CoFe2O4?SiO2-NH-βCD-BF3 as a supramolecular nanocomposite: Synthesis, characterization and catalytic activity

Article abstract of DOI:10.1016/j.poly.2019.114219

This manuscript describes synthesis of BF₃-functionlized β-cylcodextrine grafted magnetic CoFe₂O₄ nanaoparticles as a hybrid magnetic nano-composite (CoFe₂O₄?SiO₂-NH-βCD-BF₃). The CoFe₂O₄?SiO₂-NH-βCD-BF₃ was fabricated by grafting of 6-O-toluenesulfonyl cyclodextrin (6-Ts-βCD) to 3-aminopropyl triethoxysilane coated magnetic CoFe₂O₄?SiO₂ nanoparticles followed by combination with BF₃. The CoFe₂O₄?SiO₂-NH-βCD-BF₃was characterized by FT-IR, TGA, VSM and SEM techniques. The feasibility of using CoFe₂O₄?SiO₂-NH-βCD-BF₃ as a magnetically recoverable catalyst was confirmed in the modified-Ritter reaction. The result showed that this novel nano-composite could serve as an efficient nanoreactor bearing super-acidic sites formed by immobilized BF₃ and reuse at least for 6 times without loss in activity.

Full text of DOI:10.1016/j.poly.2019.114219

Journal Pre-proofs
CoFe2O4@SiO2-NH-βCD-BF3 as a Supramolecular Nanocomposite: Synthesis,
Characterization and Catalytic Activity
Hosein Hamadi, Zohreh Zanjani, Mahtab Yadollahi
PII:
S0277-5387(19)30664-3
DOI:
https://doi.org/10.1016/j.poly.2019.114219
POLY 114219
Reference:
Polyhedron
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Accepted Date:
6 August 2019
25 October 2019
Please cite this article as: H. Hamadi, Z. Zanjani, M. Yadollahi, CoFe2O4@SiO2-NH-βCD-BF3 as a Supramolecular
Nanocomposite: Synthesis, Characterization and Catalytic Activity, Polyhedron (2019), doi: https://doi.org/
10.1016/j.poly.2019.114219
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CoFe2O4@SiO2-NH-βCD-BF3 as a Supramolecular Nanocomposite:
Synthesis, Characterization and Catalytic Activity
Hosein Hamadi*, Zohreh Zanjani, Mahtab Yadollahi
Department of Chemistry, Faculty of Sciences, Shahid Chamran University of
Ahvaz, Ahvaz, Iran
Abstract
This manuscript describes synthesis of BF3-functionlized β-cylcodextrine grafted
magnetic CoFe2O4 nanaoparticles as a hybrid magnetic nano-composite
(CoFe2O4@SiO2-NH-βCD-BF3).
The
CoFe2O4@SiO2-NH-βCD-BF3
was
fabricated by grafting of 6-O-toluenesulfonyl cyclodextrin (6-Ts-βCD) to 3-
aminopropyl triethoxysilane coated magnetic CoFe2O4@SiO2 nanoparticles
followed by combination with BF3. The CoFe2O4@SiO2-NH-βCD-BF3was
characterized by FT-IR, TGA, VSM and SEM techniques. The feasibility of using
CoFe2O4@SiO2-NH-βCD-BF3 as a magnetically recoverable catalyst was
confirmed in the modified-Ritter reaction. The result showed that this novel nano-
composite could serve as an efficient nanoreactor bearing super-acidic sites formed
by immobilized BF3 and reuse at least for 6 times without loss in activity.
1

Keywords: Nano-composite, Heterogeneous catalyst, Ritter reaction, magnetic
nanoparticle, Cyclodextrine
Introduction
The development of hybrid inorganic-organic nanocomposite catalyst, owing
magnetic properties have gained considerable attention due to their processability,
multifunctionality, and potential large-scale production [1-3]. Immobilization of
homogeneous catalysts on these nanocomposites as a solid support will aid
recovery of the catalyst and minimize pollution via simple magnetic decantation.
The combination of magnetic property of magnetic nanoparticle (MNPs) and
molecular recognition of a specific organic structure exposed their individual
distinct advantages [4-7]. Magnetic nanoparticles can be well dispersed in the
reaction mixtures in the absence of magnetic field providing large surface for
readily access of substrate molecules. On the other hand the organic coat owing
catalytic sites along with structural approach, improve the catalytic activity of such
nanocomposite [8].
β-Cyclodextrins (β-CDs) is a type of crystalline and torus-like macro-rings
consisting of seven glucopyranose units. The lipophilic interior cavity of β-CDs
has about 256 Å3 cavity volume and outer diameter of 15.4 Å which has a
hydrophilic outer surface [9]. β-CDs cavities have the ability to bind a wide range
2

