containing 1 g of Fe3O4, 20 ml of water, 80 ml of ethanol,
3 ml of ammonia and 3 ml of tetraethylorthosilicate (TEOS) was
refluxed to afford silica-coated Fe3O4 (Fe3O4@SiO2).[65] Subse-
quently, 3 g of Fe3O4@SiO2 and (3-chloropropyl)triethoxysilane
(10 mmol) in 80 ml of dry toluene were refluxed under nitrogen
for 12 h. The obtained Fe3O4@SiO2@(CH2)3-Cl (grafted with
chloropropyl group) was filtered, washed twice with dry toluene
and anhydrous diethyl ether, and dried at 80°C for 6 h in vacuum.
Then semicarbazide (0.751 g, 10 mmol) in 50 ml of dry toluene
was added to the Fe3O4@SiO2@(CH2)3Cl and the mixture was
refluxed for 12 h. The resulting solid was filtered, washed and dried
in a similar process to afford Fe3O4@SiO2@(CH2)3-Semicarbazide.
Finally, chlorosulfonic acid (1.165 g, 10 mmol) was added
dropwise to the Fe3O4@SiO2@(CH2)3-Semicarbazide in dry dichloro-
methane and the mixture was stirred for 6 h. Then with similar
steps of filtering, washing and drying, {Fe3O4@SiO2@(CH2)3
Semicarbazide-SO3H/HCl} as MNP catalyst was obtained. The
synthetic route to the described catalyst is shown in Scheme 5.
[9] S. C. Basa, Phytochemistry 1988, 27, 1933.
[10] R. D. H. Murray, J. Medez, S. A. Brown, The Natural Coumarins:
Occurrence, Chemistry and Biochemistry, Wiley, New York, 1982.
[11] M. I. Choudhary, N. Fatima, K. M. Khan, S. Jalil, S. Iqbal, Atta-ur-Rahman.
Bioorg. Med. Chem. 2006, 14, 8066.
[12] C. X. Su, J. F. Mouscadet, C. C. Chiang, H. J. Tsai, L. Y. Hsu, Chem. Pharm.
Bull. 2006, 54, 682.
[13] S. S. Li, Z. Gao, X. Feng, S. M. Hecht, J. Nat. Prod. 2004, 67, 1608.
[14] B. Y. Park, B. S. Min, S. R. Oh, J. H. Kim, K. H. Bae, H. K. Lee, Phytother. Res.
2006, 20, 610.
General procedure for synthesis of 3,3′-(Arylmethylene)bis(4-
hydroxycoumarin) derivatives
[15] F. Borges, F. Roleira, N. Milhazes, L. Santana, E. Uriarte, Curr. Med. Chem.
To
a mixture of aromatic aldehyde (1 mmol) and 4-
2005, 12, 887.
hydroxycoumarin (0.324 g, 2 mmol) was added 10 mg of
{Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} MNPs followed by
mixing under solvent-free conditions at 80°C for the appropriate
time given in Table 3. After completion of the reaction, which was
determined with TLC (n-hexane–ethyl acetate, 5:2), the MNP
catalyst was recovered magnetically and the mixture was purified
via recrystallization from ethanol–water (10:1), which resulted
in precipitation of the anticipated 3,3′-(arylmethylene)bis
(4-hydroxycoumarin) derivatives. All of the products were identified
by comparison of their physical data with those of known
compounds (supporting information).
[16] M. Mercep, I. Malvar, B. Hrvacic, S. Markovic, A. Filipovic-Sucic,
B. Bosnjak, A. Cempuh-Klonkay, R. Rupcic, A. Hutinec, I. J. Elenkov,
M. Mesic, Patent WO 2006111858, 2006.
[17] I. Manolov, C. Maichle-Moessmer, I. Nicolova, N. Danchev, Arch. Pharm.
2006, 339, 319.
[18] R. Nagashima, G. Levy, R. A. O’Reilly, J. Pharm. Sci. 1968, 57, 1888.
[19] A. Romeo, M. Prosdocimi, Patent WO 9222545, 1992.
[20] E. Altieri, M. Cordaro, G. Grassi, F. Risitano, A. Scala, Tetrahedron 2010,
66, 9493.
[21] M. V. R. Reddy, R. E. Premkumar, Patent WO 2006132947, 2006.
[22] I. Kostova, G. Momekov, Eur. J. Med. Chem. 2006, 41, 717.
[23] I. Kostova, G. Momekov, M. Zaharieva, M. Karaivanova, Eur. J. Med.
Chem. 2005, 40, 542.
[24] J. Wang, D. Q. Shi, Q. Y. Zhuang, X. S. Wang, S. J. Tu, Chin. J. Org. Chem.
2005, 25, 926.
[25] M. Kidwi, V. Bansal, P. Mothsra, S. Saxena, R. K. Somvanshi, S. Dey, J. Mol.
