Fe3O4@PEG core/shell nanoparticles as magnetic nanocatalyst for acetylation of amines and alcohols using ultrasound irradiations under solvent-free conditions

Article abstract of DOI:10.1007/s11164-018-3614-7

Abstract: Ultrasound irradiation was used to prepare one-pot Fe₃O₄@PEG core/shell nanostructure for the first time. The morphology, structure, and physicochemical properties were specified by different analytical techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray powder diffraction, and vibrating sample magnetometer. For acetylation of phenols, alcohols, and amines, the synthesized Fe₃O₄@PEG core/shell nanoparticles were used as an efficient heterogeneous and green catalyst with acetic anhydride under sonication applying mild reaction conditions. Different electron-withdrawing and electron-donating substrates indicate a prominent yield of desired products with the merit of reusability of Fe₃O₄@PEG nanocatalyst and magnetic separation. Graphical Abstract: [Figure not available: see fulltext.].

Full text of DOI:10.1007/s11164-018-3614-7

Research on Chemical Intermediates
https://doi.org/10.1007/s11164-018-3614-7
Fe O @PEG core/shell nanoparticles as magnetic
3
4
nanocatalyst for acetylation of amines and alcohols using
ultrasound irradiations under solvent‑free conditions
1
1
1
1
Hojat Veisi · Ahmad Nikseresht · Afsaneh Rostami · Saba Hemmati
Received: 7 April 2018 / Accepted: 28 September 2018
©
Springer Nature B.V. 2018
Abstract
Ultrasound irradiation was used to prepare one-pot Fe O @PEG core/shell nano-
3
4
structure for the ꢀrst time. The morphology, structure, and physicochemical prop-
erties were speciꢀed by diꢁerent analytical techniques including ꢀeld emission
scanning electron microscopy, Fourier transform infrared spectroscopy, energy-
dispersive X-ray spectroscopy, transmission electron microscopy, X-ray powder dif-
fraction, and vibrating sample magnetometer. For acetylation of phenols, alcohols,
and amines, the synthesized Fe O @PEG core/shell nanoparticles were used as an
3
4
eꢂcient heterogeneous and green catalyst with acetic anhydride under sonication
applying mild reaction conditions. Diꢁerent electron-withdrawing and electron-
donating substrates indicate a prominent yield of desired products with the merit of
reusability of Fe O @PEG nanocatalyst and magnetic separation.
3
4
Extended author information available on the last page of the article
Vol.:(012
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H. Veisi et al.
Graphical Abstract
FeCl
3
.6H
2
O
2 2
FeCl .4H O
R XH
R = alkyl, aryl
X = NH, O
PEG400
Fe
PEG400
NaOH
Ac
2
O
3
O
4
Sonication, r.t.
R XAc
Ultrasounic
3 4
Fe O @PEG400
Keywords PEGylation · Core/shell · Magnetic · Ultrasonic · Acetylation · Amine ·
Alcohol
Introduction
Researchers have conducted many eꢁorts with respect to the necessity of generat-
ing drugs through eꢁective procedures to prepare organic compounds [1]. In recent
years, ultrasound irradiation has progressively been considered as a simple, clean,
and suitable method in synthesis of drugs [2]. Ultrasound irradiation is used to
accelerate a number of synthetically beneꢀcial reactions using the growth, forma-
tion, and implosive collapse of bubbles in a liquid [3]. Bubble collapse initiated by
cavitation causes intense local heating, high pressures, and very short lifetimes [4,
5
]. Ultrasound irradiation can activate many reactions, compared with conventional
heating, which generates thermal energy in the macrosystem, through providing the
activation energy in a microenvironment [6–8]. The ultrasound approach proposes
many privileges, such as enhanced organic reaction rates, higher yields, milder reac-
tion conditions, nontoxicity, environmentally friendly solvent, and waste minimiza-
tion in comparison to traditional methods, and also saves money, energy, and raw
materials [9, 10].
