Efficient synthesis of symmetrical anhydrides by cross dehydrogenative coupling of aryl aldehydes over CuFe2O4 nanoparticles

Article abstract of DOI:10.1007/s00706-021-02741-7

Nano copper ferrite catalyst is prepared and characterized by scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, vibrational sample magnetometry, and Fourier transform infrared. The catalytic activity is probed for cross-dehydrogenative coupling of aromatic aldehydes in the presence of tert-butyl hydroperoxide as the oxidant. This catalytic protocol appears as a simple, rather cheap, clean, and efficient practical strategy for the synthesis of symmetrical anhydrides, with proper efficiency (66%). The catalyst can be easily separated from the reaction mixture by an external magnet and reused several times in subsequent reactions, without any measurable loss of its efficiency. Graphic abstract: [Figure not available: see fulltext.]

Full text of DOI:10.1007/s00706-021-02741-7

Monatshefte für Chemie - Chemical Monthly (2021) 152:461–468
https://doi.org/10.1007/s00706-021-02741-7
ORIGINAL PAPER
Efcient synthesis of symmetrical anhydrides
by cross dehydrogenative coupling of aryl aldehydes over CuFe2O4
nanoparticles
Esmaiel Eidi1 · Mohamad Z. Kassaee1 · Zahra Nasresfahani1
Received: 16 October 2019 / Accepted: 2 February 2021 / Published online: 6 April 2021
© Springer-Verlag GmbH Austria, part of Springer Nature 2021
Abstract
Nano copper ferrite catalyst is prepared and characterized by scanning electron microscopy, energy dispersive X-ray, X-ray
difraction, vibrational sample magnetometry, and Fourier transform infrared. The catalytic activity is probed for cross-
dehydrogenative coupling of aromatic aldehydes in the presence of tert-butyl hydroperoxide as the oxidant. This catalytic
protocol appears as a simple, rather cheap, clean, and efcient practical strategy for the synthesis of symmetrical anhydrides,
with proper efciency (66%). The catalyst can be easily separated from the reaction mixture by an external magnet and reused
several times in subsequent reactions, without any measurable loss of its efciency.
Graphic abstract
Keywords Copper ferrite · Aldehyde · Coupling · Magnetic nanocatalyst · Recyclable
Introduction
applications in science and technology, extensive works on
certain spinel ferrites have been carried out [3, 4]. Recently,
magnetic nanoparticles have materialized as efcient cata-
lysts because they are recyclable, reusable and stable. In
addition, large surface/volume ratio of the nanoparticles is
mainly responsible for their catalytic performance. Hence,
the catalytic power of the spinel ferrites as a magnetic cata-
lyst has been studied in some chemical reactions [5–7]. In
recent years, copper catalysts have received broad inter-
ests because of their many advantages such as availability,
economy, high activity, high efciency and low toxicity
[8–11]. So, between diferent spinel ferrites with formula
MFe2O4 (M=Mn, Fe, Ni, Co, Cu, etc.), CuFe2O4 has quite
interesting properties and is used for a variety of applications
[12–14]. They can be prepared using various methods such
as co-precipitation [15], mechano-chemical [16], micelle
Ferrites are ceramic-like materials with magnetic properties
which are described by the formula M(FexOy). Combination
of two metals in the oxide matrix and their distribution on
octahedral and tetrahedral sites may afect ferrites chemi-
cal and physical properties. In general, there are three types
of ferrites (spinel ferrite, garnet, and hexagonal ferrite) [1,
2]. Among them, the spinel ferrites are an important class
of magnetic nanoparticles where the metallic cations M2+
and Fe3+ distribution appear on octahedral and tetrahedral
sites. Due to their theoretical understanding and potential
* Mohamad Z. Kassaee
kassaeem@modares.ac.ir
1
Department of Chemistry, Tarbiat Modares University,
Tehran, Iran
Vol.:(0123456789)
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E. Eidi et al.
synthesis [17], hydrothermal synthesis [18], etc. Recently,
many research groups have explored the vital use of these
nano ferrites as green, recyclable, and reusable catalysts in
organic synthesis [19–21].
In the FT-IR spectrum, two absorption bands correspond-
ing to the stretching vibrations of the tetrahedral and octa-
hedral sites are observed around 600 and 400 cm−1, respec-
tively [42, 43]. The broad absorption band at 3417 cm−1
corresponds to hydroxyl groups stretching vibrations. The
peak 1628 cm−1 is due to bendings of H2O adsorbed at the
surface of CuFe2O4 (Fig. 1).
