
==== Front
Nanoscale Adv
Nanoscale Adv
NA
NAADAI
Nanoscale Advances
2516-0230
RSC

d4na00448e
10.1039/d4na00448e
Chemistry
Fe3O4/PANI/CuI as a sustainable heterogeneous nanocatalyst for A3 coupling†
† Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d4na00448e

Nisha a
Kohli Sahil bg
Singh Snigdha a
Sharma Neera c
https://orcid.org/0000-0002-7150-3604
Chandra Ramesh adef
a Drug Discovery & Development Laboratory, Department of Chemistry, University of Delhi Delhi-110007 India acbrdu@hotmail.com

b Department of Chemistry, School of Basic Sciences, Galgotias University Greater Noida-203201 Uttar Pradesh India
c Department of Chemistry, Hindu College, University of Delhi Delhi-110019 India
d Dr. B. R. Ambedkar Centre for Biomedical Research (ACBR), University of Delhi Delhi-110007 India
e Institute of Nanomedical Science (INMS), University of Delhi Delhi-110007 India
f Maharaja Surajmal Brij University Bharatpur-321201 Rajasthan India
g Manav Rachna International Institute of Research & Studies Faridabad Haryana-121004 India
22 7 2024
24 9 2024
22 7 2024
6 19 48424851
30 5 2024
19 7 2024
This journal is © The Royal Society of Chemistry
2024
RSC
https://creativecommons.org/licenses/by/3.0/ This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.
The prepared copper iodide nanoparticles were impregnated on the support of ferrite nanoparticles functionalized with polyaniline, resulting in a magnetically recoverable heterogeneous nanocomposite. The activity of the prepared nanocomposite was investigated in the synthesis of propargylamine derivatives via A3 coupling under mild conditions. Techniques such as FESEM, EDAX, XRD, XPS, TEM, BET and FTIR were used to characterize the effective and unique heterogeneous Fe3O4/PANI/CuI nanocomposite developed in this work. This method used in the current study has several advantages, including a short reaction time, neat conditions, good product yield, ideal green matrices values, reusability for up to seven cycles, and magnetic retrievability.

The prepared copper iodide nanoparticles were impregnated on the support of ferrite nanoparticles functionalized with polyaniline, resulting in a magnetically recoverable heterogeneous nanocomposite.

Council of Scientific and Industrial Research, India 10.13039/501100001412 09/045(1792)/2020-EMR-I Science and Engineering Research Board 10.13039/501100001843 TAR/2022/000618 pubstatusPaginated Article
==== Body
pmcIntroduction

Magnetic nanoparticles (MNPs) are of great importance due to their various applications in catalysis, magnetic resonance imaging (MRI), magnetic fluids, and biotechnology.1 MNPs can serve as magnetically recoverable catalysts for a variety of catalytic reactions because of their insoluble and paramagnetic character, which allows for easy separation from the reaction medium. Moreover, magnetic separation has evolved into one of the most significant and well-known catalytic methods in organic chemistry without the need for filtering, centrifugation, or other laborious workup procedures, simply by using an external magnet.2 However, bare MNPs have some limitations such as the tendency to easily agglomerate, colloidal instability, and dissolution in acids.3 The colloidal instability of MNPs leads to their agglomeration due to magnetic dipole–dipole interaction.4,5 This issue can be resolved by surface functionalization of MNPs using protective shells or coatings such as silica, carbon, or organic polymers.3 Furthermore, these coatings allow the covalent attachment of organic compounds on distinct nanoparticles, facilitating applications such as drug carriers, heterogeneous catalysis, and absorption media.3 The magnetic nature of nanoparticles permits facile recovery of nanocatalysts from reaction mixtures through magnets.5

One of the polymeric shells synthesized via oxidative polymerization is polyaniline (PANI).6 The choice of polyaniline is because of its various properties such as facileness of synthesis, conductivity as a polymer, low cost, and a porous structure that can enhance the catalytic activity of nanoparticles. The Fe3O4/PANI hybrid shell can be considered a multifunctional support for metal nanocatalysts with significant catalytic performance.7

The benefits of a metal nanoparticle supported on nano-size heterogeneous material include good selectivity, minimal accumulation of metal nanoparticles, high dispersion in a liquid medium, and excellent reusability.8 Copper-based nanoparticles not only enhance the physicochemical characteristics of the nanoparticles but also reinforce the interface between the metal and the support.9 Cu-based nanocatalysts have abundant applications in nanotechnology due to their special properties and features such as catalysing organic transformations, electrocatalysis, and photocatalysis.10 Supported copper nanoparticles, such as CuO/NiO,9 CuO/Al2O3,11 ZnO/CuI/PPy,12 and Cu–MgO,13 have been used in many organic transformations. Copper-based nanocatalysts are found to be useful in various reactions including C–H activation of alkynes, oxygen arylation reaction, Suzuki reaction, Click reaction, Knoevenagel condensation-Michael addition cyclization reaction, Heck reaction and producing copper-acetylated species in situ to afford propargylamines.14