Acetylation of phenols, alcohols, and amines is a regularly used transformation
in synthetic chemistry and is extensively applied as a protection agent in multi-step
pharmaceutical synthesis and food or cosmetic industries [11, 12]. The acetylation
of hydroxyl and amino groups has been carried out commonly by acetic anhydride
or acetyl chloride through either base [13–16] or acid catalysts [17–23]. Although
1
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Fe O @PEG core/shell nanoparticles as magnetic…
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4
there are diꢁerent acetylation methods, most protocols have innate shortcom-
ings such as harsh conditions, long reaction times, tedious work-up procedures,
and harmful organic solvents [24–26]. Using green and insoluble nanocatalysts or
applying eco-friendly solvent-free conditions is possibly one of the solutions. These
premises support the use of nanomaterials and supported nanoparticles as catalysts
in diꢁerent types of chemistries.
Accomplishing synthetic reactions with a heterogeneous catalyst under ultrasonic
irradiation may enhance their eꢁectiveness regarding operating cost and ecological
aspects [27, 28]. Core/shell nanoparticles have received great attention due to their
unique features [29, 30]. The magnetic core/shell Fe O nanoparticles can be used
3
4
as an appropriate catalyst in many reactions [31, 32]. Thus, surface modiꢀcation of
magnetic nanoparticles (MNPs) is an issue of increasing interest in chemical reac-
tions in the eꢁort to ꢀnd supporting catalysts. The surface of MNPs can be simply
functionalized via suitable surface modiꢀcations to make the loading of diꢁerent
favorable functionalities possible [33, 34]. In the current study, Fe O @polyethylene
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4
glycol (PEG) composite MNPs with a core/shell structure were provided for the ꢀrst
time through ultrasound irradiation. Afterwards, a new methodology was presented
for the acetylation of phenols, alcohols, and amines with acetic anhydride, apply-
ing sonication energy under solvent-free conditions (Scheme 1). The synthesized
Fe O @PEG nanoparticles show good catalytic activity for the reaction, with the
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4
merit of catalyst recyclability. The catalyst could be used again 10 times without los-
ing catalytic activity. The reaction functions under solvent-free conditions at room
FeCl .6H O
FeCl .4H O
2 2
3
2
24%
R XH
R = alkyl, aryl
X = NH, O
7
3%
PEG400
Fe O
PEG400
NaOH
Ac O
2
3
4
Sonication, r.t.
R XAc
Ultrasounic
Fe O @PEG400
3
4
yield 90%
Scheme 1 Schematic preparation of core/shell Fe O @PEG NPs and its application for acetylation of
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4
alcohols, phenols, and amines
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H. Veisi et al.
temperature. This is a simple procedure to synthesize Fe O @PEG core/shell nano-
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4
particles, and it also can be further extended for synthesis of other metal oxides.
Experimental
Ultrasonic‑assisted preparation of Fe O @PEG core/shell nanoparticles
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4
FeCl .6H O (10.4 g) was mixed with 4.0 g of FeCl ·4H O and 1.7 mL of HCl (con-
3
2
2
2
centrated) in 50 mL water. The mixture was then added dropwise to 100 mL of an
aqueous solution of NaOH (1.5 M) and PEG400 (1 mL) in an ultrasonic bath at
6
0 °C for 20 min, as shown in Scheme 1. The mixture was sonicated at 60 W of
power and the drip rate was 5 mL/min. After complete addition, the reaction contin-
ued for another 20 min under ultrasonic conditions. Then, the mixture was cooled to
room temperature and the Fe O @PEG MNPs as a dark solid were isolated from the
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4
solution by magnetic separation and washed several times with deionized (DI) water
and ethanol.
General procedure for acylation reaction under ultrasonic conditions
A 10-mL balloon was charged with phenol/alcohol/amine (1 mmol) and acetic anhy-
dride (3 mmol), with Fe O @PEG (10 mg) as catalyst. The reaction balloon was
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4
taken in the ultrasonic bath, where the level of the reaction mixture is lower than the
surface of the water. Then, the mixture was sonicated under 60 W of power of the
ultrasonic bath at room temperature for the appropriate time, as shown in Table 2.