Carboxylic anhydrides are an important class of organic
compounds used as versatile reagents in the preparation of
carboxylic acid derivatives. They are also employed as a
reactive intermediate in various types of reactions [22–25].
Anhydrides are important but less abundant in nature. There-
fore, their synthesis is signifcant for organic chemists. Tra-
ditionally, these compounds are prepared by dehydrating
carboxylic acids with dehydrating agents such as thionyl
chloride [26], phosgene [27], isocyanates [28], carbodiim-
ides [29], phosphoranes [30], and 1,3,5-triazines [31]. Since
these procedures are afected by many drawbacks, the devel-
opment of an improved methodology for the synthesis of
anhydrides from easily available starting materials is highly
desirable.
The crystalline structure of CuFe2O4 is studied via XRD
analysis, where all the X-ray difraction peaks are compared
with the standard card (JCPDS NO. 34-0425). Six distinct
difraction peaks can be observed at 21.2°, 35.10°, 41.59°,
50.69°, 63.38°, 67.50° and 74.55° (2θ), which correspond
to the (111), (220), (311), (400), (511), and (440) planes,
respectively (Fig. 2). It is revealed that the CuFe2O4 nano-
particles have a cubic structure and show the presence of
only spinel phase without any impurities.
The SEM image of CuFe2O4 shows nanocrystals that have
a rod-shaped morphology with a particle size of 70–150 nm
and a diameter of about 20–50 nm (Fig. 3). In addition, the
energy dispersive X-ray (EDX) analysis shows the presence
of Cu, Fe, and O elements in the product (Fig. 4). The ratio
of Fe/Cu is very close to their atomic ratio (2:1) in CuFe2O4
formula, confrming the formation of nanoparticles.
In recent years, considerable attention has been attracted
to the cross-dehydrogenative coupling (CDC) reactions
because of their atom economy, step-economy, and the out-
standing role in the formation of C–C and C–X (X=heter-
oatom) bonds [32, 33]. Aldehydes and other readily avail-
able materials are advantageous in CDC reactions [34, 35].
These compounds have been used in signifcant organic
transformations [36–38]. Also, a number of metal catalytic
approaches have been developed towards the synthesis of
symmetrical anhydrides from aldehydes using tert-butyl
hydroperoxide (TBHP) as an oxidant [39–41].
Magnetic properties of CuFe2O4 nanoparticles may be
estimated by VSM. Its magnetization curves display a sat-
uration magnetization value of 30 emu g−1 (Fig. 5). This
shows high permeability in magnetization and high revers-
ibility in the hysteresis loop.
After the preparation and characterization, the catalytic
activity of CuFe2O4 is explored through the synthesis of
symmetrical anhydrides by the CDC of aldehydes. Firstly,
to optimize reaction conditions for the formation of benzoic
anhydride, the efect of catalyst amount, solvent, oxidant,
and reaction temperature are probed. Initial investigation is
started in CH3CN as a solvent, TBHP as oxidant, at dif-
ferent temperatures, and with various amounts of catalyst
(Table 1). The results show when the reaction is performed
with 1.5 equivalent of TBHP and 20 mg of the catalyst, a
maximum yield of 66% is observed in refux condition in
CH3CN (entry 8). However, with the increasing quantity of
TBHP and the catalyst, yield of the product does not improve
(entries 9, 10). Furthermore, in the absence of TBHP, no
yield for the product is detected (entry 16). The efect of
other solvents and oxidants is also tested but the results are
inefective and obtain in lower yields (entries 11–15).
To explore the efciency and the scope of this proto-
col, the reaction is evaluated using a range of aromatic
aldehydes in optimum conditions (Table 2). Aldehydes
having electron-donating groups such as CH3 and OCH3
react efciently to furnish their corresponding anhydrides,
under the reaction conditions. For benzaldehydes with
methyl group in ortho or para positions, products 2b and
2c are obtained in 61 and 62% yields, respectively. While
Due to copper is a superior activity, in this study we
report a novel CDC based approach for the synthesis of sym-
metrical anhydrides through oxidative activation of sp2 C–H
bond of aldehydes using TBHP as an oxidizing agent and
copper ferrite nanoparticles (CuFe2O4 NPs) as the catalyst
(Scheme 1).
Results and discussion
Here we discuss characterizations of synthesized CuFe2O4
nanoparticles by various techniques including Fourier
transform infrared spectroscopy (FT-IR), X-ray difraction
(XRD), scanning electron microscopy (SEM), energy dis-
persive X-ray (EDX), and vibrating sample magnetometer
(VSM).