of organic, inorganic and biological molecules as a guest substrate, in solution and
solvent-free conditions [10]. On the other hand these interesting characteristics
enable them to provide nanostructured supramolecular assemblies in their
hydrophobic cavity. The intramolecular interactions between β-CDs cavity and
guest molecule are predominantly via hydrogen bond, hydrophobic and van der
Waals interactions [11]. The enzymes properties encouraged scientists to design
supramolecular nanoreactors in order to accelerate catalytic reactions [12-14]. The
nanoreactors such as cyclodextrins provide hydrophobic cages with strong
substrate binding therein, transition-state or intermediate stabilization, while weak
product binding via supramolecular interactions [15].
β-CDs have been extensively used to promote and catalyzed organic reactions
via guest-host complex formation. The hydroxy groups of β-CDs can either react
with the guest molecule themselves or attach to other catalytic and functional
groups in which develop the composite as a supramolecular nanoreactor. Using the
immobilized catalyst on this nanoreactor makes it possible to enhance the catalytic
activity [16-19].
In continue to our research in designing new catalytic system, [20-24] the aim
of this paper is to develop a novel catalyst by combination of β-CDs with magnetic
nanoparticles (CoFe2O4) following by immobilization of BF3 to yields an efficient
acid catalyst (CoFe2O4@SiO2-NH-βCDs-BF3). The performance of the prepared
3

catalyst was investigated in the modified-Ritter reaction (Scheme 1). The Ritter
reaction, the reaction of nitrile with a substituted alkene or alcohols using an acid
catalyst, is a method of choice for the production of amides, which are versatile
intermediates in organic synthesis [25-27]. Due to its potential importance,
remarkable progress has been made in the field of catalytic Ritter-type reactions
with the betterment in terms of milder reaction conditions, better catalysts,
substrate diversities, increased yields etc, like acid catalyzed methods [28-31],
solid supported-acid catalysts [32, 33], triflamides [34], Nafion-H [35] and many
others catalyzed methods [36-39]. On the other hand, various modified versions of
this reaction have been reported for Ritter-type reaction by relatively stable in situ-
generated carbocations from , esters, alkenes, alcohols, ethers, silyl ethers,
alkylborons and carbonium salts [37, 40-43] by using heterogeneous and
homogeneous acidic catalysts. One of the best approaches was to generate the tert-
butyl cation from a non-alcoholic source to yield N-tert-butyl amides which among
them the tert-butyl acetate due to its ease of handling (bp 97-98 ºC), availability as
a common solvent, and low cost is more attractive. Our approach is directed by
four imperatives; (i) the catalyst should be easily recoverable; (ii) using the
supramolecular cavities as nanoreactor; (iii) enhance the catalytic activity by
grafted BF3 (iv) catalyst performing in an acid catalyzed reaction.
4

BF3 is a strong Lewis acid used in the direct gas phase and complex form in
many organic transformations [44-52]. A range of solid supported BF3 was
developed [53-56]. It has been claimed that supporting of BF3 on the various
-
oxides, yield superacid solid via –OBF3 H+ and –OBF2 formation [57, 58].
O
O

CoFe2O4@SiO2-NH- CDs-BF3
R CN
+
N
O
R
r.t
H
Scheme 1.
2. Experimental
2.1. Materials and Measurements
All chemical compounds, with high purity, were purchased from Sigma-
Aldrich or Merck and directly used without more purification. CoFe2O4 was
prepared according to the literature [59]. The tosylated β-cyclodextrin (Ts-βCD)
was prepared according to the reported method [60]. Fourier transform infrared
spectroscopy (FT-IR) was obtained by FT Perkin Elmer spectrophotometer.
Powder X-ray diffraction patterns (PXRD) were recorded by using Philips X-ray
diffractometer (model PW1840). Field-scanning electron microscope images (FE-
SEM) have taken by the MIRA3 model. Magnetic properties of nanoparticles were
5

