Journal of Chemistry

Journal of Chemistry / 2020 / Article

Research Article | Open Access

Volume 2020 |Article ID 7960648 | https://doi.org/10.1155/2020/7960648

Mouhsine Laayati, Ali Hasnaoui, Nayad Abdallah, Saadia Oubaassine, Lahcen Fkhar, Omar Mounkachi, Soufiane El Houssame, Mustapha Ait Ali, Larbi El Firdoussi, "M-Type SrFe12O19 Ferrite: An Efficient Catalyst for the Synthesis of Amino Alcohols under Solvent-Free Conditions", Journal of Chemistry, vol. 2020, Article ID 7960648, 10 pages, 2020. https://doi.org/10.1155/2020/7960648

M-Type SrFe12O19 Ferrite: An Efficient Catalyst for the Synthesis of Amino Alcohols under Solvent-Free Conditions

Academic Editor: Andrea Penoni
Received01 Apr 2020
Revised28 May 2020
Accepted17 Jun 2020
Published11 Jul 2020

Abstract

Magnetically separable strontium hexaferrite SrFe12O19 was prepared using the chemical coprecipitation method, and the nanostructured material was characterized by X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and BET analysis. The SEM images showed the homogeneity of the chemical composition of SrFe12O19 and uniform distribution of size and morphology. The pore size of the nanomaterial and its specific area were determined by BET measurements. Strontium hexaferrite SrFe12O19 exhibited a strong magnetic field, which is highly suitable in the heterogeneous catalysis as it can be efficiently separated from the reaction. The magnetic nanocatalyst showed high activity and environmentally benign heterogeneous catalysts for the epoxide ring-opening with amines affording β-amino alcohols under solvent-free conditions. When unsymmetrical epoxides were treated in the presence of aromatics amines, the regioselectivity was influenced by the electronic and steric factors. Total regioselectivity was observed for the reactions performed with aliphatic amines. The magnetically SrFe12O19 nanocatalyst showed excellent recyclability with continuously good catalytic activities after four cycles.

1. Introduction

β-Amino alcohols are molecules with an interesting role as intermediates in the synthesis of a wide range of biologically active natural and synthetic products [14]. The presence of these functional groups with a defined stereochemistry is of great importance in the biological activity of these molecules. They are also widely used as potential chiral auxiliaries and chiral ligands in asymmetric synthesis [5]. The nucleophilic ring-opening of epoxides with amines represents one of the most important and straightforward methods for the preparation of the β-amino alcohols [6]. While the classical methods require a high temperature [7], various methodologies developed the epoxide ring-opening using homogenous catalysts but suffer from several disadvantages such as low regioselectivity, toxic solvents, toxic metal ions, and nonreusable catalysts [814].

On the other hand, only a few reports are focused on the use of heterogeneous catalysts such as silica nanoparticles [15], Fe-MCM-41 [16], zeolites [17], heteropoly acid, and MCM-22 [18, 19].

Recently, green chemistry has gained considerable importance in chemical design processes that utilize environmental-friendly processes to reduce or eliminate the generation of toxic by-products [20]. In addition, heterogeneous catalysts offer interesting advantages compatible with the green chemistry approach in catalytic reactions, such as high activity, atom economy, good regioselectivity, and especially the reusability of the catalyst. Furthermore, solvent-free conditions have a supplementary advantage in avoiding toxic solvents.

In recent years, magnetic nanoparticles have emerged as efficient heterogeneous catalysts in organic synthesis that offer a major advantage with its easy magnetic separation [2125]. In particular, magnetic nano-Fe3O4 and sulfonic acid-functionalized silica-coated magnetic Fe3O4 were used as efficient heterogeneous catalysts for the aminolysis of epoxides by amines [26, 27]. The same reaction was performed under solvent-free conditions using various spinel nanoferrites MFe2O4 (M = Co, Ni, Cu, Zn) [28].

Hexagonal strontium hexaferrite (SrFe12O19), known as M-type strontium hexaferrite (SrM), was discovered in the 1950s by Philips’ laboratories [29]. Strontium hexaferrite is usually used as magnetic recordings, permanent magnets, and microwave devices [3032]. In organic synthesis, it was applied as a catalyst in the synthesis of 2-amino-4,6-diphenylnicotinonitrile derivatives [33]. The magnetic properties of SrFe12O19 depend on the shape and size of the particles. Several methods have been used to prepare this nanomaterial, such as sol-gel [34], hydrothermal [35], salt-melt methods [36], ball milling [37], self-propagating high-temperature synthesis [38], and the chemical coprecipitation method [39]. However, the coprecipitation method is the most widely used in the synthesis of magnetic oxides due to its simplicity and good control of the grain size [40].

