Green and eco-friendly mica/Fe₃O₄ as an efficient nanocatalyst for the multicomponent synthesis of 2-amino-4H-chromene derivatives

ABSTRACT

Mica/Fe₃O₄ nanocomposite was easily synthesized under the mild conditions and completely identified by Fourier transform infrared (FT-IR) spectra, field-emission scanning electron microscopy (FE-SEM) images, X-ray diffraction (XRD) pattern, energy-dispersive X-ray (EDX) analysis, thermogravimetric analysis (TGA) curve and vibrating sample magnetometer (VSM) curve analyses. Also, to environment-friendly, low cost and non-toxic features, this nanocomposite has unique physical and chemical properties such as magnetic separation, thermal stability and uniform size distribution. Then, the activity of mica/Fe₃O₄ magnetic nanocomposites as an efficient heterogeneous nanocatalyst was investigated in the synthesis of 2-amino-4H-chromene derivatives as an important group of organic pharmaceutical compounds. The catalyst can be separated by an external magnet and reused in numerous cycles without loss of its catalytic activity as well as maintenance of its stability. Green and highly efficient catalyst based on mica and mild reaction conditions is further advantages of the present work.

GRAPHICAL ABSTRACT

KEYWORDS:

• Mica
• magnetic nanoparticle
• nanocatalyst
• 2-amino-4H-chromene
• green chemistry

1. Introduction

Recently, magnetic nanoparticles (MNPs) owing to their considerable properties such as their relatively low cost, suitable reactive sites, high specific surface area and easy separation have been applied in various branches of sciences [1–4]. The surface of MNPs is typically modified or coated with renewable polymers, carbon materials, silica compounds and clay minerals to improve their colloidal stability and reduce their toxicity [5–9]. The obtained magnetic nanocomposites can be used in various fields including medical therapy and diagnosis, adsorption and catalysis [10–14].

Newly, the clay minerals with their environmental compatibility, low cost, high selectivity, reusability and operational simplicity features have received considerable attention in different industries and fundamental researches [15]. Also, they have good potential to be used as a substrate for the preparation of nanocomposite [16]. Clay minerals are divided into different types based on their crystal and structural chemistry. The structure of mica sheets, as a subset of clay mineral, composed of two layers of silica tetrahedrons and one central dioctahedral or trioctahedral layer of alumina [17]. According to mica’s accessibility, eco-friendly character, elasticity, insolubility in acid and alkali solution resistance, it was very much considered for the synthesis of nanocomposites. Also, mica by including large sheets can be modified by different metal oxides such as TiO₂, ZrO₂, SnO₂, Cr₂O₃, Fe₂O₃ and Al₂O₃ with epitaxial growth [18].

Multicomponent reactions (MCRs) are the most effective strategy in the field of green chemistry and are important tools in material, medical and modern synthetic organic chemistry; especially, for the construction of heterocyclic scaffolds [19–21]. 4H–Chromene derivatives with biological activities such as mutagenicity [22], antitumor [23] antimicrobial [24] and antiproliferative [25] are more attractive. Furthermore, the synthesis of 2-amino-4H-chromenes with CN functionality, due to the biomedical properties and usage in the treatment of psoriasis cancer and rheumatoid are considerable importance to chemists [26]. Therefore, according to the importance of these components several homogeneous or heterogeneous catalysts and various methods have been applied to improve the synthesis of 2-amino-4H-chromenes reaction such as Fe₃O₄@SiO₂@propyltriethoxysilane@o-phenylenediamine [27]. Most of these reported methods have undesirable conditions like long catalyst synthesis processes, rigorous catalyst regeneration and long reaction times. In continuation of our research on introducing new recoverable, efficient and eco-friendly nanocatalysts in organic synthesis [28–38], herein, we report the synthesis and characterization of a mica/Fe₃O₄ nanocomposite as a heterogeneous catalyst and its application in the effective synthesis of 2-amino-4H-chromenes derivatives 5a-j and 6a-d (Scheme 1). To the best of our knowledge, there is no previously reported work on the catalytic activity investigation of magnetized mica.

Scheme 1. Synthesis of 2-amino-4H-chromenes derivatives in the presence of mica/Fe₃O₄ nanocatalyst.

