Preparation and characterization of Fe3O4@SiO2/APTPOSS core–shell composite nanomagnetics as a novel family of reusable catalysts and their application in the one-pot synthesis of 1,3-thiazolidin-4-one derivatives

Article abstract of DOI:10.1002/aoc.3520

Octakis[3-(3-aminopropyltriethoxysilane)propyl]octasilsesquioxane (APTPOSS) as a polyhedral oligomeric silsesquioxane derivative was prepared and used as a pioneer reagent to obtain a novel core–shell composite using magnetic iron oxide nanoparticles as t

Full text of DOI:10.1002/aoc.3520

Full paper
Received: 12 April 2016
Revised: 23 April 2016
Accepted: 28 April 2016
Published online in Wiley Online Library
(wileyonlinelibrary.com) DOI 10.1002/aoc.3520
Preparation and characterization of
Fe3O4@SiO2/APTPOSS core–shell composite
nanomagnetics as a novel family of reusable
catalysts and their application in the one-pot
synthesis of 1,3-thiazolidin-4-one derivatives
Javad Safaei-Ghomi*, Seyed Hadi Nazemzadeh and Hossein Shahbazi-Alavi
Octakis[3-(3-aminopropyltriethoxysilane)propyl]octasilsesquioxane (APTPOSS) as a polyhedral oligomeric silsesquioxane derivative
was prepared and used as a pioneer reagent to obtain a novel core–shell composite using magnetic iron oxide nanoparticles as the
core and the inorganic–organic hybrid polyhedral oligomeric silsesquioxane as the shell. Fe3O4@SiO2/APTPOSS were confirmed
using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, dynamic light
scattering, thermogravimetric analysis, X-ray diffraction and vibrating sample magnetometry. The inorganic–organic hybrid
polyhedral oligomeric silsesquioxane magnetic nanoparticles were used as an efficient new heterogeneous catalyst for the one-
pot three-component synthesis of 1,3-thiazolidin-4-ones under solvent-free conditions. Moreover, these nanoparticles could be
easily separated using an external magnet and then reused several times without significant loss of catalytic activity. 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: Fe3O4 MNPs; 1,3-thiazolidin-4-one; solvent-free; POSS
materials, medical devices, anti-tumour agents, tissue engineering
Introduction
scaffolds, semiconductors devices, optical devices, binders for
ceramics, catalysis and solar cells.[12–16] Moreover, POSS molecules
During the past few decades, magnetic nanoparticles (MNPs) have
received a lot of interest owing to their unique features such as easy
synthesis, good stability, low toxicity, high activity, efficient recov-
ery, high surface area and facile separation from mixtures using
an external magnet.[1–3] Thus, a lot of MNP-supported catalysts
with excellent catalytic activities have been developed and applied
in versatile organic synthesis, including coupling reactions
(C&bond;C, C&bond;N, C&bond;S, etc.), hydrogenations, oxidations,
photocatalysis and cycloaddition reactions, as well as in novel
applications in hydration, asymmetric synthesis, CO2 cycloaddition,
and Knoevenagel condensations.[4,5] Meanwhile, MNPs (Fe3O4) can
be used as a versatile support for functionalization of N-heterocyclic
carbenes, metals, organocatalysts and chiral catalysts.[3,6] They are
often prepared with functional groups by the reaction with
alkylsilane derivatives, containing different functional groups
(SiR13R2, where R1 = OCH3, OC2H5, Cl; and R2 = alkane, alkene, alkoxy,
etc.) to form ether bonds.[7] For example, Davarpanah et al.
reported the synthesis and the characterization of a nanomagnetic
double-charged diazoniabicyclo[2.2.2]octane dichloride silica hy-
brid (Fe3O4@SiO2/DABCO).[8]
are composed of Si&bond;O&bond;Si and Si&bond;C bonds, with
an empirical formula RSiO1.5, in which R may be a hydrogen atom
or an alkyl, aryl, vinyl, alkoxy, silyl or siloxy derivative.[17]
4-Thiazolidinones serve as a vital part of a broad diversity of bio-
logically active products and synthetic compounds. They represent
a common scaffold in numerous bioactive compounds and have a
number of pharmacological properties such as anticancer,[18]
anti-HIV,[19–21] anti-inflammatory,[22] antibacterial,[23,24] histamine
antagonist[25] and antifungal[26] properties. Therefore, the improve-
ment of simple methods for the synthesis of thiazolidinones is still
desirable and in demand.