After completion of the reaction (monitored by thin-layer chromatography), the
reaction mixture was diluted with ethyl acetate and the catalyst was separated from
reaction mixture by an external magnet. The separated catalyst was washed with DI
water and absolute ethanol several times then dried in oven and reused for further
reaction. The reaction mixture was washed with sat. NaHCO solution (1×15 mL)
3
and the product was extracted with ethyl acetate (3×10 mL) and dried over Na SO
2
4
and evaporated under vacuum. All the obtained products are well known in the liter-
ature and were conꢀrmed by nuclear magnetic resonance (NMR) analysis and com-
parison with literature data.
Results and discussion
Characterization of nanocomposite
The core/shell Fe O @PEG nanoparticles were directly provided using ultrasound
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irradiation (Scheme 1). When the solution with precursor [Fe(II), Fe(II), PEG400,
and NaOH] is exposed through an ultrasound method, very high temperatures and
pressures are generated to produce core/shell Fe O @PEG nanoparticles. Field
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4
emission scanning electron microscopy (FESEM), Fourier transform infrared
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Fe O @PEG core/shell nanoparticles as magnetic…
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4
(
FT-IR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), transmission
electron microscopy (TEM), X-ray powder diꢁraction (XRPD), and vibrating sam-
ple magnetometer (VSM) analyses were performed to characterize the nanoparti-
cles. Then, core/shell Fe O @PEG nanoparticles were used as a green and recy-
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clable heterogeneous nanocatalyst to acetylate alcohols, phenols, and amines with
acetic anhydride using sonication energy under solvent-free conditions (Scheme 1).
The core/shell Fe O @PEG NPs’ surface chemical structure was characterized
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4
using FT-IR spectroscopy. FT-IR spectra of Fe O (Fig. 1a) showed characteristic
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4
−1
−1
peaks at 569 cm and 1383 cm due to Fe–O bending and Fe–O stretch vibra-
−1
tions, respectively. The peak at 1624 cm was attributed to the bending vibra-
−
1
tion of water adsorbed on the surface of Fe O . The peak at 3424 cm appeared
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4
due to the OH present on the surface of Fe O NPs [35, 36]. The FT-IR spectra
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4
−
1
−1
of PEG400 showed its characteristic vibrations at 3405 cm and 1406 cm due
−
1
to the OH stretching and bending vibration, respectively, along with at 2923 cm
Fig. 1 FT-IR spectra of a Fe O , b PEG400, and c Fe O @PEG
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4
3
4
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H. Veisi et al.
−
1
−1
(
C–H stretch), 1460 cm (C–H bending and scissoring), 1378 cm (–OH bending),
−1
−1
1
247 cm (C–O stretch), and 1160 cm (–C–O–C– stretching) and other peaks
in the ꢀngerprint region (Fig. 1b) [37, 38]. The presence of characteristic peaks of
PEG in the FT-IR spectra of Fe O @PEG further conꢀrmed the successful forma-
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tion of PEGylated Fe O MNPs (Fig. 1c).
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The particle size and morphology of the synthesized nanocomposite were exam-
ined by recording FESEM, indicating Fe O @PEG particle formation with diam-
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eters in the range of nanometers (Fig. 2).
The EDX spectrum of the nanostructure is displayed in Fig. 3. Signals relating
oxygen, carbon, and iron were detected. Metallic Fe nanocrystals commonly indi-
cate typical optical absorption peaks about 1.0 and 7.0 keV because of surface plas-
mon resonance. The strong signals of iron, carbon, and oxygen regions approved the
formation of the nanocomposite under study.
TEM presents more insight into the nanostructures’ morphology, shape, and size.
The synthesized NPs’ TEM image showed that NPs with almost spherical core/shell
morphology are generated with relatively decent dispersity. The sizes of particles
are 8–12 nm (Fig. 4). The TEM image depicts that a clear PEG coat (about 3 nm in
thickness) is immobilized on the Fe O nanoparticles’ surface, showing the core/
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shell structure of Fe O @PEG.
