Palladium nanoparticles immobilized on a magnetic chitosan-anchored Schiff base: Applications in Suzuki-Miyaura and Heck-Mizoroki coupling reactions

Article abstract of DOI:10.1039/c7nj00283a

A palladium nanocatalyst Fe₃O₄@CS-SB-Pd has been synthesized and characterized by FT-IR, XRD, XPS, FESEM, EDX, TEM, TGA, and ICP-AES analysis. The nanocatalyst has been found to be an efficient and magnetically separable heterogeneous catalyst for Suzuki-Miyaura and Heck-Mizoroki coupling reactions at a low concentration (0.02 mol% of Pd). The nanocatalyst afforded arylated products with high TON (4950) and TOF (9900 h^-1) in the Suzuki-Miyaura coupling reactions. However, for the Heck-Mizoroki coupling reaction, the values of TON and TOF were found to be 4900 and 7350 h^-1, respectively. The nanocatalyst could be easily recovered from the reaction mixture by using an external magnet and recycled up to five times without significant decrease in its catalytic activity. All isolated products were obtained as white to off-white crystalline solids and brown oils and fully characterized by ¹H and ¹³C NMR spectroscopy.

Full text of DOI:10.1039/c7nj00283a

View Article Online
View Journal
NJC
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: A. Anuradha, S.
Kumari, S. Layek and D. D. Pathak, New J. Chem., 2017, DOI: 10.1039/C7NJ00283A.
Volume 40 Number
1
January 2016 Pages 1–846
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
NJC
New Journal of Chemistry
www.rsc.org/njc
A journal for new directions in chemistry
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1144-0546
PAPER
Jason B. Benedict et al.
The role of atropisomers on the photo-reactivity and fatigue of
diarylethene-based metal–organic frameworks
rsc.li/njc

Page 1 of 8
PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
View Article Online
DOI: 10.1039/C7NJ00283A
Journal Name
ARTICLE
Palladium nanoparticles immobilized on a magnetic
Chitosan-anchored Schiff base: Application in Suzuki-
Miyaura and Heck-Mizoroki coupling reactions
Received 00th January 20xx,
Accepted 00th January 20xx
a
b
a
a*
DOI: 10.1039/x0xx00000x
Anuradha , Shweta Kumari , Samaresh Layek , and Devendra D. Pathak
3 4
A palladium nanocatalyst Fe O @CS-SB-Pd has been synthesized and characterized by FT-IR, XRD, XPS, FESEM, EDX,
www.rsc.org/
TEM, TGA, and ICP-AES analysis. The nanocatalyst has been found to be an efficient and magnetically separable
heterogeneous catalyst for Suzuki-Miyaura and Heck-Mizoroki coupling reactions at a low concentration (0.02 mol% of
-
1
Pd). The nanocatalyst afforded arylated products with high TON (4950) and TOF (9900 h ) in the Suzuki-Miyaura coupling
-1
reactions. However, for Heck-Mizoroki coupling reaction, the values of TON and TOF were found to be 4900 and 7350 h ,
respectively. The nanocatalyst could be easily recovered from reaction mixture by using external magnet and recycled up to
five times without significant decrease in its catalytic activity. All isolated products were obtained as white to off-white
1
13
crystalline solids and brown oils and fully characterized by H
and C NMR spectroscopy.
magnetic porous chitosan-based palladium catalyst for Heck-
Introduction
6
f
Mizoroki coupling reaction. In spite of various remarkable
advancements in heterogeneous catalysis, important environmental
aspects related to the physical profile of the heterogeneous catalysts,
catalytic activity and selectivity, leaching or recovery and recycling
are still of concern. Thus, the development of efficient and
recyclable catalysts has been one of the forefront areas of
contemporary research.
Palladium-catalyzed C-C coupling reactions such as, Suzuki-
1
2
Miyaura and Heck-Mizoroki have received considerable attention
for the construction of C-C bond in organic synthesis. Such reactions
have great potential for the synthesis of a large number of natural
products,
biologically
active
compounds,
herbicides,
pharmaceuticals, many organic building blocks and therapeutic
drugs and their intermediates. Considering the importance of C-C
coupling reactions, a large number of homogeneous palladium
catalysts having a diversity of ancillary ligands such as, N-
3
Magnetic nanoparticles (MNPs) have attracted increasing
attention because of their unique magnetic properties and easy
separation from the reaction mixture by magnetic decantation rather
7
than filtration or centrifugation. Unprotected MNPs are often
heterocyclic carbenes (NHC), arenes, phosphines, bipyridine, pincer4,
unstable and tend to aggregate during the catalytic transformations,
resulting in a remarkable drop in the catalytic activity due to the
and acyclic diaminocarbene (ADC), etc have been reported.
However, these homogeneous catalytic systems suffer from various
drawbacks such as, tedious separation, poor recyclability, use of
synthetically cumbersome and expensive ligands, and palladium
8
decrease of MNPs surface areas. Therefore, encapsulation of
magnetic nanoparticles by a polymer shell could stabilize and protect
them from agglomeration and oxidation. In addition to this, the
polymer shell can be chemically modified to provide a suitable
5
contamination in products etc. These drawbacks can be overcome
by the use of heterogeneous catalysts. Bumagin and Bykov have
reported the heterogeneous catalyst Pd(0)/C for the cross coupling of
water soluble 3-bromobenzoic acid with tetraphenylborate in neat
9
support for metal nanoparticles. Modification of Chitosan polymer
shell with Schiff base ligand may provide additional sites for
interactions with palladium nanoparticles and thus further augment
stability of the catalyst, prevent the agglomeration and the formation
6
a
water. Sullivan et al. have reported the modified multi-walled
carbon nanotubes MWCNT/Pd-DMAP nanocomposites for the cross
coupling reaction in water. Kantam and co-workers prepared the
polyaniline-supported palladium PANI-Pd for Suzuki-Miyaura
coupling of bromo- and chloroarenes in water. Paul and Clark have
reported the Suzuki-Miyaura coupling of aryl bromides and
phenylboronic acid using silica-supported imidazole-palladacycles
9
c
6
b
of palladium black.
Recently, Wang et al. prepared NHC-functionalized magnetic
1
0a
6
c
polymer nanocomposites for immobilizing palladium. Wang and
co-workers developed magnetic polymer nanocomposites-
supported palladium, Fe O @PUVS-Pd.
a
1
0b
Recently, Bian et al.
reported a novel palladium supported on metformin-functionalized
3
4
6
d
SiO -IM-Pd-H and SiO -IM-Pd-Me. Molnar et al. reported the Pd
2
2
1
0c
magnetic polymer nanocomposites, Pd/Fe O @PMAA-Met.
