Nanomagnetic zirconia-based sulfonic acid (Fe3O4@ZrO2-Pr-SO3H): A new, efficient and recyclable solid acid catalyst for the protection of alcohols: Via HMDS under solvent free conditions

Article abstract of DOI:10.1039/c6ra09930k

In the present work, sulfonic acid functionalized nanomagnetic zirconia is prepared by the reaction of (3-mercaptopropyl)trimethoxysilane and nanomagnetic zirconia. Then, nanomagnetic zirconia-based sulfonic acid (Fe₃O₄@ZrO₂

Full text of DOI:10.1039/c6ra09930k

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Nanomagnetic zirconia-based sulfonic acid (Fe3O4@ZrO2-Pr-SO3H):a new,
efficient and recyclable solid acid catalyst for the protection of alcohols via
HMDS under solvent free conditions
Received 00th January 20xx,
Accepted 00th January 20xx
Azadeh Tadjarodia, , Rahim Khodikara, Hosssein Ghafuria
*
DOI: 10.1039/x0xx00000x
In the present work, sulfonic acid functionalized nanomagnetic zirconia is prepared by the reaction of
(3ꢀmercaptopropyl)trimethoxysilane and nanomagnetic zirconia. Then, nanomagnetic zirconiaꢀbased sulfonic
acid (Fe3O4@ZrO2ꢀPrꢀSO3H) is synthesized through direct oxidation of thiol group by hydrogen peroxide and
H2SO4 subsequently. The catalyst was charactrized by fourier transform infrared spectroscopy (FTꢀIR), field
emission scanning electron microscopy (FEꢀSEM) image, energy dispersive Xꢀray spectroscopy (EDX),
Xꢀray diffraction (XRD), measurement and vibrational sample magnetometry (VSM). It was used as an
effective nanocatalyst with high catalytic activity for the protection of alcohols using hexamethyldisilazane
(HMDS) under solventꢀfree conditions at room temperature. The solid nanocatalyst can easily be separated
and reused several times without significant loss of its catalytic activity. Also, morethan inexpensive and
simplicity of separation process, this heterogeneous catalyst has shown a good chemoselectivity in the
reactions.
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suffered from serious problems such as toxicity, low yield of
product, low selectivity, but HMDS are the useful and more popular
Introduction
During the last decade, over 90% organic reaction processes have
employed catalysts. These catalysts play an important role in the
organic synthesis and transformations1. Catalysts can be
classified into two categories: homogenous2 and heterogeneous3.
Homogeneous acid catalysts such as HCl, H2SO4, HNO3, HClO4 and
HF are considerably used in the industrial processes but these
catalysts have drawbacks in handling, having toxic waste and
corrosiveness. In recent years, there has been a growing interest in
developing heterogeneous acid catalyst in the organic reactions.
Solid acid catalysts supply few opportunities for recovering and
recycling catalysts from organic reaction. Also these catalysts are
environmental friendly.
In this context, a heterogeneous catalyst based on nanoparticle
(ZrO2) has been introduced, which is an inorganic material with
chemical inertness. Also zirconia has a powerful resistance in
comparison with alkalis and acids. Therefore, it can be used as
suitable core for coating nanoparticle Fe3O44ꢀ7. Also in this work,
magnetic zirconia functionalized sulfonic acid as heterogeneous
solid acid catalyst used for carried various organic reactions.
compound for the protection of hydroxyl functional group by
transforming silylether. Bis(trimethylsilyl)amine (HMDS), a cheap
and stable reagent, can be used as an alternative silylating agent for
preparation of silylethers from -OH alcohols compound13,14. The
main problem is the low silylating power and unsatisfactory yield15.
Therefore, asuitable catalyst in the reactions should be used16.
Lately, some catalysts used for the protection of alcohols reaction
21
such as, (CH3)3SiCl17, ZnCl418, LiClO419, MgBr2.OEt220, LaCl3
,
sulfonic acidꢀfunctionalized nanoporous22. These catalysts are
effective, however, they have some significant drawbacks such as
poor silylating power, moistureꢀsensitive, long reaction time,
wearisome workups, solvent usage and difficulty in the recovery of
catalyst, severe reaction condition and high cost23.