Previously, we have shown the catalytic efficiency of calcium trifluoroacetate Ca(CF3CO2)2 as a highly chemoselective homogenous catalyst in the epoxide ring-opening with amines [9]. As part of our studies directed towards the development of green chemistry protocols by performing organic transformations under solvent-free conditions [41, 42], we have focused our attention on the preparation, characterization, and catalytic application of magnetic strontium hexaferrite SrFe12O19 nanoparticles. The magnetic behavior of SrFe12O19 was evaluated by measurement of the hysteresis loops at room temperature. Furthermore, SrFe12O19 nanoparticles were tested as a heterogeneous catalyst in the ring-opening reactions with various amines.

2. Experimental Details

2.1. Materials

All reagents and solvents were purchased from commercial sources and used as received without further purification (Aldrich, Acros).

The synthesized NPs were characterized by X-ray powder diffraction (XRD) using D8 Discover Bruker (AXS) with Cu Kα radiation (λCu = 1.5407 Å) model. Microstructural characterization was performed using a Scanning Electron Microscope (SEM) (FEI, Quanta FEG 450) from BRUKER. Aliquots samples from the reaction mixture were monitored by Shimadzu gas chromatography (GC) with a flame ionization detector using nitrogen as a carrier gas. GC parameters for capillary columns BP (25 m × 0.25 mm, SGE) are injector 250°C; detector 250°C; oven 70°C for 5 min then 3°C/min until 250°C for 30 min; column pressure 20 kPa; column flow 6.3 mL/min; linear velocity 53.1 cm/s; total flow 138 mL/min. The products were confirmed by injecting the reaction mixture on an ISQ LT single quadrupole mass spectrometer in positive EI mode using a mass scan range of 50 to 400 Da. BET measurements were performed using 3Flex 3500 Micromeritics instruments. The magnetic propriety was determined by the Quantum Design XL-SQUID magnetometer.

2.2. Preparation of the Catalyst

The M-type hexaferrite SrFe12O19 was obtained by the co-precipitation method of Sr2+ and Fe3+ in the presence of NaOH as a precipitate agent in an aqueous medium. Briefly, stoichiometric amount of SrCl2 (0.068 g) and FeCl3.6H2O (2 g), were dissolved in 30 mL of deionized water. To the resulting mixture, 100 mL of NaOH (1.5 M) solution was added dropwise at 60°C. Next, the temperature was increased to 100°C for 2 hours. The precipitated solid was separated magnetically and washed several times to remove the excess of salts and then dried at 80°C overnight. The obtained powder was annealed at 1000°C for 6 hours and subjected to various analyses.

2.3. Catalytic Activity

In a typical reaction, a mixture of epoxide (1.02 mmol), amine (1.1 mmol), and SrFe12O19 (9.4 10−3 mmol) was introduced into a 50 mL Rotaflow tube and stirred at 60°C for 17 hours. The evolution of the reaction was monitored by gas chromatography. At the end of the reaction, the catalyst was easily recovered by applying a magnetic field, then washed with acetone and distilled water, and dried in an oven for 6 hours before reuse.

3. Results and Discussion

3.1. Characterization

Figure 1 presents the XRD pattern of hexagonal SrFe12O19 sample with corresponding diffraction lines. The prepared nanomaterial crystallizes in a pure hexagonal structure with a space group 194/P63 mmc. As shown in Figure 1, no impurity phases were detected from the XRD pattern. Rietveld refinement of the sample was performed by TOPAS software in order to define the lattice parameters of SrFe12O19 according to JCPDS 01-084-1531. The result is presented in Table 1.


CatalystSpace groupStructurea (Å)C (Å)Ddrx (nm)V (Å3)

SrFe12O19194/P63 mmcHexagonal5.8856 (±0.0047)23.0790 (±0.0082)95.4 (±0.4)692.1410 (±0.0056)

To confirm the nanoparticles formation, Debye–Scherrer formula was used to calculate the crystallite size of the prepared nanoparticles:where λ is the wavelength (Cu Kα), β is the full width to half-maximum (FWHM) of line broadening, and θ is the Bragg angle of diffraction. The average crystallite size was found to be 85.4 nm.