Propargylamines are crucial building blocks for organic synthesis because they can be utilized as synthetic precursors for synthesizing various medicinally essential compounds.8 Propargylamines are formed via a three-component reaction known as A3 coupling, which comprises a terminal alkyne, an aldehyde, and an amine.15 Moreover, a variety of propargylamines have been used to cure neuropsychiatric conditions like anxiety, Parkinson's disease, and depression.16 Various approved drugs, such as pargyline, selegiline, and rasagiline (Fig. 1), have a propargylamine scaffold.8,17 Late transition metals such as Au, Cu, and Ag are used to catalyse A3 reactions via one-pot synthesis.18

Fig. 1 Examples of approved drugs containing propargylamine skeletons.

Over the past two decades, a catalytic variation of A3 coupling has attracted chemists' attention15 A3 coupling catalysed by various nanocatalysts such as Fe3O4@R. tinctorum/Ag,19 Cu/C,16 Fe3O4@SiO2@DNHCS-Tr@CuI,20 Au nanoparticles,21 Fe3O4–MoO3 (ref. 22) and CuO/GNS23 have been reported. However, these methods involve use of harmful reagents, prolonged reaction time, use of additives and costly reagents. Hence, there is a need for a sustainable heterogeneous nanocatalyst for the facile synthesis of propargylamines via A3 coupling.

In the current work, we successfully develop a novel heterogeneous nanocatalyst, Fe3O4/PANI/CuI, for the synthesis of propargylamines via A3 coupling using pyrrolidine, phenylacetylene, and different benzaldehydes under neat conditions at 80 °C in a N2 atmosphere. The reaction was completed in 10 min with a high yield of the desired product. The fabricated nanocatalyst was easily recoverable and reusable with high catalytic efficiency for the synthesis of propargylamines.

Results and discussion

Synthesis and characterisation

Synthesis of Fe3O4 nanoparticles

Fe3O4 nanoparticles were synthesised using the co-precipitation approach. To a 250 mL round bottom flask containing 100 mL of water, 4.2 g of FeSO4·7H2O and 6.1 g of FeCl3·6H2O were added. The mixture was stirred at 80 °C for 1 h. Then, 10 mL of ammonia solution (25%) was added dropwise into the reaction mixture with continuous stirring. Then, the reaction was continuously stirred for another 1.5 h at the same temperature. The Fe3O4 nanoparticles were collected using a magnet and washed with water many times and then with ethanol. Finally, the synthesised nanoparticles were dried in an oven at 50 °C.5

Synthesis of Fe3O4/PANI nanoparticles

The obtained Fe3O4 nanoparticles were dispersed in 10 mL of deionized water. Subsequently, 0.3 mL of HCL (0.1 M) and 0.2 mL of aniline were added to this solution. Then, the solution was stirred for 1 h at room temperature. Then, the aqueous solution of ammonium persulfate (5 mL) was poured dropwise to the above reaction under ultrasonic irradiation. The stirring was then continued for 3 h in an ice bath. Then, nanoparticles were collected with a magnet and then washed many times with water and three times with ethanol, and further dried in an oven at 50 °C.

Synthesis of Fe3O4/PANI/CuI nanoparticles

The prepared Fe3O4/PANI nanoparticles were dispersed in water via stirring for 10 min. Then, copper iodide nanoparticles were added to this solution and it was stirred overnight at room temperature. Then, nanoparticles were washed with water and ethanol and dried in an oven overnight at 50 °C (Fig. 2).

Fig. 2 Schematic diagram for the synthesis of nanocomposite.

Characterisation of developed Fe3O4/PANI/CuI nanocatalyst

X-ray diffraction analysis of the Fe3O4/PANI/CuI nanocomposite is shown in Fig. 3. The diffraction angles (2θ) at 35.46° and 57.06° correspond to the crystal planes (311) and (511), respectively, of the Fe3O4 nanoparticles.24,25 The peaks at 2θ = 25.42°, 30.06°, 42.2°, 49.86°, 57.14°, 61.22°, and 67.3° correspond to the crystal planes (200), (311), (111), (420), (222), (220), and (420), respectively, of the cubic phase of CuI.26

Fig. 3 XRD pattern of Fe3O4/PANI/CuI nanocatalyst.

