Ni2+ supported on hydroxyapatite-core-shell γ-Fe 2O3 nanoparticles: A novel, highly efficient and reusable lewis acid catalyst for the regioselective azidolysis of epoxides in water

Article abstract of DOI:10.1007/s13738-013-0304-7

In this research, Ni²⁺ supported on hydroxyapatite-core-shell magnetic γ-Fe₂O₃ nanoparticles (γ-Fe ₂O₃@HAp-Ni²⁺) as a novel, efficient, reusable and heterogeneous catalyst was reported. In

Full text of DOI:10.1007/s13738-013-0304-7

J IRAN CHEM SOC
DOI 10.1007/s13738-013-0304-7
ORIGINAL PAPER
Ni2+ supported on hydroxyapatite-core-shell c-Fe2O3
nanoparticles: a novel, highly efficient and reusable lewis acid
catalyst for the regioselective azidolysis of epoxides in water
•
Sami Sajjadifar Zahra Abbasi Eshagh Rezaee Nezhad
•
•
•
Mojtaba Rahimi Moghaddam Saaid Karimian
•
Sara Miri
Received: 4 February 2013 / Accepted: 20 June 2013
Ó Iranian Chemical Society 2013
Abstract In this research, Ni2? supported on hydro-
xyapatite-core-shell magnetic c-Fe2O3 nanoparticles
(c-Fe2O3@HAp-Ni2?) as a novel, efficient, reusable and
heterogeneous catalyst was reported. In this protocol, we
used this catalyst for the ring opening of epoxide with
sodium azide in water. The catalyst can be readily isolated
using an external magnet and no obvious loss of activity
was observed when the catalyst was reused in seven con-
secutive runs. The mean size and the surface morphology
of the nanoparticles were characterized by transmission
electron microscopy, scanning electron microscope,
vibrating sample magnetometry, X-ray powder diffraction
and Fourier transform infrared techniques.
Besides, the utilization of magnetic nanoparticles as
heterogeneous and easily recycled catalysts has gained a
significant attention. Moreover, they can be used in various
organic reactions such as knoevenagel reaction [8, 9],
nucleophilic substitution reactions of benzyl halides [10],
epoxidation of alkenes [11], synthesis of a-amino nitriles
[12], hydrogenation of alkynes [13], esterifications [14],
CO2 cycloaddition reactions [15], Suzuki coupling reac-
tions [16] and three-component condensations [17].
2-Azidoalcohols would also be regarded as useful
compounds in organic synthesis as either precursors of
2-amino alcohols or in the chemistry of carbohydrates,
nucleosides, lactames, and oxazolines [18]. These com-
pounds are versatile intermediates in organic synthesis and
increasingly important in drugs and pharmaceutics [19,
20]. The ring opening of epoxides, which have been
innovation ways to obtain the direct azidolysis of epoxides
in the presence of sodium azide, are frequently performed
under several different conditions [21–25]. But some of
these methods are limited to specific epoxides and are not
applicable as versatile reagents in the preparation of azi-
dohydrines; it is worth mentioning that these methods
suffer from disadvantages such as long reaction times, low
regioselectivity, using of expensive catalysts and difficulty
in preparation of catalysts, difficulty in work-up and iso-
lation of products. Therefore, it seems that there is still a
need for development of novel methods that proceed under
green and ecofriendly conditions.
Keywords c-Fe2O3 ꢀ Ni2? supported ꢀ Lewis acid ꢀ
Epoxide ꢀ Regioselective ꢀ Azidohydrins
Introduction
Recently, the application of nanoparticles (NPs) as attrac-
tive and interesting materials has been more and more
increased, because of their high surface area and unique
magnetic properties. Moreover, they have a wide range of
usage in various fields; such as magnetic fluids [1], biology
and medical applications [2], magnetic resonance imaging
[3], data storage [4], environmental remediation [5], and
their application as catalysts in organic transformations
[6, 7].