Jin
deposited onto organic-inorganic hybrid supports for the Heck-
Mizoroki coupling reaction. Movassagh and co-workers reported
3
4
6
e
and co-workers reported the magnetically recoverable Pd-NHC
immobilized on Fe O nanoparticles-ionic liquid matrix Pd-
3
4
1
0d
NHC/Fe O -IL.
These catalysts were highly active and
3
4
magnetically separable in Suzuki-Miyaura coupling reactions. Thus,
the search for new catalytic systems is one of the ever green areas of
research.
a.
Department of Applied Chemistry, Indian Institute of Technology (ISM), Dhanbad-
b.826004, India.
Department of Chemical Engineering, Indian Institute of Technology,
Gandhinagar- 382355, India
.
Chitosan (CS), the second most abundant natural polysaccharide
1
1
after cellulose, is obtained by the alkaline deacetylation of chitin.
CS can undergo a variety of chemical modification due to
†
Footnotes relating to the title and/or authors should appear here.
Electronic Supplementary Information (ESI) available: [details of any
supplementary information available should be included here]. See
DOI: 10.1039/x0xx00000x
1
2
accessibility to free amine and hydroxyl groups. The formation of
1
3
Schiff base with CS is one of its modifications. Hardy et al
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Page 2 of 8
ARTICLE
Journal Name
reported the Chitosan-based heterogeneous catalysts for Suzuki and filtrate was extracted with ethyl acetate (3x10 mL). TViheweAcrtoicmlebOinnliende
1
4
Heck reactions. For the last few years, we have been interested in organic layers were treated with saturated bDrOinI:e10so.1l0u3t9io/Cn7aNnJd00d2r8i3eAd
developing Chitosan-based heterogeneous catalysts for organic over anhydrous sodium sulphate. The removal of solvent yields
1
5
transformations. As a further extension of our ongoing work, we crude product, which after purification by column chromatography
herein describe the synthesis of palladium nanoparticles immobilized over silica gel (100-200 mesh), afforded the desired products.
on magnetic Chitosan-anchored Schiff base (Fe O @CS-SB-Pd) and
3
4
demonstrate its application in Suzuki-Miyaura and Heck-Mizoroki General procedure for Heck-Mizoroki coupling reaction
coupling reactions.
A 50 mL round-bottomed flask was charged with arylbromide (1
mmol), styrene or methyl acrylate (1.0 mmol), Et N (2.0 mmol), and
3
Experimental
Fe O @CS-SB-Pd nanocatalyst (0.2 mol%) in PEG-200 (4.0 mL).
3
4
The reaction mixture was heated to 110°C for appropriate time. At
the end of the reaction, the mixture was cooled to room temperature
and the catalyst was separated with an external magnet. The reaction
mixture was diluted with water and extracted with ethyl acetate
Synthesis of Fe O nanoparticles
3
4
Fe O nanoparticles were synthesized by using chemical co-
3
4
1
6
precipitation method according to the literature procedure. An
aqueous solutions of FeCl .6H O (2.0 mmol), FeCl .4H O (1.0
(3x10 mL). The combined organic layers was dried over anhydrous
3
2
2
2
Na SO , the removal of solvent yields crude product, which after
2
4
mmol) were mixed together and allowed to react under constant
o
purification by column chromatography over silica gel (100-200
mesh), afforded the desired products.
stirring and heating at 40 C, then added the aqueous solution of
NaOH (2M) drop-wise until the pH reached up to 12. The formation
of nanoparticles was marked by the appearance of an intense black
precipitate. The resulted mixture was then allowed to settle and cool Results and discussion
down onto a permanent magnet followed by repeated washing with
deionized water and ethanol. The resulting magnetic Fe O
nanoparticles were dried in an oven under vacuum at 50 C.
Magnetic nanoparticles Fe O , Fe O @CS, Fe O @CS-SB and
3 4 3 4 3 4
3
4
o
nanocatalyst Fe
O @CS-SB-Pd were synthesized as outlined in
3 4
9
b,16,17
Scheme using reported methods.
1
All products were
Synthesis of Fe O @CS
characterized by FT-IR, XRD, XPS, FESEM, EDX, TEM, and TGA.
The palladium content of the nanocatalyst Fe O @CS-SB-Pd was
3
4
3
4
1
7
Fe O @CS was synthesized by literature procedure.
To
a
determined by the ICP-AES analysis. The Fe O nanoparticles,
3 4
3
4
1
6
suspension of Fe O nanoparticles (1.15 g, 5.0 mmol) in deionized obtained by chemical co-precipitation method , were coated with
3
4
1
7
water (50 mL), 300 mL of 2% (v/v) acetic acid solution of CS (0.5 g, Chitosan to give Fe O @CS. The Schiff base derivatization of
3
4
2
.5 mmol) was added drop-wise at room temperature. The mixture Fe O @CS with o-vanilline in ethanol yielded Fe O @CS-SB. The
3
4
3
4
was vigorously stirred for 2 h at room temperature and then palladium nanocatalyst Fe
neutralized with 10% (w/v) solution of NaHCO . After the foam was reacting Fe @CS-SB with Pd(OAc)
subsided, the resulting Fe O @CS precipitate was isolated using an hydrazine. The catalytic activity of the Fe O @CS-SB-Pd
O
4
@CS-SB-Pd was synthesized in situ by
3
O
4
, followed by reduction with
3
3
2
3
4
3
4
external magnet, washed twice with deionized water and dried at nanocatalyst was explored in Suzuki-Miyaura and Heck-Mizoroki
6
0°C under vacuum for 6 h.
coupling reaction as shown in Scheme 2.
OH
Synthesis of Fe O @CS-SB
NH2
3
4
H2N
OH
FeCl3.6H2O
+
FeCl2.4H2O
NaOH
oC, 2 h
Ethanol
rt, 2 h
+
O
HO
O
HO
*
n
OH
An ethanolic solution of Fe O @CS (0.4305 g, 1.0 mmol) in a 50
40
*
3
4
NH2
mL round-bottom flask was magnetically stirred for 5 h. The clear
ethanolic solution of o-vanillin (0.1521g, 1.0 mmol) was added to
the resulting ethanolic suspension of Fe O @CS. The reaction
Fe3O4
NH2
H2N
OH
Fe3O4@CS
3
4
mixture was heated under reflux for 30 h. After cooling, the brown
solid was filtered, washed with ethanol (1 x 2 mL) and ether and
then dried at 50 C under vacuum for 12-15 h.