The field-emission scanning electron microscopy (FESEM) technique reveals the spherical morphology of the nanocomposite (Fig. 4). The transmission electron microscopy (TEM) analysis of the Fe3O4/PANI/CuI nanocomposite indicates that CuI is well embedded over the core–shell structure of Fe3O4 nanoparticles and the average size of nanoparticles is 42.6 nm, as shown in Fig. 5.

Fig. 4 FESEM analysis of Fe3O4/PANI/CuI nanocatalyst.

Fig. 5 TEM analysis of Fe3O4/PANI/CuI nanocatalyst.

The energy-dispersive X-ray analysis of the Fe3O4/PANI/CuI nanocatalyst revealed the presence of iron (42.74 wt%), nitrogen (1.47 wt%), copper (11.7 wt%), oxygen (15.29 wt%), iodine (19.9 wt%), and carbon (8.9 wt%), as can be seen in Fig. 6.

Fig. 6 EDAX analysis of Fe3O4/PANI/CuI nanocatalyst.

Fig. 7 illustrates the X-ray photoelectron spectra (XPS) of the Fe3O4/PANI/CuI nanocomposite. The spectra revealed the presence of Cu 2p1/2 and Cu 2p3/2 with binding energies at 952.88 and 932.44 eV, respectively, and the presence of I 3d3/2 and 3d5/2 with binding energies at 631 and 619.23 eV, respectively. The values for copper and iodine resemble the reported binding energy values of CuI, which confirm the +1 oxidation state of copper in the nanocomposite.27 The peak at 284.78 eV corresponds to the binding energy value of C 1s. The values of binding energies at 724.53 and 710.63 eV resemble the reported values of Fe 2p3/2 and Fe 2p1/2, respectively, while the peak at 530.17 eV corresponds to O 1s, confirming the presence of Fe3O4 in the nanocomposite. The broadness of the iron peaks indicates the presence of both oxidation states (Fe2+ and Fe3+) in Fe3O4.28

Fig. 7 XPS of Fe3O4/PANI/CuI nanocatalyst.

Fig. 8 shows the FTIR spectrum of Fe3O4/PANI/CuI; it depicts a peak at 3311 cm−1, which is attributed to the presence of the surface OH group in the nanocomposite.29 The peaks at 1598 and 1494 cm−1 are attributed to the C <svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="13.200000pt" height="16.000000pt" viewBox="0 0 13.200000 16.000000" preserveAspectRatio="xMidYMid meet"><metadata> Created by potrace 1.16, written by Peter Selinger 2001-2019 </metadata><g transform="translate(1.000000,15.000000) scale(0.017500,-0.017500)" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg> C stretching vibrations of a quinoid and benzenoid ring, respectively.30 A peak that appeared at 1374 cm−1 is similarly typical of polyaniline and is considered to be a consequence of C–N stretching vibrations near a quinonoid ring.31 The peak at 1161 cm−1 is due to the C–N stretching vibration.30 The peak at 553 cm−1 is the characteristic peak of ferrite nanoparticles.30

Fig. 8 FTIR of Fe3O4/PANI/CuI nanocatalyst.

N2-Adsorption desorption isotherm was collected using the Brunauer–Emmett–Teller (BET) technique, which is portrayed as a H3 hysteresis loop of isotherm and shows a surface area of 38.471 m2 g−1, pore radius of 2.16 nm, and pore volume of 0.076 cm3 g−1 (Fig. 9).

Fig. 9 N2 adsorption–desorption isotherm of nanocatalyst.

Fe3O4/PANI/CuI as heterogeneous nanocatalysts for the synthesis of propargylamine derivatives

We synthesized propargylamine derivatives using Fe3O4/PANI/CuI to investigate its catalytic properties in organic transformations (Scheme 1). For optimization, a model reaction was performed involving phenylacetylene (1), pyrrolidine (2), and 4-methyl benzaldehyde (3) using the nanocatalyst in various solvents or under neat conditions at 80 °C in a nitrogen atmosphere for the preparation of the desired product 4b, as shown in Table 1. We examined how different catalyst loading amounts, solvent concentrations, and temperatures affected the reaction kinetics, as presented in Table 1. Initially, the model reaction was performed in toluene (Table 1, entry 1), resulting in a 47% yield of the product. Subsequently, the reaction was carried out in polar aprotic solvents such as THF, acetonitrile, DMSO, and DMF. The desired product did not form in both acetonitrile and THF (Table 1, entries 2 and 3). However, the product was obtained with a 40% yield in DMF (Table 1, entry 4). The reaction was then monitored in environmentally friendly solvents such as ethanol, water, and ethylene glycol (EG), yielding no product in water (Table 1, entry 5), trace amounts of product in ethanol, and 30% product yield in EG (Table 1, entry 7). The product was isolated in good yield in neat conditions (Table 1, entry 8). By altering the catalyst loading, the % yield was found to remain unchanged on lowering or increasing the catalyst amount respectively (Table 1, entries 9 and 10). Further, we studied the influence of temperature on development of reaction. On raising the temperature, there was no change in product yield (Table 1 entry 11), while on decreasing the temperature, there was a reduction in the product yield (Table 1, entry 12).