measured by vibrating sample magnetometer (VSM) (Meghnatis Daghigh Kavir
Company, Iran) at room temperature.
2.2. Preparation of CoFe2O4@SiO2-NH2
The CoFe2O4 MNPs were synthesized using co-precipitation method
according to the reported procedure by treatment of FeCl3.6H2O, CoCl2.6H2O and
oleic acid as surfactant. Oleic acid was removed from the synthesized CoFe2O4
MNPs by calcination at 600 ᵒC for 10 hours to give the black CoFe2O4 MNPs. The
as-synthesized CoFe2O4 then coated with silica via reported sol-gel method [59].
Treatment the silica coated MNPs with 3-aminopropyl tri ethoxy silane (APTES)
produce modified surface terminated with amine groups [61]. Briefly 0.5 g of
APTES reacts with 100 mL solution of CoFe2O4@SiO2 (1 g) in ethanol under
reflux for 12 h to promote covalent bonding of the APTES to the MNPs surface.
The solution then centrifuged and washed 3 times with ethanol to remove the
unreacted material and the CoFe2O4@SiO2-NH2 was dried in air.
2.3. Preparation of CoFe2O4@SiO2-NH-βCDs-BF3
2 g of CoFe2O4@SiO2-NH2 and 0.25 g of Ts-βCD were added to 30 mL of dry
DMF and the mixture was stirred for 24 h in oil bath (60 ̊C) under N2 atmosphere.
6

Then the mixture was cooled to room temperature and washed with DMF,
methanol-water, and ethanol under sonication. The CoFe2O4@SiO2-NH-βCDs was
isolated by external magnet. The CoFe2O4@SiO2-NH-βCDs-BF3 was prepared by
combination of BF3.OEt2 (0.13 g, 0.9 mmol) over 30 min drop by drop to 0.3 g of
the sonicated CoFe2O4@SiO2-NH-βCDs in 30 mL dry diethyl ether at room
temperature and stirred for 2 h following by magnetic decantation. The final
CoFe2O4@SiO2-NH-βCDs-BF3 dried in an oven at 60 ̊C for 8 h.
2.4. General procedure for the modified-Ritter reaction catalyzed by
CoFe2O4@SiO2-PrNH-βCDs-BF3
A mixture of tert-butyl acetate (2.5 mmol), nitirle (1 mmol), and
CoFe2O4@SiO2-NH-βCDs-BF3 (0.08 g) was stirred in neat condition till
completion of the reaction (monitored by TLC). After reaction completion, CH2Cl2
was added to the reaction mixture and the organic layer was simply decanted by
means of an external magnet. Then, the reaction mixture was extracted with
CH2Cl2, dried over Na2SO4, concentrated under vacuum and the pure product was
obtained. This was further purified by recrystallization with suitable solvent
1
13
(EtOAc/hexane). Melting point, H NMR, C NMR and FT-IR spectra were
consistent with the assigned structures in literature [43, 62, 63].
7

3. Results and discussion
3.1. Characterization of CoFe2O4@SiO2-NH-βCDs-BF3
Immobilization of the strong Lewis acid, BF3, on the β-CDs functionalized
MNPs, combines the host-guest ability of the β-CDs and the acidity of BF3 to
produce an acidic nanoeactor. The β-CDs in the prepared catalyst are bonded
strongly by covalent bonds. The BF3 may interact with OH functionality of the β-
CDs. Herein the aim is to use the supramolecular structure of the β-CDs which
could be act as a nanoreactor and the super-acidic sites formed by the immobilized
BF3. Schematic representation of the catalyst preparation is shown in Scheme 2.
The FT-IR spectra of the prepared CoFe2O4@SiO2-NH-βCDs-BF3, CoFe2O4@SiO2
and CoFe2O4 are shown in Figure 1. The stretching vibrational of Fe-O appears at
588 cm-1 and the peaks at 800 and 1083 cm-1 are attributed to Si-O-Si.
8

OTs
TsO
O
H3C
S Cl
O
OH
HO
Ts-Cl
OH
OH
O
OH
O
HO
O
OH
HO
OH
O
HO
OH
OH
HO
OH
HO
OH
O
OH
O
OH
-CD
O
HO

OH
HO
OH
+
O
OH
OH
O
OH
OH
OH
OH
OH
O
O
HO
OH
O
HO
HO
1) TEOS, sol gel
2) APTES
NaOH, H2O
FeCl 6H O CoCl 6H O
+
3.
2
2.
2
1 h, 80°C
CoFe2O4
+
2
OBF3-EtOH2
OBF3-EtOH2
+
EtOH
-
APTES= (CH3CH2-O-)3Si-(CH2)3NH2
3
+
OBF