The scanning electron microscope (SEM) shows the homogeneity of the chemical composition and regular distribution of size and morphology (Figure 2). EDS results confirmed the elements that consist of strontium hexaferrite (Sr, Fe, and O) (Figure 3). The percentage of elements is in good agreement with the chemical composition of SrFe12O19, which confirms the absence of impurities.

Figure 4 shows the isotherm of M-type hexaferrite SrFe12O19 material. According to the IUPAC classification, the isotherm of the catalyst is assigned to type II, which is characteristic of nonporous materials, due to the high calcination temperature. This was confirmed by the pore size distribution curve determined by the Barrett–Joyner–Halenda (BJH) method, which showed a centered pore size at 2.21 nm. The BET surface area of the SrFe12O19 material was found to be 25 m2/g.

3.2. Magnetic Measurement

The magnetic propriety of SrFe12O19 at room temperature was investigated (Figure 5). The hysteresis loops of the samples showed that strontium hexaferrite exhibits a ferrimagnetic behavior characterized by high coercivity (5.37 KOe), high magnetization saturation (81.79 emu/g), and remanence magnetization of about 39.74 emu/g. The values are higher than those found when the material was prepared by other methods and confirm the hard magnetic behavior of SrFe12O19 [4345].

3.3. Catalytic Application

The catalytic activity of the SrFe12O19 nanocatalyst was evaluated for the nucleophilic ring-opening of cyclohexene oxide with aniline (Scheme 1). The scope and limitation of the catalytic system were examined by testing different parameters (Table 2).


EntrySolventC/S mol (%)T (°C)Conversiona (%)Selectivityb (%)

1Solvent-free0.9280100100
2Water0.92808080
3Methanol0.92808080
4THF0.9280NoneNone
5Acetonitrile0.9280NoneNone
6Solvent-freeNone801919
7Solvent-free0.64802828
8Solvent-free1.38809696
9Solvent-free1.84807979
10Solvent-free0.9260100100
11Solvent-free0.92509696
12Solvent-free0.92409695
13Solvent-free0.92252020

Reaction conditions: solvent (1 mL), reaction time 17 h, cyclohexene oxide (1.02 mmol), and aniline (1.1 mmol). aConversion and bselectivity were determined by GC.

Preliminary experiments were conducted at 80°C with 1.02 mmol of cyclohexene oxide (1) and 1.1 mmol of aniline (2a) catalyzed by SrFe12O19 NPs (0.01 g, 0.92 mol%) in various solvents or under solvent-free conditions (Table 2). The reaction was high stereoselective and afforded the trans amino alcohol 3a. In protic polar solvents, amino alcohol derivative 3a was obtained in good yield (entries 2 and 3). However, in an aprotic solvent such as THF or acetonitrile, no reaction took place (entries 4 and 5). In solvent-free conditions, total conversion and high selectivity were achieved (entry 1). In the absence of catalysts, only 19% of selectivity was obtained (entry 6). The optimal catalytic amount was found to be 0.92 mol% and the optimum temperature was 60°C (entry 10).

A kinetic study was performed with 0.01 g of the nanocatalyst SrFe12O19 (Figure 6). Based on Figure 6, the evolution of the reaction versus time shows that a maximum of the desired amino alcohol 3a was obtained after 17 h of reaction time. Under the optimized conditions, various aromatic and aliphatic amines were examined. The results are summarized in Table 3.


EntryAmineProductConversion (%)aYield (%)b

110097
24949
34242
48282
58484
610097
71010
89087
99795

Reaction conditions: cyclohexene oxide (1.02 mmol), amine (1.1 mmol), C/S = 0.92 mol%, solvent-free, and 17 h 60°C. aConversion was determined by GC; bisolated yield.

With all amines used, high stereoselectivity was observed. Exclusive trans amino alcohol derivatives were obtained in the cleavage of the epoxide ring of cyclohexene oxide which is in good agreement with the literature [46, 47]. Table 3 shows that electron-withdrawing effects resulted in the decrease of the nucleophilicity of the aromatic amines (entries 2 and 3). In the presence of cyclic secondary amines, a slight decrease in yield was detected (entries 4 and 5). All the primary amines afford the corresponding amino alcohols in high yields under solvent-free conditions (entries 6, 8, and 9). Among aliphatic amines, diethylamine exhibited a low activity due to its low boiling temperature (55°C) (entry 7).