Scheme 1 Fe3O4/PANI/CuI catalysed synthesis of propargyl derivatives via A3 coupling. Reaction conditions: nanocatalyst (10 mg), phenylacetylene (1 mmol), pyrrolidine (1 mmol), aromatic aldehyde (1 mmol), neat, 80 °C, N2 atm, 10 min.

Optimization of nanocatalyst for the synthesis of propargyl derivatives via A3 coupling using phenyl acetylene (1), pyrrolidine (2), and 4-methylbenzaldehyde (3)a

	
S. no.	Nanocatalyst (mg)	Solvent	Temp. (°C)	Time (min)	Yield (%)	
1	Fe3O4/PANI/CuI (10)	Toluene	80	10	47	
2	Fe3O4/PANI/CuI (10)	CH3CN	80	10	—	
3	Fe3O4/PANI/CuI (10)	THF	80	10	—	
4	Fe3O4/PANI/CuI (10)	DMF	80	10	40	
5	Fe3O4/PANI/CuI (10)	Water	80	10	—	
6	Fe3O4/PANI/CuI (10)	Ethanol	80	10	Trace	
7	Fe3O4/PANI/CuI (10)	EG	80	10	30	
8	Fe3O4/PANI/CuI (10)	Neat	80	10	96	
9	Fe3O4/PANI/CuI (5)	Neat	80	10	53	
10	Fe3O4/PANI/CuI (20)	Neat	80	10	96	
11	Fe3O4/PANI/CuI (10)	Neat	110	10	96	
12	Fe3O4/PANI/CuI (10)	Neat	50	10	22	
13	CuI (10)	Neat	80	10	41	
a Reaction conditions: catalyst (5–20 mg), 1 (1.0 mmol), 2 (1 mmol), 3 (1 mmol), solvent (2–3 mL), N2 atm, 80 °C, 10 min.

Under optimized conditions, we examined the recyclability of the catalyst to produce the product 4b. Once the reaction was completed, the catalyst was recovered from the reaction using a magnet and then washed many times with water and ethanol before being dried in the oven. The recovered catalyst was then used for seven cycles (Fig. 10). The stability of the recycled catalyst after seven cycles was confirmed by XRD, SEM, FTIR, EDAX and TEM, which confirmed that there was no change in the activity and morphology of the catalyst (ESI Fig. S1–S5†). An ICP study of the filtrate was done after catalyst recovery and showed the leached metal concentrations of copper and iron ion to be 2.08 and 0.12 ppm, respectively, which are lower than the authentic values of the respective ions according to WHO terms.32

Fig. 10 Catalyst recyclability test.

The existing methodology demonstrates sustainability and eco-friendliness, as evidenced by the green metrics values, as shown in Table 2 (refer to calculations in the ESI†), which closely approach the ideal values.

Green matrices values

Catalyst	Reaction mass efficiency	E-Factor	Process mass intensity	Carbon efficiency	
Fe3O4/PANI/CuI	90%	0.10	1.10	96%	

Table 3 provides a summary of the literature review, listing the previously established methods for producing propargyl derivatives, including the reaction conditions and corresponding yields.

Comparative analysis of various catalysts for the synthesis of propargylamine derivatives

S. no.	Nanocatalyst	Reaction conditions	Time	% Yield	Ref.	
1	Fe3O4@SiO2–Se-T/CuI	Neat, 80 °C	2 h	95	33	
2	ZSM-5/APTMS/(E)-4-((pyridine-2-ylimino)methyl)benzaldehyde/Cu-NPs	K2CO3, H2O, 60 °C	2 h	94	34	
3	UIO-66-NH2G1@PdNPs	Toluene, N2 gas, 110 °C	3 h	93	35	
4	[Fe3O4@bisimidazolium-Pd]2Cl−	PEG-400, 100 °C	2 h	98	36	
5	Fe3O4@starch-Acr@Cu(ii)	H2O, reflux	35 min	99	37	
6	g-C3N4-TCT-2AEDSEA-Ag-Cu-Ni	Toluene, 80 °C	8 h	91	38	
7	Fe3O4@SiO2-di-(pyridin-2-yl)amine-Cu	H2O, reflux	2 h	99	39	
8	Co2+-Cu@SA(0)-600	Toluene, 110 °C	1 h	89	40	
9	MMT-K10/Fe3O4/CuO	Toluene, 80 °C	8 h	91	41	
10	o-Cu2O-PVP	Neat, 100 °C	5 min	80	42	
11	Fe3O4/PANI/CuI	Neat, 80 °C	10 min	96	Our work	

