Palladium nanoparticlesin situsynthesized onCyclea barbatapectin as a heterogeneous catalyst for Heck coupling in water, the reduction of nitrophenols and alkynes

Article abstract of DOI:10.1039/d0nj05032f

This study develops an effective method for thein situsynthesis of palladium nanoparticles (PdNPs) usingCyclea barbatapectin as a green reducing and stabilizing reagent. The PdNP@pectin nanocomposite was well characterized by analysis techniques such as UV-vis, FTIR, EDX, XRD, SEM, HR-TEM and STEM-mapping. Crystalline PdNPs were found to be distributed in the size range of 1-25 nm with the highest frequency of 6-12 nm. PdNP@pectin exhibited excellent recyclable catalysis activity for the Heck coupling reaction in water medium. The kinetics and recyclability of nanoparticles were investigated for the catalytic reduction ofo-,m- andp-nitrophenol. The result showed a good catalysis efficiency with five successful recycles without compromising much. In particular, the nanocomposite was used as a catalyst for the conversion of alkynes intocis-alkenes with KOH/DMF as a hydrogenation source. The reaction was also utilized effectively for the synthesis of sex pheromones, includingPlutella xylostella((Z)-11-hexadecen-1-yl acetate) andCylas formicarius((Z)-3-dodecen-1-yl(E)-2-butenoate) with the total yields of 70% and 68%, respectively. Therefore, PdNPs supported onC. barbatapectin are promising catalysis materials for application in various fields.

Full text of DOI:10.1039/d0nj05032f

NJC
View Article Online
View Journal | View Issue
PAPER
Palladium nanoparticles in situ synthesized on
Cyclea barbata pectin as a heterogeneous catalyst
for Heck coupling in water, the reduction of
nitrophenols and alkynes†
Cite this: New J. Chem., 2021,
45, 4746
Van-Dung Le,‡ab T. Cam-Huong Le,‡ab Van-Trung Chau,b T. Ngoc-Duyen Le,b
c
Chi-Hien Dang,*ab T. To-Nguyen Vo,b Trinh Duy Nguyen
and
ab
Thanh-Danh Nguyen
*
This study develops an effective method for the in situ synthesis of palladium nanoparticles (PdNPs)
using Cyclea barbata pectin as green reducing and stabilizing reagent. The PdNP@pectin
a
nanocomposite was well characterized by analysis techniques such as UV-vis, FTIR, EDX, XRD, SEM,
HR-TEM and STEM-mapping. Crystalline PdNPs were found to be distributed in the size range of
1–25 nm with the highest frequency of 6–12 nm. PdNP@pectin exhibited excellent recyclable catalysis
activity for the Heck coupling reaction in water medium. The kinetics and recyclability of nanoparticles
were investigated for the catalytic reduction of o-, m- and p-nitrophenol. The result showed a good
catalysis efficiency with five successful recycles without compromising much. In particular, the
nanocomposite was used as a catalyst for the conversion of alkynes into cis-alkenes with KOH/DMF as a
hydrogenation source. The reaction was also utilized effectively for the synthesis of sex pheromones,
including Plutella xylostella ((Z)-11-hexadecen-1-yl acetate) and Cylas formicarius ((Z)-3-dodecen-1-
yl(E)-2-butenoate) with the total yields of 70% and 68%, respectively. Therefore, PdNPs supported on
C. barbata pectin are promising catalysis materials for application in various fields.
Received 13th October 2020,
Accepted 10th February 2021
DOI: 10.1039/d0nj05032f
rsc.li/njc
Palladium-catalyzed coupling reactions play a vital role in
organic synthesis for the assembly of organic molecules with
1. Introduction
Transition metal nanoparticles have been extensively explored for complex structures which are obtained via carbon–carbon
advanced catalysis applications in numerous organic reactions. formation.11–15 Cross-coupling reactions such as the Heck
These nanomaterials play a crucial role in the field of hetero- reaction have been developed using palladium as a homogeneous
geneous catalysis because their high surface area endows them catalyst. Recently, PdNPs have been explored widely to enhance the
with many highly active uncoordinated metal sites.1–3 Recently, catalytic activity and selectivity of these reactions.16–19 The impor-
PdNPs have attracted tremendous efforts in the study of catalysis tance of nanomaterials not only includes the enhancement of
due to their broad applications in the pharmaceutical industry, synthetic performance, but also promotes the use of mild and less
agriculture, biochemistry and environment.4–8 Green synthesis of harmful conditions and the development of green chemistry. In fact,
PdNPs using organic materials such as plant extracts, natural PdNP catalysts may enhance cross-coupling reactions in aqueous
compounds and polysaccharides possesses many advantages, media without using any ligand or co-catalyst.20–23
including effective cost, simple technique and high bio-
compatibility.9,10
Hydrogenation of nitrophenols into aminophenols is an
important reaction not only in the degradation of toxic compounds
but also in the pharmaceutical industry as essential precursors for
the synthesis of common drugs, such as paracetamol and
phenacetin.24 Moreover, selective reduction of alkynes into cis/
trans-alkenes has been paid considerable attention in the synthesis
of bioactive compounds.25–27 Hydrogen gas is an effective reducing
source that is commonly selected for the hydrogenation of these
compounds.28,29 However, difficulties in the reaction design and
production cost, such as special equipment and storage of hydro-
gen gas, are main problems inducing disadvantages and barriers
a Graduate University of Science and Technology, Vietnam Academy of Science and
Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
E-mail: dangchihien@gmail.com, danh5463bd@yahoo.com, ntdanh@ict.vast.vn
b Institute of Chemical Technology, Vietnam Academy of Science and Technology,
1A, TL29 Street, Thanh Loc Ward, District 12, Ho Chi Minh City, Vietnam
c Center of Excellence for Green Energy and Environmental Nanomaterials, Nguyen
Tat Thanh University, Ho Chi Minh City 755414, Vietnam
† Electronic supplementary information (ESI) available. See DOI: 10.1039/d0nj05032f
‡ These authors contributed equally to this study.