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4
Adequate magnetic properties are crucial for practical usages of magnetic materi-
als in aqueous solution. The saturation magnetization value of Fe O @PEG NPs is
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4
−1
5
9.1 emu g (Fig. 5) and could be strong enough to provide an easy and eꢁective
way to separate the catalyst from the reaction system.
The Fe O @PEG NPs’ high-angle XRD patterns are presented in Fig. 6. The
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4
strong characteristic diꢁraction peaks at 2 h of 30.1°, 35.5°, 43.1°, 53.4°, 56.9°, and
6
2.6° can be attributed to the diꢁraction of (220), (311), (400), (422), (511), and
(
440) of the Fe O as core, revealing successful synthesis of the core/shell Fe O @
3
4
3
4
PEG NPs without spoiling the Fe O core’s crystal structure.
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4
Fig. 2 FESEM image of core/
shell Fe O @PEG NPs
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4
1
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Fe O @PEG core/shell nanoparticles as magnetic…
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Fig. 3 EDX spectrum of core/shell Fe O @PEG NPs
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4
Fig. 4 TEM image of core/shell
Fe O @PEG NPs
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4
Thermogravimetric analysis (TG) of core/shell Fe O @PEG NPs was applied
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4
to prove the existence of diꢁerent groups on the NPs’ surface (Fig. 7). The ini-
tial weight loss from the catalyst was below 200 °C, and attributed to the loss of
physically adsorbed solvent or bound water. The weight loss at 220–500 °C in
the TG curve of core/shell Fe O @PEG NPs is mainly assigned to the decompo-
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sition of PEG groups linked to the Fe O surface.
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H. Veisi et al.
60
40
20
0
-
-
-
20
40
60
-
10000 -8000 -6000 -4000 -2000
0
2000 4000 6000 8000 10000
Applied Field(Oe)
Fig. 5 VSM image of core/shell Fe O @PEG NPs
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Fig. 6 XRD pattern of core/shell Fe O @PEG NPs
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4
Fig. 7 TG curve of core/shell Fe O @PEG NPs
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4
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Fe O @PEG core/shell nanoparticles as magnetic…
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Catalytic application of core/shell Fe O @PEG NPs in the acetylation of Nitrogen/
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4
Oxygen (N/O)
In continuation of our works in developing heterogeneous magnetic nanocata-
lysts [39–49], the catalytic activity of the prepared core/shell Fe O @PEG NPs
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4
was investigated as a novel heterogeneous magnetic nanocatalyst for acetylation
of alcohols, phenols, and amines with acetic anhydride using sonication energy
at room temperature under solvent-free conditions (Scheme 1). The sonication
energy has many merits including high eꢂciency, low waste, and less energy
requirement; also, it generates cavitation bubbles which enhance the interaction
between reactant and catalyst; it accelerates the reaction speed, and it produces
better mass and heat transfer eꢂciency in comparison to conventional heating; it
is also economical with easy operation [50, 51].
The reaction of phenol with acetic anhydride as acetylating agent was selected
as a model reaction and conducted in the presence of Fe O @PEG NPs under
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4
solvent-free conditions at room temperature to determine the best conditions
using a sonication bath (60 W of power). The reaction occurred in the absence of
the catalyst at the beginning to examine the inꢃuence of sonication on reaction.
Formation of 15% yield of acylation product was observed (Table 1, entry 1).
