A nanoscopic icosahedral {Mo72Fe30} cluster catalyzes the aerobic synthesis of benzimidazoles

Article abstract of DOI:10.1039/c9ra06581d

In this study, the catalytic efficiency of amorphous {Mo₇₂Fe₃₀} nanocapsules as a safe Keplerate polyoxometalate in organic synthesis was exploited. The easy-made solid catalyst exhibited high efficiency using a very low dosage (0.02

Full text of DOI:10.1039/c9ra06581d

RSC Advances
View Article Online
View Journal | View Issue
PAPER
A nanoscopic icosahedral {Mo Fe } cluster
7
2
30
catalyzes the aerobic synthesis of benzimidazoles†
Cite this: RSC Adv., 2019, 9, 34854
Zohreh Garazhian, Abdolreza Rezaeifard * and Maasoumeh Jafarpour
*
In this study, the catalytic efficiency of amorphous {Mo72Fe30} nanocapsules as a safe Keplerate
polyoxometalate in organic synthesis was exploited. The easy-made solid catalyst exhibited high
efficiency using a very low dosage (0.02–0.05 mol%) in the catalyzed condensation of various aromatic
1
,2-diamines and aldehydes for the aerobic synthesis of benzimidazoles with very small E-factor values
Received 21st August 2019
Accepted 19th October 2019
(0.11–0.33). The superior catalytic activity of amorphous nanoclusters compared to that of its crystalline
counterpart was demonstrated. The high activity and recyclability of heterogeneous catalysts in a green
reaction media under oxygen atmosphere, make this environmentally benign organic process
appropriate for our applied goals.
DOI: 10.1039/c9ra06581d
rsc.li/rsc-advances
catalysts have been developed as heterogeneous catalysts for
benzimidazole derivatives synthesis.
Polyoxometalates (POMs) as a subset of metal oxides, have
Introduction
9,10
In recent decades, carbon–heteroatom bond formations have
been the central subject of modern organic synthesis. Among an unmatched range of physical and chemical properties and
them, N-containing heteroaromatic compounds are useful and the ability to form dynamic structures. They have been well
important structures found in natural and synthetic considered as alternative oxidation catalysts in the past few
1
,2
11
compounds. Benzimidazole and its derivatives are an impor- decades. POMs with a structure of Keplerate, are giant metal-
tant and promising class of N-heterocycles due to their diverse oxide-based nanocapsules in which 12 pentagonal [(Mo)–Mo
5
-
6
ꢀ
3
biological activities and pharmacological properties. Extensive
interest in benzimidazole-containing structures has led to wide {Mo
O
21(H
2
O)
6
]
units are linked together by 30 linkers such as
V
III
III
2+
2
O
4
} in {Mo132}, or Feaq, Craq and VOaq in mixed metal
studies for their synthesis. Three methods have been reported derivatives. Keplerate-type polyoxometalates have attracted
for the synthesis of these compounds including (i) condensa- more and more attention of scientists in the areas of chemistry,
12
tion of o-phenylenediamines with carboxylic acids and their physics, biology, and materials. Recently, it was established
derivatives (imidates, nitriles, or orthoesters) which oen that, iron containing Keplerate, {Mo72Fe30} nanocluster, has
requires high reaction temperatures and strong acidic condi- potential for using in targeted delivery of drugs because of lack
4
13
tions, (ii) transition-metal catalyzed coupling reactions to of toxicity. It can be isolated in two forms, (i) crystalline form
V
5
2 4
create the benzimidazole nucleus, and (iii) the condensation of of cluster resulting from replacement of the {Mo O } linkers in
o-phenylenediamine with aldehydes, which has been exten- {Mo132} by aqua-Fe polyhedra [Fe O (H O)] in a long time,
5 2
sively used due to the accessibility of a large number of alde- and (ii) amorphous form of cluster, which is prepared easily
hydes although it requires a stoichiometric oxidant for and immediately in high yield by addition of an iron salt to an
dehydration. In addition to some signicant limitations such acidied aqueous solution of sodium molybdate. The amor-
III
III
3+
14
6
15
7
as the use of expensive and noxious reagents, harsh conditions, phous cluster is insoluble in water and ethanol making a golden
low isolation yields and toxic metal oxidants, the use of opportunity for heterogeneous catalysis in green media. Just
homogeneous catalysts that cannot be recovered from the recently, we discovered catalase-like activity of {Mo72Fe30
}
reaction medium is a serious drawback. Accordingly, the design nanoclusters in aqueous solution under visible-light irradia-
16
of heterogeneous catalysts for the straight and easy synthesis of tion. Our nding revealed the superior catalytic activity of
8
16
benzimidazoles is of extreme demand. In recent years, various amorphous {Mo72Fe30} than that of crystalline counterpart.