4746 | New J. Chem., 2021, 45, 4746ꢀ4755
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021

View Article Online
Paper
NJC
for the application of these reactions in industry. Transfer hydro- Pd2+@pectin possesses a peak at 375 nm ascribed to the charge-
genation, which is well known as the addition of hydrogen to a transfer transition of Pd2+ ions. This peak disappeared after heating
hydrogen-accepting molecule from a source other than H2, is an at 100 1C for 1 h, which confirms the formation of PdNPs on the CB
important alternative for the synthesis of these derivatives.30 This pectin. The nanocomposite was physicochemically characterized by
method uses various hydrogen-donation sources, including analysis techniques. The nanocomposite was used as a catalyst for
hydrazine,31 HCOOH,32 H2O,33 NaBH4 and DMF.35
the Heck reaction in water medium, reduction of nitrophenols and
34
Cyclea barbata is a species of flowering plant. Its leaves are reduction of alkynes into cis-alkenes; also, its applications in the
usually used as a medicinal plant and are also used to produce synthesis of insect pheromones were explored.
a jelly that is typically consumed as a stomach medicine.36
2.2. Physicochemical characterization of the catalyst
Cyclea barbata is distributed widely and used popularly in many
countries in Asia, including China, India, Indonesia, Malaysia, To study the stabilization of the nanocomposite, solutions of
Thailand and Vietnam. Its gel has attracted significant atten- PdNPs@pectin were utilized to investigate the zeta potential
tion because it can form at room temperature without any other and dynamic light scattering (DLS) distribution at 25 1C
reagents. The aqueous extract contains pectin chains with a (Fig. 2A and B). The results showed that the colloidal solution
main component of polygalacturonic acid and divalent cations, of the synthesized nanocomposite possesses a high negative zeta
which can form cross-links during gelation.37 Application of potential value (ꢀ24 mV), which confirms its high stability in
this pectin has been limited to the food industry to date. aqueous solution. The size distribution profile showed a mono-
Therefore, further application of this pectin should be extended dispersed distribution of the nanocomposite PdNPs@pectin in
to other fields, such as the environment, energy and catalysis. the range of 315–580 nm with a mean hydrodynamic diameter of
To the best of our knowledge, the application of this pectin for 455 nm. The results revealed that the synthesized PdNPs were
synthesis of metallic nanoparticles, including PdNPs, has not well stabilized by the polymer chains of CB pectin in aqueous
yet been reported in the literature.
solution.
The functional groups of the organic components could be
Insect pheromones are chemicals capable of acting like
hormones outside of the insect’s body. Highly selective synthesis determined by using FTIR measurements. The spectra of CB
of cis/trans-alkenes is a particularly important key in the preparation pectin and the nanocomposite are shown in Fig. 2C. Similar
of pheromones of various insect species. In the present work, PdNPs absorption bands are observed from both spectra. For the CB
have been synthesized in situ using pectin prepared from Cyclea pectin, the broad band recognized at 3408 cmꢀ1 is assigned to
barbata leaves as a reductant and stabilizing agent. Their catalytic the OH groups of saccharide. The shoulder that appeared at
activity was evaluated for Sonogashira coupling, reduction of nitro- 1750 cmꢀ1 is assigned to the CQO stretching vibration of
phenols and selective hydrogenation of alkynes into cis-alkenes as methyl esterified carboxylic groups, and the sharp peaks at
well as its application for synthesis of Plutella xylostella and Cylas 1639 and 1415 cmꢀ1 correspond respectively to symmetric and
formicarius pheromones.
asymmetric stretching vibrations of COOꢀ groups of the galacturonic
acid units.41,42 Similar peaks shifted by several wavelength numbers
were observed in the spectrum of PdNPs@pectin, which confirmed
that the polysaccharide chains played a principal role as stabilization
agents of the PdNPs.
2. Results and discussion
2.1. Preparation of PdNPs@pectin
The crystalline structure of the PdNPs was determined by
X-ray crystallography. Fig. 2D confirms the presence of PdNP
crystals in the nanocomposite. The XRD pattern showed peaks
with Bragg angle values (2y) of 40.11, 46.31 and 68.81, indexed
respectively to reflections from the (111), (200) and (220) planes
of the face centred cubic (fcc) crystal structure of metallic
palladium.43,44 The preferential orientation of palladium crystals
with strong intensity of the peak at the (111) plane was clearly
observed.
The elemental composition presented in the powder com-
posite and average percentages of the elements was determined
by EDX measurements (Fig. 2E). The presence of carbon and
oxygen confirmed that the organic components appeared in
the nanocomposite PdNPs@pectin. The content of elemental
palladium found in the powder sample was about 30.7%. Some
other elements, including sodium (2.8%) and calcium (3.8%),
were also determined.
The CB pectin was prepared according to a previous report.38
The main component of CB pectin is well known to be poly-
galacturonic acid,39,40 which can transform in situ metallic ions into
MNPs as reducing and capping agents in aqueous solutions.
Pd2+ ions were added to the aqueous solution of the pectin and
in situ reduced under heating at 100 1C to form the composite
PdNPs@pectin (Fig. 1). The formation of PdNPs can be observed
from the UV-vis spectra (Fig. S1, ESI†). There is no absorption peak
in the spectrum of the CB pectin, while the gel solution of
The thermal behavior of CB pectin and PdNPs@pectin was
evaluated by TGA measurements in an air flow of 20 mL minꢀ1
at a heating rate of 10 1C minꢀ1 (Fig. 2F). Similar thermal
Fig. 1 Schematic of the in situ preparation and catalysis application of
PdNPs on pectin extracted from Cyclea barbata leaves.
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
New J. Chem., 2021, 45, 4746ꢀ4755 | 4747

View Article Online
NJC
Paper
Fig. 2 Zeta potential (A) of PdNPs@pectin; dynamic light scattering (B) of PdNPs@pectin; FT-IR spectra (C) of CB pectin (a) and PdNPs@pectin (b); XRD
pattern of PdNPs@pectin (D), EDX spectrum of PdNPs@pectin (E), and TGA curves (F) of CB pectin and PdNPs@pectin in an air flow of 20 mL minꢀ1 at a
heating rate of 10 1C minꢀ1
.
behaviors were observed for both the samples, which occurred the pectin chains relative to the C/O/Na/Ca elements of the
in two stages. In the first stage (30–217 1C), the CB pectin and framework. These results reflect good stability, a crystalline
the nanocomposite showed weight losses of 10% and 12%, nanostructure and a high specific surface area, which are
respectively, which are related to the loss of volatile compo- expected to aid effective catalysis for organic reactions.
nents and adsorbed water.45 The weight loss of the nanocom-
2.3. Catalytic performance for the Heck coupling reaction
posite was much lower than that of CB pectin in the next
temperature range of 217–800 1C. The weight loss of CB pectin Heck coupling is an important C–C coupling reaction that is
is about 61%, while that of PdNPs@pectin is about 49%. Thus, employed in many fields, such as the pharmaceutical industry,
the ash of the nanocomposite (41%) is much higher than that agriculture, and chemical engineering. In the present work, we
of CB pectin (27%), which can be interpreted as due to the applied the PdNPs@pectin catalyst for this coupling in water as
presence of metallic palladium in the nanocomposite.
a non-toxic solvent. The results are summarized in Table 1. It is
The morphology and size of the nanocomposite were well known that the Heck coupling reaction is strongly affected
evaluated by SEM and TEM analysis. The SEM image (Fig. 3A) by the base agent and reaction time.46 To explore these conditions,
reveals a rough surface with spherical particles present in the reaction of styrene with iodobenzene was used as a model
typical cluster shapes. The TEM image confirmed the success- reaction. The investigation was carried out with three different
ful synthesis of PdNPs in spherical particles distributed in the alkalines, including K3PO4, CH3COONa and Na2CO3 (entries 1–3).