Afterwards, the reaction was replicated in the presence of Fe O NPs and pro-
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4
vided 45% yield of favored product (Table 1, entry 2). Then, the catalyst load-
ing was screened via the model reaction catalyzed by Fe O @PEG NPs (Table 1,
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4
entries 3–7). Catalyst at 5 mol% provided great yield (96%) of the favored prod-
uct (Table 1, entry 6). A pronounced increase in the product yield did not occur
through increasing the catalyst concentration (Table 1, entry 7). The reaction was
carried out in the absence of sonication at room temperature with Fe O @PEG
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4
NPs, but the reaction did not work. The possibility of homogeneous catalysis
of the acylation with PEG are investigated (Table 1, entries 8, 9), but it did not
provide a good result. The increased catalytic activity of the PEG-coated Fe O
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4
Table 1 Investigation of best
conditions in the acetylation
of phenol in the presence of
the Fe O @PEG NPs and
Entry
Catalyst
Catalyst (mol%)
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
9
No catalyst
0.0
1.0
1.0
2.0
3.0
5.0
10
4
2
2
2
15
45
60
70
85
96
96
60
70
3
4
Fe O
sonication energy
3
4
Fe O @PEG
3
4
Fe O @PEG
3
4
Fe O @PEG
1
3
4
Fe O @PEG
0.5
0.5
2
3
4
Fe O @PEG
3
4
PEG
PEG
5.0
10
2
Reaction conditions: phenol (1 mmol), acetic anhydride (2 mmol),
room temperature, and sonication (60 W of power) under solvent-
free conditions at room temperature
The reactions were conducted in duplicate
1
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H. Veisi et al.
nanoparticles can be a result of the higher speciꢀc surface area of the prepared
Fe O @PEG NPs.
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4
Assuming the optimized conditions for the acetylation of alcohols (Table 1,
entry 6), a wide range of various alcohols, such as benzylic, primary, secondary,
and tertiary alcohols were screened. All the alcohols tested were converted, under
the optimized conditions, to the corresponding acetates in excellent yields (Table 2).
Benzylic alcohols with electron-donating groups were the most reactive of all sub-
strates examined and were converted, in the shortest reaction times, to the corre-
sponding acetates. Moreover, the reaction progressed at a slower rate for aromatic
substrates with an electron-withdrawing group (Table 2, entries 2–4). The tertiary
alcohol 1-adamantanol was also acetylated successfully in high yield to provide the
corresponding acetylated material (Table 2, entry 12). In addition, cinnamyl alcohol,
an allyllic alcohol, was converted selectively to the corresponding acetate, in which
the carbon double bond was intact in the process of acetylation reaction (Table 2,
entry 7).
To study this catalytic system’s potential, the acetylation of a variety of phe-
nols and amines was studied assuming solvent-free conditions (Table 2). The
Table 2 O,N acetylation with Ac O under solvent-free conditions in the presence of Fe O @PEG NPs
2
3
4
Entry
Substrate
Time (min)
Yield (%)a
References
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
Benzyl alcohol
10
10
10
10
30
40
60
25
10
30
45
60
10
10
15
20
30
10
10
10
96
96
96
90
96
90
85
85
96
90
90
70
96
96
90
96
88
96
96
96
[52]
[52]
[53]
[52]
[25]
[52]
[52]
[52]
[52]
[52]
[52]
[52]
[39]
[39]
[52]
[24]
[52]
[52]
[52]
[52]
4-Bromo-benzyl alcohol
4-Chloro-benzyl alcohol
2,4-Dichloro-benzyl alcohol
Phenol
4-Chlorophenol
Cinnamyl alcohol
2-Phenylethanol
Diphenylmethanol
Cyclohexanol
2-Adamantanol
1-Adamantanol
Benzyl amine
4-Methyl-benzyl amine
4-Methoxy-benzyl amine
Aniline
4-Methyl-aniline
Dibenzylamine
Piperazine
Ethane-1,2-diamine
0
1
2
3
4
5
6
7
8
9
0
Reaction conditions: substrate (1 mmol), catalyst (5 mol %), acetic anhydride (2 mmol), sonication
(
60 W of power) for desired time at room temperature under solvent-free conditions
Isolated yields
a
1
3

Fe O @PEG core/shell nanoparticles as magnetic…
3
4
acetylation of phenols proceeded slowly in comparison to amines. Acetylation of
benzylic amines and aliphatic amines was indicated to be more rapid compared
with anilines and needed lower reaction times.
A possible mechanism for the reaction applying Fe O @PEG nanoparticle
3
4
is depicted in Scheme 2, showing the activation of the carbonyl group of acetic
anhydride via coordinating to PEG groups. Then, the activated carbonyl reacts
with the substrates to provide the corresponding acetates.