catalysts including metal oxides and supported heteropolyacid The catalytic utilization of Keplerates in organic reaction, unlike
the Keggin and Dawson POMs, has not been considered
11
extensively. The oxidation of suldes catalyzed by crystalline
form of {Mo72Fe30} reported in 2009 is the rst study on catalytic
activity of Keplerate. Aer that, other research groups
Catalysis Research Laboratory, Department of Chemistry, Faculty of Science,
University of Birjand, Birjand, Iran 97179-414. E-mail: rrezaeifard@birjand.ac.ir;
mjafarpour@birjand.ac.ir; Fax: +98 56 32202515; Tel: +98 56 32202516
17
†
Electronic supplementary information (ESI) available: FT-IR, DRS, Raman, XRD, including us, tried to use different Keplerates in a variety of
TGA, EDS, VSM, FESEM, TEM and BET of as-prepared clusters. See DOI:
18–25
organic transformations.
As {Mo72Fe30} as concerned,
1
0.1039/c9ra06581d
34854 | RSC Adv., 2019, 9, 34854–34861
This journal is © The Royal Society of Chemistry 2019

View Article Online
Paper
RSC Advances
2
Scheme 1 Synthesis of benzimidazole derivatives by {Mo72Fe30} nanoclusters and O as oxidant.
17,23
22
suldes oxidation,
and epoxidation of olens, are few utilization of amorphous {Mo Fe } as a high yield and easy-
72 30
works performed in the present of crystalline form of cluster, made heterogeneous catalyst in organic transformation yet.
and to the best of our knowledge, there is no report on catalytic Following our ongoing research on catalytic activity of
Fig. 1 The screening of (i) solvent nature (ii) solvent amount (iii) catalyst dose (iv) temperature and (v) various oxidant on synthesis of benz-
imidazole from 4-chlorobenzaldehyde and o-phenylenediamine with molar ratio of 1/1.2 catalyzed by amorphous {Mo72Fe30}.
This journal is © The Royal Society of Chemistry 2019
RSC Adv., 2019, 9, 34854–34861 | 34855

View Article Online
RSC Advances
Paper
a
Table 1 Effect of substituent (on aromatic ring) on the reaction rate of benzimidazoles synthesis
b
c
Entry
1
R
1
R
2
Product
Yield%
E-factor
Time (min)
25
H
H
H
91
0.194
d
e
2
3
4-Cl
94
87
0.167
0.286
20 (40)
H
2-Cl
20
e
4
5
H
H
4-OMe
92
85
0.198
0.29
40 (60)
4-NO
2-NO
4-Me
2
150
150
6
7
8
9
H
H
H
H
H
2
88
90
87
83
89
0.26
e
0.234
0.276
0.337
0.235
25 (35)
2-Me
25
4-OH
2-OH
50
1
0
125
1
1
1
2
NO
2
3
4-Cl
4-Cl
36
93
1.71
150
40
CH
0.178
1
1
3
4
H
89
34
0.21
2.28
25
NO
2
4-CH
3
150
34856 | RSC Adv., 2019, 9, 34854–34861
This journal is © The Royal Society of Chemistry 2019

View Article Online
Paper
RSC Advances
Table 1 (Contd.)
b
c
Entry
R
1
R
2
Product
Yield%
E-factor
Time (min)
150
1
5
Br
4-Cl
88
0.11
a
ꢁ
2
The reactions were run under continues stream of O conditions at 60 C using 0.2 mmol aldehydes and 0.21 mmol 1,2-phenylenediamines (1/1.2
24
b c
molar ratio), 2 mg catalyst (0.05 mol%), in 1 mL EtOH. The products were identied by comparison with authentic samples.
