Magnetically recoverable 2-(aminomethyl)phenols-modified nanoparticles as a catalyst for Knoevenagel condensation and carrier for palladium to catalytic Suzuki coupling reactions

Article abstract of DOI:10.1002/aoc.5907

A class of magnetic nanoparticles modified by 2-(aminomethyl)phenols has been successfully designed and synthesized as a reusable catalyst for Knoevenagel reaction. What's more, such nanomaterial also proved as suitable carrier for immobilization of palladium nanoparticles and the obtained composite exerted potent catalytic activity in Suzuki coupling reactions. Both of the (aminomethyl)phenols-modified nanoparticles and its related palladium nanocatalyst could be easily separated and reused for several consecutive runs by magnetic decantation without significant loss of their catalytic efficiency.

Full text of DOI:10.1002/aoc.5907

Received: 16 December 2019
DOI: 10.1002/aoc.5907
Revised: 18 May 2020
Accepted: 8 June 2020
F U L L P A P E R
Magnetically recoverable 2-(aminomethyl)phenols-
modified nanoparticles as a catalyst for Knoevenagel
condensation and carrier for palladium to catalytic Suzuki
coupling reactions
Gongshu Wang1 | Zhiqiang Ding1 | Lingxin Meng1 | Guiyang Yan2
Zhangpei Chen1 | Jianshe Hu1
|
1Center for Molecular Science and
A class of magnetic nanoparticles modified by 2-(aminomethyl)phenols has
been successfully designed and synthesized as a reusable catalyst for
Knoevenagel reaction. What's more, such nanomaterial also proved as suitable
carrier for immobilization of palladium nanoparticles and the obtained com-
posite exerted potent catalytic activity in Suzuki coupling reactions. Both of
the (aminomethyl)phenols-modified nanoparticles and its related palladium
nanocatalyst could be easily separated and reused for several consecutive runs
by magnetic decantation without significant loss of their catalytic efficiency.
Engineering, College of Science,
Northeastern University, Shenyang,
110819, P. R. China
2Fujian Provincial Key Laboratory of
Featured Materials in Biochemical
Industry, College of Chemistry and
Materials, Ningde Normal University,
Fujian, 352100, P. R. China
Correspondence
Guiyang Yan, Fujian Provincial Key
Laboratory of Featured Materials in
Biochemical Industry, College of
Chemistry and Materials, Ningde Normal
University.
K E Y W O R D S
2-(aminomethyl)phenols, Konevenagel condensation reaction, magnetic nanoparticles,
palladium, Suzuki coupling reaction
Email: ygyfjnu@163.com
Zhangpei Chen and Jianshe Hu, Center
for Molecular Science and Engineering,
College of Science, Northeastern
University, Shenyang 110819, P. R. China.
Email: chenzhangpei@mail.neu.edu.cn;
hujs@mail.neu.edu.cn
Funding information
Fundamental Research Funds for the
Central Universities, Grant/Award
Number: N180705004 and N2005004;
Science and Technology Foundation of
Liaoning Province, Grant/Award Number:
20170520185; National Natural Science
Foundation of China, Grant/Award
Number: 21702026
1 | INTRODUCTION
chemicals such as fuels and lubricants.[1,2] In the past
decades, rapid progress has been made in the field of
Carbon–carbon single and double bond formation are
paramount in the synthesis of biologically relevant mole-
cules, modern synthetic materials and commodity
homogeneous reactions and many types of difficult trans-
formations have been realized, including Konevenagel
condensation reaction and Suzuki coupling reaction to
Appl Organomet Chem. 2020;e5907.
wileyonlinelibrary.com/journal/aoc
© 2020 John Wiley & Sons, Ltd.
1 of 12
https://doi.org/10.1002/aoc.5907