Among various chromene4H–Chromenes containing CN are of the heterocyclic compounds with unique pharmaceutical and biological activities that has recently attracted great interests by chemists. Due to the importance of 4H–chromene derivatives, various synthetic method with different homogeneous or heterogeneous catalysts such as alumina [30], silica nanoparticles [31] methane sulfonic acid [28], [BMIm]BF4, nano-sized MgO [24], and K3PO4 have been used to promote 2-amino-4H-chromenes [21]. Many of these methods suffer from disadvantages such as toxic catalysts, tedious work-up procedures, long times, low yields and high temperatures.

2. Experimental

2.1. General

Solvents, reagents and chemicals were obtained from Merck, Sigma and Aldrich companies. Melting points were measured on an Electrothermal 9100 apparatus and are uncorrected. Fourier transforms infrared spectroscopy (FT-IR) spectra were recorded by the method of KBr pellet on a Shimadzu IR-470 spectrometer. Thermogravimetric analysis (TGA) was taken by Bahr-STA 504 instrument. Field-emission scanning electron microscopy (FE-SEM) images were achieved by a MIRA 3 TESCAN microscope with an attached camera. Elemental analysis of the nanocatalyst was carried out by energy-dispersive X-ray (EDX) analysis recorded Numerix DXP-X10P. Lakeshore 7407 vibrating sample magnetometers (VSM) was used for examining the magnetic measurement of the solid sample. X-ray diffraction (XRD) measurements was taken on a JEOL JDX–8030 (30 kV, 20 mA). ¹H and ¹³C nuclear magnetic resonance (NMR) spectra were recorded on a Bruker DRX-500 Avance spectrometer at 500 and 125 MHz, respectively.

2.2. Synthesis of catalyst

2.2.1. Synthesis of mica/Fe₃O₄ Nanocatalyst

Mica/Fe₃O₄ nanocomposite was synthesized by analytically pure reagents. Firstly, 50 mL of distilled water was boiled for five minutes to eliminate oxygen. Then, 0.5 g of mica added to boiling water and the suspension vigorously stirred at room temperature with the mechanical stirrer. The mix solution of FeCl₃⋅6H₂O (1.06 g, 4 mmol) and FeCl₂⋅4H₂O (0.39 g, 2 mmol) was added to the above solution. Next, sodium hydroxide solution (10 mL, 4 M) was dropped into the mix solution in the atmosphere of nitrogen. The suspension was stirred for 120 min to complete the reaction. Finally, black precipitate was collected using an external magnet and washed several times with ethanol and distilled water. the synthesize nanocomposite mica/Fe₃O₄ was dried in an air oven at 60°C for 5 h and keep in the furnace at 350°C for 3 h in nitrogen gas flow.

2.2.2. General procedure for the synthesis of 2-amino-4H-chromene derivatives

A mixture of aromatic aldehyde 1 (1 mmol), malononitrile 2 (1 mmol) and dimedone 3 or barbituric acid 4 (1 mmol) in the presence of mica/Fe₃O₄ nanocatalyst (3.0 mg) was reacted in 3 mL ethanol at room temperature. The completion of the reaction was monitored by thin-layer chromatography (TLC) and all of derivatives were synthesis in less than 10 min. After completion of the reaction, the catalyst was easily separated by an external magnet. The pure products were obtained from the reaction mixture by recrystallization from hot EtOH and no more purification was required. All the products were known compounds which were identified by characterization of their melting points (as indicated in Table 3) and by comparison with those authentic literature samples and also in some cases their FT-IR, ¹H and ¹³C spectral data (See copies of ¹H and ¹³C NMR spectra of the selected products (5a, 5b, 5 h and 6e) in Supplementary Materials file as Figures S1–S7).

2.2.3. Spectral data of the selected products

2-Amino-4-phenyl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (5a)

M.p. 236–238 °C; ¹H NMR (500 MHz, DMSO-d₆): δ_H (ppm) = 0.94 (3H, s, CH₃), 1.02 (3H, s, CH₃), 2.08-2.25, 2.50 (4H, 2 CH₂), 4.17 (1H, s, CH), 7.00 (2H, s, NH₂) 7.13–7.27 (5H, m, H-Ar). ¹³C NMR (125 MHz, DMSO-d₆): δ_c (ppm) = 27.4, 29.0, 32.4, 36.2, 40.7, 50.6, 58.9, 113.4, 120.4, 127.2, 127.8, 128.7, 129.0, 145.4, 159.1, 163.1, 196.3.