In this work, c-Fe2O3@HAp-Ni2? was synthesized and
used as catalyst for the ring opening of epoxide with
sodium azide in water. We thought that there is scope for
further innovation towards milder reaction conditions,
shorter reaction time, and high yields, which can be
achieved using c-Fe2O3@HAp-Ni2?, as reaction media as
well as a promoter in the absence of any toxic solvents.
S. Sajjadifar ꢀ Z. Abbasi ꢀ E. Rezaee Nezhad (&) ꢀ
M. R. Moghaddam ꢀ S. Karimian ꢀ S. Miri
Department of Chemistry, Payame Noor University,
PO BOX 19395-4697, Tehran, Iran
e-mail: e.rezaee66@yahoo.com
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J IRAN CHEM SOC
Experimental section
6.4 mmol of NiCl2ꢀ6H2O. The mixture was stirred
(500 rpm) for 48 h, filtered, and washed several times with
ethanol. The recovered solid was dried at 50 °C overnight
(Scheme 1). The mean size and the surface morphology of
the Ni2? supported on hydroxyapatite-core-shell c-
Fe2O3ꢀNPs were characterized by TEM, SEM, VSM, XRD
and FTIR techniques.
General
Products were characterized by comparison of their spec-
troscopic data (1H NMR, 13C NMR and IR) and physical
properties with those reported in the literature. NMR
spectra were recorded in DMSO-d6 on a Bruker advanced
DPX 500 and 400 MHz instrument spectrometers using
TMS as internal standard. IR spectra were recorded on a
Frontier Fourier transform infrared (FTIR) (Perkin Elmer)
spectrometer using a KBr disk. All yields refer to isolated
products. The characterization Ni2? supported on hydro-
xyapatite-core-shell c-Fe2O3 NPs, and its structural and
morphological analysis was carried out by transmission
electron microscopy (TEM), scanning electron microscope
(SEM), vibrating sample magnetometry (VSM), X-ray
diffractometer (XRD) and FTIR techniques. The phases
present in the magnetic materials were analyzed using a
powder XRD, Philips (Holland), model X0 Pert with
Reactions of epoxides with NaN3 catalyzed
by c-Fe2O3@HAp-Ni2?
c-Fe2O3@HAp-Ni2? (20 mg) was added to a mixture of
the epoxide (1.0 mmol) and NaN3 (3 mmol) in water
(5 mL). The reaction mixture was magnetically stirred at
80 °C for the appropriate time. Progress of reaction was
monitored by TLC using ethylacetate:n-hexane (1:4). After
reaction completion, the mixture was extracted with ethyl
ether (5 mL 9 3), washed with brine, dried with CaCl2 and
evaporated under reduced pressure. The desired azi-
dohydrines were obtained in good to excellent isolated
yields (84–93 %).
˚
CuKa1 radiation (k = 1.5406 A), and the X-ray generator
was operated at 40 kV and 30 mA. Diffraction patterns
The catalyst can be separated from the reaction mixture
using an external magnetic field; it was recovered with a
simple magnet after the dilution of the reaction mixture
with water.
were collected from 2h = 20°–80°.
Preparation of c-Fe2O3@HAp-Ni2?
The spectral data (1H NMR, 13C NMR and IR) of some
In this study, c-Fe2O3@HAp-Ni2? was prepared in two
steps. The iron oxide magnetic particles (IOMP) were
synthesized by chemical coprecipitation technique of
ferric and ferrous chlorides in aqueous solution. Solu-
tions of FeCl3ꢀ6H2O (0.25 mol L-1) and FeCl2ꢀ4H2O
(0.125 mol L-1) were mixed and precipitated with NH4OH
solution (25 %) at pH 12, while stirring vigorously. The
black suspension, which formed immediately, was main-
representative compounds are given below:
Spectral data for 1-Azido-3-phenoxy-2-propanol (Entry
1). IR mmax/cm-1: 2103(N3) 1H NMR (CDCl3, 400 MHz):
3.45–3.54 (m, 2H), 3.89 (m, 1H), 3.97–4.03 (m, 2H), 4.18
(s, 1H), 6.95–7.00 (m, 2H), 7.02–7.06 (m, 1H), 7.27–7.36
(m, 2H) 13C NMR (CDCl3, 100 MHz): 53.51, 69.21, 69.30,
114.35, 121.16, 129.42, 158.36.