Catal. A 2007, 268, 76.
General procedure for synthesis of
1-Carbamato-alkyl-2-naphthol derivatives
[26] J. M. Khurana, S. Kumar, Tetrahedron Lett. 2009, 50, 4125.
[27] S. Qadir, A. Dar, K. Zaman, Synth. Commun. 2008, 38, 3490.
[28] G. X. Gong, J. F. Zhou, L. T. An, X. L. Duan, S. J. Ji, Synth. Commun. 2009,
39, 497.
[29] N. Hamdi, M. C. Puerta, P. Valerga, Eur. J. Med. Chem. 2008, 43, 2541.
[30] T. Dingermann, D. Steinhilber, G. Folkers, Molecular Biology in Medicinal
Chemistry, Wiley-VCH, Weinheim, 2004.
To a mixture of aromatic aldehyde (1 mmol), benzyl carbamate
(0.151 g, 1 mmol) and β-naphthol (0.144 g, 1 mmol) was added 7 mg
of {Fe3O4@SiO2@(CH2)3Semicarbazide-SO3H/HCl} MNPs followed
by mixing under solvent-free conditions at 70°C for the appropriate
time given in Table 5. After completion of the reaction, which was
determined with TLC (n-hexane–ethyl acetate, 5:2), the MNP
catalyst was recovered magnetically and the mixture was purified
[31] A. Y. Shen, C. T. Tsai, C. L. Chen, Eur. J. Med. Chem. 1999, 34, 877.
[32] A. Y. Shen, C. L. Chen, C. I. Lin, Chin. J. Physiol. 1992, 35, 45.
wileyonlinelibrary.com/journal/aoc
Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2016, 30, 500–509

Nano magnetic with semicarbazide-based acidic ionic liquid tag
[33] M. Damodiran, N. P. Selvam, P. T. Perumal, Tetrahedron Lett. 2009, 50,
5474.
[34] R. D. Clark, J. M. Caroon, A. F. Kluge, D. B. Repke, A. P. Roszkowski,
A. M. Strosberg, S. Baker, S. M. Bitter, M. D. Okada, J. Med. Chem.
1983, 26, 657.
[35] H. Ren, S. Grady, D. Gamenara, H. Heinzen, P. Moyna, S. Croft,
H. Kendrick, V. Yardley, G. Moyna, Bioorg. Med. Chem. Lett. 2001, 11,
1851.
[55] a) M. A. Zolfigol, T. Azadbkht, V. Khakizadeh, R. Nejatyami, D. Perrin, RSC
Adv. 2014, 4, 40036. b) T. Azadbakht, M. A. Zolfigol, R. Azadbakht,
V. Khakizadeh, D. Perrin, New J. Chem. 2015, 39, 439.
[56] a) M. A. Zolfigol, S. Baghery, A. R. Moosavi-Zare, S. M. Vahdat, RSC Adv.
2015, 5, 32933. b) A. R. Moosavi-Zare, M. A. Zolfigol, V. Khakyzadeh,
C. Bottcher, M. H. Beyzavi, A. Zare, A. Hasaninejad, R. Luque, J. Mater.
Chem. A 2014, 2, 770. c) A. R. Moosavi-Zare, M. A. Zolfigol,
O. Khaledian, V. Khakyzadeh, M. Darestani-Farahani, H. G. Kruger, New
J. Chem. 2014, 38, 2342. d)A. Khazaei, M. A. Zolfigol,
A. R. Moosavi-Zare, Z. Asgari, M. Shekouhy, A. Zare, A. Hasaninejad,
RSC Adv. 2012, 2, 8010.
[57] a) A. Taheri, X. Pan, C. Liu, Y. Gu, Chem. Sus. Chem. 2014, 7, 2094.
b) A. Taheri, B. Lai, C. Cheng, Y. Gu, Green Chem. 2015, 17, 812.
c) A. Taheri, C. Liu, B. Lai, C. Cheng, X. Pan, Y. Gu, Green Chem. 2014,
16, 3715.
[36] S. Remillard, L. I. Rebhun, G. A. Howie, S. M. Kupchan, Science 1975, 189,
1002.
[37] H. S. Mosher, M. B. Frankel, M. Gregory, J. Am. Chem. Soc. 1953, 75, 5326.
[38] F. Benedini, G. Bertolini, R. Cereda, G. Doná, G. Gromo, S. Levi, J. Mizrahi,
A. Sala, J. Med. Chem. 1995, 38, 130.
[39] J. L. Peglion, J. Vian, B. Gourment, N. Despaux, V. Audinot, M. Millan,
Bioorg. Med. Chem. Lett. 1997, 7, 881.
[40] G. Y. Lesher, A. R. Surrey, J. Am. Chem. Soc. 1955, 77, 636.