Yield of isolated
products. 91% yield within 35 min at 40 C using 0.025 mol% of catalyst. The numbers in parentheses are the reaction time for crystalline
Mo72Fe30}.
d
ꢁ
e
{
21–25
Keplerates,
new green methods for the synthesis of benzimidazoles,
herein, for the rst time the catalytic efficiency of amorphous ence of amorphous {Mo Fe }, the effect of solvent,
and in the line of our interest on development of need of catalyst for successful conversion of reactants to prod-
24,26,27
ucts. To obtain the optimum reaction conditions in the pres-
7
2
30
{
Mo Fe } in organic synthesis is exploited. A simple, mild, and temperature, catalyst dose and oxidant was screened (Fig. 1). As
72 30
efficient procedure for the synthesis of benzimidazole deriva- shown in Fig. 1(i and ii) ethanol is the best solvent for the
tives that employs only oxygen as the oxidant in the presence of reaction to proceed faster. In addition to solubility of materials,
amorphous {Mo72Fe30} as a safe heterogeneous catalyst in hydrogen bonding between alcohol molecules and hydroxyl/
ethanol is described (Scheme 1). The nanoscopic poly- water sites on POM surface is reasonable for such an exhibi-
28
oxometalate catalyst proved to be reusable while maintaining tion. The results presented in Fig. 1(iii) showed that the model
icosahedral integrity.
reaction reached to highest performance using only 1 mg (0.05
mmol, 0.025 mol%) of the catalyst featuring a turnover number
of 4000 within 25 min. Also, a minor increasing in the
Experimental
ꢁ
temperature to 35 and 40 C reduces signicantly the reaction
The synthesis procedures for amorphous and crystalline time from 300 to 150 and 35 min respectively (iv) for conden-
{Mo72Fe30} with full characterization are given in ESI.†
sation of the above mentioned substrates. However, less reac-
tive substituted aldehydes and diamines required higher
ꢁ
catalyst dose of 0.05 mol% (2 mg) and temperature of 60 C to
react efficiently at appropriate times (Table 1).
General procedure for the synthesis of benzimidazoles
To a mixture of benzaldehyde (0.2 mmol) and o-phenylendi-
amine (0.21 mmol) in 1 mL EtOH, 2 mg {Mo72Fe30} nanocluster
Finally, different common oxidants were screened and both
molecular oxygen and TBHP showed to be the best (v). Never-
theless, clear environmental and economic benets of using O
(
0.1 mmol, 0.05 mol%) was added and the reaction mixture was
2
ꢀ1
ꢁ
stirred under 1 atm O (7–10 mL min ) at 40–60 C for the
2
as the terminal oxidant as well as the possible disintegration of
capsule in the presence of TBHP should be taken into account.
Under these optimized aerobic conditions, the catalytic system
showed a wide applicability for a range of substrates for the
synthesis of various benzimidazole derivatives. A variety of
benzaldehydes and o-phenylenediamines carrying different
substituents reacted successfully together under the catalytic
inuence of amorphous {Mo72Fe30} and good to excellent
product yields were obtained (Table 1).
required time. Progress of the reaction was monitored by TLC.
Aer the completion of the reaction, the mixture was cooled to
room temperature and the catalyst was separated by ltration
and washed with EtOH. The desired product (liquid phase) was
extracted by plate chromatography, and eluted with n-hexane/
ethyl acetate (10/3). Assignments of the products were made
24
by comparison with authentic samples.