CHO
Ethanol,
reflux
24 h
OH
o
OCH3
Synthesis of Fe O @CS-SB-Pd nanocatalyst
H3CO
3
4
OCH3
OH
OH HO
A solution of Pd(OAc) (0.2245 g, 1.0 mmol) in acetone was added
L
L
HC
N
N
CH
2
N
CH
Chitosan
Fe3O4
to an ethanolic suspension of Fe O @CS-SB, and then hydrazine (5
3
4
OH
Pd(OAc)2
HO
HC
OH
L=
L
mg, 1.5 mmol) was added and allowed to heat under reflux for 36
h under N2 atmosphere. The final product, after filtration, was
L
Ethanol, reflux, N2, 36 h
H2NNH2
OCH3
= Pd(0)
N
N
CH
o
L
L
OH
washed with ether (3x10 mL) and dried at 50 C in vacuum for 12-15
OH HO
H3CO
h.
OCH3
Fe3O4@CS-SB-Pd
Fe3O4@CS-SB
General procedure for Suzuki-Miyaura coupling reaction
Scheme 1. Synthesis of Fe O , b) Fe O @CS, c) Fe O @CS-SB and
3
4
3
4
3
4
d) Fe O @CS-SB-Pd nanocatalyst.
3
4
Arylboronic acid (1.0 mmol) and arylhalides (X=Br and Cl) (1.0
X
B(OH)2
mmol) were dissolved in PEG-200:H O (1:1) (10 mL) in a 50 mL
2
Z
Z
Fe3O4@CS-SB-Pd (0.2 mol%)
round-bottomed flask and stirred for 10-15 minutes. K CO3 (2.0
+
2
PEG-200:H2O, 30 min, 50o
K2CO3
C
R
R1
R
=
R1
-H, -OCH3, -COCH3, -CHO
R1 = -H, -OCH3, -CH2CH3, -Cl,
F, -CH3 , napthyl,
mmol) and Fe O @CS-SB-Pd nanocatalyst (0.2 mol%) were added
3
4
o
X = Br, Cl
Z = CH, N
R
to the reaction flask. The reaction mixture was heated at 50 C. The
progress of the reaction was monitored by TLC at regular intervals.
After completion, the reaction mixture was cooled to room
temperature and the catalyst removed by external magnet. The
-
Suzuki-Miyaura coupling reaction (2a)
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 8
PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Journal Name
ARTICLE
Br
Z
View Article Online
DOI: 10.1039/C7NJ00283A
O
Fe3O4@CS-SB-Pd (0.2mol%)
PEG-200, Et3N, 40 min, 110oC
Z
or 2HC
CH3
Y
+
O
X
X
Y
X = -H, -CHO, -COCH3, -OCH3,
Y = -H, -CH3, -CH2Cl
Z = CH, N
Heck-Mizoroki coupling reaction (2b)
Scheme 2. The catalytic activity of Fe O @CS-SB-Pd nanocatalyst
3
4
in Suzuki-Miyaura (2a) and Heck-Mizoroki coupling reaction (2b).
The FT-IR spectra of Fe O , Fe O @CS, Fe O @CS-SB and
3
4
3
4
3
4
Fe O @CS-SB-Pd nanocatalyst are shown in Fig. 1. The FT-IR
3
4
-
1
-1
spectrum of Fe O exhibited two bands at 3439 cm and 579 cm
due to ν (OH) and ν (Fe-O), respectively.
of Fe O @CS, a peak at 3410 cm was observed, corresponds to ν
3
4
1
6a
In the FT-IR spectrum
-
1
3
4
-
1
Fig. 2. XRD spectra of a) Fe O , b) Fe O @CS, c) Fe O @CS-SB and d)
3
4
3
4
3
4
(
OH) and two diagnostic peaks were observed at 2931 cm and 2854
-
1
Fe
3
O
4
@CS-SB-Pd nanocatalyst.
cm due to the symmetric and asymmetric aliphatic -C-H stretching
1
7a
vibrations of CS.
Due to the coating of CS over Fe O , the v Fe-
3 4
-
1
-1
The XPS spectrum of Fe O @CS-SB-Pd nanocatalyst was recorded
3 4
O was slightly shifted from 579 cm to 581 cm . The FT-IR
spectrum of Fe O @CS-SB contained a sharp peak at 1632 cm due
to the ν (C=N) of azomethine group. However, Fe O @CS-SB-Pd
nanocatalyst showed a peak at 1610 cm due to ν (C=N) indicating
-
1
to ascertain the oxidation state of palladium (Fig. 3). In XPS
spectrum, peaks at binding energy of 723.6, 529.6, 399.4, and 339.6
and 283.2eV were assigned to Fe, O, N, Pd, and C, respectively. The
presence of carbon, nitrogen and oxygen species confirmed that CS-
3
4
1
8
3
4
-
1
the interaction of palladium nanoparticles with the azomethine
group.
1
9
SB was coated over the surface of Fe O nanoparticles. However, a
3 4
characteristic doublet (see inset) at 333.8 eV and 339.6 eV,
assignable to 3d5/2 and 3d3/2 3states respectively, confirmed the zero
2
oxidation state of palladium.
3 4
Fig. 3. XPS spectrum of Fe O @CS-SB-Pd nanocatalyst.
Fig. 1. FT-IR spectra of a) Fe
3 4 3 4 3 4
O , b) Fe O @CS, c) Fe O @CS-SB and d)
The surface morphology of Fe O , Fe O @CS, Fe O @CS-SB and
Fe @CS-SB-Pd nanocatalyst.
3
O
4
3
4
3
4
3
4
Fe O @CS-SB-Pd nanocatalyst are shown in Fig. 4. The FESEM
3
4
image analysis indicates that the Fe O nanoparticles are spherical in
The XRD spectra of Fe O , Fe O @CS, Fe O @CS-SB and
3
4
3
4
3
4
3
4
2
4
shape, homogeneously dispersed , and have average particle size
15 nm (Fig. 4a). On the other hand, FESEM image of Fe O @CS
Fe O @CS-SB-Pd nanocatalyst are shown in Fig. 2. Fe O
3
4
3
4
~
nanoparticles showed the characteristic diffraction peaks at 2θ =
3
4
o
o
o
o
o
clearly reveales the coating of CS on the surface of Fe O
3
(
0.2 , 35.4 , 43.2 , 57.2 , and 62.7 , ascribed to the reflections of
3
4
2
0
nanoparticles (Fig. 4b). However, the rough surface with spherical
morphology was observed for Fe O @CS-SB (Fig. 4c). The FESEM
220), (311), (422), (511) and (440) planes, respectively , (Fig. 2a).
Similarly, these characteristics peaks were also present in
3
4
o
o
image of Fe O @CS-SB-Pd confirmed the immobilization of
Fe O @CS with weak broad peak between 2θ = 22 -26 , indicating
3
4
3
4
2
1
palladium nanoparticles (average size is ~5-7 nm) on the surface of
Fe O @CS-SB (Fig. 4d). These observations are well supported by
CS coated at the surface of magnetic Fe O nanoparticles (Fig. 2b).