[41] Y. Kusakabe, J. Nagatsu, M. Shibuya, O. Kawaguchi, C. Hirose, S. Shirato,
J. Antibiot. 1972, 25, 44.
[42] H. Matsuoka, N. Ohi, M. Mihara, H. Suzuki, K. Miyamoto, N. Maruyama,
K. Tsuji, N. Kato, T. Akimoto, Y. Takeda, K. Yano, T. Kuroki, J. Med.
Chem. 1997, 40, 105.
[43] M. A. Zolfigol, A. Khazaei, A. R. Moosavi-Zare, A. Zare, V. Khakyzadeh,
Appl. Catal. A 2011, 400, 70.
[44] A. Zare, S. Akbarzadeh, E. Foroozani, H. Kaveh, A. R. Moosavi-Zare,
A. Hasaninejad, M. Mokhlesi, M. H. Beyzavi, M. A. Zolfigol, J. Sulfur
Chem. 2012, 33, 259.
[45] V. K. Das, M. Borah, A. J. Thakur, J. Org. Chem. 2013, 78, 3361.
[46] A. Zare, H. Kaveh, M. Merajoddin, A. R. Moosavi-Zare, A. Hasaninejad,
M. A. Zolfigol, Phosph. Sulfur Silicon Relat. Elem. 2013, 188, 573.
[47] H. Alinezhad, M. Tajbakhsh, M. Norouzi, S. Baghery, M. Akbari, C. R.
Chim. 2014, 17, 7.
[58] a) A. R. Moosavi-Zare, M. A. Zolfigol, M. Zarei, A. Zare, J. Afsar, Appl.
Catal. A 2015, 505, 224. b) A. R. Moosavi-Zare, M. A. Zolfigol, M. Zarei,
A. Zare, V. Khakyzadeh, J. Mol. Liq. 2015, 211, 373.
[59] a) N. Tavakoli-Hoseini, M. M. Heravi, F. F. Bamoharram, A. Davoodnia,
M. Ghassemzadeh, J. Mol. Liq. 2011, 163, 122. b) K. M. Khan, S. Iqbal,
M. A. Lodhi, Gh. M. Maharvi, Zia-Ullah, M. I. Choudhary, Atta-
ur-Rahmana, Sh. Perveen, Bioorg. Med. Chem. 2004, 12, 1963;
c) K. Niknam, A. Jamali, Chin. J. Catal. 2012, 33, 1840.
[60] a) A. Khazaei, F. Abbasi, A. R. Moosavi-Zare, RSC Adv. 2014, 4, 1388.
b) H. R. Shaterian, A. Hosseinian, M. Ghashang, Tetrahedron Lett.
2008, 49, 5804.
[61] K. Tabatabaeian, H. Heidari, A. Khorshidi, M. Mamaghani,
N. O. Mahmoodi, J. Serb. Chem. Soc. 2011, 76, 1.
[62] R. Karimian, F. Piri, A. A. Safari, S. J. Davarpanah, J. Nanostruct. Chem.
2013, 3, 52.
[63] H. Mehrabi, H. Abusaidi, J. Iran. Chem. Soc. 2010, 7, 890.
[64] a) N. Koukabi, E. Kolvari, A. Khazaei, M. A. Zolfigol,
B. Shirmardi-Shaghasemi, H. R. Khavasi, Chem. Commun. 2011, 47,
9230. b) S. Qu, H. Yang, D. Ren, S. Kan, G. Zou, D. Liand, M. Li,
J. Colloid Interface Sci. 1999, 215, 190.
[48] M. A. Zolfigol, S. Baghery, A. R. Moosavi-Zare, S. M. Vahdat, H. Alinezhad,
M. Norouzi, RSC Adv. 2015, 5, 45027.
[49] S. B. Patil, P. R. Singh, M. P. Surpur, S. D. Samant, Synth. Commun. 2007,
37, 1659.
[50] S. B. Patil, P. R. Singh, M. P. Surpur, S. D. Samant, Ultrason. Sonochem.
[65] Y. H. Deng, C. C. Wang, J. H. Hu, W. L. Yang, S. K. Fu, Colloids Surf. A 2005,
262, 87.
2007, 14, 515.
[51] H. R. Shaterian, H. Yarahmadi, M. Ghashang, Tetrahedron 2008, 64,
1263.
[52] A. Dorehgiraee, H. Khabazzade, K. Saidi, Arkivoc 2009, 7, 303.
[53] a)D. Azarifar, S. M. Khatami, M. A. Zolfigol, R. Nejat-Yami, J. Iran. Chem.
Soc. 2014, 11, 1223. b)M. Safaiee, M. A. Zolfigol, M. Tavasoli,
M. Mokhlesi, J. Iran. Chem. Soc. 2014, 11, 1593.
[54] M. A. Zolfigol, F. Shirini, P. Salehi, M. Abedini, Curr. Org. Chem. 2008, 12,
183.
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Appl. Organometal. Chem. 2016, 30, 500–509
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