Several methods for the synthesis of 1,3-thiazolidin-4-ones
through multicomponent reactions have been described in the
presence of diverse catalysts such as Saccharomyces cerevisiae,[27]
[29]
Bi(SCH2COOH)3,[28] [BMIM]BF4 and HClO4–SiO2,[30] but some of
the reported methods have disadvantages, including use of non-
reusable and toxic catalyst, use of specific conditions and long
*
Correspondence to: Javad Safaei-Ghomi, Department of Organic Chemistry,
Faculty of Chemistry, University of Kashan, Kashan, 87317, IR Iran. E-mail:
safaei@kashanu.ac.ir
Inorganic–organic hybrid polyhedral oligomeric silsesquioxanes
(POSSs) have attracted much attention in recent years, due to their
unique cage-shaped structures, nanometre-sized structures and
easy chemical modification.[9–11] These hybrid nanoparticles have
been used in several applications including drug delivery, dental
Department of Organic Chemistry, Faculty of Chemistry, University of Kashan,
Kashan, 87317, IR, Iran
Appl. Organometal. Chem. (2016)
Copyright © 2016 John Wiley & Sons, Ltd.

Safaei-Ghomi J., Nazemzadeh S. H. and Shahbazi-Alavi H.
reaction times. Therefore, to avoid these limitations, the exploration
of an efficient, easily available catalyst with high catalytic activity for
the preparation of 1,3-thiazolidin-4-ones in short reaction times is
of interest. In recent years, utilizing environmental catalysts which
can be simply recycled has received significant attention.[31,32] In
the study reported here, in continuation of our recent researches
on the synthesis of nanoparticles,[33–35] we prepared a novel
recyclable heterogeneous core–shell nanomagnetic Fe3O4@SiO2/
octakis[3-(3-aminopropyltriethoxysilane)propyl]octasilsesquioxane,
using iron oxide MNPs as the core and the organic–inorganic hybrid
silica as the shell. Then, the inorganic–organic hybrid POSS MNPs
were used as an efficient new heterogeneous catalyst for the
one-pot three-component synthesis of 1,3-thiazolidin-4-ones under
solvent-free conditions (Scheme 1).
Experimental
Materials and physical measurements
All organic materials were purchased commercially from Merck or
Sigma-Aldrich and were used without further purification. Fourier
transform infrared (FT-IR) spectra were recorded with KBr pellets
using a Nicolet Magna IR-550 spectrometer. All melting points are
uncorrected and were determined in capillary tubes with a Boetius
melting point microscope. NMR spectra were recorded using a
Bruker 400 MHz spectrometer with DMSO-d6 or CDCl3 as solvent
and tetramethylsilane as internal standard. Powder X-ray diffraction
(XRD) was carried out using a Philips X’pert diffractometer with
monochromatized Cu Kα radiation (λ
= 1.5406 Å). CHN
compositions were measured with a Carlo ERBA model EA 1108
analyser. Also, the magnetic property of magnetite nanoparticles
was measured with a vibrating sample magnetometer (PPMS-9 T)
at 300 K in Iran (Kashan University). Dynamic light scattering (DLS)
was performed using a Malvern Zetasizer Nano-S (Malvern
Instruments). Field emission scanning electron microscopy (FE-SEM)
and energy dispersive spectroscopy (EDS) of the products were
conducted with a Sigma ZEISS instrument (Oxford Instruments).
Thermogravimetric analysis (TGA) curves were recorded using a
V5.1 A DuPont 2000.
Scheme 2. Preparation routes to Fe3O4@SiO2/APTPOSS nanoparticles.
Preparation of Fe3O4 MNPs
The Fe3O4 MNPs were prepared according to a procedure reported
in the literature.[36] Superparamagnetic nanoparticles were pre-
pared by co-precipitating Fe3+ and Fe2+ ions in NH4OH solution
(28 wt.%) and treating under hydrothermal conditions (Scheme 2).