2 of 12
WANG ET AL.
construct complicated molecular structures with high
selectivity.[3–5] Among numerous catalytic protocols, the
nanoparticles (NPs) catalyzed synthesis has gained exten-
sive research interest because they perfectly fuse both of
the advantages of homogeneous catalyst-high efficiency
and heterogeneous catalyst-reusability.[6] However, cata-
lysts having nanometer sizes are difficult to separate by
conventional filtration techniques, and these conven-
tional methods often result in loss of catalyst particles.[7]
Thus, the agglomeration and leaching of NPs problems
limit the application of nanoscale catalysts. In order to
overcome these problems, magnetic nanoparticles have
become a practical alternative; their magnetic properties
provide a way to easily and efficiently separate the cata-
lyst from the reaction mixture by using an external mag-
netic field.
organic ligands, such as phosphine ligands.[28–32] Consid-
ering the coordination between 2-aminomethyl phenol
and palladium, we loaded palladium NPs onto
2-aminomethylphenol modified magnetic nanomaterials
to prepare a cheap magnetic nano-palladium catalyst,
which was used as a reusable catalyst in the Suzuki
reaction.
2 | EXPERIMENTAL
2.1 | Measurements
FT-IR spectra of all samples were carried out with KBr
pellets
using
a
PerkinElmer
spectrum
One
1H
(B) spectrometer in the region of 500–4,000 cm−1
.
2-(Aminomethyl)phenols contain both Lewis basic and
Brønsted acidic functional groups, which can form a stable
rigid structure and have a wide range of applications in
organic synthesis.[8–11] Despite much progress having been
achieved in the field of employing 2-(aminomethyl)phenols
as organocatalyst in the synthetic chemistry, further
research on its application has not been reported for some
time. Considering that 2-(aminomethyl)phenol compounds
possessed an amino functional group and could form dou-
ble hydrogen bond structure to facilitate various
catalysis,[12] we envision that anchoring such compounds
on the surface of specially developed supports may enable
the development of efficient recyclable catalysts. Magnetic
iron oxides (FeO, Fe2O3, Fe3O4) are most concerned sup-
porter because they can be easily synthesized by co-
precipitation and their strong magnetic properties.[13–15] In
order to prevent the loss of magnetism and broaden their
application scope, modifying the surface of these magnetic
carriers is necessary.[16,17] Silica is the most commonly used
modified material because of the advantages of high specific
surface area and favorable biocompatibility, superior perme-
ability, fast mass transfer and easy of surface
modification.[18–21] In addition, magnetic nanoparticles,
especially silica coated Fe3O4 (Fe3O4@SiO2) NPs is becom-
ing an effective carrier for immobilized homogeneous cata-
lysts.[22,23] Herein, we designed and synthesized a magnetic
nanocatalyst modified by 2-(aminomethyl)phenols and
applied it as a reusable catalyst to the Knoevenagel reaction.
Besides, supported metal nanoparticles also play a
vital role in organic synthesis.[24–26] In particularly, load-
ing palladium onto magnetic nanomaterials opens up an
economical and effective green way for the wide applica-
tion of palladium catalysts in cross coupling reactions.[27]
Suzuki coupling reaction is one of the most commonly
used methods to construct C-C bonds. The traditional
Suzuki coupling catalyst requires not only a large amount
of precious metal palladium (Pd) but also expensive
NMR spectra were measured using a Bruker ARX
600 high resolution NMR spectrometer. The morphology
of all samples was determined with scanning electron
microscopy (SEM, JEOL 6500F) and transmission elec-
tron microscopy (TEM, JEM-2000EX). X-ray diffraction
(XRD) patterns of samples were detected by a Bruker D8
Advance powder diffractometer. The TGA analyses of
samples were tested with a Netzsch 209C at a heating
rate of 20 ꢀC/min under nitrogen atmosphere.
2.2 | Preparation of the (aminomethyl)
phenols-modified nanoparticles
Figure 1 shows the chemical structures and synthetic
route
to
the
(aminomethyl)phenols-modified
nanoparticles including the silica-coated magnetic
nanoparticles SMNPs-Amp and its related palladium
nanocatalyst SMNPs-Amp-Pd. The detailed synthesis
steps are described below.
2.2.1 | Preparation of SMNPs-amp
The core-shell silica-coated magnetic nanoparticles
(SMNPs) and its related amino-modified nanoparticles
(SMNPs-NH2) were prepared according to our previously
reported methods.[33] The obtained SMNPs-NH2
nanoparticles (500 mg) were dispersed in 30 ml of THF,
and then 2-(phenyl (tosyl)methyl)phenol (0.181 mmol
61.17 mg) and K2CO3 (0.362 mmol 50 mg) were added to
the reaction mixture. The reactioꢀn mixture was stirred
under nitrogen atmosphere at 40 C for 4 hr. Then, the
reaction mixture was cooled to room temperature, and
the resulting NPs was separated through magnetic decanta-
tion and washed with ethanol several times. The desired
product SMNPs-Amp was dried at room temperature.

