Catalytic application of sulfonic acid-functionalized titana-coated magnetic nanoparticles for the preparation of 1,8-dioxodecahydroacridines and 2,4,6-triarylpyridines via anomeric-based oxidation

Article abstract of DOI:10.1002/aoc.4063

We have developed green, efficient and powerful protocols for the preparation of 2,4,6-triarylpyridines and 1,8-dioxodecahydroacridines in the presence of Fe₃O₄@TiO₂@O₂PO₂(CH₂)₂NHSO₃H as a sulfonic acid-functionalized titana-coated magnetic nanoparticle catalyst under mild and solvent-free reaction conditions. These protocols furnished the desired products in short reaction times with good to high yields (20–40?min and 80–86% in the case of 2,4,6-triarylpyridines; 15–90?min and 80–93% in the case of 1,8-dioxodecahydroacridines). The final step of the mechanistic route in the synthesis of 2,4,6-triarylpyridines proceeds via an anomeric-based oxidation. Also, the nanomagnetic core–shell catalyst can be recycled and reused in both cases of the scrutinized one-pot multicomponent reactions with high turnover number and turnover frequency.

Full text of DOI:10.1002/aoc.4063

Received: 13 April 2017
DOI: 10.1002/aoc.4063
Revised: 5 July 2017
Accepted: 3 August 2017
F U L L P A P E R
Catalytic application of sulfonic acid‐functionalized titana‐
coated magnetic nanoparticles for the preparation of 1,8‐
dioxodecahydroacridines and 2,4,6‐triarylpyridines via
anomeric‐based oxidation
Mohammad Ali Zolfigol
| Fatemeh Karimi | Meysam Yarie
| Morteza Torabi
Faculty of Chemistry, Bu‐Ali Sina
University, Hamedan 6517838683, Iran
We have developed green, efficient and powerful protocols for the preparation
of 2,4,6‐triarylpyridines and 1,8‐dioxodecahydroacridines in the presence of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐functionalized titana‐
coated magnetic nanoparticle catalyst under mild and solvent‐free reaction
conditions. These protocols furnished the desired products in short reaction
times with good to high yields (20–40 min and 80–86% in the case of
2,4,6‐triarylpyridines; 15–90 min and 80–93% in the case of
1,8‐dioxodecahydroacridines). The final step of the mechanistic route in the
synthesis of 2,4,6‐triarylpyridines proceeds via an anomeric‐based oxidation.
Also, the nanomagnetic core–shell catalyst can be recycled and reused in both
cases of the scrutinized one‐pot multicomponent reactions with high turnover
number and turnover frequency.
Correspondence
Mohammad Ali Zolfigol or Meysam Yarie,
Faculty of Chemistry, Bu‐Ali Sina
University, Hamedan 6517838683, Iran.
Email: zolfi@basu.ac.ir; mzolfigol@yahoo.
com; myari.5266@gmail.com
Funding information
Iran National Science Foundation (INSF),
Grant/Award Number: 95831207;
National Elites Foundation
KEYWORDS
1,8‐dioxodecahydroacridines, 2,4,6‐triarylpyridines, anomeric‐based oxidation,
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H, multicomponent reactions, solvent‐free reactions
1 | INTRODUCTION
onto appropriate magnetic supports. Magnetic nanoparti-
cles are very useful alternatives for support materials in
In contemporary research programmes, catalysis has
become one of the most persuasive areas and has found
an important position in developing fields of organic
synthesis.[1] Nanosized catalysis is one of the most influ-
ential fields for the synthesis of novel catalytic systems.
Due to their small diameters, nanoparticles provide many
profits like high external surface area, superior activity
and selectivity and high reaction rates. However, the
aggregation and also isolation and recovery of nanosized
catalytic systems are the main defects linked with these
versatile species. Employing appropriate supporting
agents is a suitable approach for avoiding aggregation.[2,3]
One of the best choices for improving the stability and
recyclability of nanomaterials is their immobilization
green chemistry research. Some of the benefits of these
support compounds are as follows: eco‐friendly benign
nature, superior thermal and mechanical stability, easy
production and functionalization, low cost and toxicity,
easy handling and treatment and unequalled paramag-
netic nature. In addition to these merits, constructed
heterogeneous nanomagnetic catalytic systems compared
with homogeneous analogues show very good catalytic
performance with high isolation, recovery and reuse
capability.[4–7]
Nitrogen‐containing heterocyclic molecules such as
pyridine derivatives are important in the natural word.
Among the pyridine ring scaffolds, aryl‐substituted ones
like 2,4,6‐triarylpyridines which are known as Kröhnke
Appl Organometal Chem. 2017;e4063.
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Copyright © 2017 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.4063