A study on the regioselectivity of the nucleophilic ring-opening reaction was evaluated in the presence of styrene oxide 4 as unsymmetrical epoxide with various aromatic and aliphatic amines (Scheme 2). The result is summarized in Table 4.


EntryAmineConversion (%)aProductSelectivity (%)b 5 5′Yield (%)c 5 5′
55′55′

19574267012
27483176110
37674265614
4990100098
5850100084
61000100099

Reaction conditions: styrene oxide (0.8 mmol), amine (1 mmol), C/S = 0.92 mol%, solvent-free, 17 h, and 60°C. aConversion and bselectivity were determined by GC; c isolated yield.

As was described in the literature with styrene oxide, the regioselectivity of the reaction is influenced by the electronic and steric factors associated with the epoxides and the amines [47]. Table 4 shows that, with aromatic amines, the reaction afforded the amino alcohols from nucleophilic attack at the benzylic carbon atom of the epoxide ring as the major products (entries 1–3). In the case of aliphatic amines, the major/exclusive product was the regioisomeric amino alcohol produced by nucleophilic attack at the less hindered carbon atom of the epoxide ring (entries 4–6).

It is commonly recognized that the epoxide ring-opening reaction under basic or neutral conditions proceeds via the SN2 mechanism, but under acidic conditions, a borderline SN2 mechanism has been invoked to justify the electronic pull on the oxygen by an acid [48, 49].

Sundararajan et al. have discovered that anilines act as superior ring-opening reagents even when the reactions were performed with CoCl2.6H2O or under aerobic conditions, thereby ruling out the possibility of the mediation by free radicals [50]. Moreover, they suggest that CoCl2 coordinates with the oxirane oxygen promote the nucleophilic attack of the anilines leading to two regioisomers. In the case of metal coordinated styrene oxide, the positive charge on oxygen appears to be localized on the more highly substituted benzylic carbon and the nucleophile attacks the benzylic carbon of the styrene oxide.

Chakraborti et al. have reported that selective formation of the regioisomeric product arising from nucleophilic attack at the benzylic carbon was observed during the reactions with aromatic amines which are less nucleophilic [46, 47]. This preference may be accounted by the fact that the phenyl group in styrene oxide assists in the stabilization/accumulation of carbocationic character at the benzylic carbon. Meanwhile, in the case of aliphatic amines, a preference for nucleophilic attack at the terminal carbon may be explained by the increased nucleophilicity of aliphatic amines favoring a more SN2 process. According to literature, a similar result was obtained during our present work and a proposed mechanism is given in Scheme 3.

3.4. Recyclability

To investigate the reusability of SrFe12O19 nanoparticles, the catalytic performance in the epoxide ring-opening reaction of cyclohexene oxide with aniline was evaluated in five consecutive cycles (Table 5). After each cycle, the catalyst was separated from the reaction mixture using an external magnet, washed with water and acetone, and dried at 100°C for 6 hours while being reused.


EntryCycleConversion (%)aSelectivity (%)b

1Fresh100100
218383
328080
437575
547171

Reaction conditions: cyclohexene oxide (1.02 mmol), aniline (1.1 mmol), C/S = 0.92 mol%, solvent-free, 17 h, and 60°C. aConversion and bselectivity were determined by GC.

As shown in Table 5, the catalyst still exhibits a good catalytic activity after the third consecutive cycle. However, a noticeable drop in cyclohexene oxide conversion was observed after the fourth consecutive run due to agglomerated particles. SEM image of SrFe12O19 after five cycles showed particle agglomeration and surface change with an increase of the oxygen content on the surface of the materials (Figure 7).

Moreover, XRD analysis of SrFe12O19 nanocatalyst after five cycles exhibited less intensities of the diffraction planes compared to the fresh one (Figure 8).

4. Conclusion

In summary, SrFe12O19 nanoparticles were prepared by the coprecipitation method and characterized using various techniques. The prepared nanomaterial exhibited a strong magnetic field and marked activity, good reusability, and stability as a heterogeneous catalyst for the regioselective ring-opening of epoxides with various amines under free solvent conditions. The easy magnetic separation of the catalyst and its good reusability make it a useful and attractive process for the synthesis of β-amino alcohols.