WANG ET AL.
3 of 12
FIGURE 1 Preparation of
(aminomethyl)phenols-modified
nanocatalysts
2.2.2 | Preparation of SMNPs-amp-Pd
The SMNPs-Amp (500 mg) was dispersed in CH3CN
(30 ml) in an ultrasonic bath for 30 min. Subsequently, a
solution of PdCl2 (30 mg) in 30 ml of acetonitrile was
added to the dispersion of SꢀMNPs-Amp and the mixture
was stirred for 10 hr at 25 C. Then, the corresponding
particles SMNPs-Amp-Pd2+ was separated by magnetic
decantation and washed with acetonitrile, water and ace-
tone to remove the unattached substrates.[34] Then, the
reduction of SMNPs-Amp-Pd2+ by NaBH4 was performed
as follows: 500 mg of SMNPs-Amp-Pd2+ was dispersed in
20 ml of water, and then 1 mmol of NaBH4 in 1 mL of
water was added and the reaction was carried out at
room temperature for 5 hr The desired product SMNPs-
Amp-Pd was washed with water and dried in vacuum at
room temperature.
FIGURE 2 FT-IR spectra of the MNPs, SMNPs, SMNPs-NH2
and SMNPs-Amp
2.3 | General procedure of Knoevenagel
condensation catalyzed by SMNPs-amp
In a typical reaction, a mixture of SMNPs-Amp composite
(50 mg), aldehyde (1 mmol), malononitrile (1.1 mmol)
was placed in a 100 ml round-bottom flask and stirred at
room temperature for 4 hr. The progress of the reaction
was monitored by TLC (monitored by thin layer chroma-
tography). After completion of the reaction, the catalyst
was separated with an external magnet and was washed
with hot ethanol. The reaction mixture was extracted
with CH2Cl2. The combined organic layer was dried over
anhydrous sodium sulfate and evaporated in a rotary
evaporator under reduced pressure. The crude product
was purified by column chromatography.
FIGURE 3 TGA curves of SMNPs, SMNPs-NH2 and SMNPs-
Amp
2.4 | General procedure of Suzuki
coupling reaction catalyzed by SMNPs-
amp-Pd
reaction, the catalyst was separated with an external
magnet and was washed several times with ethanol and
deionized water. The reaction mixture was extracted with
CH2Cl2. The combined organic layer was dried over
anhydrous sodium sulfate and evaporated in a rotary
evaporator under reduced pressure. The crude product
was purified by column chromatography.
In a typical reaction, a mixture of SMNPs-Amp-Pd
(40 mg), aryl halide (1 mmol), K2CO3 (2 mmol),
arylboronic acid (1.2 mmol) and ethanol (3 ml) was
placed in a 100 mL round bottom flask, and stirred at
room temperature for 3 hr. After completion of the