The plausible mechanism for the synthesis of propargylamine via A3 coupling catalysed by the Fe3O4/PANI/CuI nanocomposite is shown in Fig. 11. The copper-based nanocatalyst activates the phenylacetylene ring and proceeds through an attack on the carbon of the iminium ion, which is formed from the aldehyde and amine and results in the formation of the desired product as well as catalyst regeneration.33,39

Fig. 11 Mechanism for Fe3O4/PANI/CuI catalysed synthesis of propargylamine derivative via A3 coupling.

General procedure for the synthesis of propargyl derivatives

In general, a mixture of phenylacetylene (1 mmol), pyrrolidine (1 mmol), aromatic aldehyde (1 mmol), and catalyst (10 mg) was added to a 50 mL round-bottom flask and stirred continuously at 80 °C. TLC was used to monitor the progress of the reaction. After the completion of the reaction, the reaction mixture was cooled and diluted with ethyl acetate, and the catalyst was separated with the aid of a magnet. The crude product was extracted with ethyl acetate and purified by column chromatography using basic alumina as a stationary phase and ethyl acetate : hexane as an eluent. The obtained pure product was confirmed by 1H and 13C NMR spectroscopy.

Conclusion

In summary, we have developed a sustainable heterogeneous copper-based magnetic nanocatalyst for the one-pot synthesis of propargylamine derivatives under solvent-free conditions with a short reaction time. The designed nanocatalyst is easily magnetically recoverable and can be recycled for up to seven runs without any drastic reduction in product yield. This protocol provides a shorter reaction time to obtain products with high yield and good catalytic activity under mild reaction conditions as compared to previously reported methods.

Data availability

The data that support the findings of this study are available from the corresponding author following reasonable request.

Conflicts of interest

The authors declare no conflicts of interest.

Supplementary Material

NA-006-D4NA00448E-s001

RC and SS acknowledges the Institution of Eminence at the University of Delhi and the Institute of Nanomedical Science (INMS) for their assistance. Nisha is obliged to USIC, University of Delhi for instrumental facilities and CSIR for awarding her a Junior Research Fellowship (09/045(1792)/2020-EMR-I). RC and SS are thankful to Indo-Russia DSTRFBR: INT/RUS/RFBR/389 and SS is thankful to SERB-TARE: TAR/2022/000618 for their financial assistance.
==== Refs
References