OBF3-EtOH2
+
OH
HO
BF3.OEt2
OH
OBF

OH
OH
-CD
3
-
OBF3-EtOH2
+
EtOH
OBF3-EtOH2
+
2
+
OBF3-EtOH2
+
Scheme 2. Schematic representation of the CoFe2O4@SiO2-NH-βCDs-BF3
synthesis
The peaks in the range between 2850 and 2930 cm-1 assigned to C-H stretching
vibrations of the β-CDs. As evidence from FT-IR spectrum, the bands appearance
at 1462 and 1637 cm-1 in which originated from the adsorption of B-O and B-F
respectively shows the successful covalent binding of BF3.Et2O on the catalyst.
9

Figure 1. FT IR spectra of a) CoFe2O4 b) CoFe2O4@SiO2 c) CoFe2O4@SiO2-NH-
βCDs d) CoFe2O4@SiO2-NH-βCDs-BF3
Figure 2 shows the X-ray diffraction patterns of the synthesized CoFe2O4 and
CoFe2O4@SiO2-NH-βCDs-BF3. The XRD data of CoFe2O4 magnetic nanoparticle
are corresponded to the standard data. Appearances the band of the pure CoFe2O4
in the CoFe2O4@SiO2-NH-βCDs-BF3 XRD indicate the retention of CoFe2O4
during coating and functionalization. The broad peak around 2θ of 20-30 assigned
to amorphous phase of SiO2. According to the XRD patterns of the
10

CoFe2O4@SiO2-NH-βCDs-BF3 there are no identical peaks for the organic coating
which probably indicate that there is no crystalline phase of this organic coating to
be detected.
Figure 2. XRD patterns of a) CoFe2O4 b) CoFe2O4@SiO2-NH-βCDs-BF3
The size and surface morphology of the CoFe2O4@SiO2-NH-βCDs-BF3
nanocomposite have been elucidated by field emission scanning electron
microscopy (FE-SEM). The FE-SEM images of CoFe2O4@SiO2-NH-βCDs-BF3
(Figure 3), indicate that the surface morphology is a quasi-spherical shape with
average size of 20-30 nm.
11

Figure 3. FE-SEM image of the CoFe2O4@SiO2-NH-βCDs-BF3
The hysteresis curves of magnetic measurements of CoFe2O4, and
CoFe2O4@SiO2-NH-βCDs-BF3 are shown in Figure 4. The decrease of
magnetization saturation (MS) in the synthesized magnetic nanocomposite is due to
the non-magnetic nature of the β-CDs attached on the magnetic particles (Figure.
5B). Although MS amount of the CoFe2O4@SiO2-NH-βCDs-BF3 has decreased, it
still could be easily separated from the reaction solution with an external magnet.
Figure 5 demonstrates the thermal stability of CoFe2O4@SiO2-NH-βCDs-BF3
measured by thermogravimetric analysis (TGA) under N2 with heating rate of 10
°C/min. CoFe2O4@SiO2-NH-βCDs-BF3 started to decompose at 481 °C resulting
12

in a weight loss of 5%. The weight loss between room temperature to 409 °C was
due to the absorbed water and dehydroxylation on the surface.
Figure 4. VSM curves of CoFe2O4, and CoFe2O4@SiO2-NH-βCDs-BF3
Figure 5. TGA curve of CoFe2O4@SiO2-NH-βCDs-BF3
13

3.2. Catalytic studies
The catalytic activity of the CoFe2O4@SiO2-NH-βCDs-BF3 was investigated
by the amidation reaction of benzonitrile (1 mmol) with tert-butyl acetate (Table
1). The model reaction without catalyst proceeded only 20% after 60 min (Table 1,
entry 1). To study the effect of the β-CDs, the reaction was performed in the
presence of 0.1 g of β-CDs (table 1, entry 2). The reaction was also carried out
using the BF3.EtO2 (Table 1, entry 3), which indicated the effect of the BF3 on the
modified-Ritter reaction. However, the recoverability of the BF3 is still a serious
problem. The result obtained from using the CoFe2O4@SiO2-NH-βCDs-BF3 as
catalyst, showed the enhanced catalytic efficiency of the synthesized catalyst
(Table 1, entry 4), which may be ascribed to the combination of the host-guest
ability of the β-CDs and the acidic sites from immobilized BF3 in addition to high
dispersion of the nanaoparticles. The effect of the reaction medium was also
screened by using different polar and nonpolar solvents in addition to solvent-free
condition, and the results were summarized in Table 1. The result indicated that
polar-protic solvents such as methanol and ethanol are the most suitable solvent for
further catalytic study (Table1, entries 7, 8). Acetonitrile and chloroform gave
comparable yields (Table 1, entries 10, 11). Furthermore water provided good
yield (Table 1, entry 9). The above results confirmed the host-guest ability of the
β-CDs in solution and solvent-free conditions. In view of green chemistry by
14