4 of 12
WANG ET AL.
FIGURE 4 SEM and TEM images of the obtained nanocatalysts
FIGURE 5 EDX spectrum of SMNPs-
Amp-Pd
3 | RESULTS AND DISCUSSION
shown in Figure 2, for all samples, the observed absorp-
tion peak at 570 cm−1 was attributed to Fe-O vibration
from the magnetic basement.[35] Two peaks at 1080 and
802 cm−1 of the samples were assigned to antisymmetric
stretching and symmetric stretching frequency of Si-O-Si,
which suggested the silica shells were successfully coated
on the magnetic microspheres surface.[36,37] The intro-
duction of the 2-(aminomethyl)phenol derivatives on the
3.1 | Characterization of the
(aminomethyl)phenols-modified
nanoparticles
The structure of the MNPs, SMNPs, SMNPs-NH2 and
SMNPs-Amp were confirmed by FT-IR spectroscopy. As

WANG ET AL.
5 of 12
All of those bands reveal that the surface of SMNPs is
successfully modified with 2-(aminomethyl)phenols
groups.
The TGA curves of SMNPs, SMNPs-NH2 and SMNPs-
Amp were shown in Figure 3. The SMNPs showed a mass
loss of 3%, which was attributed to the loss of water phys-
ically adsorbed on the surface of the sample. The mass
loss of SMNPs-NH2 could be calculated as 2.7% according
to the weight loss of SMNPs, which was mainly attributed
to the loss of -NH2 groups. Furthermore, the mass loss of
SMNPs-Amp was 7.7% and the loading amount of
2-(aminomethyl)phenol derivatives was calculated as 2%
based on the mass loss of 5.7% in the TGA analysis of
SMNPs-NH2. The TGA analysis further supported the
result that 2-(aminomethyl)phenols was introduced onto
the surface of SMNPs.
The SEM and TEM images of the obtained
nanocatalysts were showed in Figure 4. As shown,
SMNPs-Amp and SMNPs-Amp-Pd were still spherical
and nearly uniform size which demonstrated that there
was no significant change in the surface of SMNPs after
the introduction of 2-(aminomethyl)phenol derivatives
FIGURE 6 XRD patterns of SMNPs-Amp-Pd
surface of SMNPs is confirmed by the bands at 1635,
2927, 1,390 and 3,447 cm−1 assigned to the C=C, alkyl C-
H, amine C-N and O-H stretching vibration, respectively.
TABLE 1 Conditions Optimization
Entry
1
Catalyst/mg
T/oC
20
20
20
20
20
20
0
Time/hr
Solvent/ml
H2O
Yield/%
13
---
4
4
4
4
4
4
4
4
4
4
1
2
3
4
4
4
4
2
MNPs(50)
H2O
10
3
SMNPs-NH2(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(50)
SMNPs-Amp(20)
SMNPs-Amp(30)
SMNPs-Amp(40)
SMNPs-Amp(60)
H2O
47
4
H2O
99
5
C2H5OH
CH3CN
H2O
62
6
69
7
98
8
25
30
40
20
20
20
20
20
20
20
H2O
98
9
H2O
99
10
11
12
13
14
15
16
17
H2O
99
H2O
83
H2O
86
H2O
93
H2O
71
H2O
75
H2O
85
H2O
99
aReaction conditions: malonatrile (1.1 mmol), benzaldehyde (1 mmol), solvent (5 ml), SMNPs-Amp.
bIsolated yield.

6 of 12
WANG ET AL.
TABLE 2 Substrate scope of Knoevenagel condensation with SMNPs-Amp
Entry
RCHO
Product
Time/h
Yield/%
1
4
99
2
3
1
2
86
91
4
5
2
3
99
86
6
7
1.5
86
4
5
79
98[b]
8
2
99