range of 1–25 nm with a mean size of 6–12 nm (Fig. 3B). The The results showed that the latter achieved a competitive yield of
crystalline structure of metallic palladium can be clearly the product (76%) at 90 1C for 2 h. On the other hand, a significant
observed from the HRTEM image and SAED pattern (Fig. 3C). yield of the product of up to 90% was achieved when the stirring
The HRTEM image displays the fringe lattice of the crystalline was carried out within 6 h. The strong effect of the reaction time
phase with a crystal spacing of 0.24 nm, which corresponds to may be related to leaching of palladium into the aqueous solution
the (111) plane of PdNPs. The SAED pattern showed bright and the diffusion rate of the reagents, which increase the acces-
circular rings related to the (111), (200), (220) and (311) Bragg’s sibility of the active palladium sites.47,48
reflection planes of crystalline metallic palladium, which is in
The best conditions were used to explore the applicability of
agreement with the earlier result of the XRD pattern. The the catalytic nanocomposite, and the influence of various
scanning transmission electron microscopy (STEM) image substrates was investigated. Fluoride and methyl (CH3) groups were
(Fig. 3D) confirmed the presence of well-dispersed PdNPs utilized to study the effects of both reagents on the performance.
embedded in the pectin without any agglomeration. EDX elemental Table 1 shows the successful conversion of iodobenzenes and
mapping analysis (Fig. 3E–K) revealed PdNPs uniformly dispersed in vinylbenzenes into the respective products with good yields,
4748 | New J. Chem., 2021, 45, 4746ꢀ4755
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021

View Article Online
Paper
NJC
Fig. 3 SEM image (A), TEM image (B) and particle distribution (inset of B), HRTEM (C) and SAED patterns (inset of C), and STEM image (D) and EDX
mapping (E–K) of PdNPs@pectin.
Table 1 Reaction conditions for Heck coupling in aqueous medium and
catalysis of PdNPs@pectin
The results are shown in Fig. 4. Isolated yields of about 87%
were achieved after five recycles. The TEM image after the
recycles confirmed the increase of the particle size, which
indicated that the reaction occurred according to the Ostwald
ripening process.49 For the comparative study, the nano-
composite PdNPs@pectin catalyst possessed competitive catalytic
activity in comparison with other catalyst systems for the Heck
coupling reaction in water, as shown in Table S1 (ESI†). There-
fore, the nanocomposite PdNPs@pectin is a promising material
for the catalysis of C–C coupling.
Entry
R
R0
Base
Time (h)
Isolated yield (%)
1
2
H
H
H
H
H
H
CH3
F
H
CH3
F
H
K3PO4
2
2
2
6
6
6
6
6
6
6
6
6
54
62
76
90
92
89
86
90
78
90
87
90
CH3COONa
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
3
4
H
H
5
6
H
H
2.4. Catalytic performance for reduction of nitrophenols
7
8
9
10
11
12
CH3
CH3
CH3
F
F
F
The catalytic reduction of nitrophenols possesses potential
applications in pharmaceutical technology. It is well known that
the products of the reduction of aminophenols are important
intermediates for the synthesis of many drugs. Thus, it is
particularly necessary to apply the simple and cost-efficient
technique of this hydrogenation for pharmaceutical products.
CH3
F
and PdNPs@pectin can be adapted to various substrates. The Additionally, reusability of the catalyst can significantly reduce
yields obtained are similar for both reagents using the different the cost of the production technique. In this work, the reduction
groups. For evaluation of the recycle capacity, the reaction of o-, m-, and p-nitrophenol using NaBH4 in water medium as a
mixture of iodobenzene and styrene was stirred in Na2CO3 for model reaction was used to evaluate the catalytic performance of
6 h, and hexane was added to collect the product. The PdNPs PdNPs@pectin. The reaction without the catalyst is well known to
catalyst was determined by a TEM image after the 6th run. be a thermodynamically favorable model; however, the kinetic
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
New J. Chem., 2021, 45, 4746ꢀ4755 | 4749

View Article Online
NJC
Paper
Fig. 4 Recyclable catalysis performance of PdNPs@pectin for Heck
coupling between iodobenzene and styrene (A); TEM image and size
distribution of the PdNPs after the 6th catalysis run (B).
ꢀ
barrier between BH4 and nitrophenolate ions results in a
Fig. 6 TEM image and particle distribution (inset) of PdNPs@pectin used
for reduction of p-nitrophenol after the 6th recycle run.
kinetically unfavorable reaction. This barrier can be overcome
by using a metallic catalyst via an electron transfer mechanism in
which borohydride and nitrophenolate ions can be absorbed and
released on the surface of MNPs. Because a large excess of NaBH4
(200 times) and a very small amount of the nanocomposite
PdNPs@pectin (3 mg) were used, the kinetics of reduction should
follow the pseudo first order reaction with respect to the
nitrophenols.50 For evaluation of the recyclability, the used
nanocomposite was washed with distilled water and then ethanol
before each reuse. The catalyst was tested for five reaction cycles.
The reduction of nitrophenols was directly monitored by
using UV-vis measurements from a cuvette. The maximum
peaks of the solutions containing o-, m- and p-nitrophenol in
the presence of NaBH4 were observed at 415 nm, 391 nm and
400 nm, respectively. When addition of the catalyst was com-
pleted, the decline of the absorbance values at the absorption
peaks of the corresponding nitrophenolate ions and gradual
increase of the peaks in the absorption range of 282–296 nm
confirmed the conversion of the nitrophenols into the respective
aminophenols. Fig. 5 showed that the reduction of o-, m- and
p-nitrophenols was complete within 10 min, 6 min and 14 min,
respectively. However, a different trend of the rate constants was
observed in a decreasing order of o-nitrophenol (2.93 ꢁ 10ꢀ3 sꢀ1) 4
m-nitrophenol (2.88 ꢁ 10ꢀ3
s
ꢀ1) 4 p-nitrophenol (2.42 ꢁ
10ꢀ3 ꢀ1). These results showed that the catalytic performance
s
of PdNPs@pectin is higher than that of other catalyst systems
reported previously.51–53 The recyclability of the nanocomposite
is slightly different among nitrophenol substrates. Although a
similar catalysis performance for all the nitrophenols was
obtained at the 6th run (about 70%), a slow decline of the
recycle performance was observed for the reduction of o- and
m-nitrophenols, with above 90% at the 3th run, while the
conversion of p-nitrophenol achieved only 75% for this run.
The difference in the recycle performance may be due to the
effect of the substrate structures on the adsorption or/and
release processes on the catalyst surface. For further study,
the TEM image of the catalyst after the 6th recycle run of
p-nitrophenol was determined, as shown in Fig. 6. The results
showed that the PdNPs existed in clusters, and the slightly
smaller particle size may have been obtained because the
product p-aminophenol stabilized the PdNPs after the catalysis
process.8 The decrease of the catalytic performance in the
reduction of nitrophenols is attributed to the Pd clusters.