Scheme 1
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Efcient synthesis of symmetrical anhydrides by cross dehydrogenative coupling of aryl…
463
Fig. 1 The FT-IR spectrum of CuFe2O4 NPs
Fig. 2 The XRD pattern of CuFe2O4 NPs
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464
E. Eidi et al.
intramolecular CDC of an aromatic o-phthaldehyde leads
to the formation of phthalic anhydride 2f in 52% yield.
For the synthesis of symmetric anhydrides with
this methodology, a plausible mechanism is suggested
(Scheme 2). Initially, t-butyloxy radical is generated by
conversion of the copper(II) to copper(III) species through
electron transfer to TBHP. Then, the t-butoxyl radical
abstracts a hydrogen atom from the aldehyde which leads
to the formation of an acyl radical. Next, the acyl radical
couples with t-butylperoxy radical, afording a perester
intermediate. The cleavage of the O–O bond in this inter-
mediate generates the carboxyl radical which combines
with another acyl radical giving the desired anhydride [39,
41].
The recovery and reuse of catalysts are desirable for
a greener process. Hence, the reusability of the catalyst
is investigated for our model reaction. The catalyst is
magnetically recovered by an external magnetic feld and
washed with EtOH. After being dried, it is reused in the
next run. The procedure is repeated and the results indicate
that the catalyst could be recycled three times without a
signifcant loss of its activity (Fig. 6).
Fig. 3 The SEM image of CuFe2O4 NPs
p-methoxybenzaldehyde give the corresponding anhydride
2d with only 56% yield. Likewise, when other aromatic
aldehydes bearing more methoxy substituents such as
3,4-dimethoxy- and 3,4,5-trimethoxybenzaldehyde are
used, respective anhydrides 2g and 2h are detected with
modest yields of 44 and 39%, respectively. Then, an aro-
matic aldehyde possessing electron-withdrawing group
such as p-chlorobenzaldehyde is reacted and converted
to the corresponding product 2e in 34% yield. Moreover,
Comparison of catalytic efciency of CuFe2O4 NPs
with those reported in the literature, for the synthesis of
anhydrides from aldehydes, indicates that our method is
simpler, more convenient with the easier operation, and
with the reusability of the nanocatalyst in several catalytic
cycles (Scheme 3) [39, 41].
Fig. 4 The EDX spectrum of CuFe2O4 NPs
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Efcient synthesis of symmetrical anhydrides by cross dehydrogenative coupling of aryl…
465
50
of symmetrical anhydride derivatives. This achievement
was reached through the treatment of substituted aromatic
aldehydes over the magnetically separable CuFe2O4 NPs
with easy handling, simple workup procedure, ease of
separation, and recyclability of the catalyst. The magnetic
nanocatalyst was stable and could be reused in three suc-
cessive runs with no signifcant structural change or loss
of activity.
40
30
20
10
0
-10
-20
-30
-40
-50
Experimental
All chemical reagents used in our experiments are purchased
from Merck or Aldrich Chemical Company with high purity.
All solvents are distilled, dried and purifed using stand-
ard procedures. Thin-layer chromatography (TLC) is per-
formed using aluminium plates coated with silica gel 60
F-254 (Merck). Melting points are measured on an Electro-
thermal 9100 apparatus. Fourier transform infrared (FT-IR)
spectra are recorded using KBr pellets on a Nicolet IR-100
infrared spectrometer. The powder X-ray difraction spec-
trum is recorded at room temperature using a Philips X-Pert
1710 difractometer with Co Kα (α=1.79285 Å) voltage of
40 kV, current of 40 mA, in the range of 20°–80° (2θ) with a
scan speed of 0.02°/s. An energy-dispersive detector (EDS)
coupled to the microscope is used to identify chemical ele-
ments of the prepared catalyst. The particle morphology
is examined by scanning electron microscopy using SEM
(HITACHI S-4160). Magnetic properties are obtained by a
vibrating magnetometer/Alternating Gradient Force Mag-
netometer (VSM/AGFM, MDK Co., Iran).
-10000-8000 -6000 -4000 -2000
0
2000 4000 6000 8000 10000
Applied field / Oe
Fig. 5 The VSM curve for CuFe2O4 NPs
Table 1 Screening of the reaction conditions for synthesis of benzoic
anhydride (2a) from benzaldehyde over CuFe2O4
Entry Catalyst/mg Solvent Oxidant
(equiv.)