The heterogeneous catalysts’ reusability is crucial, particularly for commercial
uses. To examine the reusability and recyclability of the catalyst, the acetylation
of aniline with acetic anhydride was investigated assuming identical reaction con-
ditions. The catalyst could be separated by an external magnet and similarly used
again for the next experiments after completion of the reaction (nine times). The
product yield and reaction time remained the same, approving the reusability and
recyclability of the catalyst without loss of its activity (Fig. 8).
The reaction of benzyl alcohol with acetic anhydride was done to compare the
eꢁectiveness of the synthesized Fe O @PEG nanoparticle with the previous cata-
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4
lyst for acetylation reaction (Table 3). The previously reported catalyst had one or
more disadvantages such as non-reusability, low yield of products, toxicity, and
longer reaction time.
H
O
HO OH
HO
OOH
OH
OH
HO
OH HO
OH
HO
OH
OH OH OH
OH
OH
HO
O
O
O
OH
OH
HO
O HO H
R
O
HO OH
OH
X
HO
OH
HO
Fe O @PEG NPs
3
4
H
H
HO OH
OOH
OH
OH
HO
OH
HO OO HO H
HO
HO
HO
OH HO
HO
OH
OH OH OH
OH
OH
HOOH OH
HO OH OHOH
HO
OH
OH
H
OH
HO OH
OH
HO
O HO H
HO
HO
O
OH
HO OH
OH
OH
OH OH
O HH O
O
OH
HO
HO
OH
2
O
OH
O
O
R
O
X
H
O
R XH
R = alkyl, aryl
X = NH, O
Scheme 2 Proposed mechanism for acetylation of alcohols, phenols, and anilines
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H. Veisi et al.
Fig. 8 Recyclability of Fe O @
110
3
4
PEG NPs
9
7
5
3
1
0
0
0
0
0
1
2
3
4
5
6
7
8
9
10
Run
Table 3 Comparison eꢂciency of Fe O @PEG NPs with some reported catalysts for the acetylation
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4
reactions of benzyl alcohol
Entry
Reaction conditions
Time
Yield%
References
1
2
3
4
5
6
7
8
9
Fe O @PEG NPs, sonication, r.t., solvent-free
10 min
3 h
14 h
3 h
15 min
6 h
30 min
1 h
15 min
96
63
25
90
93
94
91
64
92
This work
[53]
[24]
[52]
[54]
[26]
[55]
[56]
[57]
3
4
ZnCl , r.t., solvent-free
2
Borated zirconia, 110 °C, toluene
SiO –ZnCl , 80 °C, CH CN
2
2
3
Silica sulfamic acid, r.t., solvent-free
Yttria-zirconia, 110 °C, solvent-free
Copper zirconium phosphate NPs, 60 °C, solvent-free
Nano γ-Fe O , sonication, r.t., solvent-free
2
3
CuO–ZnO, r.t., CH Cl
2
2
Conclusion
In this research, a simple and eꢂcient procedure is developed for ultrasonic-assisted
one-pot synthesis of Fe O @PEG core/shell nanostructure as a green magnetic cata-
3
4
lyst under ultrasonic irradiation for the acetylation of various alcohols, phenols, and
amines at room temperature under solvent-free conditions. The catalyst generates
excellent yields of acetate products and is recyclable. The signiꢀcant merits of this
method are its easy work-up, one-pot preparation of core/shell Fe O @PEG NPs,
3
4
recycling of the catalyst, short reaction times, and using ultrasonic irradiation as an
eꢂcient technology.
Acknowledgements We are thankful to Payame Noor University, Tehran, Iran, for partial support of this
work.
References
1
.
C. Hulme, V. Gore, Curr. Med. Chem. 10, 51 (2003)
2
.
N.C. Eddingsaas, K.S. Suslick, Nature 444, 163 (2006)
3
.
K.S. Suslick, Science 247, 1439 (1990)
4
.
K.S. Suslick, Sci. Am. 260, 80 (1989)
5
.