WANG ET AL.
7 of 12
TABLE 2 (Continued)
Entry
RCHO
Product
Time/h
Yield/%
9
4
86
10
4
98
aReaction conditions: aldehyde (1 mmol), malononitriles (1.1 mmol), H2O (5 ml), SMNPs-Amp (50 mg).
bReaction temperature is 40 ꢀC.
cIsolated yield.
(PDF#89–0735) and palladium (PDF#46–1,043). The posi-
tion and relative intensity of the peaks in the XRD pattern
of SMNPs-Amp-Pd were consistent with the standard XRD
pattern of Fe3O4, indicating that the crystal structure of
Fe3O4 was maintained during silica coverage, amino func-
tionalization, grafting 2-(aminomethyl)phenol derivatives
and palladium loading processes. In addition, no peaks of
SiO2 were observed compared with standard XRD patterns
of SiO2, which demonstrated that the coated silica belonged
to amorphous silica,[29] and no obvious peaks were in
accord with the standard XRD pattern of palladium and this
could be due to the ultralow loading amount of palladium.
3.2 | The performance of SMNPs-amp in
Knoevenagel condensation reaction
FIGURE 7 Recycling of SMNPs-Amp for Knoevenagel
condensation reaction
3.2.1 | Optimization of Knoevenagel
and palladium nanoparticles. The TEM image showed
SMNPs-Amp-Pd had a regular spherical shape which has
an average diameter of 180 nm, and the interface
between the MNPs core and the silica layer (the thickness
of which was about 27 nm) was clear, meanwhile, the
palladium nanoparticles (mainly 2.9 nm) were uniformly
anchored on the surface of the silica. The elemental com-
position was determined by using EDX analysis and the
results, shown in Figure 5, indicated Si, O, C, N, Fe and
Pd signals that are provided by SMNPs-Amp-Pd.
reaction conditions
In order to optimize the reaction conditions, benzalde-
hyde and malonitrile were used as model substrates and
the detailed optimizing investigations of reaction were
provided in the table 1. The results demonstrated that the
best reaction conditions were that benzaldehyde
(1 mmol), malonitrile (1.1 mmol), H2O (5 ml) and
SMNPs-Amp (50 mg) reacted at room temperature for
4 hr. Notably, the yield of the desired product with
SMNPs-NH2 as catalyst was only 47%, while, the yield of
the target product reached 99% when SMNPs-Amp was
The Figure 6 showed the XRD patterns of SMNPs-
Amp-Pd, JCPDS files of Fe3O4 (PDF#72–2,303), SiO2

8 of 12
WANG ET AL.
used as the catalyst. Therefore, it can be inferred that the
2-(aminomethyl)phenol group grafted on SNMPs played
a key role in this reaction.
reactive (Table 2, entries 2–4). Moreover, aliphatic alde-
hydes (such as butyraldehydes) were also tolerated in this
SMNPs-Amp NPs catalytic condensation (Table 2, entry 6).
However, it was found that the reactivity of
4-pyridylformaldehyde in Knoevenagel condensation was
much lower than that of other aldehydes, and only about
79% of the conversion was observed (Table 2, entry 8).
Since one of the key characteristics of our catalyst is
magnetic response, we have studied the reusability and
recycling of the catalysts. To our delight, we found that the
catalysts could be easily and quickly recovered from the
product through an external magnetic field (Figure S1).
Compared with the literature, the catalyst has good
stability and reusability.[38] The separated catalysts were
reused 8 times in Knoevenagel condensation reaction
without any significant loss of activity, and the yield was
still reach to 82% after 12 times reused (Figure 7).
3.2.2 | Substrate scope and recyclability
investigations
After determined of the optimized reaction conditions, the
catalytic performance of SMNPs-Amp was detected through
Knoevenagel condensation reaction with various substrates
(Table 2). To our delighted, the products were obtained with
good to excellent yields in a short time for almost all investi-
gated substrates. In addition, it was found that the substitu-
ents of aromatic aldehydes had a great influence on
Knoevenagel reaction: aldehydes with electron-withdrawing
groups (Table 2, entries 3–8) were more reactive than alde-
hydes with electron-donating groups (Table 2, entry 9). Cin-
namaldehyde and 2-furaldehyde were found to be more
However, the activity of MNPs-Amp catalyst
decreased to 81% after five recycling cycles (Figure S2).
TABLE 3 Conditions Optimization
Entry
1
Catalyst/mg
Solvent
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
H2O
Base
Time/h
Yield/%
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
SMNPs-Amp-Pd(50)
---
K2CO3
Cs2CO3
NaHCO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
1.5
1.5
1.5
1
94
90
77
84
96
99
0
2
3
4
5
2
6
3
7
3
8
CH3OH
CH3CN
DMSO
3
73
67
55
0
9
3
10
11
12
13
14
15
16
17
18
19
20
3
DMF
3
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
C2H5OH
3
0
Fe3O4(50)
3
0
SMNPs(50)
3
0
SMNPs-NH2(50)
SMNPs-NH2-Pd(50)
SMNPs-Amp(50)
SMNPs-Amp-Pd(20)
SMNPs-Amp-Pd(30)
SMNPs-Amp-Pd(40)
3
0
3
14
0
3
3
75
95
98
3
3
aReaction conditions: aryl halide 1 mmol; phenylboronic acid 1.2 mmol; solvent 3 ml; catalyst; room temperature.
bIsolated yield.