Results and discussion
The environmental impact of the catalytic protocol which
measures the amount of waste generated during a synthetic
process was assessed through E-factor calculations (E-factor ¼
The catalytic activity of {Mo72Fe30} was tested in the synthesis of
benzimidazoles (Scheme 1) by choosing a model reaction
between o-phenylenediamine and 4-chlorobenzaldehyde. Trace
amount of benzimidazole product was detected in a blank
experiment where the model reaction was performed in the
absence of {Mo72Fe30} at different conditions, suggesting the
29
total waste (kg)/total product (kg)). It should be noted that
the mass of {Mo Fe } cluster has been omitted from the E-
7
2
30
factor calculations, because of efficient recovery during the
process for further usage. The calculated E-factor values for
This journal is © The Royal Society of Chemistry 2019
RSC Adv., 2019, 9, 34854–34861 | 34857

View Article Online
RSC Advances
Paper
a
the synthesis of all the benzimidazole derivatives given in Table 3 Structural properties of {Mo72Fe30} nanoclusters
Table 1, are very small ranging between 0.11 and 0.33. These
results highlight the green nature of the protocol resulting
from minimum waste generation using this aerobic protocol
b
2
ꢀ1
c
3
ꢀ1
d
Catalyst
SBET (m g
)
V
BJH (cm g
)
RBJH (nm)
Amorphous {Mo72Fe30
}
15.38
5.9
0.2777
0.0098
72.206
6.6
employing ethanol as reaction medium in the presence of Crystalline {Mo72Fe30
}
highly active recyclable heterogeneous {Mo72Fe30} nano-
cluster. However, the reaction performance was greatly
decreased by introduction of electron withdrawing substitu-
ents on the aromatic ring of diamine molecule. E-factor values
for nitro containing benzimidazoles formation resulting from
a
b
BET hysteresis curves are given in Fig. S10 and S19. Specic surface
c
d
area. Pore volume. Average pore diameters.
VI
4
-nitro-1,2-phenylenediamine increased to 1.7 and 2.28 for inside it. As depicted in Scheme 2, the Mo sites in the
condensation with 4-chlorobenzaldehyde and 4-methyl- {Mo72Fe30} activate the carbonyl carbon of the aromatic alde-
benzaldeyde respectively (entries 11 and 14). As expected from hyde for nucleophilic attack by –NH group of o-phenylenedi-
the rst step of mechanism (vide infra) which is nucleophilic amine. The resulting imine is further attacked by second –NH
attack of o-phenylenediamine on aromatic aldehyde, electron to form dihydrobenzimidazole (benzimidazoline) followed by
withdrawing nitro group decreases the nucleophilicity of –NH
aromatization in the presence of molecular oxygen mediated by
2
2
2
III
group of o-phenylenediamine retarding the formation of C]N Fe centers to give 2-aryl-1H-benzimidazoles as product. Con-
bonds, and consequently declines the conversion and selec- ducting the reaction under anoxic conditions (Ar) removed the
tivity of desired benzimidazoles.
oxidation product (benzimidazole) and just 20% by-product was
observed accompanied with imine as main product. This result
Mechanistic aspects of catalysis with {Mo72Fe30
}
To clarify the catalytic role of {Mo72Fe30}, the effect of the simple
salts used in the synthesis of Keplerate was investigated.
Inspection of the results in Table 2 demonstrated the superi-
ority of Keplerate in terms of activity and particularly selectivity.
We also replaced the amorphous {Mo Fe } by crystalline
7
2
30
counterpart to compare their catalytic performance. As shown
in Table 1 (entries 2, 4 and 7) and Table 2, the use of crystalline
{Mo72Fe30} lengthened the reaction with a factor of 1.5–2, while
maintaining the selectivity. The larger specic surface area and
particularly pore volume of amorphous cluster (Table 3, Fig. S10
and S19†) caused by its low crystallinity and formation of
blackberry structures resulting from aggregation of nano-
particles (evidenced by SEM images; Fig. S8 and S17†) may be
30
reasonable for this exhibition. Furthermore, greater disorders
in the structure of amorphous materials providing more
unsaturated sites for adsorption of molecules onto the solid
31,32
surface, increase their catalytic activity.