According to this method, FeCl3Á6H2O3 (5 g) and FeSO4Á7H2O (2.6 g)
were dissolved in 93 ml of distilled water. By adding 69 ml of
ammonia solution into this mixed solution, solid precipitates were
formed at 25 °C under vigorous stirring. The solution was heated
at a constant temperature of 80 °C for 30 min and then was filtered
and washed with distilled water and acetone. Finally, the black
MNPs were dried under vacuum at 70 °C.
Preparation of ClPOSS nanoparticles
The starting material octakis(3-chloropropyl)octasilsesquioxane
was prepared using the method described by Dittmar et al.[37]
3-Chloropropyltrimethoxysilane (20 g), 450 ml of methanol and
22.5 ml of concentrated hydrochloric acid were mixed and the mix-
ture was stirred for at least 4 weeks at room temperature. Colourless
crystals (3.6 g) were obtained after being washed with water and
dried in vacuum at 60 °C for 24 h. Anal. Calcd for Si8O12C24H48Cl8
(1036.9) (%): C, 27.80; H, 4.67. Found (%): C, 27.89; H, 4.82. FT-IR
(KBr; ν, cmÀ1): 2953, 1104, 810, 697, 476. 1H NMR (400 MHz, CDCl3;
δ, ppm): 0.81 (m, 2H), 1.88 (m, 2H), 3.54 (m, 2H) (Fig. 1).
Preparation of octakis[3-(3-aminopropyltriethoxysilane)pro-
pyl]octasilsesquioxane (APTPOSS)
3-Aminopropyltriethoxysilane (4.43 g, 20 mmol) and ClPOSS (2.07 g,
2 mmol) were transferred to a reaction vessel under nitrogen
Scheme 1. Synthesis of 1,3-thiazolidin-4-ones using MNPs@SiO2/APTPOSS.
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Copyright © 2016 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. (2016)

Synthesis of 1,3-thiazolidin-4-ones using Fe3O4@SiO2/APTPOSS MNPs
afforded the core–shell composite of Fe3O4@SiO2/APTPOSS
(Fe3O4 MNPs as the core and SiO2/APTPOSS as the shell).
Characterization of catalyst
Figure 2 depicts the XRD patterns of the prepared APTPOSS, Fe3O4
and Fe3O4@SiO2/APTPOSS. The same peaks are observed in both
the MNP (without and with POSS) XRD patterns, indicating
retention of the crystalline spinel Fe3O4 core structure during the
APTPOSS coating process. The XRD patterns of the particles show
six characteristic peaks, revealing a cubic iron oxide phase
(2θ = 30.18°, 35.97°, 43.22°, 53.92°, 57.42°, 63.03°) which are
observed for Fe3O4 and Fe3O4@SiO2/APTPOSS in Figs 2(b) and (c).
The broad peaks at 2θ from 17° to 27° in Figs 2(a) and (c) are as-
cribed to amorphous Si&bond;O.
The FT-IR spectra of the prepared ClPOSS, Fe3O4, APTPOSS and
Fe3O4@SiO2/APTPOSS are shown in Fig. 3. The significant features
observed for ClPOSS molecules are the appearance of the peaks
at 2953 cmÀ1 (C&bond;H stretching), 1104 cmÀ1 (Si&bond;
O&bond;Si stretching), and 810 cmÀ1 (C&bond;Cl stretching). The
common features observed in Figs 3(b) and (d) are the peaks near
573, 3433 and 1629 cmÀ1 ascribed to the Fe&bond;O stretching
vibration, O&bond;H stretching vibration and O&bond;H bending
Figure 1. 1H NMR spectrum of octakis(3-chloropropyl)octasilsesquioxane.
atmosphere and the reaction solution was stirred at 100 °C for 2 days
(Scheme 2). Then the mixture was cooled to room temperature and
the solution was filtered and washed with methanol and acetone.