Moreover, the loss of catalyst during the recycle process signifi-
cantly affected the catalytic efficiency of PdNPs@pectin.54 The
PdNPs@pectin was shown to be a good recyclable catalyst in
comparison with previous reports.55,56
2.5 Catalytic performance for the reduction of alkynes
The reduction of alkynes into cis-alkenes was performed using
KOH in DMF solvent as a reductant, heated at 100 1C in the
presence of PdNPs@pectin catalyst (2 mol%). The reaction was
tested with different substrate structures. The results are sum-
marized in Table 2. Excellent yields (above 90%) were obtained
for the reduction of aromatic alkynes (entries 1–3), which
confirmed that the catalytic performance was similar to that
of Pd(OAc)2 catalyst as previously reported.35 Unfortunately,
reduction of 3-butyn-1-ol (entry 4) and 3-hexyn-1-ol (entry 6) to
the corresponding cis-alkenes was not observed, although the
reaction time was lengthened to 12 h. However, the protection
of these alcohols by tetrahydrofuran (OTHP) showed significant
Fig. 5 UV-vis spectra (left), first order kinetics (middle) and conversion
efficiencies for six running numbers (right) of o-nitrophenol (A–C), m-
nitrophenol (D–F) and p-nitrophenol (G–I) in the presence of
PdNPs@pectin.
4750 | New J. Chem., 2021, 45, 4746ꢀ4755
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021

View Article Online
Paper
NJC
pheromone was identified as (Z)-3-dodecen-1-yl (E)-2-butenoate.63
The synthetic route is described in Scheme 2. The key reactions
used are similar to the synthesis of P. xylostella pheromone. The
derivative of dodecyne (8) was obtained by a coupling reaction
between a lithium reagent prepared from (6) and octyl bromide (7).
The reduction of (8) was performed using KOH/DMF in the
presence of PdNPs@pectin at 100 1C, followed by protective group
cleavage to afford (Z)-3-dodecen-1-ol (9) in a yield of 90% for two
steps. The esterification of compound (9) used (E)-2-butenoyl
chloride in pyridine to obtain pheromone 10 in a yield of 86%.
1H-NMR data of 9 and 10 showed a coupling constant of the two
protons of double bond at about 10.5–11.0 Hz, which confirmed
the cis-configuration of the synthesized alkene. The total yield
achieved for the synthesis of pheromone 10 was about 68%.
Table 2 Reaction conditions for the Heck reaction in the presence of
PdNPs@pectin
Entry
R
R0
Time (h)
Isolated yield (%)
1
2
3
4
5
6
7
H
C6H5
C6H5
p-(CH3)C6H5
–CH2CH2OH
–CH2CH2OTHP
–CH2CH2OH
–CH2CH2OTHP
6
6
6
12
6
12
6
91
92
90
Trace
73
Trace
78
C6H5
C6H5
H–
H–
C2H5–
C2H5–
3. Experimental
3.1. Materials
enhancements in the reaction yield. Isolated yields of the
products of above 70% were obtained (entries 4 and 7). The
lower performance in comparison with the reduction of aryl
alkynes may be due to the high evaporation rate of alkyl alkenes.
Moreover, the results indicated no influence of the triple bond
position on the reduction of alkynes using PdNPs@pectin (entries
All chemicals were used as received without further purification.
The major reagents, including vinylbenzenes, iodobenzenes,
palladium acetate, nitrophenols, and sodium borohydride (NaBH4),
were purchased from Acros (Belgium). Diphenyl acetylenes were
synthesized according to a previous report. Cyclea barbata was
collected from Ho Chi Minh city. Deionized water was used
throughout.
1
1, 2, 5 and 7). The H-NMR data (entry 7, Supplementary data,
ESI†) showed that the coupling constant between two protons of
the double bond was estimated to be at 10.5–11.0 Hz, which
confirmed the formation of cis-alkenes for the reduction of
these alkynes.
3.2. Preparation of Cyclea barbata pectin
Extract of C. barbata (CB) pectin was carried out according to a
previous report with slight modification.38 Briefly, dried
C. barbata leaf powder (40 g) was ground well and stirred with
water (500 mL) at room temperature. The extract was filtered
rapidly under vacuum. Ethanol was added to the extract, and
the precipitated pectin was separated from aqueous solution.
The obtained pectin was centrifugated and washed with water
(20 mL ꢁ 3). The pectin was freeze-fried for 24 h. The samples
were stored at room temperature for further use.
2.6 Synthesis of insect pheromones
The reduction reaction of alkynes into cis-alkenes is a key step
in the synthesis of many insect pheromones. In the present work,
two pheromones of P. xylostella and C. formicarius which possessed
cis configurations were selected to evaluate the application of the
nanocomposite catalyst. P. xylostella, a cabbage moth, is a moth
species of the family Plutellidae and is distributed worldwide.
Its sex pheromone has been identified to have three components,
including (Z)-11-hexadecen-1-ol, (Z)-11-hexadecenal and (Z)-11-hexa-
decen-1-yl acetate.57–59 The composition for effective insect
attraction is strongly dependent on the original insect; however,
the acetate derivative is well known to be a major component of
the sex pheromone.60–62 Therefore, facile synthesis of (Z)-11-
hexadecen-1-yl acetate is a particularly important key to apply
this pheromone in field trials. The synthetic route of this
component is presented in Scheme 1. A coupling between
1-hexynyllithium and 2-((10-bromodecanyl)oxy)tetrahydro-2H-
pyran (2) was performed to obtain the derivative of hexadecyne
(3). The reduction of (3) was carried out in the presence
of PdNPs@pectin to afford (4) in a yield of 91%. The protective
group cleavage was performed with PTSA, followed by acetylation
with acetic anhydride in the presence of pyridine to obtain the
3.3. Synthesis of PdNPs@pectin
The pectin (0.50 g) was stirred in water (50 mL) for 2 h. Then,
5 mL of Pd(OAc)2 solution in DMSO (30.0 mg mLꢀ1) was
dropped into a gel solution of the pectin. The yellow solution
was stirred at 100 1C (1200 rpm) for 1 h to obtain a black
solution, which confirmed the conversion of Pd2+ ions into
PdNPs. PdNPs@pectin was separated and washed by a centri-
fugal process (3000 rpm, 30 1C, 30 min). The nanocomposite
powder was dried at 60 1C for 12 h to obtain the composite
PdNPs@pectin (0.32 g, 49.2%). The nanocomposite was stored
at room temperature for further use.