It should be noted
that, metal-oxide {Mo } pores resulting from structural
9 9
O
organization of the pentagons and linkers in Keplerates
provides access to the capsule's interior just for very small
14
molecules. Thus, considering the above mentioned structural
properties, it is reasonable to accept that the reaction taking
Scheme 2 Proposed mechanism for catalytic action of {Mo72Fe30
}
place on the surface of the {Mo72Fe30} nanocapsule and not nanoclusters.
a
Table 2 The comparison of catalytic activity of amorphous {Mo72Fe30} with its simple salts
Catalyst
Conversion%
Benzimidazole selectivity%
Time (min)
FeCl
Na MoO
FeCl $6H
Amorphous {Mo72Fe30
3
$6H
2
O
$2H
80
90
80
100
100
30
40
40
100
100
35
80
10
20
40
2
4
2
O
3
2
O + Na
2
MoO
4
$2H
2
O
}
Crystalline {Mo72Fe30
}
a
ꢁ
Reaction conditions: 4-chlorobenzaldehyde: o-phenylenediamine molar ratio is 1/1.2, catalyst 0.05 mol%, EtOH (1 mL) at 60 C. The simple salts
were used according to their stoichiometry in {Mo72Fe30}.
34858 | RSC Adv., 2019, 9, 34854–34861
This journal is © The Royal Society of Chemistry 2019

View Article Online
Paper
RSC Advances
characteristic ngerprint of the icosahedral structure (1000–
ꢀ
1
5
00 cm ) as well as the typical bands for bridging acetate ligands
ꢀ
1
15
at 1534 and 1416 cm remained intact. Aer the completion of
the reaction, ethanol was added, and the catalyst was separated
by centrifugation and decantation of the reaction mixture, dried
and then reused. The recovered heterogeneous catalyst exhibited
the same activity and selectivity and just a 4 percentage reduction
in conversion was observed aer ve runs (90% compared to
entry 2 in Table 1), demonstrating the reusability of catalyst
under the reaction conditions.
Comparison with other catalytic systems
To show the merit of title methodology for the synthesis of 2-
aryl-1H-benzimidazole derivatives, the reaction conditions
and the catalytic performance of a number of catalysts in
literature, are summarized in Table 4 in comparison with this
Fig. 2 FT-IR spectra of fresh (black) and used catalyst (red).
3
5–46
work.
Most of the catalysts given in Table 4, suffer seri-
ously from toxicity and high catalyst dose. Additionally, they
require toxic solvents and tedious work-up procedures or long
reaction times. Although, the transition metal oxide nano-
particles demonstrated high efficiency and recoverability, in
along with the lack of 1,2-disubstituted benzimidazole products
are reasonable to suggest an oxidative mechanism for this
reaction under catalytic inuence of {Mo72Fe30} as presented in
33
III
Scheme 2. Deprotonation of water molecules ligated to Fe
6
44
some cases such as LaCl
3
, and Pt@TiO
2
,
the cost factor
ꢀ
30
centers in the amorphous cluster generating 16OH groups,
facilitates the inner sphere interaction of the metal ion with
cannot be ignored for the industrial implementation. The
present system employing {Mo72Fe30} nanocluster as an easy-
made biocompatible heterogeneous catalyst in ethanol green
solvent under oxygen atmosphere is found to minimize the
environmental impacts evidenced by very small E-factor
values and consequently qualify all requirements of an effi-
cient catalytic system for applied goals. The high activity,
34
oxygenic species, which accelerates the oxidative aromatiza-
tion process at nal step of reaction.