3
4
In XRD spectra of Fe O @CS-SB (Fig. 2c) and Fe O @CS-SB-Pd
3
4
3
4
3
4
the EDX analysis (Fig. 5). The EDX analysis of Fe O nanoparticles
catalyst (Fig. 2d), all peaks corresponding to Fe O nanoparticles
3
4
3
4
ensured the presence of Fe and O elements (Fig 5a).The EDX
analysis revealed the elemental composition (by weight %) of
were observed with slight decrease in intensity of peaks presumably
due to coating of Chitosan. However, the presence of all peaks in the
XRD spectrum confirmed that coating of Chitosan did not change
the phase of Fe O nanoparticles. Moreover, the XRD spectrum of
Fe O @CS are 5.71%, 0.68%, 30.59% and 43.33% for C, N, O, and
3
4
Fe, respectively (Fig. 5b). This implies that CS was coated on the
surface of Fe O nanoparticles. However, the elemental composition
3
4
Fe O @CS-SB-Pd nanocatalyst (Fig. 2d) displayed additional
3
4
3
4
o
o
o
of Fe O @CS-SB revealed the weight % of C, O, N increases after
diffraction peaks at 2θ = 40.5 46.9 and 68.8 , which were assigned
3
4
the Schiff base formation (Fig. 5c). The palladium content by EDX
in Fe O @CS-SB-Pd was found to be 5.50% (by weight). Further,
to the reflections of (111), (200), and (220) planes of palladium(0),
2
2
respectively.
3
4
elemental mapping of Fe, C, N, O, and Pd in the Fe O @CS-SB-Pd
3
4
nanocatalyst (Fig. 6), indicated the uniform distribution of Fe, C, N,
O, and Pd on the catalyst surface.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Page 4 of 8
ARTICLE
Journal Name
o
three stages of weight loss. The weight loss (~5%) below 150 C may
View Article Online
be due to the removal of moisture presentDOoIn: 1t0h.1e03s9u/rCfa7cNeJ0o0f28t3hAe
o
catalyst. The other weight loss (~11%) up to 310 C, this may be due
to the degradation of glycoside bonds of CS coated over Fe O
3
4
nanoparticles. On the other hand, the third weight loss (~20%) up to
o
6
30 C, may be due to the decomposition of SB-Pd supported on
2
6
Fe O @CS surface.
3
4
3 4 3 4 3 4
Fig. 4. FESEM image of a) Fe O , b) Fe O @CS, c) Fe O @CS-SB and d)
Fe O @CS-SB-Pd nanocatalyst.
3 4
3 4
Fig. 8. TGA of Fe O @CS-SB-Pd nanocatalyst.
After the successful synthesis and characterization of the
Fe O @CS-SB-Pd nanocatalyst, its catalytic application was
3
4
assessed in Suzuki-Miyaura and Heck-Mizoroki coupling reactions.
Initially, a reaction of 4-bromoanisole with phenylboronic acid was
selected as a model reaction and effect of different factors such as,
catalyst, catalyst loading, solvents, base, and temperature were
investigated (Table 1, entries 1-20). When the model reaction was
carried out in the presence of Fe O nanoparticles (5.0 mol% and 10
3
4
Fig. 5. EDX analysis of a) Fe
3 4 3 4 3 4
O , b) Fe O @CS, c) Fe O @CS-SB and d)
mol%) and K CO (2.0 mmol) in PhMe at room temperature and at
2
3
Fe @CS-SB-Pd nanocatalyst.
3
O
4
reflux for 24 h, no coupling product was obtained (Table1, entries 1-
). The same reaction in the presence of CS (10 mol%) at room
temperature and under reflux for 24 h, no product was isolated
Table 1, entries 4-5). Similarly, the reaction was carried out in
presence of Fe O @CS (10 mol%) in PhMe using K CO for 24 h,
3
(
3
4
2
3
no coupling product was observed (Table 1, entry 6). From this
observation, it is concluded that Fe atom and CS do not catalyze the
reaction. Then, the reaction was carried out in the presence of
Fe O @CS-SB-Pd nanocatalyst (1.0 mol%) using K CO as base
3
4
2
3
and PhMe as solvent, trace amount of product was obtained (Table
, entry 7). The same reaction under reflux, gave product in 86%
1
yield (Table1, entry 8). To optimize the catalyst loading, amount of
catalyst was decreased to 0.5 mol%, yield of the product increased to
3 4
Fig. 6. Elemental mapping of Fe O @CS-SB-Pd naocatalyst
9
5% (Table 1, entry 9). Further decrease the catalyst loading to 0.2
mol% and 0.1 mol%, yield of the product was 95% and 92%,
respectively (Table 1, entries 10-11). From this, it may be concluded
that 0.2 mol% catalyst loading was optimum. To optimize the
suitable solvent, a similar reaction was performed in the presence of
The TEM micrograph of the palladium nanocatalyst is shown in Fig.
7
. It indicates that Fe O nanoparticles have average particle size
3 4
~
10-15 nm (shown by black color) and embedded in ash color CS-
2
5
SB shell. Both the SEM and TEM analysis results about the size of
particles agreed well. The TEM images confirms the thickness of CS
over Fe O nanoparticles to be ~2 nm. The palladium nanoparticles,
o
o
PEG-200 at 110 C and 50 C, the yield was obtained in 56% and
5% (Table 1, entries 12-13). From green chemistry point of view,
8
3
4
o
the reaction was also performed in H O as a solvent at 100 C
2
shown by small spherical grey spots, have average particle size of
about ~5-7 nm uniformly dispersed over CS-SB shell. This indicates
the successful formation of Fe O @CS-SB-Pd nanocatalyst. Based
temperature, trace amount of product was obtained (Table 1, entry
1
4). After that, mixture of PEG-200:H O as a solvent in the ratio of
2
3
4
(1:1, 2:1, and 1:2) were used to carried out the reaction, results
upon ICP-AES analysis, the palladium content in the catalyst was
found to be 0.15 mmol/g.
indicated that PEG-200:H O was the best solvent in 1:1 ratio (Table
2
1
, entries 15-17). Then base was optimized, since base plays an
important role in Suzuki-Miyaura coupling reaction. When the
reaction was carried out in Na CO and Et N, yield of the product
2
3
3
was decreased to 74% and 45%, respectively (Table 1, entries 18-
9). Base free reaction was also carried in the presence of optimized
1
catalyst and solvent, no product was observed (Table 1 entry 20).
Table 1. The optimization of reaction parameters such as catalysts,
solvents, base, temperature and time for the reaction of 4-
a
bromoanisole with phenylboronic acid .