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ZOLFIGOL ET AL.
pyridine motifs are particularly fascinating.[8] These inter-
esting structures have a unique position in medicinal
chemistry and have various pharmaceutical and biologi-
cal activities. They can be employed as intermediates for
the preparation of medicinally active compounds such as
those with antimalarial, anticonvulsant and antitumour
activities[9] and furthermore in agrochemical active mate-
rials such as herbicides, insecticides, desiccants and sur-
factants.[10] Also, these molecules have been applied for
the preparation of organometallic polymers,[11]
unsatisfactory yields, large amount of catalyst loading,
deactivation of catalyst, use of toxic volatile organic sol-
vents, unpleasant reaction conditions and tedious work‐
up procedure on repeated use.
In the area of combinatorial chemistry, one‐pot multi-
component reactions have been identified as influential
methods in the toolbox of synthetic chemists. Multicom-
ponent reactions, due to their full compliance with
criteria set by the principles of green chemistry, have been
widely applied in the design, construction and improve-
ment of synthetic organic methodologies.[29–37]
polyimides,[12]
,
photoluminescent polymers[13] and
chemosensors,[14] and in asymmetric catalysis[15] and
supramolecules.[16] Due to the previously mentioned
medicinal benefits and applications connected with
2,4,6‐triarylpyridine derivatives, a variety of protocols
have been reported for their synthesis.[17–23]
In the work reported in this paper, by considering the
above‐mentioned 2,4,6‐triarylpyridine derivatives and 1,8‐
dioxodecahydroacridines as significant nitrogen‐containing
structures and in order to develop new methodologies for
the synthesis of heterocyclic molecules[38–45] and expand our
new introduced technique of ‘anomeric‐based oxidation’ for
the oxidation of target molecules,[46] we studied the catalytic
applicability of Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as
sulfonic acid‐functionalized titana‐coated magnetic nanopar-
ticles for the preparation of 2,4,6‐triarylpyridines and 1,8‐
dioxodecahydroacridines under mild and solvent‐free condi-
tions (Schemes 1 and 2).
Other important nitrogen‐containing heterocyclic
structures are acridines and 1,8‐dioxodecahydroacridine
scaffolds. These compounds have found diverse utilities
in laser dyes and photoinitiators.[24] Additionally, in
medicinal chemistry as pharmaceutical materials they
can also serve as antimalarial, anticancer, cytotoxic, anti-
microbial, anticancer and antifungal agents and are rec-
ommended as calcium β‐blockers.[25] Furthermore, due
to the intercalation versatility of some natural and synthe-
sized acridine derivatives, they are striking DNA‐ and
RNA‐binding structures.[26] Considering the diverse appli-
cations of acridine derivatives, their preparation is a con-
tinuing focal point for synthetic chemists and several
catalytic procedures have been investigated for this
goal.[27,28] However, most of these reported protocols
encounter some drawbacks including long reaction times,
2 | RESULTS AND DISCUSSION
The sulfonic acid‐functionalized titana‐coated magnetic
nanoparticles, namely Fe3O4@TiO2@O2PO2(CH2)2NHSO3H,
were prepared based on our previously reported protocol as
presented in Scheme 3.[46b]
In the first stage, in attempting to investigate the cata-
lytic performance of Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
O
H
O
O
O
H
P
N
O
SO H
SO H
X
X
Fe O
TiO
O
H
O
O
O
Me
P
N
1a-n
O
Y
10 mg
Y
Solvent free, 110
20-40 min., 80-86%
C
N
O
Me
Y
Y
SCHEME 1 Synthesis of 2,4,6‐
NH OAc
triarylpyridines in the presence of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
X= H, 4-Me, 4-OMe, 3-OH, 4-Cl, 2-Cl
Y= H, 4-Me, 4-OMe, 4-Cl, 4-NO , 2-Acetylpyridine
O
H
O
O
O
P
N
O
SO H
SO H
R
R
Fe O
TiO
O
H
H
O
O
O
O
O
O
O
O
P
N
2a-q
O
Me
Me
7 mg
Me
Me
Me
Me
Me
Me
Solvent free, 90
15-90 min., 80-93%
C
N
H
NH OAc
SCHEME 2 Synthesis of acridines in
the presence of
R= H, 4-Cl, 2-Cl, 4-Br, 3,5-(F) , 2-NO , 3-NO , 4-CN, 3-OH-4-Me,
2-OMe, 4-OMe, 3-OEt-4-OH, 3,4-(OMe) , 3,4,5-(OMe) ,4-Me,
Terephetaldehyde, Thiophen-2-carbaldehyde
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H