2-Amino-4-(3-nitrophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (5b)

M.p. 210–212°C; ¹H NMR (500 MHz, DMSO-d₆): δ_H (ppm) = 0.93 (3H, s, CH₃), 1.01 (3H, s, CH₃), 2.08–2.11 (1H, d, J = 16 Hz, CH₂), 2.23–2.26 (1H, d, J = 16 Hz, CH₂), 2.48 (2H, s, CH₂), 4.40 (1H, s, CH), 7.18 (2H, s, NH₂), 7.58–7.61 (1H, m, H-Ar), 7.65–7.66 (1H, d, J = 7 Hz, H-Ar), 7.97 (1H, s, H-Ar), 8.05–8.06 (1H, d, J = 7 Hz, H-Ar). ¹³C NMR (125 MHz, DMSO-d₆): δ_c (ppm) = 27.3, 28.9, 32.4, 36.0, 40.6, 50.5, 57.8, 112.4 120.0, 122.3, 122.4, 130.6, 134.8, 147.6, 148.4, 159.2, 163.8, 196.4.

2-Amino-4-(4-cyanophenyl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (5 h)

M.p. 230–232 °C; ¹H NMR (500 MHz, DMSO-d₆): δ_H (ppm) = 0.93 (3H, s, CH₃), 1.01 (3H, s, CH₃), 2.08–2.11 (1H, d, J = 16 Hz, CH₂), 2.22–2.25 (1H, d, J = 16 Hz, CH₂), 2.48 (2H, s, CH₂), 4.28 (1H, s, CH), 7.14 (2H, s, NH₂) 7.34– 7.35 (2H, d, J = 8 Hz, H-Ar). 7.74–7.74 (2H, d, J = 8 Hz, H-Ar). ¹³C NMR (125 MHz, DMSO-d6): δ_c (ppm) = 27.5, 28.8, 32.4, 36.4, 50.5, 57.7, 60.4, 110.1, 112.4, 119.4, 120.0, 129.0, 133.0, 150.8, 159.2, 163.7, 170.9, 196.3.

7-amino-2,4-dioxo-5-(3,4,5-trimethoxyphenyl)-1,3,4,5-tetrahydro-2H-pyrano[2,3-d]pyrimidine-6-carbonitrile (6e)

M.p. 261–262°C; ¹H NMR (500 MHz, DMSO-d₆): δ_H (ppm) = 3.77 (3H, s, CH₃), 3.84 (6H, s, CH₃), 4.49 (1H, s, CH), 6.78 (2H, s, NH₂), 6.96 (2H, s, H-Ar), 10.11 (1H, s, NH), 11.05 (1H, s, NH).

3. Results and discussion

In this work, a natural, eco-friendly and magnetic mica/Fe₃O₄ nanocatalyst was synthesis in the mild condition. Mica/Fe₃O₄ was fully characterized by FT-IR, FE-SEM, EDX, XRD, TGA, VSM analyzes. All of these analyzes confirmed the synthesis of mica/Fe₃O₄ with features such as thermal stability, acceptable magnetic property and crystalline nature. Also, the catalytic activity of mica/Fe₃O₄ as a reusable magnetic catalyst was examined in the synthesis of 2-amino-4H-chromene derivatives without any considerable loss of catalyst activity after 7 cycles.

3.1. Characterization of mica/Fe₃O₄ nanocatalyst

3.1.1. Fourier transform infrared (FT-IR) spectroscopy

The FT-IR results spectra were used as a common method for investigating the synthesized of mica/Fe₃O₄ nanocomposite (Figure 1). As can be seen in the FT-IR spectrum of mica, the bands at 491 and 549 cm⁻¹ were assigned to the bending vibration of Si-O-Si and Al-O-Si, respectively. The peak at 983 cm⁻¹ was related to the bending vibration of Al-OH of mica. Also, the peak at 1043 was attributed to the Si-O-Si bond. All the motion peaks of mica were appeared in the mica/Fe₃O₄ spectrum, too. The stretching vibrations of hydroxyl groups from iron oxide were shown at 3300 cm⁻¹. The Fe-O adsorption at around 580 cm⁻¹ was overlapped with the bending vibration of Al–O-Si [18].

Figure 1. FT-IR spectra of mica and mica/Fe₃O₄ nanocomposite.

3.1.2. Scanning electron microscopy (SEM)

The SEM image indicated the morphology and size distribution of the nanocatalyst. As can be seen in Figure 2, the roughness on the surface of mica can be related to Fe₃O₄ nanoparticles with its cubic shape. The mica/Fe₃O₄ nanocatalyst has uniform size distribution with an average size of 20 ± 16 nm.

Figure 2. The SEM image of mica/Fe₃O₄ nanocomposite.