elimination of the solvent, the solvent-free condition was chosen for the optimum
condition. Using lower amount of catalyst (0.08 g) lead to lower yield (95%)
(Table 1, entry 4) whereas increasing the amount of catalyst to 0.1 g, the yields
maintained at 96% (Table 1, entry 6).
Table 1. Optimization of reaction conditions
Entry Solvent
Catalyst a
-
Yields (%)
1
2
3
4
5
6
7
8
9
-
-
-
-
-
-
20
40
85
75
95
96
92
94
88
88
85
β-CD (10 mg)
BF3.EtO2 (10 mg)
CoFe2O4@SiO2-NH-βCDs-BF3 (5 mg)
CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
CoFe2O4@SiO2-NH-βCDs-BF3 (9 mg)
MeOH CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
EtOH CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
H2O
CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
10 CH3CN CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
11 CH3Cl CoFe2O4@SiO2-NH-βCDs-BF3 (8 mg)
a Reaction condition: benzonitrile (1 mmol), t-BuOAc (2 mmol), r.t, 30 min.
15

Therefore using CoFe2O4@SiO2-NH-βCDs-BF3 (0.08 g) under solvent-free
condition was the optimum condition for the modified-Ritter reaction of nitriles
and tert-butyl acetate.
By optimum conditions in hand, and in order to determine the scope and
versatility of the present catalytic system, amidation reaction of various aromatic
and aliphatic nitriles, bearing wide range of functional groups with tert-butyl
acetate were carried out by using CoFe2O4@SiO2-NH-βCDs-BF3 as the catalyst
under solvent-free condition (Table 2). The results presented in Table 2 point out
that, excellent yields were obtained for electron-rich as well as electron-deficient
benzonitiles and all nitriles give readily the corresponding amides. As shown in
Table 2 Primary aliphatic nitriles such as cyclopropanecarbonitrile, acrylonitrile
and acetonitrile were easily reacted to provide the corresponding tert-butylamide in
excellent yields (Table 2, Entries 13-15).
The activity of CoFe2O4@SiO2-NH-βCDs-BF3 by considering the yield for the
model reaction is compared with various heterogeneous catalysts in Table S1. We
found the CoFe2O4@SiO2-NH-βCDs-BF3 catalyst in solvent free condition,
provides excellent catalytic activities, and performed the model reaction with
yields up to 95%, in shortest reaction time and highest reusability.
16

Table 2. Synthesis of t-butyl amide derivatives in the presence CoFe2O4@SiO2-
NH-βCDs-BF3
Entry Nitrile
Product
Time
(min)
Yield
(%)a
Mp (ᵒC)
Ref.
O
O
134-137
[64]
CN
N
H
1
2
30
50
60
60
95
90
82
85
Cl
Cl
178-181
[43]
N
H
CN
O
Cl
75-81
[30]
Cl
N
3
H
CN
O
113-116
[43]
N
H3C
CN
4
H
H3C
O
65-67
[30]
Cl
CN
N
5
50
50
50
93
95
90
H
Cl
O
131-134
[43]
Br
CN
N
H
6
Br
O
125-128
[64]
F
CN
N
7
H
F
17

O
110-113
[64]
H3CO
CN
N
H
8
9
40
70
90
45
H3CO
O
116-118
[43]
O
C
N
H
CN
O
C
H3C
CH3
CN
H
112-115
[43]
N
10
11
12
13
14
15
40
60
88
80
87
92
95
93
O
CN
H
N
84-87
[30]
S
S
O
H
N
Viscose
[65]
CN
120
40
N
O
N
O
136-139
[64]
CN
N
H
120-124
[43]
O
30
CN
N
H
78-81
[30]
O
CH3CN
30
N
H
a Isolated yields
18