3.4. Physicochemical characterization of PdNPs@pectin
pheromone (Z)-11-hexadecen-1-yl acetate (5) in a yield of 89% for two UV-Vis spectroscopy was carried out on a JASCO V-630 spectro-
steps. A total yield for the synthesis of pheromone 5 of up to 70% photometer (U.S.A.) in the wavelength range of 200–700 nm.
was achieved. All pure compounds were identified by NMR spectra. The Fourier-transform infrared (FTIR) spectra of the gum and
Cylas formicarius, a species of sweet potato weevil of PdNPs@pectin samples were measured on a FTIR spectrophoto-
the family Brentidae, is widely distributed worldwide. Its sex meter (Bruker, Tensor 27, Germany). The X-ray diffraction (XRD)
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
New J. Chem., 2021, 45, 4746ꢀ4755 | 4751

View Article Online
NJC
Paper
Scheme 1 Synthesis of Plutella xylostella pheromone.
Scheme 2 Synthesis of Cylas formicarius pheromone.
pattern of PdNPs crystal was obtained on an X-ray diffracto- at 100 1C. After cooling the solution, ethyl acetate (20 mL) was
meter (Bruker, Model-D8 Advance). An aqueous solution of the added. The water layer was separated and extracted. The organic
nanocomposite was used to determine the particle size and zeta layer was collected and washed with water. The solvent was
potential using a nanoPartica Horiba SZ-100 analyzer (Japan) at evaporated under reduced pressure. The product was purified
25 1C. The morphology and crystalline structure of the nano- by silica gel column chromatography eluting with an ethyl acetate
composite were analyzed using field emission scanning electron and hexane mixture. The purity of the product was determined by
microscopy (FESEM, JSM7401F, Japan) and high resolution 1H-NMR measurements. For the recycling, after completing the
transmission electron microscopy (HRTEM, JEOL JEM2100) – reaction, hexane was added to the reaction mixture and the
selected area electron diffraction (SAED). The chemical elements product was collected from the organic layer. For the next
and elemental distribution in the nanocomposite were identified reaction, the mixture of iodobenzene and styrene was added to
by an energy dispersive X-ray spectroscopy (EDX) analyzer (Hor- the aqueous layer and stirred for 6 h.
iba, EMAX ENERGY EX-400). Thermogravimetry (TG) analysis was
performed on a LabSys evo S60/58988 Thermoanalyzer (Setaram,
3.6. Catalytic activity for reduction of nitrophenols
France) in the temperature range from 30 1C to 800 1C at a Catalytic reduction of o-, m-, p-nitrophenol in the presence of
heating rate of 10 1C minꢀ1 in air atmosphere. 1H (500 MHz) and PdNPs@pectin was investigated at room temperature in aqueous
13C (125 MHz) NMR spectra were recorded on a NMR spectro- medium, and an excess amount of NaBH4 was used as a reductant.
meter (Bruker Advance 500) using CDCl3 solvent and tetramethyl- Each nitrophenol (2.5 mL, 0.1 mM) and NaBH4 solution (0.5 mL,
silane (TMS) as an internal standard. GC analyses were carried 0.1 M) were placed into a cuvette, and the catalyst (3 mg) was
out using an Agilent Technologies 6890N chromatograph (USA) added to the reaction mixture. The performance of the catalyst was
with an HP-5MS column.
determined by UV-vis measurements. The reaction was confirmed
by a gradual decrease of absorbance at the corresponding peaks of
nitrophenol. Due to the great amount of NaBH4 and very small
3.5. Catalytic activity for Heck coupling
In a 25 mL round-bottom flask equipped with a magnetic stirrer amount of the catalyst used, the reaction rate was evaluated
and a reflux condenser, iodobenzenes (1.0 mmol), vinylbenzenes according to the pseudo-first-order reaction with respect to nitro-
(1.1 mmol), bases (2 mmol) and PdNPs@pectin powder (6.4 mg, phenol. Thus, the kinetics of the reduction reaction was described
0.7% mol) were added to 1 mL of water. The mixture was stirred by the equation ln(At/A0) = ꢀkt, where k is the reaction rate
4752 | New J. Chem., 2021, 45, 4746ꢀ4755
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021

View Article Online
Paper
NJC
constant (sꢀ1); t is the reaction time (s); and A0 and At are the 13C NMR (125 MHz, CDCl3, d ppm): 129.9, 129.8, 67.7, 62.3,
nitrophenol absorbances at the initial time and t, respectively. The 32.6, 31.9, 31.8, 29.8, 29.5, 29.5, 29.4, 29.43, 29.3, 29.1, 27.2, 26.9,
rate constant could be found from the slope of the line generated by 25.5, 22.3, 19.5, 13.9.
plots of ln(At/A0) versus the reaction time. For evaluation of the reuse
Synthesis of (Z)-11-hexadecenyl acetate (5). A mixture of
performance of the catalyst, PdNPs@pectin was separated and alkene 4 (0.4 g, 1.34 mmol) and PTSA (0.011 g, 0.067 mmol)
washed with water and then ethanol several times before reuse.
in MeOH was stirred at room temperature for 16 h. After the
evaporation of MeOH, the residue was treated with NaHCO3
solution and extracted with n-hexane. The combined organic
3.7. Catalytic activity for reduction of alkynes
Alkynes (0.25 mmol), KOH (30.7 mg), DMF (2.0 mL) and PdNPs layer was washed with brine, dried over MgSO4, filtered and
(6.4 mg, 0.7% Pd catalyst) were added to a Pyrex screw-cap tube concentrated in vacuo to afford (Z)-hexadec-11-en-1-ol as a
(25 mL) under nitrogen atmosphere. The mixture was stirred at brown oil. The crude product was used directly for the next
150 1C for 8 h. After the solution cooled, the mixture was diluted in reaction without further purification.
ethyl acetate and water. The organic layer was separated and washed
A mixture of (Z)-hexadec-11-en-1-ol, pyridine (0.11 g,
with water. The solvent was evaporated and the crude product was 1.05 mmol) and anhydric acetic acid (0.083 g, 1.05 mmol) was
purified by silica gel column chromatography eluting with hexane/ stirred at 0 1C for 2 h and then warmed to room temperature.
diethyl ether (9 : 1) or hexane/ethyl acetate (9 : 1).
After 24 h, the residue was treated with HCl solution (10%) and
extracted with diethyl ether (50 mL ꢁ 3). The combined organic
layer was washed with saturated CuSO4, NaHCO3, water, and
brine, dried over MgSO4, filtered, and concentrated in vacuo.