3 4
Fig. 7. TEM micrograph of Fe O @CS-SB-Pd nanocatalyst at 20 nm scale.
TGA was used to determine the thermal stability of Fe O @CS-SB-
3
4
Pd nanocatalyst (Fig. 8). The theromgram of the nanocatalyst shows
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 8
PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Journal Name
ARTICLE
Br
B(OH)2
View Article Online
DOI: 10.1039/C7NJ00283A
X
B(OH)2
Catalyst, solvent
base, temp, time
+
H CO
Z
3
Z
3 4
Fe O @CS-SB-Pd (0.2 mol%)
+
o
PEG-200:H2O, 30 min, 50 C
K CO
R1
OCH3
R
R1
R
2
3
X = Br, Cl
Z = CH, N
R
=
-H, -OCH3, -COCH3, -CHO
R1 = -H, -OCH3, -CH2CH3, -Cl,
Entry
Catalysts and
catalyst loading
Solvents
Base
Temp
( C)
Time
(h)
Yield
(%)
-
F, -CH3 , napthyl,
o
b
1
2
3
(
mol%)
1
2
3
4
5
6
7
Fe
Fe
Fe
CS (10)
CS (10)
3
3
3
O
O
O
4
4
4
(5)
(10)
(10)
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
PhMe
K
2
K
2
K
2
K
2
K
2
K
2
K
2
CO
CO
CO
CO
CO
CO
CO
3
3
3
3
3
3
3
rt
rt
24
24
24
24
24
24
24
-
-
-
-
-
-
H3CO
3
H COC
reflux
rt
reflux
reflux
rt
3a, 99%
TON= 4950
TOF = 9900
3b, 95%
TON= 4750
TOF = 9500
3c, 96%
TON = 4800
TOF = 9600
Fe
Fe
3
O
O
4
@CS (10)
@CS-SB-
3
4
trace
Pd (1.0)
Fe @CS-SB-
Pd (1.0)
Fe @CS-SB-
Pd (0.5)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.1)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
CH3
H3CO
OCH3
H3CO
CH3
8
9
1
1
1
1
1
1
3
O
4
PhMe
PhMe
PhMe
PhMe
PEG
K
K
K
K
K
K
K
K
2
2
2
2
2
2
2
2
CO
CO
CO
CO
CO
CO
CO
CO
3
3
3
3
3
3
3
3
reflux
reflux
reflux
reflux
110
12
12
6
86
3
d, 97%
3e, 99%
TON = 4950
TOF = 9900
3f, 98%
3
O
4
95
TON = 4850
TOF = 9700
TON = 4900
TOF = 9800
0
1
2
3
4
5
3
O
4
95
3
O
4
6
92
CH CH3
OCH3
H3CO
CH2CH3
2
3
O
4
6
56
3
h, 99%
3i, 96%
TON = 4800
TOF = 9600
3
g, 96%
TON = 4950
TOF = 9900
TON = 4800
TOF = 9600
3
O
4
PEG
50
10
15
85
3
O
4
H
2
O
100
trace
99
Cl
3
O
4
PEG-
200:H
50
30
min
CN
CH3
3l, 94%
TON = 4700
TOF = 9400
3
j, 92%
3k, 95%
TON = 4750
TOF = 9500
2
2
2
2
2
2
O
O
O
O
O
O
TON = 4600
TOF = 9200
(1:1)
1
1
1
1
6
7
8
9
0
Fe
3
O
4
@CS-SB-
PEG-
200:H
K
2
2
CO
CO
3
3
50
50
50
50
50
30
min
91
93
74
45
-
Pd (0.2)
OHC
(2:1)
Cl
H CO
F
H3CO
3
Fe
3
O
4
@CS-SB-
PEG-
200:H
K
30
min
Pd (0.2)
3
m, 93%
3n, 93%
TON = 4650
TOF = 9300
(1:2)
TON = 4650
TOF = 9300
3o, 94%
TON = 4700
TOF = 9400
Fe
3
O
4
@CS-SB-
PEG-
200:H
Na
3
2
CO
30
min
Pd (0.2)
N
(1:1)
CH3
Fe
3
O
4
@CS-SB-
PEG-
200:H
Et
3
N
30
min
Pd (0.2)
3
p, 72%
3
q, 88%
(1:1)
TON= 3600
TOF = 7200
TON = 4400
TOF = 8800
2
Fe
3
O
4
@CS-SB-
PEG-
200:H
No
base
30
min
Pd (0.2)
(
1:1)
Fig. 9. The reaction of various aryl halides (X= Br and Cl) with various
phenylboronic acid under optimized reaction conditions (Suzuki-Miyaura
coupling).
a
Reaction condition: 4-bromoanisole (1.0 mmol), phenylboronic acid (1.0 mmol), base
(
2.0 mmol), solvent (5.0 mL).
b
Isolated yield after column chromatography.
Table 2. A comparison study of Fe O @CS-SB-Pd nanocatalyst
with the previous reported catalysts in Suzuki-Miyaura coupling
reaction in terms of TON and TOF.
3
4
With the optimized reactions conditions in hand, the scope of the
Fe O @CS-SB-Pd nanocatalyst in Suzuki-Miyaura coupling
3
4
reaction was further extended to the reaction of aryl bromide and
phenylboronic acid having various electron-withdrawing and
electron-donating substituents. The results are shown in Fig. 9. The
electron-withdrawing and electron-donating substituents on both aryl
bromide and phenylboronic acid (Fig. 9, entries 3b-3p) afforded the
coupling products in good to excellent yields (92-99%). The
substituent in the meta-position (entry 3j) of phenylboronic acid
resulted in lower yield than the para-position (entry 3d) presumably
due to the steric hindrance. The reaction of sterically hindered
napthylboronic acid also afforded the good yield of the
corresponding product (Fig. 9, entries 3b and 3o). The reaction of
chlorobenzene with 4-methylphenylboronic acid afforded the
product in lower yield of 72% (Fig. 9, entry 3p) than the
bromobenzene. On the other hand, the reaction of hetero-aryl halides
i.e. 2-bromopyridne with phenylboronic acid afforded the product in
moderate yield (88%) (Fig. 9, entry 3q). All isolated products were
obtained as white to off-white crystalline solids to brown oils and
Entry
Catalysts
Metal
Yield
/conv
TON
TOF
Ref
-
1
(
mol %)
(h )
.