Therefore, this protocol is, the development of not extreme and
selective method for protection of alcohols that is done without
solvent and in a short time and also has simple recovery by magnet,
and environmentally friendly at room temperature (r.t)24. In this
paper, the synthesis of chemically adsorbed sulfonic acid on
Fe3O4@ZrO2 was obtained by the reaction postꢀsynthesis (grafting)25
of (3ꢀmercaptopropyl) trimethoxysilane and Fe3O4@ZrO2. Then
oxidation of thiols by H2O2 and 1 mL H2SO4 successfully was
carried out26. Catalyst Fe3O4@ZrO2ꢀPrꢀSO3H as a new catalyst has
high efficiency for organic reactions and also it is useful as catalyst
having bronsted acid properties for the preparation derivatives
protection of alcohols. The characterization of Fe3O4@ZrO2ꢀPr
ꢀSO3H was performed with use of different techniques such as
The protection of alcohols is one of important and necessary process
for multistep organic synthesis. Generally, protection of alcohols has
been carried out by different reagents such as alkylsilanes8,9,10 and
bis(trimethylsilyl)amine (HMDS)11 in the presence of a suitable
catalyst12. However, all above mentioned agents except HMDS
a.Department of chemistry, Iran university of Science and Technology, Narmak,
Tehran 16846-13114, Iran.
FTꢀIR, SEM, EDX, VSM and XRD 27
.
*corresponding author: tajarodi@iust.ac.ir
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was separated by magnet and washed three times with distilled water
and acetone to get Fe3O4@ZrO2–PrꢀSO3H catalyst (Scheme 2).
Scheme. 1 The protection reaction of alcohol in the presence of synthesized magnetic
acidic nanocatalyst (Fe3O4@ZrO2ꢀPrꢀSO3H) in room temperature and solvent free
condition.
Experimental
Chemical materials were purchased from Merck Co. and utilized
without further purification. FTꢀIR spectra were recorded as KBr
pellets on a Shimadzuꢀ8400 sin the range 400ꢀ4000 cmꢀ1. The XꢀRay
diffraction (XRD) pattern was recorded using a STOE powder
diffractometer with Co kα, (λ= 1.789 Å) irradiation.Also for
studyingthe morphology of catalyst scanning electron microscopy
(SEM), entire image were taken bya Hitachi S4160 FESM. Magnetic
characteristic of the particle was assessed with a vibrating sample
magnetometer (VSM, lake shore 7410). The protection products
were analyzed with a gas chromatograph (Shimadzu) equipped with
a HPꢀ5 capillary column.
Scheme. 2 Preparation of catalyst Fe3O4@ZrO2ꢀPrꢀSO3H
FT-IR analysis
FTꢀIR spectra of Fe3O4, Fe3O4@ZrO2 and Fe3O4@ZrO2ꢀPrꢀSO3H
samples are shown in Fig.1. In Fig.1a, there are the peaks at 1635
and 3452 cmꢀ1, which related to –OH bending and stretching
vibrations of the absorbed water molecules, respectively.
There is the peak at 584 cmꢀ1 that showing the presence of FeꢀO.
Also the peaks at 1054 and 630 cmꢀ1 belong to vibrations SiꢀO and
ZrꢀO, respectively (Fig.1b). The vibrational peak of SꢀH is seen at
2559 cmꢀ1 as shown in Fig.1c. Because of weak dipole vibration of
thiol bonds, observed peak is weak34, 35. The appeared peaks at 1045,
1089 and 1188 cmꢀ1 were attributed to the O=S=O asymmetric,
Preparation of Fe3O4@ZrO2nanoparticle
Fe3O4 nanoparticles were synthesized utilizing massart's procedure28
and then the coreꢀshell Fe3O4@ZrO2 was prepared according to the
applying method reported previously29ꢀ33. Briefly, 0.2 g of Fe3O4
nanoparticles (NPs) homogenously were dispersed in HCl 0.1 M for
15 min in order to activate the nanoparticles surface. After magnetic
particles were separated by magnet from aqueous solution. It was
washed with distilled water two times. The nanoparticles again were
dispersed in the mixture of 70 mL ethanol, 30 mL distilled water and
symmetric and SꢀO vibrations of the
. In addition, the CH stretching vibrations
were observed at 2842 and 2929 cmꢀ1.