3.1.3. Energy-dispersive X-ray (EDX)

The elemental content of mica/Fe₃O₄ magnetic nanocomposite was determined through EDX analysis and the result was illustrated in Figure 3. It confirms the presence of iron (39.6%), aluminum (4.5%), oxygen (49.3%), potassium (1.3%) and silicon (4.5%) elements in the nanocomposite. Furthermore, recycled nanocomposite was characterized by EDX analysis (Figure S8). The existence of aluminum, silicon, iron, oxygen, and potassium elements in the reused nanocomposite confirm the stability of mica/Fe₃O₄ nanocatalyst.

Figure 3. The EDX analysis of the mica/Fe₃O₄ nanocomposite.

3.1.4. Vibrating sample magnetometer (VSM)

The magnetic properties of mica/Fe₃O₄ nanocatalyst were measured by VSM curve at room temperature (Figure 4). According to reported articles, the saturation magnetization value (Ms) of neat Fe₃O₄ nanoparticles was found around 69 electromagnetic units per gram (emu g⁻¹). While, the mica/Fe₃O₄ nanocomposite exhibits lower magnetic value around 55.69 emu g⁻¹. This decrease in magnetic property could be attributed to the loading of Fe₃O₄ MNPs on the surface of mica and confirmed the successful synthesis of mica/Fe₃O₄ nanocomposite.

Figure 4. VSM magnetization curve of mica/Fe₃O₄ nanocatalyst.

3.1.5. X-ray diffraction (XRD)

The crystal structure of the mica/Fe₃O₄ nanocomposite was studied by XRD analysis. It can be seen that the diffraction peaks of the nanocomposite appeared at 2θ = 25.70, 27.09, 30.67, 36.00, 43.69, 57.67, 63.17, and 75.79° (Figure 5a).‏ According to JCPDS card No 00-002-0227 (Figure 5b), the diffraction peaks at 2θ = 25.70, 30.67 and 63.17° are related to the mica. Moreover, the Fe₃O₄ cubic magnetic nanoparticles corresponding to the characteristic diffraction angles (2θ) of 30.67, 36.00, 43.69, 57.67, 63.17, and 75.79 are similar to the characteristic data of Fe₃O₄ (JCPDS card No. 01-075-0449) (Figure 5c). Therefore, the crystalline nature of nanocomposite and loading of Fe₃o₄ on mica were confirmed by XRD analysis.

Figure 5. The XRD pattern of: (a) mica/Fe₃O₄, (b) the reference mica, and (c) the reference Fe₃O₄.

3.1.6. Thermogravimetric analysis (TGA)

The thermal stability of the synthesized nanocomposite was investigated by thermogravimetric analysis (TGA) over the temperature range of 20–800 °C and air atmosphere. As can be seen in the TG curve in Figure 6, the magnetic nanocomposite is high thermal stability and the degradation is linear. The low percentage losing weight around 20–250°C was related to the evaporation of solvent (water) and other molecules that are physically absorbed on to the surface of mica/Fe₃O₄ nanocomposite. As a result, the thermal degradation of nanocomposite was very slight and mica/Fe₃O₄ nanocomposite exhibited remarkable thermal stability.

Figure 6. The TGA analysis of the mica/Fe₃O₄ nanocomposite.

3.2. Optimization of the mica/Fe₃O₄ nanocomposite

In order to achieve the highest efficiency of magnetic nanocomposite, multiple amounts of mica and iron salts with the approximate ratio were used to prepare different magnetic nanocomposite. The efficiency of them was investigated in the synthesis of 5a at 10 min. as can be seen in Table 1, the performance of the mica/Fe₃O₄ nanocomposite was decreased by the increase of iron oxide nanoparticles due to agglomeration of iron oxide nanoparticles.

Table 1. Optimization of the mica/Fe₃O₄ nanocomposite.

Entry	Amount of mica (g)	Amount of FeCl3⋅6H2O (g)	Amount of FeCl2⋅4H2O (g)	Approximate ratio of Fe3O4/mica	Yield (%)
1	1	1.06	0.392	1	78
2	0.5	1.06	0.392	2	97
3	0.25	1.06	0.392	4	30
4	0.125	1.06	0.392	8	Trace

^a Reaction condition: aromatic aldehyde (1.0 mmol), malononitrile (1 mmol), dimedone (1.0 mmol) or barbituric acide (1.0 mmol), and mica/Fe₃O₄ composite (3.0 mg) in 3 mL of ethanol at room temperature.

^b Isolated yield.