J.H. Bang, K.S. Suslick, Adv. Mater. 22, 1039 (2010)
6
.
H. Xu, K.S. Suslick, J. Am. Chem. Soc. 133, 9148 (2011)
S. Allahyari, M. Haghighi, A. Ebadi, S. Hosseinzadeh, Ultrason. Sonochem. 21, 663 (2014)
. M. Mirza-Aghayan, N. Ganjbakhsh, M. Molaee Tavana, R. Boukherroub, Ultrason. Sonochem. 32, 37
7
.
8
(2016)
1
3

Fe O @PEG core/shell nanoparticles as magnetic…
3
4
9
. H. Xu, B.W. Zeiger, K.S. Suslick, Chem. Soc. Rev. 42, 2555 (2013)
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
0. G. Cravotto, P. Cintas, Chem. Soc. Rev. 35, 180 (2006)
1. T.W. Green, P.C.M. Wuts, Protective Groups in Organic Synthesis, 3rd edn. (Wiley, New York, 1999)
2. J. Otera, Esterifcation: Methods, Reactions and Applications, 1st edn. (Wiley, New York, 2003)
3. W. Steglich, G. Hoꢃe, Angew. Chem. Int. Ed. 8, 981 (1969)
4. E. Vedejs, T.S. Diver, J. Am. Chem. Soc. 115, 3358 (1993)
5. E.F.V. Scriven, Chem. Soc. Rev. 12, 129 (1983)
6. S. Tomohumi, O. Kousaburo, O. Takashi, Synthesis 12, 1141 (1991)
7. A. Orita, C. Tanahashi, A. Kakuda, J. Otera, Angew. Chem. Int. Ed. 39, 2877 (2000)
8. R. Alleti, M. Perambuduru, S. Samanha, V.P. Reddy, J. Mol. Catal. A Chem. 226, 57 (2005)
9. B. Karimi, J. Maleki, J. Org. Chem. 68, 4951 (2003)
0. N. Ghaꢁari Khaligh, J. Mol. Catal. A Chem. 363–364, 90 (2012)
1. F. Rajabi, Tetrahedron Lett. 50, 395 (2009)
2. L. Osiglio, A.G. Sathicq, G.P. Romanelli, M.N. Blanco, J. Mol. Catal. A Chem. 359, 97 (2012)
3. I. López, J.L. Bravo, M. Caraballo, J.L. Barneto, G. Silvero, Tetrahedron Lett. 52, 3339 (2011)
4. F. Tamaddon, M.A. Amrollahi, L. Sharafat, Tetrahedron Lett. 46, 7841 (2005)
5. R. Gupta, V. Kumar, M. Gupta, S. Paul, R. Gupta, Indian J. Chem. Sect. B 47, 1739 (2008)
6. P. Kumar, R.K. Pandey, M.S. Bodas, S.P. Dagade, M.K. Dongare, A.V. Ramaswamy, J. Mol. Catal. A
Chem. 181, 207 (2002)
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
7. P.G. Mandhane, R.S. Joshi, D.R. Nagargoje, C.H. Gill, Tetrahedron Lett. 51, 3138 (2010)
8. E. Mosaddegh, Ultrason. Sonochem. 20, 1436 (2013)
9. F. Wang, R. Deng, J. Wang, Q. Wang, Y. Han, H. Zhu, X. Chen, X. Liu, Nat. Mater. 10, 968 (2011)
0. S.H. Joo, J.Y. Park, C.K. Tsung, Y. Yamada, P. Yang, G.A. Somorjai, Nat. Mater. 8, 126 (2009)
1. Z. Xu, Y. Hou, S. Sun, J. Am. Chem. Soc. 129, 8698 (2007)
2. R. Liu, Y. Guo, G. Odusote, F. Qu, R.D. Priestley, A.C.S. Appl, Mater. Interfaces. 5(18), 9167 (2013)
3. J. Safaei-Ghomi, R. Masoomi, M. Hamadanian, S. Naseh, New J. Chem. 40, 3289 (2016)
4. F. Mi, X. Chen, Y. Ma, S. Yin, F. Yuan, H. Zhang, Chem. Commun. 47, 12804 (2011)