Data Availability

SEM, EDS, XRD, BET, and the device types used for recording spectra and other analytical data used to support the findings of this study are included within the manuscript.

Disclosure

The present research is a part of a Ph.D. thesis work of the author Mouhsine Laayati.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

The authors are grateful to the Center for Analysis and Characterization (CAC) at Cadi Ayyad University, Marrakech, for the spectroscopic analysis.

References

  1. M. T. Barros, M. A. J. Charmier, C. D. Maycock, and T. Michaud, “Stereoselective synthesis of optically active mono and diaminoalcohols,” Tetrahedron, vol. 61, no. 33, pp. 7960–7966, 2005. View at: Publisher Site | Google Scholar
  2. E. J. Corey and F.-Y. Zhang, “Re- andsi-face-selective nitroaldol reactions catalyzed by a rigid chiral quaternary ammonium salt: a highly stereoselective synthesis of the HIV protease inhibitor amprenavir (vertex 478),” Angewandte Chemie International Edition, vol. 38, no. 13-14, pp. 1931–1934, 1999. View at: Publisher Site | Google Scholar
  3. C. W. Johannes, M. S. Visser, G. S. Weatherhead, and A. H. Hoveyda, “Zr-catalyzed kinetic resolution of allylic ethers and mo-catalyzed chromene formation in synthesis. Enantioselective total synthesis of the antihypertensive agent (S,R,R,R)-nebivolol,” Journal of the American Chemical Society, vol. 120, no. 33, pp. 8340–8347, 1998. View at: Publisher Site | Google Scholar
  4. S. Pulla, C. M. Felton, Y. Gartia, P. Ramidi, and A. Ghosh, “Synthesis of 2-oxazolidinones by direct condensation of 2-aminoalcohols with carbon dioxide using chlorostannoxanes,” ACS Sustainable Chemistry & Engineering, vol. 1, no. 3, pp. 309–312, 2013. View at: Publisher Site | Google Scholar
  5. D. J. Ager, I. Prakash, and D. R. Schaad, “1,2-Amino alcohols and their heterocyclic derivatives as chiral auxiliaries in asymmetric synthesis,” Chemical Reviews, vol. 96, no. 2, pp. 835–876, 1996. View at: Publisher Site | Google Scholar
  6. S. C. Bergmeier, “The synthesis of vicinal amino alcohols,” Tetrahedron, vol. 56, no. 17, pp. 2561–2576, 2000. View at: Publisher Site | Google Scholar
  7. W. Chrisman, J. N. Camara, K. Marcellini et al., “A simple and convenient synthesis of β-amino alcohol chiral auxiliaries based on limonene oxide,” Tetrahedron Letters, vol. 42, no. 34, pp. 5805–5807, 2001. View at: Publisher Site | Google Scholar
  8. R. Torregrosa, I. M. Pastor, and M. Yus, “Solvent-free direct regioselective ring opening of epoxides with imidazoles,” Tetrahedron, vol. 63, no. 2, pp. 469–473, 2007. View at: Publisher Site | Google Scholar
  9. R. Outouch, M. Rauchdi, B. Boualy, L. El Firdoussi, A. Roucoux, and M. Ali, “Calcium trifluoroacetate as an efficient catalyst for ring-opening of epoxides by amines under solvent-free conditions,” Acta Chimica Slovenica, vol. 61, no. 1, pp. 67–72, 2014. View at: Google Scholar
  10. S. V. Malhotra, R. P. Andal, and V. Kumar, “Aminolysis of epoxides in ionic liquid 1-ethylpyridinium trifluoroacetate as green and efficient reaction medium,” Synthetic Communications, vol. 38, no. 23, pp. 4160–4169, 2008. View at: Publisher Site | Google Scholar
  11. M. J. Bhanushali, N. S. Nandurkar, M. D. Bhor, and B. M. Bhanage, “Y(NO3)3·6H2O catalyzed regioselective ring opening of epoxides with aliphatic, aromatic, and heteroaromatic amines,” Tetrahedron Letters, vol. 49, no. 22, pp. 3672–3676, 2008. View at: Publisher Site | Google Scholar
  12. G. Singh, “Synthesis and characterization of Si(IV) complexes with tetradentate Schiff base ligands,” Journal of Applied Chemistry, vol. 3, pp. 2176–8221, 2014. View at: Google Scholar