(
ꢀ
SO3H) groups,
respectively36,37 (Fig.1d)
1 mL concentrated NH3 solution (28%). Finally TEOS (0.05 g, 2.4
mmol) was added to the mixture and stirred for 6 h at r.t. Afterward,
silica coated Fe3O4 was separated by magnet and washed with
ethanol and distilled water at least three times. Nanoparticles coated
in the previous step, in the mixture of 0.4 g (1.1 mmol) CTAB (as
surfactants), 70 mL distilled water, 2 mL NH3 and 70 mL ethanol for
30 min was stirred continuously until homogenized and uniform
dispersion. Then zirconium nitrate Zr(NO3)4 (0.7 g, 3.03 mmol)
dissolved in the water) was added dropꢀwise to the stirring mixture
for 6 h at r.t. The final product was collected by magnet and washed
with ethanol and distilled water. For removal of surfactant, the
obtained particles were refluxed by acetone in the soxhelt extractor
for 32 h. Afterward, it was separated, washed by distilled water and
dried at 80 °C to get Fe3O4@ZrO2.
Preparation of 3-mercaptopropyl magnetic Zirconia (MPMZ)
0.6 g of Fe3O4@ZrO2 was added to 4 mL dry toluene, 2 mL (10.77
mmol) of (3ꢀmercaptopropyl) trimethoxysilane, and the reaction
mixture was refluxed for 18 h. The nanoparticles were separated by
magnet and washed with hot toluene for 12 h in the continuous
extraction. Then it was dried for overnight at 110 °C to achieve
surface bond thiol from Fe3O4@ZrO2ꢀPrꢀSH (MPMZ) group.
Fig. 1 FTꢀIR spectra of (a) Fe3O4, (b) Fe3O4@ZrO2, (c) Fe3O4@ZrO2ꢀPrꢀSH and
(d) Fe3O4@ZrO2ꢀPrꢀSO3H
XRD patterns
Xꢀray diffraction patterns (XRD) for Fe3O4, Fe3O4@ZrO2 and
Fe3O4@ZrO2ꢀPrꢀSO3H are given in Fig.2. As well as XRD of the
magnetic nanoparticles of Fe3O4 in the cubic phase is a good
agreement with (PDF no: 01ꢀ075ꢀ0499) as shown in Fig.2a. Also the
XRD patterns of Fe3O4@ZrO2 and Fe3O4@ZrO2ꢀPrꢀSO3H are
similar with XRD pattern for Fe3O430,31 as given in Fig.2b and 2c. It
demonstrates that the modification has not considerable effect on the
Preparation of solid Fe3O4@ZrO2 –based sulfonic acid
MPMZ was oxidized by 5 mL H2O2 and 1 mL H2SO4 in the 20 mL
methanol for 12 h at r.t and washed three times with distilled water.
In order to ensure complete protonation, the solid catalyst will be
suspended in the H2SO4 solution 20% for 5 h. After that, the mixture
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phase of Fe3O4. For this reason, ZrO2 is amorphous. Organic groups EDX analysis for Fe3O4@ZrO2 and Fe3O4@ZrO2-Pr-SO3H
and nanoparticles available in amorphous structure have no effect in
the crystal structure of compounds. Due to this fact, XRD patterns of
iron, zirconium and oxygen elements. After modification of
Fe3O4@ZrO2 and Fe3O4@ZrO2ꢀPrꢀSO3H are similar.
The EDX spectrum of Fe3O4@ZrO2 (Fig.5a) displays the presence of
Fe3O4@ZrO2, in the EDX spectrum of Fe3O4@ZrO2ꢀPrꢀSO3H
(Fig.5b), some other elements such as sulphur and carbon were
observed. The content of sulfur and carbon was 6.56 and 17.08 wt%,
respectively. Also the reduction of iron peak intensity demonstrates
that Fe3O4@ZrO2 coated by (3ꢀmercaptopropyl) trimethoxysilane,
which confirms the synthesis process was successful.