The stability and reusability of Keplerate
To elucidate the heterogeneity of the solid catalyst, hot ltration environment benignity, cost effectiveness, recyclability and
test in association with AAS for elemental analysis of Mo and Fe ease of product separation highlights the potential of this
was performed. The amount of elements in ltrate were trace and protocol in industry and make it amenable to scalability
not detectable using this analysis method (<1 ppm) conrming readily. When the reaction performed under a semi scale up
the real heterogeneity of the reaction and structural stability of procedure (10 mmol), 90% of the corresponding benzimid-
catalyst. More evidence for this issue was observed by comparing azole (Table 1, entry 2) was secured at the same time and
the FT-IR spectra of used catalyst with fresh one (Fig. 2). The conditions mentioned in Table 1.
Table 4 Comparison of catalytic performance of present catalytic system with literature reports for the synthesis of 2-substituted
benzimidazoles
ꢁ
Entry
Catalyst
Catalyst dose/mol%
Time/h
Solvent
T/ C
Yield/%
Ref.
a
1
2
3
4
5
6
7
8
9
{Mo72Fe30
}
0.025 (0.05)
3
10
30
4 equiv.
20
220 mg
2
10
20 mg
1
0.5 (0.3)
1
0.8
1.5–2
2
EtOH
EtOH
EtOH
DMF
DMF
Toluene/O
40 (60)
r.t.
91 (94)
92
86
93
95
89
90
93
96
97
78
25
85–95
Trace-85
This work
VOSO
TiCl OTf
Ce(NO
PhSiH
CuFe
Fe
a-MoO
CuI Nps
TiO –Fe
Pt/TiO
/SiO
4
35
36
37
38
39
40
41
42
43
44
45
6
3
r.t.
80 C
120 C
110 C
ꢁ
3
)
3
$6H
2
O
ꢁ
ꢁ
3
2
O
4
NPs
24
2
3
O
4
–SiO
2
–(NH
4
)
6
Mo
7
O
24
0.5
0.5
1
3
1
0.5
2–4
0.2–1
EtOH/H
S$F/TBHP
CH CN/O
O/O
2
O
2
r.t.
50 C
ꢁ
3
nanobelts
3
2
r.t.
40 C
ꢁ
10
11
12
13
14
2
2
O
3
H
2
2
2
Mesitylene
Solvent-free
Reux
ꢁ
H
2
O
2
2
–FeCl
3
100 mg
10
10
150 C
LaCl
p-TsOH
3
CH
3
CN
r.t.
80 C
ꢁ
DMF
46
a
Entry 2 in Table 1.
This journal is © The Royal Society of Chemistry 2019
RSC Adv., 2019, 9, 34854–34861 | 34859

View Article Online
RSC Advances
Paper
1
3 A. A. Ostroushko, I. G. Danilova, I. F. Gette, S. Y. Medvedeva,
M. O. Tonkushina, A. V Prokoeva and M. V Morozova, J.
Biomater. Nanobiotechnol., 2011, 2, 557–560.
Conclusion
In conclusion, Keplerate {Mo72Fe30} as a safe nanoscopic
icosahedral polyoxometalate was demonstrated as a robust, 14 A. M u¨ ller, S. Sarkar, S. Q. N. Shah, H. B ¨o gge,
efficient, and recyclable solid molecular catalyst for aerobic
synthesis of benzimidazoles under mild conditions. Amor-
phous {Mo72Fe30} exhibited superior catalytic activity in the
M. Schmidtmann, S. Sarkar, P. K ¨o gerler, B. Haupteisch,
A. X. Trautwein and V. Sch u¨ nemann, Angew. Chem., Int.
Ed., 1999, 38, 3238–3241.
synthesis of benzimidazole derivatives than that of crystalline 15 K. Kuepper, M. Neumann, A. J. M. Al-Karawi, A. Ghosh,
one. The larger specic surface area and particularly pore
volume of amorphous cluster evidenced by BET analysis
S. Walleck, T. Glaser, P. Gouzerh and A. M u¨ ller, J. Cluster
Sci., 2014, 25, 301–311.