Finally, it was dried under vacuum to afford a pale brown solid of
APTPOSS and stored for future use. Anal. Calcd for C96H224N8O36Si16
(2516.2) (%): C, 45.82; H, 8.97; N, 4.45. Found (%): C, 41.98; H, 8.44; N,
5.03. FT-IR (KBr; ν, cmÀ1): 2927, 1636, 1118, 1029, 693.
Preparation of Fe3O4@SiO2/APTPOSS MNPs
To create an active site for binding to Fe3O4, initially 1.0 g of the
synthesized magnetic iron oxide was dispersed in 30 ml of absolute
ethanol, 10 ml of deionized water and 1.6 ml of ammonium
hydroxide solution by ultrasonic vibration for 20 min. Then to this
suspension was added 0.45 g of APTPOSS, previously sonicated in
deionized water. Afterwards, 0.9 ml of tetraethylorthosilicate (TEOS)
diluted in ethanol (9 ml) was added the mixture dropwise under
continuous stirring at 80 °C. The reaction was carried out for 2 days
to reach completion (Scheme 2). Eventually, the mixture was cooled
and MNPs@SiO2/APTPOSS was collected using a magnet. The prod-
uct was washed several times with acetone and ethanol and was
dried in vacuum at 70 °C. FT-IR (KBr; ν, cmÀ1): 3441, 2930, 1641,
1469, 1094, 692, 458.
General preparation of 1,3-thiazolidin-4-ones
A mixture of amine (1 mmol), aromatic aldehyde (1 mmol),
thioglycolic acid (1 mmol) and MNPs@SiO2/APTPOSS (0.008 g)
was stirred at 60 °C for the appropriate time. Upon completion,
the progress of the reaction being monitored by TLC, hot ethanol
was added to the reaction mixture and the catalyst was separated
using a magnet. Then the solvent was removed from solution
under reduced pressure and the crude solid residue was recrystallized
from n-hexane–ethyl acetate.
Figure 2. XRD patterns of (a) APTPOSS, (b) Fe3O4 and (c) Fe3O4@SiO2/
APTPOSS.
Results and discussion
The arrangement of steps in the immobilization of the iron oxide
MNPs with POSS-based organic–inorganic hybrid is shown in
Scheme 2. In the first step, MNPs (Fe3O4) were synthesized in basic
solution by a co-precipitation route. As we know, the MNP surface
can be functionalized using a variety of particular surface modifiers.
Secondly, octakis(3-chloropropyl)octasilsesquioxane was prepared
by the hydrolysis of 3-chloropropyltrimethoxysilane under acidic
conditions. The next step involved reaction of ClPOSS with 3-
aminopropyltriethoxysilane to yield APTPOSS. Finally, treatment of
Fe3O4 with aminopropyltriethoxysilane derivative and TEOS
Figure 3. Comparison of FT-IR spectra of (a) ClPOSS, (b) Fe3O4, (c) APTPOSS
and (d) Fe3O4@SiO2/APTPOSS.
Appl. Organometal. Chem. (2016)
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Safaei-Ghomi J., Nazemzadeh S. H. and Shahbazi-Alavi H.
vibration, respectively. The successful functionalization of the SiO2/
POSS-based organic–inorganic hybrid on Fe3O4 surface is evi-
denced by two broad peaks at about 1000–1150 cmÀ1, assigned
to Si&bond;O stretching vibrations, as well as the presence of
C&bond;H stretching at 2920–2960 cmÀ1 and C&bond;H bending
vibration at approximately 1469 cmÀ1 observed in Figs 3(c) and (d).
The components of the MNPs and APTPOSS were analysed using
EDS (Fig. 4). The presence of Si, O, N and Fe signals in Fig. 4(c)
indicates that the iron oxide particles are loaded into APTPOSS, and
the higher intensity of Si peak compared with Fe peak indicates iron
oxide MNPs are trapped by octa(4,4,4-trihydroxybutyl)amino POSS.
The TGA curve of MNPs@SiO2/APTPOSS is shown in Fig. 5. The
curve shows a weight loss of about 26% from 200 to 500 °C attrib-
uted to the decomposition of the organic species. Thus, the catalyst
is stable up to 190 °C, confirming that it could be safely used in
organic reactions at temperatures in the range of 60 °C.
Figure 6 shows FE-SEM images comparing the MNPs. It can be
seen from Fig. 6(a) that the naked Fe3O4 seeds are nearly spherical
in shape with an average grain size 24 nm and show high
monodispersity. The SEM image shown in Fig. 6(b) demonstrates
that most of MNPs supporting SiO2/POSS still keep the mor-
phological properties of Fe3O4 except for larger particle size,
Figure 6. FE-SEM images of (a) Fe3O4 and (b) Fe3O4@SiO2/APTPOSS.
agglomeration and smoother surface. According to the agglomera-
tion and change in the size of particles, it can be concluded the
nanocatalyst has been successfully synthesized.