  13. A. Procopio, M. Gaspari, M. Nardi, M. Oliverio, and O. Rosati, “Highly efficient and versatile chemoselective addition of amines to epoxides in water catalyzed by erbium(III) triflate,” Tetrahedron Letters, vol. 49, no. 14, pp. 2289–2293, 2008. View at: Publisher Site | Google Scholar
  14. V. Rajendiran, R. Karthik, M. Palaniandavar et al., “Mixed-Ligand copper(II)-phenolate complexes: effect of coligand on enhanced DNA and protein binding, DNA cleavage, and anticancer activity,” Inorganic Chemistry, vol. 46, no. 20, pp. 8208–8221, 2007. View at: Publisher Site | Google Scholar
  15. B. Sreedhar, P. Radhika, B. Neelima, and N. Hebalkar, “Regioselective ring opening of epoxides with amines using monodispersed silica nanoparticles in water,” Journal of Molecular Catalysis A: Chemical, vol. 272, no. 1-2, pp. 159–163, 2007. View at: Publisher Site | Google Scholar
  16. M. M. Heravi, B. Baghernejad, and H. A. Oskooie, “A new strategy for the aminolysis of epoxides with amines under solventfree conditions using Fe-Mcm-41 as a novel and efficient catalyst,” Catalysis Letters, vol. 130, no. 3-4, pp. 547–550, 2009. View at: Publisher Site | Google Scholar
  17. M. Kuriakose, M. R. Prathapachandra Kurup, E. Suresh, and E. Suresh, “Synthesis, spectroscopic studies and crystal structures of two new vanadium complexes of 2-benzoylpyridine containing hydrazone ligands,” Polyhedron, vol. 26, no. 12, pp. 2713–2718, 2007. View at: Publisher Site | Google Scholar
  18. N. Azizi and M. R. Saidi, “Highly efficient ring opening reactions of epoxides with deactivated aromatic amines catalyzed by heteropoly acids in water,” Tetrahedron, vol. 63, no. 4, pp. 888–891, 2007. View at: Publisher Site | Google Scholar
  19. T. Baskaran, A. Joshi, G. Kamalakar, and A. Sakthivel, “A solvent free method for preparation of β-amino alcohols by ring opening of epoxides with amines using MCM-22 as a catalyst,” Applied Catalysis A: General, vol. 524, pp. 50–55, 2016. View at: Publisher Site | Google Scholar
  20. E. S. Beach, Z. Cui, and P. T. Anastas, “Green Chemistry: a design framework for sustainability,” Energy & Environmental Science, vol. 2, no. 10, pp. 1038–1049, 2009. View at: Publisher Site | Google Scholar
  21. J. H. Lee, S. M. Lee, and S. W. Lee, “Synthesis and structures of a palladium macrocycle, a six-membered palladacycle, and a palladium compartment complexes: [Pd(L1)Cl], [Pd(NH2CH2CH2CH2NH2)Cl2], and [Pd(L2)] (HL1= (E)-2-)(((3-aminopropyl)imino)methyl)-6-methoxyphenol; H2L2=N,N-bis(3-methoxysalicylidenimino-1,3-diaminopropane),” Polyhedron, vol. 119, pp. 120–126, 2016. View at: Publisher Site | Google Scholar
  22. K. K. Senapati, S. Roy, C. Borgohain, and P. Phukan, “Palladium nanoparticle supported on cobalt ferrite: an efficient magnetically separable catalyst for ligand free Suzuki coupling,” Journal of Molecular Catalysis A: Chemical, vol. 352, pp. 128–134, 2012. View at: Publisher Site | Google Scholar
  23. K. Swapna, S. N. Murthy, and Y. V. D. Nageswar, “Magnetically separable and reusable copper ferrite nanoparticles for cross-coupling of aryl halides with diphenyl diselenide,” European Journal of Organic Chemistry, vol. 2011, no. 10, pp. 1940–1946, 2011. View at: Publisher Site | Google Scholar
  24. D. Wang, L. Salmon, J. Ruiz, and D. Astruc, “A recyclable ruthenium(ii) complex supported on magnetic nanoparticles: a regioselective catalyst for alkyne-azide cycloaddition,” Chemical Communications, vol. 49, no. 62, pp. 6956–6958, 2013. View at: Publisher Site | Google Scholar