Lu A. H. Salabas E. E. Schuth F. Magnetic nanoparticles: synthesis, protection, functionalization, and application Angew. Chem., Int. Ed. 2007 46 8 1222 1244 10.1002/anie.200602866 17278160
Abedi M. Hosseini M. Arabmarkadeh A. Kazemi M. Magnetic nanocatalysts in A3-coupling reactions Synth. Commun. 2021 51 6 835 855
Saraswati T. E. Ogino A. Nagatsu M. Plasma-activated immobilization of biomolecules onto graphite-encapsulated magnetic nanoparticles Carbon 2012 50 3 1253 1261 10.1016/j.carbon.2011.10.044
Yeap S. P. Lim J. Ooi B. S. Ahmad A. L. Agglomeration, colloidal stability, and magnetic separation of magnetic nanoparticles: collective influences on environmental engineering applications J. Nanopart. Res. 2007 19 11 1 15
(a) Bohara R. A. Thorat N. D. Pawar S. H. Role of functionalization: strategies to explore potential nano-bio applications of magnetic nanoparticles RSC Adv. 2016 6 50 43989 44012 10.1039/C6RA02129H
(b) Singh S. Goel T. Singh A. Chugh H. Chakraborty N. Roy I. Tiwari M. Chandra R. Synthesis and characterization of Fe3O4@SiO2@PDA@Ag core–shell nanoparticles and biological application on human lung cancer cell line and antibacterial strains Artif. Cells, Nanomed., Biotechnol. 2024 52 1 46 58 10.1080/21691401.2023.2295534 38156875
(c) Kazemi M. Mohammadi M. Magnetically recoverable catalysts: catalysis in synthesis of polyhydroquinolines Appl. Organomet. Chem. 2020 34 3 e5400 10.1002/aoc.5400
(a) Morais J. P. L. Bernardino D. V. Batista B. d. S. Pereira W. O. Amaral F. M. B. Branca M. C. M. P. Gasparin F. P. Conductive polymer blend based on polyaniline and galactomannan: optical and electrical properties Synth. Met. 2023 295 117346 10.1016/j.synthmet.2023.117346
(b) Kohli S. Rathee G. Hooda S. Chandra R. Al2O3/CuI/PANI nanocomposite catalyzed green synthesis of biologically active 2-substituted benzimidazole derivatives Dalton Trans. 2021 50 22 7750 7758 10.1039/D1DT00806D 33989371
(a) Chenjing J. Jie H. Fangyuan C. Xiaoxia W. Rong G. Fe3O4@PANI hybrid shell as a multifunctional support for Au nanocatalysts with a remarkably improved catalytic performance Langmuir 2017 33 4520 4527 10.1021/acs.langmuir.7b00640 28412814
(b) Nisha Kohli S. Sharma N. Chandra R. Development of ZnO/PANI/Ag nanocomposite for synthesis of bioactive xanthene-1, 8 (2H)-dione derivatives Appl. Organomet. Chem. 2023 37 e7049 10.1002/aoc.7049
(a) Zarenezhad E. Taghavi R. Kamrani P. Farjam M. Rostamnia S. Gold nanoparticle decorated dithiocarbamate modified natural boehmite as a catalyst for the synthesis of biologically essential propargylamines RSC Adv. 2022 12 49 31680 31687 10.1039/D2RA03725D 36380962
(b) Munnik P. De Jongh P. E. De Jong K. P. Recent developments in the synthesis of supported catalysts Chem. Rev. 2015 115 14 6687 6718 10.1021/cr500486u 26088402
(c) Mohammadi M. Khodamorady M. Tahmasbi B. Bahrami K. Ghorbani-Choghamarani A. Boehmite nanoparticles as versatile support for organic–inorganic hybrid materials: synthesis, functionalization, and applications in eco-friendly catalysis J. Ind. Eng. Chem. 2021 97 1 78 10.1016/j.jiec.2021.02.001
(d) Zheng X. Li P. Dou S. Sun W. Pan H. Wang D. Li Y. Non-carbon-supported single-atom site catalysts for electrocatalysis Energy Environ. Sci. 2021 14 5 2809 2858 10.1039/D1EE00248A
Rawat M. Rawat D. S. CuO@NiO nanocomposite catalyzed synthesis of biologically active indenoisoquinoline derivatives ACS Sustain. Chem. Eng. 2020 36 13701 13712 10.1021/acssuschemeng.0c03898
Ojha N. K. Zyryanov G. V. Majee A. Charushin V. N. Chupakhin O. N. Santra S. Copper nanoparticles as inexpensive and efficient catalyst: A valuable contribution in organic synthesis Coord. Chem. Rev. 2017 353 1 57 10.1016/j.ccr.2017.10.004
Khan S. Shah S. S. Janjua N. K. Yurtcan A. B. Nazir M. T. Katubi K. M. Alsaiari N. S. Alumina supported copper oxide nanoparticles (CuO/Al2O3) as high-performance electrocatalysts for hydrazine oxidation reaction Chemosphere 2023 137659 10.1016/j.chemosphere.2022.137659 36603674