Spectral data for 2-Azido-2-phenyl-1-ethanol (Entry 2).
IR mmax/cm-1: 2102(N3) 1H NMR (CDCl3, 400 MHz):
3.37 (s, 1H), 3.74 (m, 2H), 4.65–4.69 (m, 1H), 7.34–7.44
(m, 5H) 13C NMR (CDCl3, 100 MHz): 66.37, 68.03,
127.49, 128.46, 128.61, 136.47.
°
tained at 70 C for approximately 1 h and washed several
times with ultra-pure water until the pH decreased to 7.
IOMP/HAP was prepared by the impregnation method
according to known procedures with some modifications
[26]. Then hydroxyapatite-core-shell c-Fe2O3 NPs (0.6 g)
was introduced into 100 ml of distilled water containing
Spectral data for 1-Azido-3-butoxy-2-propanol (Entry
3). IR mmax/cm-1: 2102(N3) 1H NMR (CDCl3, 400 MHz):
FeCl2 4H2O
NH4OH (25%)
25 oC, O2
300 oC, 3h
Ca(NO3)2 4H2O
NiCl2 6H2O
48 h, 25 o
+
(NH4)2HPO4
90oC, 2 h
FeCl3 6H2O
C
γ-Fe2O3
γ-Fe2O3@HAP-Ni2+
γ-Fe2O3@HAP
Ni2+
γ-Fe2O3
HAP
Scheme 1 Synthesis of Ni2? supported on hydroxyapatite-core-shell c-Fe2O3
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J IRAN CHEM SOC
0.87 (t, 3H), 1.31–1.35 (m, 2H), 1.50–1.53 (m, 2H), 3.14 (s,
1H), 3.30–3.32 (m, 2H), 3.39–3.44 (m, 4H), 3.87 (m, 1H)
13C NMR (CDCl3, 100 MHz): 13.78, 19.16, 30.74, 53.52,
69.74, 70.59, 70.71.
Result and discussion
Synthesis of c-Fe2O3@HAp-Ni2? and its structural
and morphological analysis
Fourier transform infrared spectra were recorded on a FTIR
spectrometer (Perkin Elmer) with a spectral resolution of
4 cm-1 in the wave number range of 450–4,000 cm-1. The
samples and KBr were fully dried before the FTIR analysis
to exclude the influence of water.
The magnetic properties were assessed with a VSM
(RIKEN DENSHI Co. Ltd., Japan). The magnetic proper-
ties of the particles were evaluated in terms of saturation
magnetization and coactivity.
Fig. 2 FTIR spectra of a c-Fe2O3@HAp, b c-Fe2O3@HAp-Ni2?
Scanning electronic microscopy, the morphology of the
surface of Ni2? supported on hydroxyapatite-core-shell c-
Fe2O3 NPs was investigated using a scanning electronic
microscope of XL30 type (Netherland).
The synthesis of Ni2? supported on hydroxyapatite-
core-shell c-Fe2O3 NPs was depicted in Scheme 1. Fig-
ure 1 shows the XRD for Ni2? supported on hydro-
xyapatite-core-shell c-Fe2O3 NPs. The characterization of
Ni2? supported on hydroxyapatite-core-shell c-Fe2O3 NPs
was further carried out by FTIR (Fig. 2). The band at
3,417 cm-1 was assigned to the stretching and bending
modes of the OH groups in the hydroxyapatite structure.
The bands at 1,042 cm-1 were attributed to the asymmetric
and symmetric stretching vibration of the phosphate group
(PO-4 3), and the bending modes of Fe–O were observed at
604,558 cm-1. In addition, the band at 875 cm-1 indicated
that HPO-4 2 may also be present in the hydroxyapatite as an
impurity.