  25. A. Hasnaoui, L. Fkhar, A. Nayad et al., “Synthesis and characterization of magnetic perovskites La1-x Srx MnO3 : green catalyst for oxidation of olefins in aqueous medium,” Journal of Inorganic Chemistry Communication, vol. 116, 2020. View at: Publisher Site | Google Scholar
  26. A. Kumar, R. Parella, and S. A. Babu, “Magnetic nano Fe3O4 catalyzed solvent-free stereo- and regioselective aminolysis of epoxides by amines; A green method for the synthesis of β-amino alcohols,” Synlett, vol. 25, no. 6, pp. 835–842, 2014. View at: Publisher Site | Google Scholar
  27. N. Azizi, P. Kamrani, and M. Saadat, “A magnetic nanoparticle-catalyzed regioselectivering opening of epoxides by aromatic amines,” Applied Organometallic Chemistry, vol. 30, no. 6, pp. 431–434, 2016. View at: Publisher Site | Google Scholar
  28. A. Sheoran, M. Dhiman, S. Bhukal et al., “Development of magnetically retrievable spinel nanoferrites as efficient catalysts for aminolysis of epoxides with amines,” Materials Chemistry and Physics, vol. 222, pp. 207–216, 2019. View at: Publisher Site | Google Scholar
  29. J. Went, G. W Ratheneau, E. W. Gorter, and G. W. van Oosterhout, “Ferroxdure, a class of new Permanent magnet Materials,” Philips Technical Review, vol. 13, pp. 194–208, 1951. View at: Google Scholar
  30. M. V. Cabañas, J. M. González-Calbet, and M. Vallet-Regı́, “Co-Ti substituted hexagonal ferrites for magnetic recording,” Journal of Solid State Chemistry, vol. 115, no. 2, pp. 347–352, 1995. View at: Publisher Site | Google Scholar
  31. M. Mozaffari and J. Amighian, “Direct use of celestite to prepare presintered SrFe12O19 powders,” Physica B: Condensed Matter, vol. 321, no. 1-4, pp. 45–47, 2002. View at: Publisher Site | Google Scholar
  32. X. Zuo, P. Shi, S. A. Oliver, and C. Vittoria, “Single crystal hexaferrite phase shifter at Ka band,” Journal of Applied Physics, vol. 91, no. 10, pp. 7622–7624, 2002. View at: Publisher Site | Google Scholar
  33. Z. kheilkordi, G. Mohammadi Ziarani, S. Bahar, and A. Badiei, “The green synthesis of 2-amino-3-cyanopyridines using SrFe12O19 magnetic nanoparticles as efficient catalyst and their application in complexation with Hg2+ ions,” Journal of the Iranian Chemical Society, vol. 16, no. 2, pp. 365–372, 2019. View at: Publisher Site | Google Scholar
  34. C. Sürig, K. A. Hempel, and D. Bonnenberg, “Formation and microwave absorption of barium and strontium ferrite prepared by sol-gel technique,” Applied Physics Letters, vol. 63, no. 20, pp. 2836–2838, 1993. View at: Publisher Site | Google Scholar
  35. A. Ataie, I. R. Harris, and C. B. Ponton, “Magnetic properties of hydrothermally synthesized strontium hexaferrite as a function of synthesis conditions,” Journal of Materials Science, vol. 30, no. 6, pp. 1429–1433, 1995. View at: Publisher Site | Google Scholar
  36. Z.-B. Guo, W.-P. Ding, W. Zhong, J.-R. Zhang, and Y.-W. Du, “Preparation and magnetic properties of SrFe12O19 particles prepared by the salt-melt method,” Journal of Magnetism and Magnetic Materials, vol. 175, no. 3, pp. 333–336, 1997. View at: Publisher Site | Google Scholar
  37. S. V. Ketov, Y. D. Yagodkin, A. L. Lebed, Y. V. Chernopyatova, and K. Khlopkov, “Structure and magnetic properties of nanocrystalline SrFe12O19 alloy produced by high-energy ball milling and annealing,” Journal of Magnetism and Magnetic Materials, vol. 300, no. 1, pp. 2005–2007, 2006. View at: Publisher Site | Google Scholar
  38. L. Qiao, L. You, J. Zheng, L. Jiang, and J. Sheng, “The magnetic properties of strontium hexaferrites with La-Cu substitution prepared by SHS method,” Journal of Magnetism and Magnetic Materials, vol. 318, no. 1-2, pp. 74–78, 2007. View at: Publisher Site | Google Scholar