3.3. Recyclability of the catalyst
The magnetic property of catalyst facilitates recovery of the catalyst from the
reaction mixture by an external magnet. So the recovery and reusability of the
CoFe2O4@SiO2-NH-βCDs-BF3 was studied in the model reaction. Once the
reaction was over, the catalyst isolated from the reaction by a simple magnetic
decantation, washed with ethanol and water, dried and reused four times with no
significant loss in activity (Figure. 6). FT-IR spectrum of the recovered catalyst
shows the main bands of the fresh catalyst (Figure S23).
Figure 6. Recyclability of the catalyst
19

Spectral data for the selected products
ᵒ
1
N-(tert-butyl)-2-phenylacetamide (10) solid M.p.: 112-115 C. H-NMR (400 MHz, DMSO-
d6):  ppm)    9H, s, 3CH3),   2H, s, CH2), 7.19-7.31 (5H, m, Ar-H), 7.69 (1H, s, NH). 13C
NMR (400 MHz, DMSO-d6):  ppm) = 28.97, 50.48, 50.56, 126.58, 128.57, 129.32, 137.43,170.03. IR
(KBr) cm-1: 3279, 1642, 1554, 700.
1
N-(tert-butyl)-2-(thiophen-2-yl) acetamide (11) M.p.: 84-87 ᵒC. H-NMR (400 MHz, DMSO-
d6):  ppm)    9H, s, 3CH3),   2H, s, CH2), 6.86-6.87 (1H, dd, Ar-H), 6.93-6.95 (1H, dd,
Ar-H), 7.33-7.34 (1H, dd, Ar-H), 7.73 (1H, s, NH). 13C NMR (400 MHz, DMSO-d6):  ppm) = 28.89,
37.77, 50.56, 125.06, 126.09, 126.90, 138.77, 168.94. IR (KBr) cm-1: 3302, 1652, 1554, 594.
4. Conclusions
In summary, we synthesized the CoFe2O4@SiO2-NH-βCD-BF3 as a
supramolecular catalyst in which the dual acidity of BF3 (Lewis and Bronsted)
resulted in a dramatic increase of acidity, thereby improving the catalytic
efficiency of the supramolecular cavities. After characterization of the catalyst, its
activity was investigated toward the modified Ritter reaction for synthesis of bulky
t-butyl amide derivatives at room temperature. The obtained products with high
yields and short reaction time in each reaction, strongly confirmed that the catalyst
could serve as an efficient heterogeneous catalyst. Also the catalyst could be
reused at least five cycles without losing its catalytic activity.
20