3.8. Application of PdNPs@pectin catalyst for synthesis of
insect pheromones
Synthesis of 2-(hexadec-11-yn-1-yloxy)tetrahydro-2H-pyran The crude product was purified by column chromatography
(3). A solution of 2.5 M n-BuLi in hexane (16.5 mL, 19.5 mmol) (silica gel, eluted by hexane to diethyl ether 9 : 1), affording
1
was introduced dropwise to a solution of 1-hexyne (1, 1.64 g, pheromone 5 as a pale yellow oil (0.19 g, 89%). H NMR (500
20 mmol) in THF (10 mL), then stirred in N2 atmosphere at MHz, CDCl3, d ppm): 5.34–5.39 (m, 2H), 4.04–4.06 (t, J = 7.5 Hz,
ꢀ78 1C. The reaction mixture was warmed to room temperature 2H), 2.01–2.03 (m, 4H), 2.04 (s, 1H), 1.60–1.63 (m, 2H),
and stirred for 1 hour. This reaction mixture was added to solid 1.26–1.34 (m, 18H), 0.88–0.91 (t, J = 7.5 Hz, 3H). 13C NMR
KI (0.25 g, 1.5 mmol) and 2-((10-bromodecyl)oxy)tetrahydro-2H- (125 MHz, CDCl3, d ppm): 171.2, 129.9, 129.9, 64.7, 31.9, 29.8,
pyran (2, 4.82 g, 15 mmol) at room temperature. The resulting 29.7, 29.5, 29.5, 29.3, 29.3, 28.6, 27.2, 26.9, 25.9, 22.4, 21.0, 13.9.
mixture was refluxed for 16 h. After cooling to room temperature,
Synthesis of 2-(dodec-3-yn-1-yloxy)tetrahydro-2H-pyran (8). A
the reaction was quenched with saturated NaHCO3 solution and solution of 2.5 M n-BuLi in hexane (16.5 mL, 19.5 mmol) was
the organic layer was separated. The aqueous layer was extracted introduced dropwise to a solution of 2-(but-3-yn-1-yloxy)tetra-
with n-hexane. The combined organic layer was washed with hydro-2H-pyran (6, 3.08 g, 20 mmol) in THF (10 mL), stirred in
brine, dried over MgSO4, filtered, and concentrated in vacuo. The N2 atmosphere, at ꢀ78 1C. The reaction mixture was warmed to
crude product was purified by column chromatography (silica room temperature and stirred for 1 hour. To this reaction
gel, eluted by hexane to diethyl ether 9: 1), affording 3 in 86% mixture was added solid KI (0.25 g, 1.5 mmol) and 1-bromo-
1
yield (4.15 g). H NMR (500 MHz, CDCl3, d ppm): 4.57–4.58 (m, octane (7, 2.88 g, 15 mmol) at room temperature. The resulting
1H), 3.70–3.89 (m, 2H), 3.36–3.52 (m, 2H), 2.12–2.16 (m, 4H), mixture was refluxed for 16 h. After cooling to room temperature,
1.52–1.84 (m, 8H), 1.28–1.48 (m, 18H), 0.89–0.92 (t, J = 7.5 Hz, the reaction was quenched with saturated NaHCO3 solution and
3H). 13C NMR (125 MHz, CDCl3, d ppm): 98.9, 80.2, 80.2, 67.7, the organic layer was separated. The aqueous layer was extracted
62.3, 31.3, 29.8, 29.8, 29.6, 29.5, 29.2, 29.1, 28.9, 26.3, 25.5, 21.9, with n-hexane. The combined organic layer was washed with
19.7, 18.8, 18.5, 13.6.
brine, dried over MgSO4, filtered, and concentrated in vacuo. The
Synthesis of (Z)-2-(hexadec-11-en-1-yloxy)tetrahydro-2H-pyran crude product was purified by column chromatography (silica
(4). To a mixture of alkyne 3 (0.55 g, 1.7 mmol), ground KOH gel, eluted by hexane to diethyl ether 9: 1), affording 8 (3.51 g,
powder (0.17 g, 2.55 mmol), and PdNPs@pectin (2% mol) in a 88%). Bp. 150–153 1C/2 mmHg. 1H NMR (500 MHz, CDCl3, d
thick-walled Pyrex seal tube was added degassed DMF (10 mL). ppm): 4.64–4.65 (m, 1H), 3.76–3.91 (m, 2H), 3.48–3.55 (m, 2H),
The tube was sealed, and the reaction mixture was stirred 2.43–2.47 (m, 2H), 2.11–2.15 (m, 2H), 1.27–1.85 (m, 18H), 0.88
vigorously at 145 1C for 6 hours. After cooling to room tempera- (t, J = 7 Hz, 3H). 13C NMR (125 MHz, CDCl3, d ppm): 98.7, 81.4,
ture, the cap was opened carefully and the resulting suspension 76.7, 66.3, 62.2, 31.8, 30.6, 29.2, 29.1, 29.0, 28.9, 25.5, 22.6, 20.2,
was passed through a silica gel bed and washed with n-hexane. 19.4, 18.7, 14.1.
The combined filtrate was washed with water (50 ml ꢁ 5) to
Synthesis of (Z)-dodec-3-en-1-ol (9). To a mixture of alkyne 8
remove DMF. The organic layer was dried over MgSO4, filtered, (0.45 g, 1.7 mmol), ground KOH powder (0.17 g, 2.55 mmol),
and concentrated in vacuo. The crude product was purified by and PdNPs@pectin (2% mol) in a thick-walled Pyrex seal tube
column chromatography (silica gel, eluted by hexane to diethyl was added degassed DMF (10 mL). The tube was sealed, and the
ether 9 : 1), affording 4 as a pale yellow oil in 91% yield (0.5 g). reaction mixture was stirred vigorously at 145 1C for 6 hours.
1H NMR (500 MHz, CDCl3, d ppm): 5.34–5.39 (m, 2H), 4.57–4.58 After cooling to room temperature, the cap was opened carefully
(m, 2H), 3.70–3.89 (m, 2H), 3.36–3.52 (m, 2H), 1.95–2.02 (m, 4H), and the resulting suspension was passed through a silica gel
1.52–1.85 (m, 8H), 1.28–1.49 (m, 18H), 0.868–0.916 (m, 3H). bed and washed with n-hexane. The combined filtrate was
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
New J. Chem., 2021, 45, 4746ꢀ4755 | 4753

View Article Online
NJC
Paper
washed with water (50 ml ꢁ 5) to remove DMF. The organic layer utilized to straightforwardly synthesize two pheromones of Plutella
was dried over MgSO4, filtered, and concentrated in vacuo. The xylostella and Cylas formicarius which possessed cis-configurations.
crude alkene product was used directly for the next reaction Therefore, this catalyst reveals wide potential applications, such as
without further purification.
in pharmaceutical, agricultural and environmental fields.
A mixture of crude alkene and PTSA (0.011 g, 0.067 mmol) in
MeOH was stirred at room temperature for 16 h. After the
evaporation of MeOH, the residue was treated with NaHCO3 Conflicts of interest
solution and extracted with n-hexane. The combined organic
No potential conflict of interest was reported by the authors.
layer was washed with brine, dried over MgSO4, filtered and
concentrated in vacuo. The product was purified by column
chromatography (silica gel, eluent of hexane to diethyl ether
4 : 1) to afford 9 (0.28 g, 90%). Bp: 120–125 1C/1 mmHg. 1H NMR
(500 MHz, CDCl3, d ppm): 5.53–5.58 (m, 1H), 5.33–5.39 (m, 1H),
3.62–3.65 (m, 2H), 2.32–2.35 (m, 2H), 2.04–2.08 (m, 2H),
1.27–1.54 (m, 13H), 0.88 (t, J = 7 Hz, 3H). 13C NMR (125 MHz,
CDCl3, d ppm): 133.6, 124.9, 62.4, 31.9, 30.8, 29.7, 29.5, 29.3,
29.3, 27.4, 22.7, 14.1.