Fig. 2 XRD patterns of (a) Fe3O4, (b) Fe3O4@ZrO2 and (c) Fe3O4@ZrO2ꢀPrꢀSO3H
FE-SEM analysis
The FEꢀSEM images for the pure Fe3O4@ZrO2 and Fe3O4@ZrO2ꢀ
PrꢀSO3H are illustrated in Fig.3. According to this chart, the particle
size bare Fe3O4@ZrO2 distribution is narrow and the size of most of
the particles is about 20ꢀ70 nm (Fig.4a) and (Fig.3). Then, the
powder is aggregated because of modification by sulphate and form
strong hydrogen bonds between theꢀSO3H groups (Fig.4b).
Fig.5 EDX analysis of (a) Fe3O4@ZrO2 and (b) Fe3O4@ZrO2ꢀPrꢀSO3H
Back titration of Fe3O4@ZrO2-PrSO3H in aqueous media
Acidity [H+] of synthesized catalyst (Fe3O4@ZrO2ꢀPrSO3H) was
indicated by back titration method. The procedure of this titration
include: 0.5 g of catalyst, 0.5 g of NaCl and 10 mL of NaOH (0.1 M)
were added to 20 mL distilled water and stirred for 24 h on a
magnetic stirrer. After that, three drops Phenolphthalein was added
to it and colour of mixture was pink. Then it was titrated with
solution of HCl (0.1 M) until reached to neutral point. After
calculations, pH value of catalyst was obtained 2.25.
Fig. 3 Distribution chart of particles size.
Surface acidity studies
The acidity strength of an acid in organic solvents can be declared by
the Hammett acidity function (H0)38,39. It can be calculated by the
following equation:
H0 = pK(I)aq + log([I]s/[IH+]s)
Here, ‘I’ represents the indicator base, [IH+] is the molar
concentrations of the protonated forms of the indicator and [I]s is the
molar concentrations of the unprotonated forms of the indicator. The
pK(I)aq values are already known and can be acquired from more
references (for example the pK(I)aq value of 4ꢀnitroaniline is 0.99).
Fig. 4 FEꢀSEM images of (a) Fe3O4@ZrO2 and (b) catalyst Fe3O4@ZrO2ꢀPrꢀSO3H
The value of [I]s/[IH+]s according to the LambertꢀBeer’s Law can be
calculated using the UVꢀvisible spectrum.
Here, we used 4ꢀnitroaniline as the basic indicator and CCl4 was
chosen as the solvent. The maximal absorbance of the unprotonated
form of 4ꢀnitroaniline was observed at 329 nm in CCl4. As can be
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resulted from Fig. 6, the indicator was partially in the form as [IH+]
(The absorbance of the unprotonated form of the indicator in
Fe3O4@ZrO2ꢀPrꢀSO3H was weak as compared to the sample of the
indicator in CCl4). The achieved results of the acidity strength of
Fe3O4@ZrO2ꢀPrꢀSO3H are listed in Table 1 and Absorption spectra
of 4ꢀnitroaniline and Fe3O4@ZrO2ꢀPrꢀSO3H can be seen in Fig 6.
Result and discussion
The trimethylsilylation of hydroxyl alcohols groups simply carried
out in the not extreme conditions, solventꢀfree and room temperature
in the presence catalyst Fe3O4@ZrO2ꢀPrꢀSO3H. The possible
mechanism has been shown in Scheme 3. This mechanism is
basedꢀon bronsted acid and explains intractions between (ꢀSO3H)
groups and nitrogen in HMDS that reactive silylating agent.
Table 1 Calculation of Hammett acidity function (H0) of Fe3O4@ZrO2ꢀPrꢀSO3Ha
Entry
Catalyst
Amax
2.147
0.933
[I]s (%)
100
43.45
[IH+]s (%)
0
H0
ꢀ
0.876
1
2
ꢀ
ROSiMe3
Fe3O4@ZrO2ꢀPrꢀSO3H
56.55
aCondition for UVꢀvisible spectrum measurement: solvent, CCl4; indicator, 4ꢀnitroaniline (pK(I)aq
0.99), 1.44 × 10ꢀ4 mol/lit; catalyst, Fe3O4@ZrO2ꢀPrꢀSO3H, 20 mg, 25 C.