Acknowledgements
The authors thank Shahid Chamran University of Ahvaz for financial support
(Grant No. 96/3/02/16670).
References
[1] L. Chen, R.M. Berry, K.C. Tam, ACS Sustain. chem. eng., 2 (2014) 951-958.
[2] C. Sanchez, B. Julian, P. Belleville, M. Popall, J. Mater. Chem., 15 (2005) 3559-3592.
[3] M. Khoobi, L. Ma’mani, F. Rezazadeh, Z. Zareie, A. Foroumadi, A. Ramazani, A. Shafiee, J.
Mol. Catal. A: Chem., 359 (2012) 74-80.
[4] R. Hajian, A. Ehsanikhah, Chem. Phys. Lett., 691 (2018) 146-154.
[5] P. Ye, D. Wu, M. Wang, Y. Wei, A. Xu, X. Li, Appl. Surf. Sci., 428 (2018) 131-139.
[6] H. Hamadi, M. Norouzi, J.chem. sci., 130 (2018) 1-11.
[7] N.H. Nasab, J. Safari, Polyhedron, 164 (2019) 74-79.
[8] L. Wu, A. Mendoza-Garcia, Q. Li, S. Sun, Chem. Rev., 116 (2016) 10473-10512.
[9] E.M. Del Valle, Process Biochem., 39 (2004) 1033-1046.
[10] K.I. Assaf, D. Gabel, W. Zimmermann, W.M. Nau, Org. Biomol. Chem., 14 (2016) 7702-7706.
[11] S. Tan, K. Ladewig, Q. Fu, A. Blencowe, G.G. Qiao, Macromol. Rapid Commun., 35 (2014)
1166-1184.
[12] C. Deraedt, D. Astruc, Coord. Chem. Rev., 324 (2016) 106-122.
[13] R. Liu, J. Liu, X. Yan, C. Yuan, Polyhedron, 157 (2019) 1-5.
[14] K. Yang, Y. Yan, W. Chen, H. Kang, Y. Han, W. Zhang, Y. Fan, Z. Li, Polyhedron, 152 (2018)
202-215.
[15] C. Putta, V. Sharavath, S. Sarkar, S. Ghosh, RSC Adv., 5 (2015) 6652-6660.
[16] E.A. Kataev, M.R. Reddy, G.N. Reddy, V.H. Reddy, C.S. Reddy, B.V.S. Reddy, New J. Chem.,
40 (2016) 1693-1697.
[17] K. Luo, L. Zhang, R. Yang, Y. Jin, J. Lin, Carbohydr. Polym., 200 (2018) 200-210.
[18] Y. Ren, B. Yang, X. Liao, Catal. Sci. Technol., 6 (2016) 4283-4293.
[19] Y. Kang, L. Zhou, X. Li, J. Yuan, J. Mater. Chem., 21 (2011) 3704-3710.
[20] M. Yadollahi, H. Hamadi, V. Nobakht, Appl. Organomet. Chem., (2018) e4629.
[21] B. Salahshournia, H. Hamadi, V. Nobakht, Appl. Organomet. Chem., (2018) e4416.
[22] M. Yadollahi, H. Hamadi, V. Nobakht, Appl. Organomet. Chem., (2019) e4819.
[23] M. Homaee, H. Hamadi, V. Nobakht, M. Javaherian, B. Salahshournia, Polyhedron, 165 (2019)
152-161.
[24] H. Hamadi, S. Javadi, J.chem. sci., 129 (2017) 75-80.
[25] T. Cupido, J. Tulla-Puche, J. Spengler, F. Albericio, Curr. Opin. Drug Discovery Dev., 10
(2007) 768-783.
[26] A. Greenberg, C.M. Breneman, J.F. Liebman, John Wiley & Sons, 2000.
[27] J.M. Humphrey, A.R. Chamberlin, Chem. Rev., 97 (1997) 2243-2266.
[28] Y. Mikhail, B. Lebedev, Tetrahedron Lett., 43 (2002) 1397.
21