5. Z. Zarnegar, J. Safari, New J. Chem. 38, 4555 (2014)
6. Y. Ahn, E.J. Choi, E.H. Kim, Rev. Adv. Mater. Sci. 5, 477 (2003)
7. G. Yuan, Y. Yuan, K. Xu, Q. Luo, Int. J. Mol. Sci. 15, 18776 (2014)
8. E. Karaoglu, H. Kavas, A. Baykal, M.S. Toprak, H.S. Ozeri, Nano-Micro Lett. 3, 79 (2011)
9. E. Farzad, H. Veisi, J. Ind. Eng. Chem. 60, 114 (2018)
0. F. Bonyasi, M. Hekmati, H. Veisi, J. Colloid, Interface Sci. 496, 177 (2017)
1. P. Heidari, R. Cheraghali, H. Veisi, Appl. Organomet. Chem. 30, 991 (2016)
2. M. Shahriary, H. Veisi, M. Hekmati, S. Hemmati, Mater. Sci. Eng. C. 90, 57 (2018)
3. H. Veisi, A. Sedrpoushan, S. Hemmati, Appl. Organomet. Chem. 29, 825 (2015)
4. H. Veisi, A. Rashtiani, V. Barjasteh, Appl. Organomet. Chem. 30, 231 (2016)
5. B. Maleki, D. Azarifar, R. Ghorbani-Vaghei, H. Veisi, S.F. Hojati, M. Gholizadeh, H. Salehabadi, M.
Khodaverdian Moghadam, Monatsh Chem. 140, 1485 (2009)
46. H. Veisi, S.A. Mirshokraie, H. Ahmadian, Int. J. Biol. Macromol. 108, 419 (2018)
47. R. Ghorbani-Vaghei, M. Chegini, H. Veisi, M. Karimi-Tabar, Tetrahedron Lett. 50, 1861 (2009)
48. H. Veisi, M. Pirhayati, A. Kakanejadifard, P. Mohammadi, M.R. Abdi, J. Gholami, S. Hemmati, Chem-
Select 3, 1820 (2018)
49. H. Veisi, S. Taheri, S. Hemmati, Green Chem. 18, 6337 (2016)
50. N.D. Koduri, B. Hileman, J.D. Cox, H. Scott, P. Hoang, A. Robbins, K. Bowers, L. Tsebaot, K. Miao,
M. Castaneda, M. Coꢂn, G. Wei, T.D.W. Claridge, K.P. Roberts, S.R. Hussaini, RSC Adv. 3, 181
(2013)
5
1. K.D. Bhatte, S.-I. Fujita, M. Arai, A.B. Pandit, B.M. Bhanage, Ultrason. Sonochem. 18, 54 (2011)
2. H. Veisi, R. Ghorbani-Vaghei, H. Eskandari, S. Hemmati, A. Rezaei, S. Hajinazari, M.R. Heidari Far,
A. Entezari, Phosphorus Sulfur Silicon 186, 213 (2011)
5
5
3. L. Osiglio, G. Romanelli, M. Blanco, J. Mol. Catal. A Chem. 316, 52 (2010)
4. K. Niknam, D. Saberi, Appl. Catal. A Gen. 366, 220 (2009)
5
5
5
5. A.R. Hajipour, H. Karimi, Chin. J. Catal. 35, 1982 (2014)
6. M.A. Bhosale, D. Ummineni, T. Sasaki, D. Nishio-Hamane, B.M. Bhanage, J. Mol. Catal. A Chem.
4
04–405, 8 (2015)
5
7. J. Albadi, A. Alihosseinzadeh, M. Mardani, Chin. J. Catal. 36, 308 (2015)
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Hojat Veisi · Ahmad Nikseresht · Afsaneh Rostami · Saba Hemmati
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Hojat Veisi
hojatveisi@yahoo.com
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Department of Chemistry, Payame Noor University, Tehran, Iran
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