3.3. Application of the mica/Fe₃O₄ nanocomposite for the synthesis of 4H–chromene derivatives

The catalytic activity was investigated in the synthesis of 4H–chromene derivatives. Initially, to optimize the reaction conditions, the three-component reaction of benzaldehyde 1, malononitrile 2 and dimedone 3 was chosen as the model reaction. The effects of the different ratios of mica/Fe₃O₄ and various solvents on the reaction efficiency were investigated and the results summarized in Table 2. The model reaction was studied in solvent-free, H₂O and EtOH as green solvents. As can be seen in this table, higher yields of the products were obtained in EtOH rather than other solvents under similar catalyst loading. In the presence of iron nanoparticles and mica the reaction efficiency was low (Table 2, entries 3 and 4). Also, Because of the agglomeration of nanoparticles, the catalyst activity of Fe₃O₄ nanoparticles was lower than the mica. Nevertheless, after using the mica/Fe₃O₄ nanocomposite the reaction yield increased significantly to 95%. This result confirmed the synergistic effect of mica and Fe₃O₄. Also, 3.0 mg of catalyst was sufficient to catalyze the reaction and synthesize desired product 5a in high yields by saving both time and energy.

Table 2. Optimization of different parameters in the model reaction^a.

Entry	Solvent	Catalyst	(mg)	Time (min)	Yield^b (%)
1	–	Mica/Fe3O	3.0	30	Trace
2	H2O	Mica/Fe3O	3.0	30	Trace
3	H2O	Mica/Fe3O	3.0	30	20
3	EtOH	Mica	3.0	10	44
4	EtOH	Fe3O	3.0	10	38
5	EtOH	–	–	30	Trace
6	EtOH	Mica/Fe3O	3.0	10	97
7	EtOH	Mica/Fe3O	0.01	10	60
8	EtOH	Mica/Fe3O	0.02	10	78
9	EtOH	Mica/Fe3O	0.04	10	73

^a Reaction condition: benzaldehyde (1.0 mmol), dimedone (1.0 mmol), malononitrile (1 mmol).

^b Isolated yield.

Finally, after optimization of the reaction conditions, in order to study the effects of substituents, number of aldehydes such as electron-withdrawing and electron-donating moieties were employed to provide the corresponding 4H–chromene derivatives in high yields (Table 3). Also, both of dimedone 3 or barbituric acid 4 have acceptable results to afford the corresponding 5a–j and 6a–d products under similar reaction conditions. Briefly, all desired products were achieved with high yields, short reaction times and mild reaction conditions.

Table 3. Synthesis of 2-amino-4H-chromene derivatives 5a-j in optimal conditions^a.

Entry	R	Product	Time (min)	Yield^b (%)	Mp (°C)
1	C6H5	5a	9	97	235–237
2	3-NO2-C6H4	5b	10	95	210–212
3	4-OH-C6H4	5c	10	93	225–227
5	2,4-(Cl)2-C6H3	5d	10	93	184–186
6	2,6-(Cl)2-C6H3	5e	10	90	248–250
7	4-NO2-C6H4	5f	10	88	180–181
8	4-CN-C6H4	5g	7	94	230–232
9	3-OH-C6H4	5h	8	87	236–237
10	2-furfural	5i	10	90	221–223
11	4-OMe-C6H4	5j	10	88	200–201
12	4-MeO-C6H4	6a	10	98	279–281
13	C6H4	6b	10	95	207–209
14	4-NO2-C6H4	6c	10	93	238–240
15	3-OH-C6H4	6d	10	82	157–159
16	3,4,5- (OMe)3-C6H2	6e	10	86	261–262

^a Reaction condition: benzaldehyde (1.0 mmol), dimedone (1.0 mmol), malononitrile (1 mmol).

^b Isolated yield.

3.4. Comparison the efficiency of mica/Fe₃O₄ with previous reported literatures

The effectiveness of mica/Fe₃O₄ with reported works was compared in the synthesis of 4H–chromene derivatives. As collected in Table 4, the reaction condition like Temperature and time of the present work were more reliable than previous ones.

Table 4. Comparison the efficiency of synthesized nanocatalyst with other reported works.