Fig. 3 Magnetization curves of c-Fe2O3@HAp-Ni2?
Figure 3 shows the magnetization curves for Ni2? sup-
ported on hydroxyapatite-core-shell c-Fe2O3 NPs. The
magnetization curve gives a saturation magnetization value
of 11.13 emu/g.
Scanning electronic microscopy image of Ni2? sup-
ported on hydroxyapatite-core-shell c-Fe2O3 NPs is given
in Fig. 4.
Transmission electron micrographs provide more accu-
rate information on the particle size, morphology and
loading of Ni2? supported on hydroxyapatite-core-shell c-
Fe2O3 NPs. These nanoparticles which consist of relatively
small, nearly spherical particles, with an average size of
50 nm, are much smaller than the sizes obtained from the
XRD measurements (Fig. 5).
Energy dispersive X-ray spectroscopy (EDX) was used
for the morphological and microchemical analysis. The
microchemical analysis was performed at 5 keV to
Fig. 1 XRD pattern of c-Fe2O3@HAp-Ni2?
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J IRAN CHEM SOC
EDX analysis of a typical sample, c-Fe2O3@HAp-Ni2?
are given in Table 1.
,
We used atomic absorbtion spectroscopy for determi-
nation of Ni2? loaded on catalyst; 240 mg of Ni2? catalyst
was found there.
Application of c-Fe2O3@HAp-Ni2? as magnetic
catalyst for the regioselective azidolysis of epoxides
in water
To evaluate the catalytic activity of c-Fe2O3@HAp-Ni2?
catalyst in azidolysis of epoxides, the reaction of 2,3-ep-
oxypropyl phenyl ether with sodium azide in water was
examined to determine whether the use of c-Fe2O3@HAp-
Ni2? was efficient and to investigate the optimized con-
ditions (Table 2).
Fig. 4 SEM images of Ni?2/HAp-c-Fe2O3 NPs
After optimizing the conditions, we examined the gen-
erality of these conditions to other substrates using several
epoxides. Table 2 shows the results which clarifies that the
reaction proceeds very efficiently in all cases. Different
epoxides underwent ring opening easily in the presence of
c-Fe2O3@HAp-Ni2? at 80 °C condition in water (Table 3).
The products were formed in excellent yields. The con-
version was complete in 20–40 min.
In view of the emerging importance of c-Fe2O3@HAp-
Ni2? as novel reaction media, we wish to report the use of
c-Fe2O3@HAp-Ni2? as efficient promoters for the ring
opening of various epoxides. In this reaction, azidohydrines
Table 1 EDX analysis of c-Fe2O3@HAp-Ni2?
Atomic weight% (5 keV)
Atomic weight% (20 keV)
O
21.04
23.83
55.12
–
30.98
14.32
26.13
23.74
4.82
Fig. 5 TEM images of c-Fe2O3@HAp-Ni2?
P
Ca
Fe
Ni
determine the chemical composition in the interior and at
the surface of the particles. Particle size distributions for
coated and uncoated IOMP were determined using a laser
diffraction particle size analyzer (Cilas, 1064L).
–
Table 2 Optimization of experimental conditions for ring opening
of epoxides
Energy dispersive X-ray spectroscopy analyses were
done to determine the chemical composition of the surface
of the sample to support our observations on coating. EDX
measurements were carried out on the same point with
electrons having accelerating voltages of 20 and 5 keV,
respectively. As 20 keV electrons have higher energy, they
penetrate the sample deeper. On the other hand, with 5 keV
electron there is a smaller penetration. Therefore, with
20 keV accelerating voltage it is likely to give the chemical
composition of essentially the core of the particle. On the
contrary with EDX studies with 5 keV, it may give the
chemical composition essentially of the surface. Results of
Entry Catalyst (mg) Temperature (°C) Time (min) Yield (%)
1
2
3
4
5
6
7
8
–
80
r.t.