(%)
1
MFI zeolite-supported
ionic liquid
Pd (0.05)
94
1880
3760
28
2
3
PdNPsכH
Fe /SiO
NH /SA/Pd
Pd(PyBNHC)@nano-
SiO
2
PCMP
Pd (0.02)
Pd (0.05)
96
85
4800
1700
6400
1854
29
19
3
O
4
2
-
2
4
Pd (0.15)
92
613
438
30
2
5
6
7
Fe
Fe
3
3
O
O
4
4
@PUVS-Pd
@PUNP-Pd
Fe O /P(GMA-AA-
Pd (0.09)
Pd (0. 1)
Pd (0.2)
93
95
96
1033
95
480
1033
95
1600
10b
31
32
3
4
MMA-Pd)
Fe /P(GMA-AA-
MMA)-Schiff base-Pd
0.1)
Fe
8
9
3
O
4
Pd (0.01)
Pd (0.02)
98
99
980
980
33
(
1
13
fully characterized by H and CNMR spectroscopy. (Fig. S5-S26).
Furthermore, the Fe O @CS-SB-Pd nanocatalyst was compared
3
O
4
@CS-SB-Pd
4950
9900
This
work
3
4
with previously reported catalysts for Suzuki-Miyaura coupling
2
7a
reaction in terms of turn over number (TON)
frequency (TOF) (Table 2).
and turn over The effectiveness of Fe O @CS-SB-Pd nanocatalyst was next
3 4
2
7b
investigated in Heck-Mizoroki coupling reaction. A model reaction
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Page 6 of 8
ARTICLE
Journal Name
of bromobenzene with styrene was carried out to study the effect of substituted bromobenzene with substituted VsiteywreAnrtiecle Onalninde
catalyst, catalyst loading, solvent, base, and temperature. The results methylacrylate. The results are illustrated inDOFIi:g1.01.100.39T/hCe7NeJl0ec0t2r8o3nA-
are summarized in Table 3. When the reaction was carried out in the donating and electron-withdrawing substituents on both
presence of Fe O nanoparticles (5.0 mol% and 10 mol%) using bromobenzene and styrene (Fig. 10, entries 3a-3f and 3j) are well
3
4
K CO and PhMe as solvent at room temperature and under reflux, tolerated and afforded the desired coupling product in good to
2
3
respectively, for 24 h, no product was isolated (Table 3, entries 1-3). excellent yields (92-98%). The reaction of substituted bromobenzene
Then the similar reaction was carried out in CS (10 mol%), using with methylacrylate also afforded the good yields (90-94%) (Fig. 10,
Et N in PhMe at room temperature and under reflux, no product was entries 3g-3i). However, the reaction of hetero-aryl halides 1.e. 2-
3
observed (Table 3, entries 4-5). Next, the same reaction was carried bromopyridine with styrene resulted the product in low yield (Fig.
1
out in Fe O @CS (5.0 mol%) using Et N as base and DMF as 10, entry 3k). The isolated products were fully characterized by H
3
4
3
1
3
solvent, no product was isolated (Table 3, entry 6). When the and C NMR (Fig. S27-S44), as given in ESI.
reaction was carried out in the presence of Fe O @CS-SB-Pd (1.0
3
4
mol%) in DMF and Na CO at room temperature, no product was
Br
2
3
Z
o
O
Fe3O4@CS-SB-Pd (0.2mol%)
isolated (Table 3, entry 7). The similar reaction under at 110 C,
trace amount of product was observed (Table 3, entry 8). When the
catalyst loading was decreased to (0.5 mol% and 0.2 mol%) in
Z
or H2C
CH3
PEG-200, Et N, 40 min, 110oC
Y
+
O
3
X
X
Y
X = -H, -CHO, -COCH3, -OCH3,
Y = -H, -CH3, -CH2Cl
Z = CH, N
o
presence of DMF and K CO at 110 C, product was obtained in 85%
2
2
3
1
3
and 89% respectively (Table 3, entries 9-10). From the catalyst
loading optimization, it concluded that 0.2 mol% was optimum for
the reaction. Several solvents such as, PEG-200, H O, PEG-200:H O
CH3
CH2Cl
2
2
and DMF were tested, the best result were obtained with PEG-200,
3b, 98%
TON = 4900
TOF = 7350
3c, 95%
TON = 4750
TOF = 7125
3
a, 98%
o
TON = 4900
TOF = 7350
gave the coupling product with 98% yield within 40 min at 110 C
CH3
(
Table 3, entry 14) and no products were obtained with H O and
CH3
2
PEG-200:H O mixture (Table 3, entries 15-16). The reaction was
2
H3CO
3
H CO
H3COC
also carried out in different base such as K CO , Na CO , and
2
3
2
3
3f, 98%
TON = 4900
TOF= 7350
3d, 97%
TON = 4850
TOF = 7275
3
e, 98%
Et N.The trace amount of product was obtained with Na CO at
3
2
3
TON = 4900
TOF = 7350
o
1
10 C (Table 3, entry 8) and moderate yield was obtained with
K CO at 110 C (Table 3, entry 10), On the other hand, Et N
2
o
3
3
COOCH3
COOCH3
COOCH3
H3COC
OHC
H3CO
enhances the yield of the product up to 98% (Table 3, entry 14).
3
g, 94%
3h, 96%
TON = 4800
TOF = 7200
3i, 90%
TON = 4500
TOF = 6750
TON = 4700
TOF = 7050
Table 3. The optimization of reaction parameters such as, catalysts,
solvents, base, temperature and time for the reaction of
bromobenzene with styrene .
Br
CH3
a
N
OHC
Catalyst, solvent
3j, 92%
TON = 4600
TOF = 6900
3k, 62%
TON = 3100
TOF = 4650
+
base, temp, time
Fig. 10. The reaction of various aryl bromide with methyl acrylate or styrene
Entry
Catalysts and
catalyst loading
Solvents
Base
Temp
( C)
Time
(h)
Yield
(%)
under optimized reaction conditions (Heck-Mizoroki coupling).
o
b
(
mol %)
Recyclability
1
2
3
4
5
6
7
Fe
Fe
Fe
CS (10)
CS (10)
3
3
3
O
O
O
4
4
4
(5)
(10)
(10)
PhMe
PhMe
PhMe
PhMe
PhMe
DMF
DMF
K
K
K
Et
Et
Et
2
2
2
CO
CO
CO
3
3
3
rt
rt
24
24
24
24
24
24
24
-
-
-
-
-
-
-
reflux
rt
reflux
reflux
rt
The recyclability of the catalyst was investigated in both Suzuki-
Miyaura and Heck-Mizoroki coupling reaction. After the first cycle
of the reaction, Fe O @CS-SB-Pd nanocatalyst was recovered by an
3
N
N
N
3
3
Fe
Fe
3
O
O
4
@CS (5)
@CS-SB-
3
4
3
4
Na
2
CO
3
3
external magnet and then washed thoroughly with ethyl acetate
(2x10 mL) and ether. Then, the recovered nanocatalyst was dried
under vacuum at 70 C. Then, a model reaction of 4-bromoanisole
with phenylboronic acid (Suzuki-Miyaura) (Fig.S1) and
bromobenzene with styrene (Heck-Mizoroki) (Fig. S2) were carried
out under optimized reaction conditions. The results indicated that at
the end of five successive runs, there is no significant loss in the
catalytic activity of the nanocatalyst. The FT-IR spectrum of residual
catalyst after the 5 catalytic cycle, exhibited all characteristics
peaks (Fig. S3) and spectrum was found to be indistinguishable to
the spectrum of fresh Fe O @CS-SB-Pd nanocatalyst (Fig. 1d). The
FESEM image of the residual catalyst recovered after the reaction
(Fig. S4), showed no significant change in the surface morphology.