ZOLFIGOL ET AL.
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O
P
triarylpyridines,
the
reaction
of
benzaldehyde,
O
P
O
O
NH2
NH2
HO
HO
NH2
O
acetophenone and ammonium acetate was selected as a
model reaction (Scheme 4). The experimental results
obtained from screening of reaction parameters are pro-
vided in Table 1. The highest yield and shortest reaction
time were achieved in the presence of 10 mg of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H at 110 °C under sol-
vent‐free conditions (Table 1, entry 2). Also, as evidence
for the final step of the suggested anomeric‐based oxidation
mechanism for aromatization of desired molecules, we
investigated the optimal reaction conditions under nitrogen
atmosphere. The results for the model reaction under air
and nitrogen atmosphere are similar. Elevating the reaction
temperature and increasing the load of catalyst did not
exhibit further positive effect. Also, performing the model
reaction in common laboratory solvents including water,
O
TEOT
Fe3O4
Fe3O4
TiO2
Fe3O4
TiO2
O
r.t., 12 h
O
O
EtOH, r.t., 12 h
P
O
O
O
H
N
O
P
S
O
O
SO3H
Cl
OH
O
Fe3O4
TiO2
O
P
H
CH2Cl2, r.t., 3 h
O
O
N
O
SO3H
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
SCHEME
3
Synthetic pathway for the preparation of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
as a sulfonic acid‐functionalized titana‐coated magnetic
nanoparticle catalyst and in order to find the optimal reac-
tion conditions in terms of amount of nanomagnetic cata-
lyst, solvent and temperature in the case of 2,4,6‐
O
H
O
O
O
H
P
N
O
SO H
SO H
Fe O
TiO
O
H
O
O
O
Me
P
N
O
Optimal reaction parameters?
N
SCHEME 4 Model reaction for
screening of reaction parameters
O
Me
NH OAc
TABLE 1 Optimizing of the reaction conditions for the synthesis of 2,4,6‐triarylpyridine derivativesa
Entry
Solvent
Temperature (°C)
Load of catalyst (mg)
Time (min.)
Yield (%)b
1
–
100
10
20
65
2c
–
110
10
10
13
7
20
20
25
25
60
60
60
45
45
60
60
60
60
80
3
–
120
80
4
–
110
78
5
–
110
65
6d
7e
8
–
110
10
10
–
40
–
110
40
–
110
40
9
H₂O
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
10
10
10
10
10
10
40
10
11
12
13
14
C₂H₅OH
CH₃CN
EtOAc
CH2Cl2
n‐Hexane
35
30
35
Trace
Trace
aReaction conditions: benzaldehyde (1 mmol, 0.106 g), acetophenone (2 mmol, 0.12 g) and ammonium acetate (5 mmol, 0.385 g),
bIsolated yields.
cThe achieved data for testing the model reaction under air and nitrogen atmosphere are similar.
dThe reaction was performed using Fe3O4 nanoparticles as catalyst.
eThe reaction was performed using TiO2 nanoparticles as catalyst.