:
(Me3Si)2NH
ROSiMe3
H
NH3
ROH
(Me3Si)2NH2
(Me3Si)NH3
ROH
ROSiMe3
Fe3O4@ZrO2ꢀPrꢀSO3
H
Scheme. 3 Suggested mechanism of protection alcohols
Alcohols or phenols (1 mmol) could be added to a stirring mixture of
Fe3O4@ZrO2ꢀPrꢀSO3H (10 mg) and HMDS (0.7 mmol) at r.t
(Scheme 1). After accomplishment of the reaction, catalyst was
separated simply from of reaction mixture by a magnet. The
optimised catalyst amount was determined by mixing benzyl
alcohol, HDMS and different amounts of the catalysts. The mixtures
were stirred at room temperature and solvent free conditions. The
results of this optimisation were presented in Table 2. According to
results, the reaction can be carried out in the presence catalyst in the
less time and the yields are outstanding. This catalyst has higher
efficiency than previous reported ones. Also this reaction will be
considered as a green reaction due to the solvent free conditions.
According to Table 2; the optimized amount of catalyst was 10 mg.
Fig 6 Absorption spectra of 4ꢀnitroaniline (indicator; curve A) and Fe3O4@ZrO2ꢀPr
ꢀSO3H (catalyst; curve B) in CCl4.
Magnetic properties for Fe3O4@ZrO2-Pr-SO3H
Results of the VSM measurement for bare Fe3O4 and Fe3O4@ZrO2
ꢀPrꢀSO3H have been reported (Fig.7). The hysteresis loop for
Fe3O4@ZrO2ꢀPrꢀSO3H with limited filed from ꢀ1000 to 1000 Oe was
shown in Fig. 7b. According to this figure, regarding to the first
amount of magnetization saturation of Fe3O4 which was 61 emu/g,
due to the coating of surface of Fe3O4 by propyl sulphate, the
amount of magnetization saturation of Fe3O4@ZrO2ꢀPrꢀSO3H was
decreased to 13.96 emu/g. This clearly has shown that the coating
process successfully was carried out.
Table 2 Optimization of the reaction condition for trimethysilylation of benzyl alcohol
with HMDSa
Entry
Amount of catalyst(mg)
Time (min)
Yield (%)
1
2
3
4
5
ꢀ
5
8
10
15
90
12
10
6
85
99
99
99
99
6
a Reaction of benzyl alcohol (1 mmol) and HMDS (0.7 mmol, 0.112 g) in the present
of different amounts of Fe3O4@ZrO2ꢀPrꢀSO3H at room temperature under solventꢀfree
conditions.
In order to show productivity of Fe3O4@ZrO2ꢀPrꢀSO3H, various
catalysts
such
as
Trichloroisocyanuricacid
(TCCA)40,
41
18
CuSO4 5H2O , MgBr2·OEt220, Iodine42, H3PW12O4043, ZrCl4
,
.
ZrO(OTf)244, Sulfonicacid@nanoporoussilica22, LaCl321, HClO4–
SiO245 and [VIV(TPP) (OTf)2] were also used for protection of
23
benzyl alcohol by HMDS. The results were given in Table 3.
According to this table, Fe3O4@ZrO2ꢀPrꢀSO3H is very superior
than the other catalysts because of solventꢀfree, simple recovery,
and environmentally friendly method, low catalyst loading, high
efficienty and reusability used.