Pd (1.0)
Fe @CS-SB-
Pd (1.0)
Fe @CS-SB-
Pd (0.5)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
Fe @CS-SB-
Pd (0.2)
8
9
3
O
4
DMF
Na
2
CO
110
110
110
110
50
24
10
10
06
06
03
trace
85
89
90
94
98
98
-
o
3
O
4
DMF
K
2
2
CO
CO
3
3
1
1
1
1
1
1
0
1
2
3
4
5
6
3
O
4
DMF
K
3
O
4
DMF
Et
Et
Et
Et
Et
Et
3
N
N
N
N
N
N
3
O
4
PEG-200
PEG-200
PEG-200
3
3
3
3
3
th
3
O
4
140
110
reflux
100
3
4
3
O
4
40
min
12
3
O
4
2
H O
The EDX analysis revealed the amount of palladium was 4.69 %
1
3
O
4
PEG-
200:H O
2
12
-
th
(
weight %) after 5 catalytic cycle.
a
Reaction condition: bromobenzene (1.0 mmol), styrene (1.0 mmol), base (2.0 mmol),
solvent (5.0 mL).
Isolated yield after column chromatography.
b
Conclusions
With the optimized reaction conditions in hand, the scope of the
catalyst was further investigated for the reaction of various
In summary Fe O @CS-SB-Pd, a magnetically separable and
recyclable heterogeneous nanocatalyst, was synthesized in four steps
3
4
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 8
PNl ee aws eJ do ou rnn oa tl ao df j uC sht emm ai rs gt ir ny s
Journal Name
Scheme 1) and
ARTICLE
(
thoroughly
characterized
by
various
(f) B. Movassagh, and N. Rezaei, New J. Chem., 2015, 39, 7988-
View Article Online
7
997.
(a) R. B. N. Baig and R. S. Varma, Chem. Commun., 2012, 48,
220-6222; (b) Y. Zhu, L. P. Stubbs, F. Ho, R. Liu, C. P. Ship, J.
A. Maguire and N. S. Hosmane, ChemCatChem, 2, 2010, 365-
74.
spectroscopic and instrumental techniques. The Fe O4 linked
DOI: 10.1039/C7NJ00283A
3
7
Chitosan derivative of Schiff base served as an ideal support for the
stabilization of palladium nanoparticles (average size 5-7 nm). The
catalyst exhibited high catalytic activities in both Suzuki-Miyaura
and Heck-Mizoroki coupling reactions at a low catalyst loading
6
3
8
9
B. Dong, D. L. Miller and C. Y. Li, J. Phys. Chem. Lett., 2012, 3,
1346-1350.
(0.02 mol% of palladium). The catalyst afforded arylated products
-
1
with high TON (4950) and TOF (9900 h ) in the Suzuki-Miyaura
coupling reactions. However, for Heck-Mizoroki coupling reaction,
(a) N. Madhavan, C. W. Jones and M. Weck, Acc. Chem. Res.,
2008, 41, 1153-1165; (b) G. Savitha, R. Saha and G. Sekar,
Tetrahedron Lett., 2016, 57, 5168-5178; (c) H. Liu, P. Wang, H.
Yang, J. Niu and J. Ma, New J. Chem., 2015, 39, 4343-4350.
(a) Z. Wang, Y. Yu, Y. X. Zhang, S. Z. Li, H. Qian and Z. Y. Lin.
Green Chem., 2015 17, 413-420; (b) D. Wang, W. Liu, F. Bian
and W. Yu, New J. Chem., 2015, 39, 2052-2059; (c) P. Yang, R.
Ma and F. Bian, ChemCatChem 2016, 8, 3746-3754; (d) A.
Taher, J.-B. Kim, J.-Y. Jung, W.-S. Ahn, M.-J. Jin, Synlett, 166,
-
1
the values of TON and TOF were found to be 4900 and 7350 h ,
respectively. The catalyst offered noticeable advantages such as,
facile recovery from the reaction mixture by external magnet and
could be reused up to five times with no significant loss of the
catalytic activity.
1
1
0
1
2
009, 2477-2482.
Acknowledgments
(a) E. Guibal, Prog. Polym. Sci., 2005, 30, 71-109; (b) S. H. Lim
and S. M. Hudson, Carbohydr. Res., 2004, 339, 313-319; (c) M.
Bodnar, J. F. Hartmann and J. Borbely, Biomacromolecules, 2005,
6, 2521-2527; (d) R. A. A. Muzzarelli, Chitin. Pergamon Press,
Oxford, 1977, 83-252.
(a) V. V. Binsu, R. K. Nagarale, V. K. Shahi and P. K. Ghosh,
React. Funct. Polym. 2006, 66, 1619-1629; (b) V. Zargar, M.
Asghari, A. Dashti, Chembioeng Rev., 2015, 2, 204-226; (c) R. B.
N. Baig and R. S. Varma, Green Chem., 2013, 15, 1839-1843.
(a) W. Li-xia, W. Zi-wei, W. Guo-song, L. Xiao-dong and R.
Jian-guo, Polym. Adv. Technol., 2010, 21, 244-249; (b) M. Lee,
B.-Y. Chen and W. Den, Appl. Sci., 2015, 5, 1272-1283.
J. J. E. Hardy, S. Hubert, D. J. Macquarrie, and A. J. Wilson,
Green Chem. 2004, 6, 53-56.
We are thankful to the CRF IIT (ISM), STIC Cochin and SAIF
Panjab University, Chandigarh for providing help in the
analysis of the samples. Anuradha and SL acknowledge the
receipt of IIT (ISM) fellowship.
1
1
2
3
Supporting Information
Supporting Information related to this article.
References
1
1
4
5
(a) Anuradha, S. Kumari and D. D. Pathak, Tetrahedron Lett.,
2015, 56, 4135-4142; (b) Anuradha, S. Kumari, S. Layek and D.