WANG ET AL.
9 of 12
TABLE 4 Substrate scope of Suzuki coupling reaction with SMNPs-Amp-Pd.
Entry
Ar1
Ar2
T/oC
Time/hr
Yield/%
1
r.t
3
99
90
94
2
3
r.t
40
3
3
4
5
6
r.t
r.t
r.t
3
3
3
99
98
99
7
8
50
r.t
2
3
98
98
9
40
3
93
(Continues)

10 of 12
WANG ET AL.
TABLE 4 (Continued)
Entry
Ar1
Ar2
T/oC
Time/hr
Yield/%
10
60
3
97
11
12
13
r.t
r.t
80
2
2
7
99
99
61
14
15
70
r.t
1.5
3
98
82
70
r.t
3
3
97
45
aReaction conditions: aryl halide 1 mmol; phenylboronic acid 1.2 mmol; EtOH 3 ml; K2CO3 2 mmol; catalyst 50 mg; room temperature.
bIsolated yield.
The comparison showed that silica shell can effectively
improve the stability and catalytic activity of the catalyst.
were provided in the Table 3. After a systematic screen of
the reaction condition, the optimum reaction condition
was established as C2H5OH as the solvent, K2CO3 as the
base and 50 mg of SMNPs-Amp-Pd as the catalyst at
room temperature for 3 hr. Compared with the existing
literature, the catalyst has the advantages of short reac-
tion time, mild reaction conditions.[5,39] Importantly, in
order to demonstrate the significance of the
2-(aminomethyl)phenol functional group, an array of
control experiments were carried out including employ-
ment of palladium immobilized on SMNPs-NH2
nanoparticles (SMNPs-NH2-Pd) as the catalyst. The
results showed that the reaction with SMNPs-NH2-Pd as
3.3 | The performance of SMNPs-amp-Pd
in Suzuki coupling reaction
3.3.1 | Optimization of Suzuki coupling
reaction conditions
Firstly, the reaction conditions were optimized by using
bromobenzene and phenylboric acid as model substrates
and the detailed optimizing investigations of the reaction