4 of 11
ZOLFIGOL ET AL.
EtOH, CH3CN, EtOAc, CH2Cl2 and n‐hexane did not lead
to satisfactory results compared to solvent‐free conditions.
Subsequently, after determining the optimal reaction
parameters, to study the efficacy and applicability of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐
functionalized titana‐coated magnetic nanoparticle cata-
lyst in the preparation of target molecules, various
arylaldehydes were treated with acetophenone derivatives
and ammonium acetate to furnish the corresponding
2,4,6‐triarylpyridines with good yields and short reaction
times. Table 2 presents the experimental data from this
new protocol.
In another exploration in the light of promising results
from the construction of 2,4,6‐triarylpyridine derivatives,
we investigated the catalytic applicability of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H in the condensation
reaction between aromatic aldehydes, dimedone and
ammonium acetate. Initially, we selected the reaction of
benzaldeyde, dimedone and ammonium acetate as a model
reaction (Scheme 5) and the effects of catalyst loading, tem-
perature and solvents were meticulously studied. The
experimental data obtained from screening of reaction
parameters are summarized in Table 3. The data indicated
that using 7 mg of Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
as a sulfonic acid‐functionalized titana‐coated magnetic
nanoparticle catalyst at 90 °C under solvent‐free conditions
are the optimal reaction conditions (Table 3, entry 4). It was
noticed that increasing the reaction temperature and
increasing the amount of nanomagnetic core–shell catalyst
did not present further improvement. Also, carrying out the
model reaction in common laboratory solvents including
water, EtOH, CH3CN, EtOAc, CH2Cl2 and n‐hexane did
not show improved results compared to solvent‐free
conditions.
After determining the optimal reaction conditions, the
scope and generality of the presented procedure for the
synthesis of desired 1,8‐dioxodecahydroacridines were
established by applying a wide range of aromatic alde-
hydes bearing electron‐releasing or electron‐withdrawing
groups for condensation with dimedone and ammonium
acetate under the optimized reaction conditions. The data
obtained, as presented in Table 4, disclose that all reac-
tions proceeded smoothly under solvent‐free conditions
with high to excellent yields.
In the novel area of green chemistry, facile separation
of catalyst from reaction mixture is an important issue.
Magnetically recoverable catalysts find a persuasive posi-
tion in green chemistry due to their merits such as high
activity and selectivity and also excellent recycling and
reusing capability. In a further study, in the case of both
multicomponent
reactions,
the
reusability
of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐
functionalized titana‐coated magnetic nanoparticle cata-
lyst was successfully investigated. At the end of the each
reaction, in order to dissolve the product and unreacted
starting material, hot EtOH was added to the reaction
mixture and undissolved nanomagnetic catalyst was sepa-
rated from it using an external magnet. In the case of
TABLE 2 Construction of desired molecules 1a‐n in the presence of Fe3O4@TiO2@O2PO2(CH2)2NHSO3Ha
Entry
Product
1a
X
Y
Time (min.)
Yield (%)b
Melting point (°C), [found]Lit.
135–137 [136–138][46g]
1
H
H
20
80
2
1b
1c
1d
1e
1f
4‐Cl
H
20
20
30
35
40
35
20
20
30
35
40
25
30
80
81
85
83
85
82
86
85
80
82
83
83
80
125–127 [133–135][46g]
183–185 [180–180.7][9b]
113–115 [124–126][17a]
142–145 [195‐200][46g]
114–115 [110–112][46g]
143–145 [149–151][17d]
153–155 [158–161][17d]
138–140 [133–136][17d]
136–138 [153–155][46g]
123–127 [135–137][46g]
175–178 [175–177][46g]
148–150 [153–155][46g]
160–164 [173–175][17e]
3
3‐OH
4‐Me
4‐Cl
H
4
H
5
4‐Me
6
4‐Cl
4‐OMe
4‐Cl
7
1g
1h
1i
4‐Cl
8
4‐Cl
4‐NO2
4‐OMe
4‐Me
9
2‐Cl
10
11
12
13
14
1j
4‐OMe
4‐OMe
4‐Me
4‐Me
4‐Cl
1k
1l
4‐OMe
4‐Me
1m
4‐OMe
1n
2‐Acetylpyridine
aReaction conditions: arylaldehyde (1 mmol), arylketone (2 mmol) and ammonium acetate (5 mmol, 0.385 g).
bIsolated yields.