Fig. 7 VSM curves of (a) the pure Fe3O4 and (b) Fe3O4@ZrO2ꢀPrꢀSO3H
4 | J. Name., 2012, 00, 1-3
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Table 3 Comparison of the obtained results for Fe3O4@ZrO2ꢀPrꢀSO3H with Yields
order to demonstrate complete protection of hydroxyl. The results
showed that all reactions were perfect in the 6ꢀ10 min in the solventꢀ
free conditions and less reaction time for all alcohols and also the
extraordinary yields at (r.t) were obtained. Also it has high efficiency
chemoseletive for hydroxyl group but it was not successful to protect
thiol and amine groups. Also recovered catalyst by magnet was
washed with acetone and distilled water and then dried at 110 °C for
30 min. Afterward, reutilize for more 10 successive runs under same
reaction conditions. These results exhibit the highest stability and
also the least change in the activity of the catalyst as shown in Fig.8.
One of the reasons for decreasing of the catalytic activities is
reduction the acidities of catalyst. To prove this, the acidity was
tested for each reaction using back titration. The results was
indicated the little reduction in the catalyst acidity in each reaction.
obtained by the recently reported catalyst.
Catalyst
Time
Yield
(%)
Temperature
(°C)
Entry
Catalyst
Solvent
Reference
40
load (mg)
(min)
Trichloroisocyanuric
acid (TCCA)
1
24
240
CH2Cl2
90
r.t
2
3
4
5
6
7
20
50
10
29
5
12
5
CH3CN
Neat
98
98
98
90
95
92
r.t
r.t
41
20
42
43
18
44
CuSO4.5H2O
MgBr2·OEt2
Iodine
2
CH2Cl2
Neat
r.t
H3PW12O40
ZrCl4
23
1
55ꢀ60
r.t
CH3CN
CH3CN
20
1
r.t
ZrO(OTf)2
Sulfonicacid@nanop
oroussilica
8
30
55
CH2Cl2
99
r.t
22
LaCl3
9
49
15
180
2
CH2Cl2
CH3CN
91
98
r.t
r.t
21
45
HClO4 –SiO2
10
Poly(Nꢀ
bromobenzeneꢀ1,3ꢀ
disulfonamide)
11
20
90
CH2Cl2
90
r.t
46
[VIV(TPP)(OTf)2]
12
13
10
10
1
6
CH3CN
Neat
100
99
r.t
r.t
23
This
work
Fe3O4@ZrO2ꢀPrꢀ
SO3H
Results of these reactions with various alcohols were summrized in
Table 4. According to this table, the different alcohols was used in
this research such as benzylic, primary, secondary, and phenolic, and
got the best result on the yields and time of the reaction. The achived
results showed that electronꢀdonating alcohols required less
reaction times in comparision to electronwithdrawing alcohols. Also
secondry alcohols reacted slowly at room temparature than primary
alcohols (Table 4). In addition to, the results displays that aliphatic
alcohols need more reaction time compared to aromatic alcohols.
The reaction progress was monitored by TLC, GC and FTꢀIR in
Fig. 8 Recyclability of Fe3O4@ZrO2ꢀPrꢀSO3H catalyst for the protection
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Table 4 HMDS protection of alcohols in the present Fe3O4@ZrO2ꢀPrꢀSO3Ha
Entry
1
Substrate
Product
Time (min)
6
Yield (%)b
99≥
2
3
4
5
6
7
8
9
6
6
6
6
8
8
9
9
99≥
99≥
99≥
99≥
99≥
99≥
99≥
99≥
10
11
7
6
99≥
99≥
12
6
99≥
13
14
10
6
99≥
99≥
15
16
17
6
7
6
99≥
99≥
99≥
18
19
20
21
7
6
6
7
99≥
99≥
99≥
99≥
22
23
24
8
8
8
99≥
99≥
99≥
(a) Reaction conditions: alcohol (1 mmol), catalyst (10 mg), HMDS (0.7 mmol, 0.112 g), room temperature (RT). (b) Yield were determined by GC.
6 | J. Name., 2012, 00, 1-3
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[28]. Das, B.; Venkateswarlu, K.; Krishnaiah, M.; Holla, H., Tetrahedron
Letters 2006, 47 (49), 8693ꢀ8697.
Conclusion
[29]. Sannino, F.; Pirozzi, D.; Aronne, A.; Fanelli, E.; Spaccini, R.; Yousuf,
A.; Pernice, P., Environmental Science & Technology 2010, 44 (24), 9476ꢀ
9481.