Figure 7 shows DLS results of the MNP-supported SiO2/APTPOSS,
dispersed in deionized water. Since the MNPs are connected to
each other by APTPOSS and TEOS to form the final three-
dimensional layered architectures, DLS can serve as an efficient tool
for monitoring this action. The value of Z-average is measured to be
148.7 nm for Fe3O4@SiO2/APTPOSS, indicating the APTPOSS and
TEOS are incorporated in the Fe3O4 coating.
Figure 4. Comparison of EDS spectra of (a) Fe3O4, (b) APTPOSS and (c)
Fe3O4@SiO2/APTPOSS.
Figure 5. TGA curve of MNPs@SiO2/APTPOSS.
Figure 7. DLS results for Fe3O4@SiO2/APTPOSS.
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Appl. Organometal. Chem. (2016)

Synthesis of 1,3-thiazolidin-4-ones using Fe3O4@SiO2/APTPOSS MNPs
The magnetic properties of Fe3O4 and MNPs@SiO2/APTPOSS were
studied using a vibrating sample magnetometer at ambient temper-
ature (Fig. 8). The saturation magnetizations of Fe3O4 and catalyst are
found to be 62.07 and 28.87 emu gÀ1 at about +6000 Oe, respec-
tively. The magnetic saturation valuedecreases by nearly 33.2 emugÀ1
compared to the initial value after coating. This difference might be
due to the accessibility of wide surface area which allows successful
coating of the MNPs nanoparticles with SiO2 and APTPOSS.
condensation of aldehydes, thioglycolic acid and aniline at 60 °C
as a model reaction. The model reactions were carried out in the
presence of various nanocatalysts such as ZrO2, Fe3O4, SnO,
Fe3O4@SiO2/APTPOSS and Fe3O4@SiO2. Also, several reactions
were scrutinized using various solvents such as EtOH, tetrahydrofu-
ran (THF), water and PhMe and under solvent-free conditions. The
best results are obtained in the presence of 8 mg of Fe3O4@SiO2/
APTPOSS as a MNP heterogeneous catalyst at 60 °C under
solvent-free conditions, which give excellent yields of products
(Table 1). In addition, no product is observed when the reaction is
heated to 60 °C for 3 h in the absence of catalyst (Table 1, entry 1).
To investigate the scope of this catalytic process, thioglycolic
acid, aniline and aldehydes were chosen as substrates in the
presence of Fe3O4@SiO2/APTPOSS under solvent-free conditions
at 60 °C (Table 2). The results illustrate that the reactions function
well with electron-withdrawing and electron-donating aromatic
aldehydes.
Application of catalyst for preparation of 1,3-thiazolidin-4-one
derivatives
Initially, we explored and optimized various reaction parameters for
the synthesis of 1,3-thiazolidin-4-one derivatives by the one-pot
Reusability of catalyst
The reusability is another very favourable property of this catalyst.
We investigated recycling of MNPs@SiO2/APTPOSS as a catalyst
Table 2. Synthesis of 1,3-thiazolidin-4-ones catalysed by Fe3O4@SiO2/
APTPOSSa
Entry
Aldehyde
C6H5
Product
Time (min)
Yield (%)b
Figure 8. Comparison of magnetization curves for naked MNPs and
MNPs@SiO2/APTPOSS.
1
2
4a
4b
4c
4d
4e
4f
30
28
24
35
33
25
36
30
33
33
93
93
94
91
94
94
90
92
92
91
2-ClC6H4
3
4-ClC6H4
Table 1. Optimization of reaction conditions using various catalysts
4
2-NO2C6H4
3-NO2C6H4
4-NO2C6H4
4-Isopropyl-C6H4
Thiophen-2-yl
Pyridin-2-yl
Pyridin-3-yl
and solventsa
5
6
7
4g
4h
4i
8
9
10
4j
Entry
Catalyst (mg)
Solvent Time (min) Yield (%)b
aAniline (1 mmol), aldehyde (1 mmol), thioglycolic acid (1 mmol) and
MNPs@SiO2/APTPOSS (0.008 g) at 60 °C.
bIsolated yield.