WANG ET AL.
11 of 12
the catalyst could furnish the product with only 14% of
yield which indicated that the 2-(aminomethyl)phenol
group grafted on SNMPs played a key role in loading of
palladium nanoparticles.
4 | CONCLUSIONS
In conclusion, two novel magnetically separable catalysts
were successfully synthesized. The structure characteriz-
ing of these materials indicated that they had a stable
structure and the organic components were attached to
the surface of the carrier by covalent bonds. These
nanocatalysts could be easily separated and reused for
several consecutive runs by magnetic decantation with-
out significant loss of their catalytic efficiency. Further
investigations on applications of these nanocatalysts are
underway in our laboratory.
3.3.2 | Substrate scope and recyclability
investigations
The catalytic activity of the SMNPs-Amp-Pd catalyst was
studied by catalyzing a series of Suzuki coupling reac-
tions with various aryl boric acids and halobenzene as
the substrates (Table 4). It could be found that the Suzuki
coupling reaction of phenylboronic acid and its deriva-
tives with bromobenzene, iodobenzene and chloroben-
zene could be carried out smoothly. Furthermore, the
reactions of bromobenzene and its methyl substituted
derivatives could be well proceeded, and the target prod-
ucts achieved in good yields (Table 4, entries 1–4). More-
over, when p-methoxybromobenzene was introduced in
the reaction, the yield of the target product reached to
98–99% (Table 4, entries 6–7). Reactions with chloro-
substituted benzenes required higher reaction tempera-
ture and longer time (Table 4, entry 13), which was
mainly due to the electronegativity of halogenated aryl
substituents. In contrast, when iodobenzene was
employed as the substrate, the reaction could proceed
smoothly with excellent yields. The reaction temperature
is much milder than the reported literature.[40]
ACKNOWLEDGMENTS
This work was supported by the National Natural Science
Foundation of China (21702026), Science and Technol-
ogy Foundation of Liaoning Province (20170520185), and
Fundamental Research Funds for the Central Universi-
ties (N180705004, N2005004).
ORCID
Jianshe Hu https://orcid.org/0000-0003-0624-0788
REFERENCES
[1] P. D. Babak Karimi, F. Mansouri, H. M. Mirzaei,
ChemCatChem 2015, 7, 1736.
[2] L. X. Yin, J. Liebscher, Chem. Rev. 2007, 107, 133.
[3] H. Veisi, R. Ghorbani-Vaghei, S. Hemmati, M. H. Aliani,
T. Ozturk, Appl. Organomet. Chem. 2015, 29, 26.
[4] V. Kandathil, M. Kempasiddaiah, S. K. Nataraj,
S. B. Somappa, S. A. Patil, Appl. Organomet. Chem. 2020, 34,
e5357.
The reusability and recycling of this palladium non-
acatalyst was also investigated with an external magnetic
field. To our delight, the catalyst could be easily and
quickly recovered from the reaction system and reused
7 consecutive times without significant loss of activity
(Figure 8).[5,40]
[5] Y. Rangraz, F. Nemati, A. Elhampour, J. Phys. Chem. Solids
2020, 138, 109251.
[6] J. N. Appaturi, M. R. Johan, R. J. Ramalingam, H. A. Al-
Lohedan, Microporous Mesoporous Mater. 2018, 256, 67.
[7] K. M. Parida, D. Rath, J. Mol. Catal. A: Chem. 2009, 310, 93.
[8] S. Bhatt, B. Trivedi, Polyhedron 2012, 35, 15.
[9] X. Y. Wang, Y. M. Dong, J. W. Sun, X. N. Xu, R. Li, Y. F. Hu,
J. Org. Chem. 2005, 70, 1897.
[10] P. F. Kaiser, J. M. White, C. A. Hutton, J. Am. Chem. Soc.
2008, 130, 16450.
[11] C. Cardellicchio, M. A. M. Capozzi, F. Naso, Tetrahedron:
Asymmetry 2010, 21, 507.
[12] C. Cardellicchio, G. Ciccarella, F. Naso, F. Perna, P. Tortorela,
Tetrahedron 1999, 55, 14685.
[13] S. Laurent, D. Forge, M. Port, A. Roch, C. Robic, L. V. Elst,
R. N. Muller, Chem. Rev. 2008, 108, 2064.
[14] A. H. Lu, E. L. Salabas, Angew. Chem. Int. Ed. 2007, 46, 1222.
[15] A. H. Lu, E. L. Salabas, Angew. Chem 2007, 119, 1242.
[16] M. Esmaeilpour, J. Javidi, F. N. Dodeji, H. Hassannezhad,
J. Iran. Chem. Soc. 2014, 11, 1703.
[17] Z. Gao, Y. J. Feng, F. M. Cui, Z. L. Hua, J. Zhou, Y. Zhu,
J. L. Shi, J. Mol. Catal. A: Chem. 2011, 336, 51.
FIGURE 8 Recycling of SMNPs-Amp-Pd for Suzuki coupling
reaction
[18] H. Qin, Z. Hu, F. Wang, Y. Zhang, L. Zhao, G. Xu, R. Wu,
H. Zou, Chem. Commun. 2013, 49, 5162.