resulting from aggregation of nanoparticles is a key factor for 16 R. Mokhtari, A. Rezaeifard, M. Jafarpour and A. Farrokhi,
such an exhibition. A variety of benzimidazole derivatives could
Catal. Sci. Technol., 2018, 8, 4645–4656.
be synthesized in good to excellent yields with catalyst dose as 17 N. V Izarova, O. A. Kholdeeva, M. N. Sokolov and V. P. Fedin,
low as 0.02 to 0.05 mol% in ethanol green solvent under oxygen
Russ. Chem. Bull., 2009, 58, 134–137.
atmosphere. These signicant conditions for
system 18 A. Rezaeifard, R. Haddad, M. Jafarpour and M. Hakimi, J.
employing a safe and biocompatible catalyst minimize the
Am. Chem. Soc., 2013, 135, 10036–10039.
environmental impact of process opening up a promising 19 A. Rezaeifard, M. Jafarpour, R. Haddad and F. Feizpour,
a
perspective within the scope of metal cluster-catalyzed organic
reactions and transformations in future.
Catal. Commun., 2017, 95, 88–91.
20 A. Rezaeifard, R. Haddad, M. Jafarpour and M. Hakimi, ACS
Sustainable Chem. Eng., 2014, 2, 942–950.
2
2
2
1 A. Rezaeifard, A. Khoshyan, M. Jafarpour and
M. Pourtahmasb, RSC Adv., 2017, 7, 15754–15761.
2 F. Jalilian, B. Yadollahi, M. R. Farsani, S. Tangestaninejad,
H. A. Rudbari and R. Habibi, RSC Adv., 2015, 5, 70424–70428.
3 F. Jalilian, B. Yadollahi, M. R. Farsani, S. Tangestaninejad,
H. A. Rudbari and R. Habibi, Catal. Commun., 2015, 66,
Conflicts of interest
There are no conicts to declare.
Acknowledgements
107–110.
2
2
2
4 A. Khoshyan, M. Pourtahmasb, F. Feizpour, M. Jafarpour
and A. Rezaeifard, Appl. Organomet. Chem., 2019, 33, e4638.
5 A. Nakhaei, A. Davoodnia and H. Nakhaei, J. Chem. Rev.,
Support for this work by Research Council of University of Bir-
jand is highly appreciated.
2
019, 1, 139–153.
6 F. Feizpour, M. Jafarpour and A. Rezaeifard, Catal. Lett.,
018, 148, 30–40.
References
2
1
2
Z. Xie, J. Peng and Q. Zhu, Org. Chem. Front., 2016, 3, 82–86. 27 A. Eskandari, M. Jafarpour, A. Rezaeifard and M. Salimi, New
S. Lei, Y. Mai, C. Yan, J. Mao and H. Cao, Org. Lett., 2016, 18,
J. Chem., 2018, 42, 6449–6456.
582–3585.
M. J. Akhtar, Y. M. Shahar, V. K. Sharma, A. A. Khan, Z. Ali,
M. R. Haider and A. Pathak, Curr. Med. Chem, 2019, DOI:
3
28 J. Zhou, J. Hu, M. Li, H. Li, W. Wang, Y. Liu, R. E. Winans,
T. Li, T. Liu and P. Yin, Mater. Chem. Front., 2018, 2, 2070–
2075.
3
10.2174/0929867326666190808122929.
29 K. Wilson, Appl. Organomet. Chem., 2007, 21, 1002.
4
5
R. J. Perry and B. D. Wilson, J. Org. Chem., 1993, 58, 7016– 30 R. Mekala, S. Supriya and S. K. Das, Inorg. Chem., 2016, 55,
021. 12504–12507.
D. Vourloumis, M. Takahashi, K. B. Simonsen, B. K. Ayida, 31 B. R. Goldsmith, B. Peters, J. K. Johnson, B. C. Gates and
7
S. Barluenga, G. C. Winters and T. Hermann, Tetrahedron
Lett., 2003, 44, 2807–2811.