Acknowledgements
The authors are thankful to Vietnam Academy of Science and
Technology (VAST) for funding this project (NCVCC15.01/20-20).
Notes and references
Synthesis of (Z)-dodec-3-en-1-yl (E)-2-butenoate (10). A mixture
of 9 (0.18 g, 1.0 mmol), pyridine (0.13 g, 1.25 mmol) and
crotonoyl chloride (0.13 g, 1.25 mmol) was stirred at 0 1C for
2 h and then warmed to room temperature. After 24 h, the
residue was treated with HCl solution (10%) and extracted with
diethyl ether (50 mL ꢁ 3). The combined organic layer was
washed with saturated CuSO4, NaHCO3, water, and brine, dried
over MgSO4, filtered, and concentrated in vacuo. The crude
product was purified by column chromatography (silica gel,
eluted by hexane to diethyl ether 9: 2), affording pheromone 10
as a pale yellow oil (0.19 g, 86%). Bp: 104–106 1C/0.1 mmHg.
1H NMR (500 MHz, CDCl3, d ppm): 6.93–7.00 (dq, J = 15.5 Hz,
7.0 Hz, 1H), 5.82–5.86 (dq, J = 15.5 Hz, 1.5 Hz, 1H), 5.48–5.53
(dtt, J = 11.0 Hz, 7.0 Hz, 1.5 Hz, 1H), 5.33–5.38 (dtt, J = 11.0 Hz,
7.5 Hz, 2.0 Hz), 4.12 (t, J = 7 Hz, 2H), 2.40 (q, J = 7.0 Hz, 2H), 1.87
(dd, J = 7 Hz, 1.5 Hz, 3H), 1.26–1.36 (m, 12H), 0.88 (t, J = 7 Hz, 3H).
13C NMR (125 MHz, CDCl3, d ppm): 166.6, 144.5, 132.9, 124.4,
122.8, 63.7, 31.9, 29.7, 29.6, 29.5, 29.2, 27.3, 26.9, 22.7, 17.9, 14.1.
1 A. Bej, K. Ghosh, A. Sarkar and D. W. Knight, RSC Adv., 2016,
6, 11446–11453.
2 F. W. Campbell and R. G. Compton, Anal. Bioanal. Chem.,
2010, 396, 241–259.
3 I. Saldan, Y. Semenyuk, I. Marchuk and O. Reshetnyak,
J. Mater. Sci., 2015, 50, 2337–2354.
4 A. M. Trzeciak and A. W. Augustyniak, Coord. Chem. Rev.,
2019, 384, 1–20.
5 S. Luo, Z. Zeng, G. Zeng, Z. Liu, R. Xiao, M. Chen, L. Tang,
W. Tang, C. Lai, M. Cheng, B. Shao, Q. Liang, H. Wang and
D. Jiang, ACS Appl. Mater. Interfaces, 2019, 11, 32579–32598.
6 F. Qazi, Z. Hussain and M. N. Tahir, RSC Adv., 2016, 6,
60277–60286.
7 F. Christoffel and T. R. Ward, Catal. Lett., 2018, 148,
489–511.
8 T.-D. Nguyen, T.-T. Vo, C.-H. Nguyen, V.-D. Doan and
C.-H. Dang, J. Mol. Liq., 2019, 276, 927–935.
9 M. Martins, C. Mourato, S. Sanches, J. P. Noronha, M. T. B.
Crespo and I. A. C. Pereira, Water Res., 2017, 108, 160–168.
10 C. P. Adams, K. A. Walker, S. O. Obare and K. M. Docherty,
PLoS One, 2014, 9, e85981.
4. Conclusions
We investigated an effective method for in situ synthesis of PdNPs 11 D. Astruc, Inorg. Chem., 2007, 46, 1884–1894.
´
using Cyclea barbata pectin as a reduction and stabilization agent. 12 I. Favier, D. Pla and M. Gomez, Chem. Rev., 2020, 120,
The nanocomposite was well characterized by analysis techniques. 1146–1183.
´
The nanocomposite contained 30% palladium, and the average 13 M. Perez-Lorenzo, J. Phys. Chem. Lett., 2012, 3, 167–174.
size of the nanoparticles was determined to be in the range of 14 R. Majumdar, S. Tantayanon and B. G. Bag, Chem. – Asian J.,
6–12 nm. The catalytic activity of the nanocomposite was evaluated
for the Heck coupling reaction, reduction of nitrophenols and 15 R. Majumdar, S. Tantayanon and B. G. Bag, Int. Nano Lett.,
reduction of alkynes. The high recyclable catalytic performance of 2017, 267–274.
Heck coupling in water medium was observed, and the Ostwald 16 P. P. Mpungose, Z. P. Vundla, G. E. M. Maguire and
ripening mechanism of the PdNPs catalyst was confirmed. The H. B. Friedric, Molecules, 2018, 23, 1676.
recyclable catalytic reduction of o-, m- and p-nitrophenols showed 17 L. Yu, Y. Huang, Z. Wei, Y. Ding, C. Su and Q. Xu, J. Org.
2016, 11, 2406–2414.
high efficiency, with five successful recycles, and the values of the
Chem., 2015, 80, 8677–8683.
rate constants were found to be 2.93 ꢁ 10ꢀ3 sꢀ1, 2.88 ꢁ 10ꢀ3 sꢀ1 18 L. O. Nyangasi, D. M. Andala, C. O. Onindo, J. C. Ngila,
and 2.42 ꢁ 10ꢀ3
s
ꢀ1, respectively. The recycle capacity of the
B. C. E. Makhubela and E. M. Ngigi, J. Nanomater., 2017,
2017, 8290892.
nanocomposite was well recorded for five catalysis cycles. The
effective reduction of alkynes into cis-alkenes was observed for 19 R. Mangaiyarkarasi, M. Priyanga, N. Santhiya and S. Umadevi,
both the aromatic and steric alkynes. This reaction was also J. Mol. Liq., 2020, 310, 113241.
4754 | New J. Chem., 2021, 45, 4746ꢀ4755
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021

View Article Online
Paper
NJC
20 G. Zhang, H. Zhou, J. Hu, M. Liu and Y. Kuang, Green Chem., 42 G. D. Manrique and F. M. Lajolo, Postharvest Biol. Technol.,
2009, 11, 1428–1432. 2002, 25, 99–107.
21 V. Calo, A. Nacci, A. Monopoli, A. Fornaro, L. Sabbatini, N. Cioffi 43 K. Walbru¨ck, F. Kuellmer, S. Witzleben and K. Guenther,
and N. Ditaranto, Organometallics, 2004, 23, 5154–5158. J. Nanomater., 2019, 2019, 4758108.