Temp./°C Yielda/%
1
2
3
4
5
6
8
9
10
11
12
13
14
15
16
10
10
10
15
15
15
20
25
20
20
20
20
20
20
20
CH3CN TBHP (1.5)
CH3CN TBHP (1.5)
CH3CN TBHP (1.5)
CH3CN TBHP (1.5)
CH3CN TBHP (1)
CH3CN TBHP (2.5)
CH3CN TBHP (1.5)
CH3CN TBHP (1.5)
CH3CN TBHP (2.5)
CH2Cl2 TBHP (1.5)
Dioxane TBHP (1.5)
Toluene TBHP (1.5)
CH3CN H2O2
25
50
–
10
28
37
22
32
66
68
50
<10
23
27
<5
–
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
Refux
General procedure for the synthesis of CuFe2O4 NPs
The CuFe2O4 nanoparticles are prepared through a co-
precipitation method [21, 45, 46]. In a typical procedure,
the required amount of Cu(NO3)2∙3H2O (0.5 g, 2.05 mmol)
and Fe(NO3)3∙9H2O (1.67 g, 4.1 mmol) are dissolved, then
NaOH solution (2 M) is added dropwise at room temperature
until a reddish-black precipitate is formed. Then, the tem-
perature is raised to 90 °C and stirring is done for 6 h. The
resulting precipitate is separated by a magnetic separator,
washed with deionized water for several times and dried at
80 °C overnight. Finally, the powder is calcined in a furnace
at 500 °C for 5 h.
CH3CN NaOCl
CH3CN
–
–
aIsolated yield
Conclusion
In continuation of our research, a heterogeneous nano-
catalyst, CuFe2O4 NPs, was fabricated and characterized.
Subsequently, it was employed in an efcient preparation
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466
E. Eidi et al.
Table 2 Substrate scope for synthesis of anhydrides from aldehydes over CuFe2O4
Comp
2a
Structure
Yield/%
66
M.p./°C
–
Lit. m.p./°C
Colorless oil [39, 41]
2b
2c
61
62
–
Liquid [41]
83–85
83–86 [39, 41]
2d
2e
2f
56
34
52
95–97
95.5–97.5 [39, 41]
180–182 [44]
179–181
130–132
132–134 [39, 41]
2g
2h
44
39
123–125
157–159
122–124 [40, 41]
158–160 [39, 40]
Reaction conditions: arylaldehyde (1 mmol), TBHP (1.5 equiv), 2 cm3 CH3CN, 20 mg CuFe2O4, 80 °C, 4 h. Isolated yield
was monitored by TLC). After completion of the reac-
tion, the solvent is evaporated and the residue is extracted
with ethyl acetate and 10% saturated NaHCO3 solution.
The organic layer is then dried with anhydrous sodium
sulfate. The crude product is purifed using silica gel col-
umn chromatography (hexane/ethyl acetate (8:2) to give
the desired anhydride.
General procedure for the synthesis of aromatic
anhydrides over CuFe2O4 catalyst
A solution of aldehyde (1 mmol) and CuFe2O4 (20 mg)
in 2 cm3 CH3CN, TBHP (1.5 eq. from a 6 M solution of
in decane) is slowly stirred. Then, the reaction mixture is
refuxed for the appropriate time (the reaction progress
1 3

Efcient synthesis of symmetrical anhydrides by cross dehydrogenative coupling of aryl…
467
Scheme 2
SupplementaryInformation Theonlineversioncontainssupplementary
material available at https://doi.org/10.1007/s00706-021-02741-7.
References
1. Muralidharan S, Saraswathy V, Berchmans LJ, Thangavel K, Ann
KY (2010) Sens Actuators B 145:225
2. Yan S, Dong L, Chen Z, Wang X, Feng Z (2014) J Magn Magn
Mater 353:47
3. Polshettiwar V, Varma RS (2010) Tetrahedron 66:1091
4. Patzke GR, Zhou Y, Kontic R, Conrad F (2011) Angew Chem Int
Ed 50:826
5. Eidi E, Kassaee MZ, Nasresfahani Z (2016) Appl Organomet
Chem 30:561
Fig. 6 Reusability of CuFe2O4 NPs in the model reaction
6. Eidi E, Kassaee MZ, Cummings PT (2018) Res Chem Intermed
44:5787
7. Moghaddam FM, Tavakoli G, Rezvani HR (2015) Catal Commun
60:82
Scheme 3
8. Monnier F, Taillefer M (2009) Angew Chem Int Ed 48:6954
9. Liu C, Zhang H, Shi W, Lei A (2011) Chem Rev 111:1780
10. Stefani HA, Guarezemini AS, Cella R (2010) Tetrahedron 66:7871
11. Li C-J (2008) Acc Chem Res 42:335
12. Singh S, Yadav BC, Gupta VD, Dwivedi PK (2012) Mater Res
Bull 47:3538
13. Haija MA, Ayesh AI, Ahmed S, Katsiotis MS (2016) Appl Surf
Sci 369:443
14. Haija MA, Abu-Hani AFS, Hamdan N, Stephen S, Ayesh AI
(2017) J Alloys Compd 690:461
15. Maaz K, Karim S, Mumtaz A, Hasanain SK, Liu J, Duan JL
(2009) J Magn Magn Mater 321:1838
1 3