1
2
—
—
—
—
—
—
—
180
100
100
100
40
Trace
<12
<10
<10
93
Nano-ZrO2 (15)
3
Nano-Fe3O4 (15)
4
Nano-SnO (15)
5
Fe3O4@SiO2/APTPOSS (15)
Nano-Fe3O4@SiO2 (15)
6
100
40
14
7
Fe3O4@SiO2/APTPOSS (15) H2O
Fe3O4@SiO2/APTPOSS (15) EtOH
Fe3O4@SiO2/APTPOSS (15) PhMe
Fe3O4@SiO2/APTPOSS (15) THF
76
8
40
88
9
40
60
10
11
12
13
14
15
16
40
85
Fe3O4@SiO2/APTPOSS (4)
Fe3O4@SiO2/APTPOSS (6)
Fe3O4@SiO2/APTPOSS (8)
Fe3O4@SiO2/APTPOSS (10)
Fe3O4@SiO2/APTPOSS (8)
Fe3O4@SiO2/APTPOSS (8)
—
—
—
—
—
—
40
90
40
92
40
93
40
93
30
93
25
89
aAniline (1 mmol), benzaldehyde (1 mmol), thioglycolic acid (1 mmol) at
60 °C.
bIsolated yield.
Figure 9. Reusability of MNPs@SiO2/APTPOSS as catalyst for the synthesis
of 4a (Table 2).
Appl. Organometal. Chem. (2016)
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

Safaei-Ghomi J., Nazemzadeh S. H. and Shahbazi-Alavi H.
[11] A. J. Waddon, E. B. Coughlin, Chem. Mater. 2003, 15, 4555–4561.
[12] D. Gnanasekaran, K. Madhavan, B. Reddy, J. Sci. Ind. Res. 2009, 68,
437–464.
[13] R. H. Baney, M. Itoh, A. Sakakibara, T. Suzuki, Chem. Rev. 1995, 95,
1409–1430.
[14] G. Li, L. Wang, H. Ni, C. U. Pittman, Jr., J. Inorg. Organometal. Polym.
2001, 11, 123–154.
[15] A. O. Oseni, P. E. Butler, A. M. Seifalian, J. Tissue Eng. Regen. Med. 2015, 9,
27–38.
under optimized conditions. Upon completion of the reaction, the
catalyst was washed with MeOH and acetone, dried in an oven at
65 °C for 70 min and used directly with new substrates under the
same conditions. The results (Fig. 9) show that the catalyst can be
reused several times (yields of 93 to 92%). The magnetite core–shell
composite was investigated using SEM before use and after reuse
of five times (see the supporting information). The SEM images of
these nanoparticles before and after the reaction show identical
shapes. Therefore, it can be concluded that the morphology of
the nanoparticles remains unchanged after reaction and SiO2/
APTPOSS is stable on the surface of iron oxide nanoparticles.
[16] P. P. Pescarmona, J. C. van der Waal, T. Maschmeyer, Chem. Eur. J. 2004,
10, 1657–1665.
[17] D. B. Cordes, P. D. Lickiss, F. Rataboul, Chem. Rev. 2010, 110, 2081–2173.
[18] S. Wu, W. Guo, F. Teraishi, J. Pang, K. Kaluarachchi, L. Zhang, J. Davis,
F. Dong, B. Yan, B. Fang, Med. Chem. 2006, 2, 597–605.
[19] M. L. Barreca, A. Chimirri, L. De Luca, A.-M. Monforte, P. Monforte,
A. Rao, M. Zappalà, J. Balzarini, E. De Clercq, C. Pannecouque, Bioorg.
Med. Chem. Lett. 2001, 11, 1793–1796.
Conclusions
[20] R. K. Rawal, R. Tripathi, S. Katti, C. Pannecouque, E. De Clercq, Bioorg.
We demonstrated the preparation of novel core–shell composite
nanoparticles composed of iron oxide MNPs (Fe3O4) and APTPOSS
for synthesis of 1,3-thiazolidin-4-ones.
Med. Chem. Lett. 2007, 15, 1725–1731.
[21] M. L. Barreca, J. Balzarini, A. Chimirri, E. D. Clercq, L. D. Luca, H. D. Höltje,
M. Höltje, A. M. Monforte, P. Monforte, C. Pannecouque, J. Med. Chem.
2002, 45, 5410–5413.