22 A. I. Ayad, C. B. Marın, E. Colaco, C. Lefevre, C. Methivier, 44 A. JyothiKora and L. Rastogi, Arabian J. Chem., 2018, 11,
´
´
´
A. O. Driss, J. Landoulsi and E. Guenin, Green Chem., 2019,
1097–1106.
21, 6646–6657.
45 A. Nuri, N. Vucetic, J. H. Smått, Y. Mansoori, J. P. Mikkola
and D. Y. Murzin, Catal. Lett., 2020, 150, 2617–2629.
46 X. Pei, Y. Li, Y. Deng, L. Lu, W. Li, R. Shi, A. Lei and
L. Zhang, Carbohydr. Polym., 2021, 251, 117020.
47 E. V. Vinogradova, C. Zhang, A. M. Spokoyny, B. L. Pentelute
and S. L. Buchwald, Nature, 2015, 526, 687–691.
23 F. Diler, H. Burhan, H. Genc, E. Kuyuldar, M. Zengin,
K. Cellat and F. Sen, J. Mol. Liq., 2020, 298, 111967.
24 R. Majumdar, B. G. Bag and P. Ghosh, Appl. Nanosci., 2016,
6, 521–528.
25 S. Furukawa and T. Komatsu, ACS Catal., 2016, 6, 2121–2125.
¨
´
´
26 B. M. Trost, Z. T. Ball and T. Joge, J. Am. Chem. Soc., 2002, 48 R. Martınez, C. Carrillo-Carrion, P. Destito, A. Alvarez,
´
˜
124, 7922–7923.
27 K. Chernichenko, A. Madarasz, I. Papai, M. Nieger,
M. Tomas-Gamasa, B. Pelaz, F. Lopez, J. L. Mascarenas
and P. Pino, Cell Rep. Phys. Sci., 2020, 1, 100076.
49 R. Ouyang, J. X. Liu and W. X. Li, J. Am. Chem. Soc., 2013,
135(5), 1760–1771.
´
´
´
¨
M. Leskela and T. Repo, Nat. Chem., 2013, 5, 718–723.
¨
28 F. A. Westerhaus, R. V. Jagadeesh, G. Wienhofer, M. M. Pohl,
J. Radnik, A. E. Surkus, J. Rabeah, K. Junge, H. Junge, M. Nielsen, 50 M. Kohantorabi and M. R. Gholami, Ind. Eng. Chem. Res.,
A. Bru¨ckner and M. Beller, Nat. Chem., 2013, 5, 537–543. 2017, 56, 1159–1167.
29 J. A. Delgado, O. Benkirane, C. Claver, D. Curulla-Ferre and 51 T. D. Nguyen, C. H. Dang and D. T. Mai, Carbohydr. Polym.,
C. Godard, Dalton Trans., 2017, 46, 12381–12403. 2018, 197, 29–37.
30 H. G. Bilgicli, H. Burhan, F. Diler, K. Cellat, E. Kuyuldar, 52 Y. Zhao, H. Zhu, Q. Zhu, Y. Huang and Y. Xia, J. Am. Chem.
´
M. Zengin and F. Sen, Microporous Mesoporous Mater., 2020,
296, 110014.
31 L. He, Y. Huang, A. Wang, X. Wang, X. Chen, J. J. Delgado
Soc., 2016, 138, 16645–16654.
53 D. Berillo and A. Cundy, Carbohydr. Polym., 2018, 192,
166–175.
and T. Zhang, Angew. Chem., Int. Ed., 2012, 51, 6191–6194. 54 V. D. Doan, V. S. Luc, T. L. H. Nguyen, T. D. Nguyen and
32 R. Shen, T. Chen, Y. Zhao, R. Qiu, Y. Zhou, S. Yin, X. Wang,
M. Goto and L. B. Han, J. Am. Chem. Soc., 2011, 133,
17037–17044.
T. D. Nguyen, Environ. Sci. Pollut. Res. Int., 2020, 27,
6148–6162.
55 S. Hao, S. Li and Z. Jia, J. Nanopart. Res., 2020, 22, 270.
33 K. Li, R. Khan, X. Zhang, Y. Gao, Y. Zhou, H. Tan, J. Chen 56 J. Li, X. Li, G. Han, C. Liu and X. Wang, BioResources, 2019,
and B. Fan, Chem. Commun., 2019, 55, 5663–5666. 14, 3630–3650.
34 Q. Ge, J. Ran, L. Wu and T. Xu, J. Appl. Polym. Sci., 2015, 57 Y. S. Chow, S. C. Chiu and C. C. Chien, Ann. Entomol. Soc.
132, 41268. Am., 1974, 67, 510–512.
35 J. Li, R. Hua and T. Liu, J. Org. Chem., 2010, 75, 2966–2970. 58 Y. Tamaki, K. Kawasaki, H. Yamada, T. Koshihara, N. Osaki,
36 S. Kusmardiyani, M. Insanu and M. A. Asyhar, Procedia
Chem., 2014, 13, 194–197.
T. Ando, S. Yoshida and H. Kankiohana, Appl. Entomol.
Zool., 1977, 12, 208–210.
37 A. Arkarapanthu, V. Chavasit, P. Sungpuag and 59 T. Koshihara and H. Yamada, Jpn. J. Appl. Entomol. Zool.,
L. Phuphathanaphong, J. Sci. Food Agric., 2005, 85, 1741–1749. 1980, 24, 6–12.
38 O. Yuliarti and R. M. B. Othman, Food Hydrocolloids, 2018, 60 T. Ishii, K. Nakamura, K. Kawasaki, H. Nemoto, K. Takahashi
81, 300–311. and A. Kubota, Jpn. J. Appl. Entomol. Zool., 1981, 25, 71–76.
39 W. Zhang, X. J. Zhao, Y. Jiang and Z. Zhou, Inorg. Nano-Met. 61 S. Lee, D. W. Lee and K. S. Boo, J. Asia-Pac. Entomol., 2005, 8,
Chem., 2017, 47, 15–20. 243–248.
40 M. R. El-Aassar, O. M. Ibrahim, M. M. G. Fouda, N. G. El- 62 T. Jimena, P. Florencia, A. Silvana, S. Horacio, R. Adela and
Beheri and M. M. Agwa, Carbohydr. Polym., 2020, 238, 116175. H. Viviana, Agrociencia Uruguay, 2016, 20, 61–67.
41 A. F. Fracasso, C. A. Perussello, D. Carpine, C. L. D. O. 63 R. R. Heath, J. A. Coffelt, P. E. Sonnet, F. I. Proshold,
´
Petkowicz and C. W. I. Haminiuk, Int. J. Biol. Macromol.,
2018, 109, 784–792.
B. Dueben and J. H. Tumlinson, J. Chem. Ecol., 1986, 12,
489–1503.
This journal is The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
New J. Chem., 2021, 45, 4746ꢀ4755 | 4755