  39. V. V. Pankov, M. Pernet, P. Germi, and P. Mollard, “Fine hexaferrite particles for perpendicular recording prepared by the coprecipitation method in the presence of an inert component,” Journal of Magnetism and Magnetic Materials, vol. 120, no. 1–3, pp. 69–72, 1993. View at: Publisher Site | Google Scholar
  40. Z. F. Zi, Y. P. Sun, X. B. Zhu, Z. R. Yang, J. M. dai, and W. H. Song, “Structural and magnetic properties of SrFe12O19 hexaferrite synthesized by a modified chemical co-precipitation method,” Journal of Magnetism and Magnetic Materials, vol. 320, no. 21, pp. 2746–2751, 2008. View at: Publisher Site | Google Scholar
  41. S. Oubaassine, A. Köckritz, R. Eckelt, A. Martin, M. Ait Ali, and L. El Firdoussi, “Catalytic β-bromohydroxylation of natural terpenes: useful intermediates for the synthesis of terpenic epoxides,” Journal of Chemistry, vol. 2019, Article ID 9268567, 8 pages, 2019. View at: Publisher Site | Google Scholar
  42. A. Aberkouks, A. A. Mekkaoui, M. Ait Ali, L. El Firdoussi, and S. El Houssame, “Selective allylic oxidation of terpenic olefins using Co-Ag supported on SiO2 as a novel, efficient, and recyclable catalyst,” Journal of Chemistry, vol. 2020, Article ID 1241952, 11 pages, 2020. View at: Publisher Site | Google Scholar
  43. A. Xia, C. Zuo, L. Chen, C. Jin, and Y. Lv, “Hexagonal SrFe12O19 ferrites: hydrothermal synthesis and their sintering properties,” Journal of Magnetism and Magnetic Materials, vol. 332, pp. 186–191, 2013. View at: Publisher Site | Google Scholar
  44. G. J. Colpas, B. J. Hamstra, J. W. Kampf, and V. L. Pecoraro, “The preparation of VO3+ and VO2+ complexes using hydrolytically stable, asymmetric ligands derived from schiff base precursors,” Inorganic Chemistry, vol. 33, no. 21, pp. 4669–4675, 1994. View at: Publisher Site | Google Scholar
  45. R. H. Arendt, “The molten salt synthesis of single magnetic domain BaFel2O19 and SrFel2O19 crystals,” Journal of Solid State Chemistry, vol. 8, no. 4, pp. 339–347, 1973. View at: Publisher Site | Google Scholar
  46. A. K. Chakraborti and A. Kondaskar, “ZrCl4 as a new and efficient catalyst for the opening of epoxide rings by amines,” Tetrahedron Letters, vol. 44, no. 45, pp. 8315–8319, 2003. View at: Publisher Site | Google Scholar
  47. B. P. Shivani, A. K. Chakraborti, and B. Pujala, “Zinc(II) perchlorate hexahydrate catalyzed opening of epoxide ring by amines: applications to synthesis of (RS)/(R)-Propranolols and (RS)/(R)/(S)-Naftopidils,” The Journal of Organic Chemistry, vol. 72, no. 10, pp. 3713–3722, 2007. View at: Publisher Site | Google Scholar
  48. R. E. Parker and N. S. Isaacs, “Mechanisms of epoxide reactions,” Chemical Reviews, vol. 59, no. 4, pp. 737–799, 1959. View at: Publisher Site | Google Scholar
  49. S. Mohseni, M. Bakavoli, and A. Morsali, “Theoretical and experimental studies on the regioselectivity of epoxide ring opening by nucleophiles in nitromethane without any catalyst: nucleophilic-chain attack mechanism,” Progress in Reaction Kinetics and Mechanism, vol. 39, no. 1, pp. 89–102, 2014. View at: Publisher Site | Google Scholar
  50. G. Sundararajan, K. Vijayakrishna, and B. Varghese, “Synthesis of β-amino alcohols by regioselective ring opening of arylepoxides with anilines catalyzed by cobaltous chloride,” Tetrahedron Letters, vol. 45, no. 44, pp. 8253–8256, 2004. View at: Publisher Site | Google Scholar

Copyright © 2020 Mouhsine Laayati et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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