ZOLFIGOL ET AL.
5 of 11
O
P
H
O
O
O
H
N
O
SO H
SO H
Fe O
TiO
O
H
O
O
O
O
O
O
O
O
P
N
O
Me
Me
Me
Me
Optimal reaction parameters ?
Me
Me
Me
Me
N
SCHEME 5 Model reaction for
H
NH OAc
screening of reaction parameters
TABLE 3 Optimizing of the reaction conditions for the synthesis of 1,8‐dioxodecahydroacridinesa
Entry
Solvent
Temperature (°C)
Load of catalyst (mg)
Time (min.)
Yield (%)b
1
–
110
5
15
81
2
–
90
5
5
7
10
7
7
–
7
7
7
7
7
7
30
60
20
20
60
60
45
40
40
50
50
60
60
80
3
–
70
70
4
–
90
90
5
–
90
88
6c
7d
6
–
90
50
–
90
55
–
90
65
7
H₂O
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
70
8
C₂H₅OH
CH₃CN
EtOAc
CH2Cl2
n‐Hexane
75
9
50
10
11
12
55
Trace
Trace
aReaction conditions: benzaldehyde (1 mmol, 0.106 g), Dimedone (2 mmol, 0.28 g) and ammonium acetate (1 mmol, 0.077 g).
bIsolated yields.
cThe reaction performed using Fe3O4 nanoparticles as catalyst.
dThe reaction performed using TiO2 nanoparticles as catalyst.
2,4,6‐triarylpyridine derivatives, the sequential reaction of
benzaldehyde, acetophenone and ammonium acetate in
20 min (target molecule 1a) was selected as a test reaction.
The recovered catalyst can be used for five continuous
reaction runs. In the case of 1,8‐dioxodecahydroacridine
chalcone intermediate A. Afterwards, a second molecule
of acetophenone in enol form attacks this intermediate
to afford the intermediate B. In situ generated NH3 from
dissociation of ammonium acetate (NH4OAc)[47] reacts
with intermediate B and leads to the imine intermediate
C. In continuation, intermediate C is converted to D by
a ring‐closing reaction. In the next step, intermediate D
is tautomerized to intermediate E which possesses a
susceptible structure for the anomeric‐based oxidation
mechanism.[46] In this intermediate, lone pair electron
of nitrogen atom can interact with anti‐bonding orbital
of C―H bond (σ*C―H) in acridine moiety via resonance.
This stereoelectronic structure weakens the C―H bond
and facilitates H2 release from intermediate E to furnish
the aromatized molecule 1a.
structural
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H was successfully
investigated in the sequential reaction of
motifs,
the
recyclability
of
4‐chlorobenzaldehyde, dimedone and ammonium acetate
in 25 min (target molecule 2c). The thoroughly washed
recovered catalyst can be used for five continuous reac-
tion runs. The resulting data for both reactions are
portrayed in Figure 1. For both of the described catalytic
reactions turnover numbers and turnover frequencies
were also calculated (see supporting information).
We propose that the final step of the mechanistic
process for the construction of target molecule 1a might
proceed via anomeric‐based oxidation, as depicted in
Figure 2. Initially, catalyst‐activated benzaldehyde is
attacked by enolic form of acetophenone to form the
Figure 3 shows a plausible mechanistic pathway for
the preparation of desired molecule 2a catalysed by
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H. In the first place,
activated benzaldehyde undergoes nucleophilic attack
to generate the intermediate G through dehydration.

6 of 11
ZOLFIGOL ET AL.
TABLE 4 Synthesis of target molecules 1a‐q in the presence of nano magnetic catalyst 1a
Entry
Product
2a
R
Time (min.)
Yield (%)b
Melting point (°C), [found]Lit.
246–248 [258–260][27j]
1
H
20
90
2
2b
2c
2d
2e
2f
2‐Cl
25
25
20
15
25
60
35
30
25
60
90
90
45
15
20
35
85
92
87
85
93
81
87
89
89
84
80
83
82
93
92
84
225–227 [220–222][27j]
303–305 [297–299][27i]
317–319 [New]
298–300 [300–302][27k]
322–324 [>300][27i]
295–298 [288–290][27g]
318–320 [>300][27i]
282–284 [New]
272–274 [261–263][27i]
250–252 [258–261][27p]
301–303 [172–174][27d]
295–297 [293–295][27j]
318–320 [324–326][27g]
269–271 [272–274][27i]
270–272 [282–284][28]
313–315 [330–333][27l]
3
4‐Cl
4
3‐OH‐4‐Me
2‐OMe
5
6
4‐Br
7
2g
2h
2i
3‐NO₂
8
4‐Me
9
3‐OEt‐4‐OH
3,4‐(OMe)2
3,4,5‐(OMe)3
3,5‐(F)2
10
11
12
13
14
15
16
17
2j
2k
2l
2m
2n
2o
2p
2q
2‐NO₂
4‐CN
4‐OMe
Terephetaldehyde
Thiophen‐2‐carbaldehyde
aReaction conditions: aryldehyde (1 mmol), dimedone (2 mmol, 0.28 g) and ammonium acetate (1 mmol, 0.077 g),
bIsolated yields
FIGURE 1 Recyclability of catalyst for
both investigated multicomponent
reactions
In the next step, dimedone in enol form attacks
Knoevenagel intermediate G to afford intermediate H
which id converted to imine intermediate I by the
reaction with in situ generated NH3 from NH4OAc.
Finally, a sequence of catalytic tautomerization and
intramolecular nucleophilic attack furnishes the desired
molecule 2a.
Since knowledge‐based development of ‘anomeric‐
based oxidation’ is our main interest, similar to 2,4,6‐
triarylpyridines, we investigated this phenomenon for
the other case of 1,8‐dioxodecahydroacridines. The reac-
tion was conducted between aryl aldehydes, dimedone
and ammonium acetate. In contrast to our prediction,
we observed that selective production of 1,8‐
dioxodecahydroacridines occurred and their correspond-
ing oxidized and/or aromatized derivatives were not pro-
duced. We believe that the unpaired electron of the
nitrogen atom within the 1,8‐dioxodecahydroacridine
structure showed a favourable resonance interaction
towards electron‐withdrawing carbonyl groups. This