[30]. Sarkar, A.; Biswas, S. K.; Pramanik, P., Journal of Materials Chemistry
2010, 20 (21), 4417ꢀ4424.
[31]. Wu. T, Wan. J and Ma. X, Chinese J. Catal., 2015, 36, 425–431.
[32]. Jiang. H, Chen. P, Zhang. W, Luo. S, Luo. X, C. (Peter) Au and M. Li,
Appl. Surf. Sci., 2014, 317, 1080–1089.
[33]. Jiang. H, Chen. P, Luo. S, Tu. X, Cao. Q and M. Shu, Appl. Surf. Sci.,
2013, 284, 942–949.
[34]. Zhang. S, Zhang. Y, Liu. J, Xu. Q, Xiao. H, Wang. X and Xu. H, Chem.
Eng. J. 2013, 226, 30–38.
[35]. Qu. Q, Gu. Q, Gu. Z, Shen. Y, Wang. C and Hu. X, Colloids Surf., A.
2012, 415, 41–46.
[36]. Miyatake, K.; Iyotani, H.; Yamamoto, K.; Tsuchida, E.,
Macromolecules 1996, 29 (21), 6969ꢀ6971.
In conclusion, Fe3O4@ZrO2ꢀPrꢀSO3H acid has been exhibited to be
an efficient and suitable catalyst. Also green procedure for the
protection of alcohols and phenols by HMDS in high yield, solventꢀ
free conditions, safe and environmentally benign method. To
conclude, simple recovery, simple work up, mild conditions, short
reaction time, inexpensive of catalyst and high efficiency make our
method to be effective and appropriate for protection alcohols and
aliphatic alcohols
.
Acknowledgements
The authors would like to thank Iran University of Science and
Technology, and Iran Nanotechnology Initiative Council for
[37]. Langner, R.; Zundel, G., The Journal of Physical Chemistry 1995, 99
(32), 12214ꢀ12219.
financial support of this work
.
[38]. Amoozadeh. A, Golian. S and Rahmani. S, RSC Adv., 2015, 5, 45974–
45982.
[39]. Xing. H, Wang. T, Zhou. Z and Dai. Y, J. Mol. Catal. A Chem., 2007,
264, 53–59.
[40]. Khazaei, Ardeshir, et al. Catalysis Communications 8.3 (2007): 543ꢀ
547.
[41]. Alvaro, M.; Corma, A.; Das, D.; Fornés, V.; García, H., Journal of
Catalysis 2005, 231 (1), 48ꢀ55.
[42]. Karimi, B.; Golshani, B.,The Journal of Organic Chemistry 2000, 65
(21), 7228ꢀ7230.
[43]. Firouzabadi, H.; Iranpoor, N.; Amani, K.; Nowrouzi, F., J. Chem. Soc.,
Perkin Trans. 1 2002, (23), 2601ꢀ2604.
[44]. Moghadam, M.; Tangestaninejad, S.; Mirkhani, V.; Mohammadpoorꢀ
Baltork, I.; Chahardahcheric, S.; Tavakoli, Z., Journal of Organometallic
Chemistry 2008, 693 (11), 2041ꢀ2046.
References
[1]. Ghafuri, H.; Rashidizadeh, A.; Ghorbani, B.; Talebi, M., New Journal of
Chemistry 2015, 39, 4821ꢀ4829.
[2]. ColeꢀHamilton, D. J., Science 2003, 299 (5613), 1702ꢀ1706.
[3]. Mizuno, N.; Misono, M., Chemical Reviews 1998, 98 (1), 199ꢀ218.
[4]. Kljajević, L.; Matović, B.; RadosavljevićꢀMihajlović, A.; Rosić, M.;
Bosković, S.; Devečerski, A., Journal of Alloys and Compounds 2011, 509
(5), 2203ꢀ2215.
[5]. Liu, H.; Sun, X.; Yin, C.; Hu, C., Journal of Hazardous Materials 2008,
151 (2), 616ꢀ622.
[6]. Zhao. Z, Liu. J, Cui. F, Feng. H and Zhang. L, J. Mater. Chem., 2012, 22,
9052.