[29] V. Justribó, M.a.I. Colombo, Tetrahedron Lett., 44 (2003) 8023-8024.
[30] E. Callens, A.J. Burton, A.G. Barrett, Tetrahedron Lett., 47 (2006) 8699-8701.
[31] N. Hazarika, G. Baishya, Eur. J. Org. Chem., 2014 (2014) 5686-5690.
[32] T. Okuhara, X. Chen, Microporous Mesoporous Mater., 48 (2001) 293-299.
[33] X.-N. Zhao, H.-C. Hu, F.-J. Zhang, Z.-H. Zhang, Appl. Catal. A: Gen., 482 (2014) 258-265.
[34] R. Sanz, A. Martinez, V. Guilarte, J.M. Alvarez‐Gutierrez, F. Rodríguez, Eur. J. Org. Chem.,
2007 (2007) 4642-4645.
[35] T. Yamato, J.-y. Hu, N. Shinoda, J. Chem. Res., 2007 (2007) 641-643.
[36] V. Polshettiwar, R.S. Varma, Tetrahedron Lett., 49 (2008) 2661-2664.
[37] B.S. Reddy, N.S. Reddy, C. Madan, J. Yadav, Tetrahedron Lett., 51 (2010) 4827-4829.
[38] L.U. Nordstrøm, H. Vogt, R. Madsen, J. Am. Chem. Soc., 130 (2008) 17672-17673.
[39] S. Yaragorla, G. Singh, P.L. Saini, M.K. Reddy, Tetrahedron Lett., 55 (2014) 4657-4660.
[40] P. Theerthagiri, A. Lalitha, P.N. Arunachalam, Tetrahedron Lett., 51 (2010) 2813-2819.
[41] T. Abe, H. Takeda, Y. Miwa, K. Yamada, R. Yanada, M. Ishikura, Helv. Chim. Acta, 93 (2010)
233-241.
[42] C. Cazorla, E. Métay, B. Andrioletti, M. Lemaire, Tetrahedron Lett., 50 (2009) 6855-6857.
[43] J.C. Baum, J.E. Milne, J.A. Murry, O.R. Thiel, J. Org. Chem., 74 (2009) 2207-2209.
[44] M.-Y. Chang, Y.-H. Kung, T.-C. Wu, Tetrahedron, 63 (2007) 3098-3101.
[45] M.A. Iglesias-Arteaga, A.A. Alvarado-Nuño, Tetrahedron Lett., 47 (2006) 5351-5353.
[46] A. Kamal, N. Shankaraiah, K.L. Reddy, V. Devaiah, Tetrahedron Lett., 47 (2006) 4253-4257.
[47] M. Hojo, N. Ushioda, A. Hosomi, Tetrahedron Lett., 45 (2004) 4499-4501.
[48] V.K. Tandon, M. Kumar, Tetrahedron Lett., 45 (2004) 4185-4187.
[49] H.S. Kumar, B.S. Reddy, S. Anjaneyulu, J. Yadav, Tetrahedron Lett., 39 (1998) 7385-7388.
[50] S.D. Debenham, E.J. Toone, Tetrahedron: Asymmetry, 11 (2000) 385-387.
[51] Y. Qian, H. Zhang, X. Qian, J. Huang, C. Shen, J. Mol. Catal. A: Chem., 192 (2003) 25-33.
[52] H. Saneyoshi, I. Okamoto, Y. Masaki, A. Ohkubo, K. Seio, M. Sekine, Tetrahedron Lett., 48
(2007) 8554-8557.
[53] M. Shekouhy, A. Moaddeli, A. Khalafi-Nezhad, Res. Chem. Intermed., 42 (2016) 3805-3827.
[54] A. Bamoniri, N. Moshtael-Arani, Bull. Chem. Soc. Jpn., 88 (2015) 662-672.
[55] A. Bamoniri, N. Moshtael-Arani, RSC Adv., 5 (2015) 16911-16920.
[56] M. Abdollahi-Alibeik, A. Moaddeli, K. Masoomi, RSC Adv., 5 (2015) 74932-74939.
[57] T.M. Klapötke, F. McMonagle, R.R. Spence, J.M. Winfield, J. Fluor. Chem., 127 (2006) 1446-
1453.
[58] B. Sadeghi, B.B.F. Mirjalili, M.M. Hashemi, Tetrahedron Lett., 49 (2008) 2575-2577.
[59] H. Hamadi, M. Kooti, M. Afshari, Z. Ghiasifar, N. Adibpour, J. Mol. Catal. A: Chem., 373
(2013) 25-29.
[60] R.I. Khan, K. Pitchumani, Green Chem., 18 (2016) 5518-5528.
[61] A. Ghorbani-Choghamarani, M. Norouzi, New J. Chem., 40 (2016) 6299-6307.
[62] E. Karimian, B. Akhlaghinia, S.S. Ghodsinia, J.chem. sci., 128 (2016) 429-439.
[63] K.L. Reddy, Tetrahedron Lett., 44 (2003) 1453-1455.
[64] M.-S. Shakeri, H. Tajik, K. Niknam, J.chem. sci., 124 (2012) 1025-1032.
[65] C. Avendano, J.D. Sanchez, J.C. Menendez, Synlett, 2005 (2005) 107-110.
Dear Editor
22

Enclosed you will find a manuscript entitled “Synthesis and Characterization of
Nanoscale UiO-66-NHSO3H via Post-synthetic Modification as
a
Heterogeneous Brønsted acid Catalyst” submitted for publication in"
Polyhedron". The manuscript reports an original research work which has not been
published or submitted elsewhere.
We confirm that the submission is original, not under consideration for publication
elsewhere, and all the authors are aware of the submission and agree to its
publication and if accepted, it will not be published elsewhere in the same form, in
English or in any other language, including electronically without the written
consent of the copyright-holder.
Sincerely yours
Hosein Hamadi
Zohreh Zanjani
Mahtab Yadollahi
Graphical Abstract
23

O
O
R CN
+
N
R
O
H
O
O
HO
O
HO
OH
OH
O
HO
O
OH
HO
OH
O
r.t
O
OH
O
HO
-
+
OBF3 EtOH2
OH
-
+
O
OBF3 EtOH2
OH
OH
OH
O
O
O
HO
Highlights
- BF3-functionlized β-cylcodextrine grafted magnetic CoFe2O4 nanaoparticles
has been synthesized as a hybrid magnetic nano-composite
- Supramolecular structure of the CoFe2O4@SiO2-NH-βCD-BF3 as a nanoreactor
- CoFe2O4@SiO2-NH-βCD-BF3 as a dual Brønsted and Lewis acid
heterogeneous catalyst for modified Ritter reaction at room temperature.
24

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