Kohli S. Nisha Rathee G. Hooda S. Chandra R. Exploring the untapped catalytic application of a ZnO/CuI/PPy nanocomposite for the green synthesis of biologically active 2,4,5-trisubstituted imidazole scaffolds Nanoscale Adv. 2023 5 8 2352 2360 10.1039/D3NA00077J 37056623
Patil K. N. Manikanta P. Nikam R. R. Srinivasappa P. M. Jadhav A. H. Aytam H. P. Rao K. S. R. Nagaraja B. M. Effect of precipitating agents on activity of co-precipitated Cu–MgO catalysts towards selective furfural hydrogenation and cyclohexanol dehydrogenation reactions Results Eng. 2023 17 100851 10.1016/j.rineng.2022.100851
(a) Cao S. Zou B. Yang J. Wang J. Feng H. Hollow CuO–CeO2 Nanospheres for an effectively catalytic annulation/A3-coupling reaction sequence ACS Appl. Nano Mater. 2022 5 8 11689 11698 10.1021/acsanm.2c02666
(b) Ndolomingo M. J. Bingwa N. Meijboom R. Review of supported metal nanoparticles: synthesis methodologies, advantages and application as catalysts J. Mater. Sci. 2020 55 15 6195 6241 10.1007/s10853-020-04415-x
(c) Ghobakhloo F. Azarifar D. Mohammadi M. Keypour H. Zeynali H. Copper (II) Schiff-base complex modified UiO-66-NH2 (Zr) metal–organic framework catalysts for Knoevenagel condensation–Michael addition–cyclization reactions Inorg. Chem. 2022 61 12 4825 4841 10.1021/acs.inorgchem.1c03284 35285616
Rokade B. V. Barker J. Guiry P. J. Development of and recent advances in asymmetric A3 coupling Chem. Soc. Rev. 2019 48 18 4766 4790 10.1039/C9CS00253G 31465045
Rathod P. V. Puguan J. M. C. Kim H. Solvent-free synthesis of propargyl amines via A3 coupling reaction and organic pollutant degradation in aqueous condition using Cu/C catalyst Appl. Organomet. Chem. 2020 34 12 e5986 10.1002/aoc.5986
Weinreb O. Amit T. Bar-Am O. Youdim M. B. Rasagiline: a novel anti-Parkinsonian monoamine oxidase-B inhibitor with neuroprotective activity Prog. Neurobiol. 2010 92 3 330 344 10.1016/j.pneurobio.2010.06.008 20600573
Farhi J. Lykakis I. N. Kostakis G. E. Metal catalysed A3 coupling methodologies: classification and visualization Catalysts 2022 12 660 10.3390/catal12060660
Veisi H. Mohammadi L. Hemmati S. Tamoradi T. Mohammadi P. In situ immobilized silver nanoparticles on Rubia tinctorum extract-coated ultrasmall iron oxide nanoparticles: an efficient nanocatalyst with magnetic recyclability for synthesis of propargylamines by A3 coupling reaction ACS Omega 2019 4 9 13991 14003 10.1021/acsomega.9b01720 31497717
Peiman S. Baharfar R. Hosseinzadeh R. CuI NPs immobilized on a ternary hybrid system of magnetic nanosilica, PAMAM dendrimer and trypsin, as an efficient catalyst for A3-coupling reaction Res. Chem. Intermed. 2022 48 4 1365 1382 10.1007/s11164-021-04654-w
Kidwai M. Bansal V. Kumar A. Mozumdar S. The first Au-nanoparticles catalyzed green synthesis of propargylamines via a three-component coupling reaction of aldehyde, alkyne and amine Green Chem. 2007 9 7 742 745 10.1039/B702287E
Gawande M. B. Branco P. S. Nogueira I. D. Ghumman C. A. A. Bundaleski N. Santos A. Teodoro O. M. Luque R. Catalytic applications of a versatile magnetically separable Fe–Mo (nanocat-Fe–Mo) nanocatalyst Green Chem. 2013 15 3 682 689 10.1039/C3GC36844K
Gopiraman M. Deng D. Ganesh Babu S. Hayashi T. Karvembu R. Kim I. S. Sustainable and versatile CuO/GNS nanocatalyst for highly efficient base free coupling reactions ACS Sustain. Chem. Eng. 2015 3 10 2478 2488 10.1021/acssuschemeng.5b00542
Karunanayake A. G. Navarathna C. M. Gunatilake S. R. Crowley M. Anderson R. Mohan D. Mlsna T. Fe3O4 nanoparticles dispersed on Douglas fir biochar for phosphate sorption ACS Appl. Nano Mater. 2019 2 6 3467 3479 10.1021/acsanm.9b00430
Silva V. A. J. Andrade P. L. Silva M. P. C. Valladares L. D. L. S. Aguiar J. A. Synthesis and characterization of Fe3O4 nanoparticles coated with fucan polysaccharides J. Magn. Magn. Mater. 2013 343 138 143 10.1016/j.jmmm.2013.04.062
Rawat M. Rawat D. S. CuI@Al2O3 catalyzed synthesis of 2-aminonicotinonitrile derivatives under solvent free condition Tetrahedron Lett. 2019 60 16 1153 1157 10.1016/j.tetlet.2019.03.048