12 of 12
WANG ET AL.
[19] H. Li, M. Yang, X. Zhang, L. Yan, J. Li, Y. Qi, New J. Chem.
2013, 37, 1343.
[34] P. Heidari, R. Cheraghali, H. Veisi, Appl. Organomet. Chem.
2016, 30, 991.
[20] S. K. Maji, S. Sreejith, A. K. Mandal, X. Ma, Y. Zhao, ACS
Appl. Mater. Interfaces 2014, 6, 13648.
[35] M. A. Ghasemzadeh, B. M. H. Abdollahi, M. Babaei, Green
Chem. Lett. Rev. 2015, 8, 40.
[21] J. Liu, W. Bu, L. Pan, J. Shi, Angew. Chem. Int. Ed. 2013, 52,
4375.
[36] Q. Yuan, Y. Chi, N. Yu, Y. Zhao, W. Yan, X. Li, B. Dong,
Mater. Res. Bull. 2014, 49, 279.
[22] Y. Kong, R. Tan, L. Zhao, C. Li, D. Yin, Green Chem. 2013, 15,
2422.
[23] H. Veisi, T. Ozturk, B. Karmakar, T. Tamoradi, S. Hemmati,
Carbohydr. Polym. 2020, 235, 115966.
[24] H. Veisi, A. Khazaei, M. Safaei, D. Kordestani, J. Mol. Catal. A:
Chem. 2014, 382, 106.
[37] F. Rafiee, N. Mehdizadeh, Catal. Lett. 2018, 148, 1345.
[38] R. Maleki, E. Kolvari, M. Salehi, Appl. Organomet. Chem.
2017, 31, e3795.
[39] P. Gao, Y. Xiao, Z. Dong, J. Saudi Chem. Soc. 2020, 24, 282.
[40] S. P. Vibhute, P. M. Mhaldar, R. V. Shejwal, Tetrahedron Lett.
2020, 61, 151594.
[25] C. Evangelisti, N. Panziera, P. Pertici, G. Vitulli, P. Salvadori,
C. Battocchio, G. Polzonetti, J. Catal. 2009, 262, 287.
[26] G. Park, S. Lee, S. J. Son, S. Shin, Green Chem. 2013, 15, 3468.
[27] J. Sun, Y. Fu, G. He, X. Sun, X. Wang, Appl Catal B 2015,
165, 661.
[28] A. Guarnizo, I. Angurell, G. Muller, J. Llorca, M. Seco,
O. Rossell, M. D. Rossell, RSC Adv. 2016, 6, 68675.
[29] M. Arghan, N. Koukabi, E. Kolvari, Appl. Organomet. Chem.
2018, 32, e4346.
[30] F. G. Rivera, I. Angurell, M. D. Rossell, R. Erni, J. Llorca,
N. J. Divins, G. Muller, M. Seco, O. Rossell, Chem. – Eur. J.
2013, 19, 11963.
[31] F. J. Caparros, A. Guarnizo, M. D. Rossell, B. Angurell,
M. Seco, G. Muller, J. Llorca, O. Rossell, RSC Adv. 2017, 7,
27872.
SUPPORTING INFORMATION
Additional supporting information may be found online
in the Supporting Information section at the end of this
article.
How to cite this article: Wang G, Ding Z,
Meng L, Yan G, Chen Z, Hu J. Magnetically
recoverable 2-(aminomethyl)phenols-modified
nanoparticles as a catalyst for Knoevenagel
condensation and carrier for palladium to catalytic
Suzuki coupling reactions. Appl Organomet Chem.
2020;e5907. https://doi.org/10.1002/aoc.5907
[32] S. Shylesh, L. Wang, W. R. Thiel, Adv. Synth. Catal. 2010,
352, 425.
[33] Y. Fu, Y. Sun, Z. P. Chen, S. M. Ying, J. W. Wang, J. S. Hu, Sci.
Total Environ. 2019, 691, 664.