468
E. Eidi et al.
16. Manova E, Kunev B, Paneva D, Mitov I, Petrov L, Estournès
C, D’Orléan C, Rehspringer J, Kurmoo M (2004) Chem Mater
16:5689
32. Zhang C, Zong X, Zhang L, Jiao N (2012) Org Lett 14:3280
33. Wang T, Chen S, Shao A, Gao M, Huang Y, Lei A (2014) Org Lett
17:118
17. Liu C, Zou B, Rondinone AJ, Zhang ZJ (2000) J Phys Chem B
104:1141
34. Allen CL, Williams JMJ (2011) Chem Soc Rev 40:3405
35. Biju AT, Kuhl N, Glorius F (2011) Acc Chem Res 44:1182
36. Liu X, Jensen KF (2012) Green Chem 14:1471
37. Ke Q, Zhang B, Hu B, Jin Y, Lu G (2015) Chem Commun 51:1012
38. Zeng J-W, Liu Y-C, Hsieh P-A, Huang Y-T, Yi C-L, Badsara SS,
Lee C-F (2014) Green Chem 16:2644
18. Chen D, Chen D, Jiao X, Zhao Y, He M (2003) Powder Technol
133:247
19. Rajput JK, Arora P, Kaur G, Kaur M (2015) Ultrason Sonochem
26:229
20. Kumar AS, Thulasiram B, Laxmi SB, Rawat VS, Sreedhar B
(2014) Tetrahedron 70:6059
39. Saberi D, Shojaeyan F, Niknam K (2016) Tetrahedron Lett 57:566
40. Nuree Y, Singha R, Ghosh M, Roy P, Ray JK (2016) Tetrahedron
Lett 57:1479
21. Dandia A, Jain AK, Sharma S (2013) RSC Adv 3:2924
22. Miyashita M, Shiina I, Miyoshi S, Mukaiyama T (1993) Bull
Chem Soc Jpn 66:1516
41. Khatun N, Santra SK, Banerjee A, Patel BK (2015) Eur J Org
Chem 2015:1309
23. Shiina I, Nakata K, Ono K, Onda YS, Itagaki M (2010) J Am
Chem Soc 132:11629
42. Yadav RS, Havlica J, Kuřitka I, Kozakova Z, Palou M,
Bartoníčková E, Boháč M, Frajkorová F, Masilko J, Hajdúchová
M (2015) J Supercond Nov Magn 28:1417
24. Mukaiyama T, Shiina I, Miyashita M (1992) Chem Lett 21:625
25. Mukaiyama T, Izumi J, Miyashita M, Shiina I (1993) Chem Lett
22:907
43. Alijani HQ, Pourseyedi S, Torkzadeh-Mahani M, Seifalian A,
Khatami M (2020) Artif Cells Nanomed Biotechnol 48:242
44. Gaspa S, Amura I, Porcheddu A, De Luca L (2017) New J Chem
41:931
26. Kazemi F, Kiasat AR, Mombaini B (2007) Synth Commun
37:3219
27. Kocz R, Roestamadji J, Mobashery S (1994) J Org Chem
59:2913
45. Kader SS, Paul DP, Hoque SM (2014) Int J Mater Mech Manuf
2:5
28. Keshavamurthy KS, Vankar YD, Dhar DN (1982) Synthesis
1982:506
46. Zhu Z, Li X, Zhao Q, Li Y, Sun C, Cao Y (2013) Mater Res Bull
48:2927
29. Stadler A, Kappe CO (2001) Tetrahedron 57:3915
30. Mestres R, Palomo C (1981) Synthesis 1981:218
31. Kaminski ZJ, Kolesinska B, Małgorzata M (2004) Synth Commun
34:3349
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