60
80
80
80
80
100
90
90
90
90
60
20
20
20
Trace
Trace
38
10
10
10
15
20
25
20
52
67
90
86
90
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J IRAN CHEM SOC
Table 3 Ring opening of various epoxides in the presence of c-Fe2O3@HAp-Ni2? in water
OH
O
N3
γ-Fe2O3@HAP-Ni2+
+
NaN3
N3
OH
+
80 oC/ Water
R
R
R
Entry
1
Substrate
Product(s)
Time (min)
20
Yield %
90
O
OH
O
O
N3
Ph
Ph
OH
2
25
88 (11:89)
O
N3
N3
Ph
+
OH
Ph
Ph
OH
3
4
25
30
89
90
O
O
O
O
O
N3
N3
OH
O
O
O
5
6
7
30
25
35
85
93
92
O
OH
OH
Cl
Cl
N3
O
H3C
H3C
N3
N3
O
OH
8
35
87
N3
O
OH
OH
9
30
40
90
84
O
O
O
N3
10
O
OH
N3
as products were obtained in good yields, short reaction
times and avoid use of organic solvents (handling, cost,
safety, pollution). Water is a desirable solvent for chemical
reactions for reasons of cost, safety and environmental
concerns; use of water in this reaction gave only greater
regioselectivity ring opening of epoxide.
As it can be seen in Table 3, c-Fe2O3@HAp-Ni2? as a
catalyst was afforded good results in comparison to the
other catalysts. In order to evaluate the efficiency of our
introduced method, more recently developed methods were
compared with our present method on the basis of the
yields and reaction times parameters. The results are given
in Table 4.
Catalyst reusability is of major importance in hetero-
geneous catalysis. The recovery and reusability of the
catalyst was studied using 2,3-epoxypropyl phenyl ether
with sodium azide as model reaction. Since the catalyst can
be separated from the reaction mixture using an external
magnetic field, it was recovered with a simple magnet after
the dilution of the reaction mixture with water. The catalyst
was consecutively reused seven times without any notice-
able loss of its catalytic activity (Table 5).
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J IRAN CHEM SOC
2. A.K. Gupta, M. Gupta, Biomaterials 26, 3995–4021 (2005)
3. S.I. Park, J.H. Kim, J.H. Lim, C.O. Kim, Curr. Appl. Phys. 8,
706–709 (2008)
Table 4 Comparison of catalytic ability of catalysts
Entry Catalyst/solvent/
temperature
Reaction
time (h)
Yield
%
References
4. T. Hyeon, Chem. Commun. 927–934 (2003)
5. A. Lu, W. Schmidt, N. Matoussevitch, H. Bonnemann, B. Spli-
¨
1
2
3
Network polymer/water/ 1.5
80 °C
89
89
[21]
[23]
[25]
ethoff, B. Tesche, E. Bill, W. Kiefer, F. Schu¨th, Angew. Chem.
116, 4403–4406 (2004)
6. S.C. Tsang, V. Caps, I. Paraskevas, D. Chadwick, D. Thompsett,
Angew. Chem. 116, 5763–5766 (2004)
7. V. Polshettiwar, R.S. Varma, Green Chem. 12, 743–754 (2010)
SiO2-OPEG(300)/water/
reflux
2
[bmim]PF6([bmim]BF4)/ 3 (5)
water/65 °C
95
(89)
˘
¨
8. E. Karaoglu, A. Baykal, M. Senel, H. Sozeri, M.S. Toprak, Mater.
Res. Bull. 47, 2480–2486 (2012)
4
5
6
7
b-Cyclodextrin/water/r.t.
5
5
45
96
94
90
[27]
9. Y. Zhang, C. Xia, Appl. Catal. A: General 366, 141–147 (2009)
10. A.R. Kiasat, S. Nazari, J. Mol. Catal. A: Chem. 365, 80–86
(2012)
11. M. Kooti, M. Afshari, Mater. Res. Bull. 47, 3473–3478 (2012)
12. M.Z. Kassaee, H. Masrouri, F. Movahedi, Appl. Catal. A: Gen-
eral 395, 28–33 (2011)
AMP/Acetonitrile/r.t.