D. Pathak, J. Mol. Struct., 2017, 1130, 368-373.
1
2
3
(a) N. Miyaura, K. Yamada and A. Suzuki, Tetrahedron Lett.,
1
4
979, 20, 3437-3440; (b) A. Suzuki, Chem. Commun., 2005,
759-4763.
16 (a) B. Karami, K. Eskandari and A. Ghasemi, Turk. J. Chem.,
2012, 36, 601-614; (b) V. Belessi, R. Zboril, J. Tucek, M.
Mashlan, V. Tzitzios and D. Petridis, Chem. Mater., 2008, 20,
3298-3305.
17 (a) J. Safari and L. Javadian, RSC Adv., 2014, 4, 48973; (b) J.
Safari and L. Javadian, Ultrason. Sonochem., 2015, 22, 341-348.
18 X. Cai, H. Wang, Q. Zhang, J. Tong, Z. Lei, J. Mol. Catal A:
Chem., 2014, 383, 217-224.
19 H. Khojasteh, V. Mirkhani, M. Moghadam, S. Tangestaninejad, I.
Mohammadpoor-Baltork, J. Nano Struct., 2015, 5, 271-280.
20 O. U. Rahman, S. C. Mohapatra, S. Ahmad, Mater. Chem. Phys.,
2012, 132, 196-202.
R. F. Heck, J. Am. Chem. Soc., 1968, 90, 5518-5526; (b) T.
Mizoroki, K. Mori and A. Ozaki, Bull. Chem. Soc. Jpn., 1971, 44,
5
81.
(a) L. E. Overman, D. J. Ricca and V. D. Tran, J. Am. Chem. Soc.,
1
7
2
6
993, 115, 2042-2044; (b) J. G. de Vries, Can. J. Chem., 2001,
9,1086-1092; (c) S. Lightowler and M. Hird, Chem. Mater.,
005, 17, 5538-5549; (d) F. Leroux, Chem. Biol. Chem., 2004, 5,
44-649; (e) A. Ogata, C. Furukawa, K. Sakurai, H. Iba, Y. Kitade
and Y. Ueno, Bioorg. Med. Chem. Lett., 2010, 20, 7299-7302; (f)
K. Sambasivarao and M. Kalyaneswar, Chem. Asian. J., 2009, 4,
3
54-362.
4
(a) M. Stradiotto, Ancillary ligand design in the development of
palladium catalysts for challenging selective monoarylation
reactions: Ch. 5, in: T. Colacot (Ed.), New Trends in Cross-
Coupling: Theory and Applications, RCS Catalysis Series No. 21,
Cambridge, UK, 2015; (b) A. Chartoire, S. P. Nolan, Advances in
C-C and C-X coupling using palladiumN-heterocyclic carbene
21 M.-B. Anoushiravan, K. Babak , R. K. Roshanak, A. Ali and K.
Azam, RSC Adv., 2015, 5, 73279-73289.
22 J. Zhou, Z. Dong, H. Yang, Z. Shi, X. Zhou and R. Li, Appl. Surf.
Sci., 2013, 279, 360-366.
23 Z. Mandegani, M. Asadi, Z. Asadi, A. Mohajeri, N. Iranpoor and
A. Omidvar, Green Chem., 2015, 17, 3326-3337.
(
Pd-NHC) complexes: Ch. 4, in: T. Colacot (Ed.), New Trends in
24 (a) T. Cheng, D. Zhang, H. Li and G. Liu, RSc Adv., 2013, 00, 1‐3
(b) M. Esmaeilpour and J. Javidi, J. Chin. Chem. Soc., 2015, 62,
614-626.
25 M. Amini, M. Hajjari, A. L. Isfahani, V. Mirkhani, M.
Moghadam, S. Tangestaninejad, M.-B. Iraj and M. Ahmadi,
Nanochem. Res., 2016, 1, 237-248.
26 A. Naghipour and A. Fakhri, Catal Commun., 2016, 73, 39-45.
27 (a) M. B. Oudart, Chem. Rev., 1995, 95, 661-666; (b) I. B. Wilson
and M. A. Harrison, J. Biol Chem., 1961, 236, 2292-2295.
28 M.-J. Jin, A. Taher, H.-J. Kang, M. Choi and R. Ryoo, Green
Chem., 2009, 11, 309-313.
29 N. Huang, Y. Xu and D. Jiang, science reports 2014.
30 Z. Pahlevanneshan, M. Moghadam, V.Mirkhani, S.
Tangestaninejad, I. Mohammadpoor-Baltork and S. Rezaei, New
J. Chem., 2015, 39, 9729-9734.
Cross-Coupling: Theory and Applications, RCS Catalysis Series
No.21, Cambridge, UK, 2015; (c) A. De Angelis, T. J. Colacot,
Prominent ligand types in modern cross-coupling reactions: Ch.
2
, in: T. Colacot (Ed.), New Trends in Cross-Coupling: Theory
and Applications, RCS Catalysis Series No. 21, Cambridge, UK,
015; (d) C. C. C. J. Seechurn, H. Li, T. J. Colacot, Pd-phosphine
2
precatalysts for modern cross-coupling reactions: Ch. 3, in: T.
Colacot (Ed.), New Trends in Cross-Coupling: Theory and
Applications, RCS Catalysis Series No. 21,Cambridge, UK, 2015.
Y. C. Hsu, J. S. Shen, B. C. Lin, W. C. Chen, Y. T. Chan, W. M.
Ching, G. P. Yap, C. P. Hsu and T. G. Ong, Angew. Chem. Int.
Ed., 2015, 54, 2420-2424.
5
6
(a) V. V. Bykov and N. A. Bumagin, Russ. Chem. Bull., 1997, 46,
1
344-1346; (b) J. A. Sullivan, K. A. Flanagan and H. Hain, Catal.
Today, 2009, 145, 108-113; (c) M. L. Kantam, M. Roy, S. Roy, B.
Sreedhar, S. S. Madhavendra, B. M. Choudary and R. L. De,
Tetrahedron, 2007, 63, 8002-8009; (d) S. Paul and J. H. Clark,
Green Chem., 2003, 5, 635-638; (e) A. Papp, K. Miklos, P. Forgo
and A. Molnar, J. Mol. Catal. A: Chemical, 2005, 229, 107-116;
31 J. Yang, D. Wang, W. Liu, X. Zhang, F. Bian and W. Yub , Green
Chem., 2013, 15, 3429-3437.
32 D. Yuan and H. Zhang, Appl. Catal. A: General, 2014, 475, 249-
255.
33 D. Yuan, L. Chen, L. Yuan, S. Liao, M. Yang and Q. Zhang,
Chem. Eng. J., 2016, 287, 241-251.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

New Journal of Chemistry
Page 8 of 8
View Article Online
DOI: 10.1039/C7NJ00283A
Graphical Abstract