[7]. N. N. Li, T. F. Kang, J. J. Zhang, L. P. Lu and S. Y. Cheng, Anal.
Methods, 2015, 7, 5053–5059.
[8]. Watahiki, T.; Matsuzaki, M.; Oriyama, Green Chemistry 2003, 5 (1), 82ꢀ
[45]. Shaterian, H. R.; Shahrekipoor, F.; Ghashang, M., Journal of Molecular
Catalysis A: Chemical 2007, 272 (1), 142ꢀ151.
[46]. GhorbaniꢀVaghei, R.; Zolfigol, M. A.; Chegeny, M.; Veisi, H.,
Tetrahedron Letters 2006, 47 (26), 4505ꢀ4508.
84.
[9]. Ito, H.; Takagi, K.; Miyahara, Organic Letters 2005, 7 (14), 3001ꢀ3004.
[10]. Suzuki, T.; Watahiki, T.; Oriyama, Tetrahedron Letters 2000, 41 (46),
8903ꢀ8906.
[11]. Ghorbani‐Choghamarani, A.; Zolfigol, M. A.; Hajjami, M.; Jafari, S.,
Journal of the Chinese Chemical Society 2008, 55 (6), 1208ꢀ1213.
[12]. Ghorbani‐Choghamarani, A.; Amani, K.; Zolfigol, M. A.; Hajjami, M.;
Ayazi‐Nasrabadi, Journal of the Chinese Chemical Society 2009, 56 (2), 255ꢀ
260.
[13]. Cossy, J.; Pale, P., Tetrahedron Letters 1987, 28 (48), 6039ꢀ6040.
[14]. Schölmerich, J.; Schmidt, E.; Schümichen, C.; Billmann, P.; Schmidt,
H.; Gerok, W., Scintigraphic Gastroenterology 1988, 95 (5), 1287ꢀ1293.
[15]. Bruynes, C. A.; Jurriens, The Journal of Organic Chemistry 1982, 47
(20), 3966ꢀ3969.
[16]. Moghadam, M.; Tangestaninejad, S.; Mirkhani, V.; Mohammadpoor
‐Baltork, I.; Gharaati, Applied Organometallic Chemistry 2009, 23 (11), 446ꢀ
454.
[17].Kulangiappar, K.; Anbukulandainathan, M.; Raju, Synthetic
Communications 2014, 1 (44), 2494ꢀ2502.
[18]. Shirini, F.; Mollarazi, E., Catalysis Communications 2007, 8 (9), 1393ꢀ
1396.
[19]. Azizi, N.; Saidi, M. R., Organometallics 2004, 23 (6), 1457ꢀ1458.
[20]. Mojtahedi, M. M.; Abbasi, H.; Abaee, M. S., Journal of Molecular
Catalysis A: Chemical 2006, 250 (1), 6ꢀ8.
[21]. Mizuno, N.; Misono, M., Chemical Reviews 1998, 98 (1), 199ꢀ218.
[22]. Zareyee, D.; Karimi, B., Tetrahedron Letters 2007, 48 (7), 1277ꢀ1280.
[23]. Moghadam, M.; Mohammadpoor‐Baltork, I.; Tangestaninejad, S.;
Mirkhani, V.; Khosropour, A. R.; Taghavi, S. A., Applied Organometallic
Chemistry 2011, 25 (9), 687ꢀ694.
[24]. Atghia, S.; Beigbaghlou, S. S., Journal of Organometallic Chemistry
2013, 745, 42ꢀ49.
[25]. Hoffmann, F.; Cornelius, M.; Morell, J.; Fröba, M., AngewandteChemie
International Edition 2006, 45 (20), 3216ꢀ3251.
[26]. Gholamzadeh, P.; Ziarani, G. M.; Lashgari, N.; Badiei, A.; Asadiatouei,
P., Journal of Molecular Catalysis A: Chemical 2014, 391, 208ꢀ222.
[27]. Nikbakht, F.; Ghonchepour, E.; Ziyadi, H.; Heydari, A., RSC Advances
2014, 4 (65), 34428ꢀ34434.
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DOI: 10.1039/C6RA09930K