Wang X. Shen Y. Xie A. Qiu L. Li S. Wang Y. Novel structure CuI/PANI nanocomposites with bifunctions: superhydrophobicity and photocatalytic activity J. Mater. Chem. 2011 21 26 9641 9646 10.1039/C0JM04558F
Kohli S. Rathee G. Hooda S. Chandra R. An efficient approach for the green synthesis of biologically active 2,3-dihydroquinazolin-4 (1H)-ones using a magnetic EDTA coated copper based nanocomposite RSC Adv. 2023 13 3 1923 1932 10.1039/D2RA07496F 36712626
Rajendran S. Pachaiappan R. Hoang T. K. Karthikeyan S. Gnanasekaran L. Vadivel S. Soto-Moscoso M. Gracia-Pinilla M. A. CuO-ZnO-PANI a lethal pnp combination in degradation of 4-chlorophenol under visible light J. Hazard. Mater. 2021 416 125989 10.1016/j.jhazmat.2021.125989 34492886
Alam J. Riaz U. Ahmad S. Effect of ferrofluid concentration on electrical and magnetic properties of the Fe3O4/PANI nanocomposites J. Magn. Magn. Mater. 2007 314 93 99 10.1016/j.jmmm.2007.02.195
Marek J. Vilcakova J. Kazantseva N. E. Prokes J. Trchova M. Stejskal J. Conducting and magnetic hybrid polyaniline/nickel composites Synth. Met. 2022 291 117165 10.1016/j.synthmet.2022.117165
Yang W. Vogler B. Lei Y. Wu T. Metallic ion leaching from heterogeneous catalysts: an overlooked effect in the study of catalytic ozonation processes Environ. Sci.: Water Res. Technol. 2017 3 6 1143 1151 10.1039/C7EW00273D
Rangraz Y. Nemati F. Elhampour A. Design, synthesis, and characterization of a novel magnetically recoverable copper nanocatalyst containing organoselenium ligand and its application in the A3 coupling reaction Ind. Eng. Chem. Res. 2019 58 37 17308 17318 10.1021/acs.iecr.9b03843
Leila M. Hosseinifard M. Vaezi M. R. Rostamnia S. Stabilization of copper nanoparticles onto the double Schiff-base-functionalized ZSM-5 for A3 coupling reaction catalysis aimed under mild conditions RSC Adv. 2023 13 4843 4858 10.1039/D2RA07700K 36760293
Mansoureh C. Alinezhad H. Ghasemi S. Post-synthetic modification of UIO-66-NH2 as a highly efficient and recyclable nanocatalyst in the three-component coupling (A3) reaction for the synthesis of propargylamine derivatives J. Organomet. Chem. 2023 1002 122903 10.1016/j.jorganchem.2023.122903
Althomali H. R. Abbood M. K. Altalbawy F. M. Saleh E. A. M. Abdullaev S. S. Ibrahim A. J. Ansari S. A. Parra R. M. R. A novel nanomagnetic palladium (II) complex of bisimidazolium-based N-heterocyclic carbene an efficient heterogeneous catalyst for A3 coupling reactions J. Mol. Struct. 2023 135911 10.1016/j.molstruc.2023.135911
Mahmood T. Mazhari F. Mavvaji M. Copper (II)-immobilized on starch-coated nanomagnetite as an efficient and magnetically recoverable catalyst for the synthesis of propargyl amines through one-pot A3 coupling reaction Org. Prep. Proced. Int. 2023 55 251 264 10.1080/00304948.2022.2134697
Zarei M. Mohammadzadeh I. Saidi K. Sheibani H. Synthesis of Ag–Cu–Ni nanoparticles stabilized on functionalized g–C3N4 and investigation of its catalytic activity in the A3-coupling reaction ACS Omega 2023 8 18685 18694 10.1021/acsomega.3c00572 37273646
Ahmad S. Ahmad A. M. Raed O. S. Mustafa Z. M. Ali K. W. Mohammed A. J. Magnetic nanoparticles modified with di (pyridin-2-yl) amine ligand supported copper complex: a novel and efficient magnetically reusable catalyst for A3 coupling and CS cross-coupling reactions Polycyclic Aromat. Compd. 2023 43 4407 4425 10.1080/10406638.2022.2091617
Kaur M. Sharma S. Choudhary A. Paul S. Tuning the catalytic performance of a Cu supported silica modified γ-Al2O3 nanocatalyst via cobalt-doping for A3-coupling React. Chem. Eng. 2023 8 2141 2155 10.1039/D3RE00131H
Fatemeh H. B. Khabazzadeh H. Fayazi M. Rezaeipour M. Synthesis of CuO and Cu2O nanoparticles stabilized on the magnetic Fe3O4-Montmorillonite-K10 and comparison of their catalytic activity in A3 coupling reaction J. Iran. Chem. Soc. 2023 20 1439 1456 10.1007/s13738-023-02768-z
Bao H. Li A. Y. Kairouz V. Moores A. Ultra-fast Cu-based A3-coupling catalysts: faceted Cu2O microcrystals as efficient catalyst-delivery systems in batch and flow conditions Can. J. Chem. 2022 100 3 217 223 10.1139/cjc-2021-0197