This protocol is compatible with various aldehydes under
solvent-free conditions. Also, the resultant catalyst combines many
advantages such as long-term stability, high catalytic activity for
this reaction, ease of separation of catalyst using an external
magnetic field, short reaction times and simple work-up. Also, the
catalyst could be easily recovered and reused several times without
significant loss of catalytic activity.
[22] I. Vazzana, E. Terranova, F. Mattioli, F. Sparatore, ARKIVOC 2004, 5,
364–374.
[23] P. Vicini, A. Geronikaki, K. Anastasia, M. Incerti, F. Zani, Bioorg. Med.
Chem. 2006, 14, 3859–3864.
[24] P. Vicini, A. Geronikaki, M. Incerti, F. Zani, J. Dearden, M. Hewitt, Bioorg.
Med. Chem. 2008, 16, 3714–3724.
[25] M. V. Diurno, O. Mazzoni, G. Correale, I. G. Monterrey, A. Calignano,
G. La Rana, A. Bolognese, Il Farmaco 1999, 54, 579–583.
[26] K. Omar, A. Geronikaki, P. Zoumpoulakis, C. Camoutsis, M. Soković,
A. Ćirić, J. Glamočlija, Bioorg. Med. Chem. 2010, 18, 426–432.
[27] U. R. Pratap, D. V. Jawale, M. R. Bhosle, R. A. Mane, Tetrahedron Lett.
2011, 52, 1689–1691.
[28] N. Foroughifar, S. Ebrahimi, Chin. Chem. Lett. 2013, 24, 389–391.
[29] A. K. Yadav, M. Kumar, T. Yadav, R. Jain, Tetrahedron Lett. 2009, 50,
5031–5034.
Acknowledgements
The authors acknowledge a reviewer who provided helpful insights.
The authors are grateful to the University of Kashan for supporting
this work under grant no. 159196/XXI.
[30] D. Kumar, M. Sonawane, B. Pujala, V. K. Jain, A. K. Chakraborti, Green
Chem. 2013, 15, 2872–2884.
[31] J. Safaei-Ghomi, M. Navvab, H. Shahbazi-Alavi, Ultrason. Sonochem.
References
2016, 31, 102–106.
[32] S. M. Sadeghzadeh, F. Daneshfar, J. Mol. Liq. 2014, 199, 440–444.
[33] J. Safaei-Ghomi, B. Khojastehbakht-Koopaei, H. Shahbazi-Alavi, RSC Adv.
2014, 4, 46106–46113.
[34] J. Safaei-Ghomi, A. Javidan, A. Ziarati, H. Shahbazi-Alavi, J. Nanopart.
Res. 2015, 17, 1–12.
[35] J. Safaei-Ghomi, S. Zahedi, Tetrahedron Lett. 2016, 10, 1071–1073.
[36] W. Xie, N. Ma, Energy Fuel 2009, 23, 1347–1353.
[37] U. Dittmar, B. J. Hendan, U. Flörke, H. C. Marsmann, J. Organomet. Chem.
1995, 489, 185–194.
[1] J. Safaei-Ghomi, S. Zahedi, Appl. Organometal. Chem. 2015, 29, 566–571.
[2] S. Sobhani, M. Honarmand, Appl. Catal. A 2013, 467, 456–462.
[3] M. B. Gawande, P. S. Branco, R. S. Varma, Chem. Soc. Rev. 2013, 42,
3371–3393.
[4] B. Karimi, F. Mansouri, H. M. Mirzaei, Chem. Cat. Chem. 2015, 7, 1736–1789.
[5] R. N. Baig, R. S. Varma, Chem. Commun. 2013, 49, 752–770.
[6] M. Kuzminska, N. Carlier, R. Backov, E. M. Gaigneaux, Appl. Catal. A.
2015, 505, 200–212.
[7] S. Laurent, D. Forge, M. Port, A. Roch, C. Robic, L. Vander Elst,
R. N. Muller, Chem. Rev. 2008, 108, 2064–2110.
[8] J. Davarpanah, A. R. Kiasat, S. Noorizadeh, M. Ghahremani, J. Mol. Catal.
A 2013, 376, 78–89.
[9] J. Tan, S. Feng, Dalton Trans. 2013, 42, 16482–16485.
[10] D. Heyl, E. Rikowski, R. C. Hoffmann, J. J. Schneider, W. D. Fessner, Chem.
Eur. J. 2010, 16, 5544–5548.
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