[28]
Polymeric PTC/water/r.t. 12
c-Fe2O3@HAp-Ni2?
water/80 °C
[29]
/
20 min
This work
13. R. Abu-Reziq, D. Wang, M. Post, H. Alper, Adv. Synth. Catal.
349, 2145–2150 (2007)
AMP ammonium-12-molybdophosphate, polymeric PTC poly[N-(2-
aminoethyl)acrylamido]-trimethyl ammonium iodide
14. Y.Y. Jiang, C. Guo, H.S. Xia, I. Mahmood, C.Z. Liu, H.Z. Liu, J.
Mol. Catal. B Enzym. 58, 103–109 (2009)
15. X.X. Zheng, S.Z. Luo, L. Zhang, J.P. Cheng, Green Chem. 11,
455–458 (2009)
16. A. Taber, J.B. Kirn, J.Y. Jung, W.S. Ahn, M.J. Jin, Synlett 15,
2477–2482 (2009)
Table 5 The catalytic activity of c-Fe2O3@HAp-Ni2? in seven
cycles
17. Q. Zhang, H. Su, J. Luo, Y.Y. Wei, Green Chem. 14, 201–208
(2012)
Run
1
2
3
4
5
6
7
18. S.W. Chen, S.S. Thakur, W. Li, C.K. Shin, R.B. Kawthekar, G.J.
Kim, J. Mol. Catal. 259, 116–120 (2006)
Yield (%)
90
90
88
86
87
85
85
19. J.S. Yadav, B.V.S. Reddy, A.K. Basak, A.V. Narsaiah, Tetrahe-
dron Lett. 44, 1047–1050 (2003)
20. B.T. Smith, V. Gracias, J. Aube, J. Org. Chem. 65, 3771–3774
(2000)
Conclusion
In this research, Ni2? supported on hydroxyapatite-core-
shell magnetic c-Fe2O3 nanoparticles was readily synthe-
sized and functionalized with Ni2?. We described a simple
and highly efficient protocol for the regioselective azidol-
ysis of epoxides. The advantages of the present procedure
are its simplicity of operation, very short reaction times in
comparison to the other procedures, and the high yields of
products. In this way, the catalyst can be easily recovered
by simple magnetic decantation and reused several times
with no loss of activity.
21. A. Mouradzadegun, A.R. Kiasat, P. Kazemian Fard, Catal.
Commun. 29, 1–5 (2012)
22. F. Heidarizadeh, A. Zarei, J. Chem. Soc. Pak. 34, 593–598 (2012)
23. A.R. Kiasat, M. Zayadi, Catal. Commun. 9, 2063–2067 (2008)
24. F. Kazemi, A.R. Kiasat, S. Ebrahimi, Synth. Commun. 33,
999–1004 (2003)
25. J.S. Yadav, B.V. Reddy, B. Jyothirmai, M.S.R. Murty, Tetrahe-
dron Lett. 46, 6559–6562 (2005)
26. K. Donadel, D.V. Marcosand, C.M. Mauro, An. Acad. Bras.
ˆ
Ciens. 81, 179–186 (2009)
27. A. Kamal, M. Arifuddin, M.V. Rao, Tetrahedron Asymmetry 10,
4261–4264 (1999)
28. B. Das, V.S. Reddy, M. Krishnaiah, Y.K. Rao, J. Mol. Catal. A:
Chem. 270 89–92 (2007)
29. B. Tamami, H. Mahdavi, Tetrahedron Lett. 42, 8721–8724 (2001)
Acknowledgments The authors gratefully acknowledge partial
support of this work by Ilam Payame Noor University, Islamic
Republic of Iran.
References
1. S. Chikazumi, S. Taketomi, M. Ukita, M. Mizukami, H. Miyaj-
ima, M. Setogawa, Y. Kurihara, J. Magn. Magn. Mater. 65,
245–251 (1987)
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