Entry	Solvent	Catalyst	Amount of catalyst (mg)	Time (min)	Temperature (°C)	Yield (%)	Ref.
1	H2O/EtOH	Mg(ClO4)2	57	180	100	87	[39]
2	Water	Tetrabutylammonium fluoride	64	30	Reflux	97	[40]
3	Choline chloride/urea	–	–	60–240	80	95	[41]
4	EtOH	nano-BF2O-coc	15	15	Reflux	95	[42]
4	EtOH	nano-BF2O-coc	15	15	Reflux	95	[43]
5	EtOH	Hal-Fe3O4	30	10	r.t.	94	This work

3.5. Proposed mechanism for the synthesis of 4H–chromene derivatives

The plausible mechanism for the synthesis of 4H–chromene derivatives in the presence of nanocomposite is shown in Scheme 2. Firstly, the Knoevenagel condensation between activated aldehyde 1 and malononitrile 2 provide the intermediate I in the existence of mica/Fe₃O₄. After that, the addition of activated dimedone 3 or barbituric acid 4 to intermediate I produce intermediate II. The tautomerization and dehydration of compound II, gave the compound III. Finally, the cyclization of intermediate III gives the final products 5a–j and 6a–d.

Scheme 2. Proposed mechanism for the synthesis of 4H–chromene derivatives by using mica/Fe₃O₄.

3.5. Reusability of mica/Fe₃O₄ nanocomposite

The recovery and reusability of the synthesized nanocomposite are one of the most important advantages for industry usage. In this regard, the mica/Fe₃O₄ nanocatalyst was reused after separation by the external magnet and washing with ethanol in the model reaction. The results confirmed the stability and efficiency of nanocomposite at least 7 times (Figure 7). Furthermore, the stability of the recycled mica/Fe₃O₄ nanocatalyst was approved by FT-IR spectra and EDX analysis (Figures S8 and S9).

Figure 7. Reusability of mica/Fe₃O₄ nanocomposite in the synthesis of 5a.

4. Conclusion

In summary, a green, efficient and magnetic nanocomposite was synthesized in the simple and mild condition. The synthesis of mica/Fe₃O₄ nanocomposite with special features such as the uniform distribution of the Fe₃O₄ nanoparticles, magnetic property and the thermal stability was confirmed by FT-IR, EDX, FE-SEM, XRD, VSM and TGA analyses. Then, the catalytic activity of the nanocomposite was investigated in the synthesis of -amino-4H-chromenes derivatives. The products were obtained in high-to-excellent yields at room temperature under mild reaction conditions. The nanocatalyst was easily recovered by an external magnetic field and reused efficiently for several times without a significant decrease in its activity. This is the first report on the performance of mica/Fe₃O₄ nanocomposite as a heterogeneous catalyst in organic reactions.

Acknowledgements

The authors gratefully acknowledge the partial support from the Research Council of the Iran University of Science and Technology.

Supplementary materials

Additional supporting information including ¹H and ¹³C NMR of the selected products (5a, 5b, 5h and 6e) and EDX analysis and FT-IR spectrum of the recycled nanocatalyst can be found in the online version of this article at the publisher’s web site.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Ali Maleki

Professor Ali Maleki was born in 1980. He received his Ph.D. in Chemistry from Shahid Beheshti University under supervision of Prof. Shaabani in 2009. He started his career as an Assistant Professor in Department of Chemistry, IUST in 2010 where he is currently Full Professor. His research interests focus on design and development of novel multicomponent reactions, organic synthesis, natural and synthetic polymers, heterocycles, pharmaceutical compounds, nanochemistry, magnetic, composite, hybrid, core/shell nanomaterials, catalysts and catalytic reactions, medicinal and green chemistry. Prof. Dr. Maleki has hundreds of ISI-JCR publications, book chapters and executed industrial and applied projects. He has been selected as a distinguished researcher of IUST within 2010-2020. He has awarded IUPAC-CHEMRAWN VII prize for green chemistry in 2016. Dr. Maleki has been ranked as top 1% International Scientists in ESI (Web of Science) in 2018-2020. He had more than 20 highly cited papers in 2010-2020. His H-index is currently 50 including more than 7000 citations.

Zoleikha Hajizadeh

Mrs. Zoleikha Hajizadeh was graduated from Shahid Beheshti University in M.Sc. in organic chemistry. Then, she continued as a Ph.D. student in IUST under supervision of Prof. Ali Maleki on the synthesis of halloysite nanocomposites and evaluation of their catalytic performance in the condensation organic reactions. She has been succeeded to publish several ISI publications. Now, she was graduated from Ph.D. course in 2019.

Kobra Valadi

Mrs. Kobra Valadi was graduated from IUST in M.Sc. in organic chemistry. Then, she continued as a Ph.D. student in IUST under supervision of Prof. Ali Maleki since 2020.