Y. Venkateswarlu, S. R. Kumar and P. Leelavathi, Org. Med.
Chem. Lett., 2013, 3, 7.
Y. Kim, M. R. Kumar, N. Park, Y. Heo and S. Lee, J. Org.
Chem., 2011, 76, 9577–9583.
S. L. Scott, ACS Catal., 2017, 7, 7543–7557.
32 J.-F. Deng, H. Li and W. Wang, Catal. Today, 1999, 51, 113–
125.
33 N. H. Cano, J. G. Uranga, M. Nardi, A. Procopio,
D. A. Wunderlin and A. N. Santiago, Beilstein J. Org. Chem.,
2016, 12, 2410–2419.
6
7
8
9
F. Rajabi, S. De and R. Luque, Catal. Lett., 2015, 145, 1566– 34 N. I. Kuznetsova, L. I. Kuznetsova and V. A. Likholobov, J.
570.
Mol. Catal. A: Chem., 1996, 108, 135–143.
C. Zheng, Z. Qunfeng, X. Xiaoliang and L. Xiaonian, Chin. J. 35 C. S. Digwal, U. Yadav, A. P. Sakla, P. V. S. Ramya, S. Aaghaz
Org. Chem., 2015, 35, 1189–1203.
and A. Kamal, Tetrahedron Lett., 2016, 57, 4012–4016.
0 M. M. Heravi, S. Sadjadi, H. A. Oskooie, R. H. Shoar and 36 J. Azizian, P. Torabi and J. Noei, Tetrahedron Lett., 2016, 57,
F. F. Bamoharram, Catal. Commun., 2008, 9, 504–507. 185–188.
1 S.-S. Wang and G.-Y. Yang, Chem. Rev., 2015, 115, 4893–4962. 37 G. M. Martins, T. Puccinelli, R. A. Gariani, F. R. Xavier,
1
1
1
1
2 A. M u¨ ller and P. Gouzerh, Chem.–Eur. J., 2014, 20, 4862–
873.
C. C. Silveira and S. R. Mendes, Tetrahedron Lett., 2017, 58,
1969–1972.
4
34860 | RSC Adv., 2019, 9, 34854–34861
This journal is © The Royal Society of Chemistry 2019

View Article Online
Paper
RSC Advances
3
3
4
4
4
8 J. Zhu, Z. Zhang, C. Miao, W. Liu and W. Sun, Tetrahedron, 43 S. Roy, B. Banerjee, N. Salam, A. Bhaumik and S. M. Islam,
017, 73, 3458–3462. ChemCatChem, 2015, 7, 2689–2697.
9 D. Yang, X. Zhu, W. Wei, N. Sun, L. Yuan, M. Jiang, J. You 44 C. Chaudhari, S. M. A. H. Siddiki and K. Shimizu,
and H. Wang, RSC Adv., 2014, 4, 17832–17839. Tetrahedron Lett., 2015, 56, 4885–4888.
0 G. Bai, X. Lan, X. Liu, C. Liu, L. Shi, Q. Chen and G. Chen, 45 A. Fazlinia, M. H. Mosslemin and H. Sadoughi, J. Korean
Green Chem., 2014, 16, 3160–3168. Chem. Soc., 2010, 54, 579–581.
1 M. Jafarpour, A. Rezaeifard, M. Ghahramaninezhad and 46 H. Xiangming, M. Huiqiang and W. Yulu, ARKIVOC, 2007,
2
T. Tabibi, New J. Chem., 2013, 37, 2087–2095.
2 P. L. Reddy, R. Arundhathi, M. Tripathi and D. S. Rawat, RSC
Adv., 2016, 6, 53596–53601.
13, 150–154.
This journal is © The Royal Society of Chemistry 2019
RSC Adv., 2019, 9, 34854–34861 | 34861