ZOLFIGOL ET AL.
7 of 11
FIGURE 2 Plausible mechanistic process for the synthesis of target molecule 1a via anomeric‐based oxidation
FIGURE 3 Plausible mechanistic pathway for the construction of target molecule 2a
phenomenon does not allow the lone pair of the nitrogen
atom to interact with the anti‐bonding orbital of C―H
bond in the 1,4‐dihydropyridine moiety of 1,8‐
dioxodecahydroacridine. Therefore, the non‐aromatized
1,8‐dioxodecahydroacridines are the preferred structures
(molecules 2a–q).

8 of 11
ZOLFIGOL ET AL.
was followed by TLC using a mixture of n‐hexane and
EtOAc as eluent. After completion of the reactions, boiling
ethanol was added to the reaction mixtures to dissolve the tar-
get products and unreacted starting materials. Then, undis-
solved nanomagnetic Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
catalyst was easily separated from the reaction mixture by uti-
lizing an external magnet, washed thoroughly with EtOH and
recovered for subsequent reaction. The desired products were
obtained by recrystallization from EtOH.
3 | CONCLUSIONS
In
summary,
the
catalytic
applicability
of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as
a
sulfonic
acid‐functionalized titana‐coated magnetic nanoparticle
catalyst was explored in the construction of
2,4,6‐triarylpyridines and 1,8‐dioxodecahydroacridines
under mild and solvent‐free reaction conditions. In the
case of 2,4,6‐triarylpyridine derivatives, a plausible
mechanism suggests an anomeric‐based oxidation route
to desired molecules as confirmed by experimental data.
Also, the applied nanomagnetic core–shell catalyst has
excellent reusability in both the investigated multicompo-
nent reactions.
4.4 | General procedure for synthesis of
1,8‐Dioxodecahydroacridine derivatives
In a test tube containing a mixture of aromatic aldehydes
(1 mmol), dimedone (2 mmol, 0.28 g) and ammonium
acetate
(1
mmol,
0.077
g),
7
mg
of
4 | EXPERIMENTAL
4.1 | General
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐
functionalized titana‐coated magnetic nanoparticle cata-
lyst was added. The resulting mixture was stirred for suit-
able times under optimal reaction conditions (Table 3)
and the resulting data are summarized in Table 4. The
reaction progress was monitored by TLC using n‐hexane
and EtOAc as eluent. After the reactions were completed,
in order to separate the catalyst, hot EtOH was added to
the reaction mixtures and desired products and unreacted
starting materials were dissolved. Afterwards, undissolved
nanomagnetic acidic catalyst was easily separated from
the reaction mixture by utilizing an external magnet,
washed with EtOH and recovered for subsequent reac-
tion. The pure products were obtained via recrystalliza-
tion from EtOH.
All starting materials were obtained from Merck and
applied without additional purification. The structures
of known products were confirmed by comparison of
their physical properties and spectral data with those of
authentic samples reported in the literature. The reac-
tion progress and purity of the prepared molecules were
monitored by TLC performed with silica gel SIL G/UV
254 plates. The 1H NMR (400 MHz) and 13C NMR
(100 MHz) spectra were recorded with a Bruker spec-
trometer. Melting points were recorded with a Buchi
B‐545 apparatus in open capillary tubes and are
uncorrected.
4.2 | General procedure for construction of
magnetically recoverable solid acid catalyst
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H
4.5 | Selected spectral data
3‐(2,6‐Diphenylpyridin‐4‐yl)phenol (1c). M.p. 183–185 °C.
FT‐IR (KBr, ν, cm−1): 3034, 1606, 1596, 1543, 1493, 1198,
1
The sulfonic acid‐functionalized titana‐coated magnetic
nanoparticles, namely Fe3O4@TiO2@O2PO2(CH2)2NHSO3H,
were prepared based on our recently reported protocol, as
visualized in Scheme 3.[46b]
764. H NMR (400 MHz, DMSO, δ, ppm): 9.73 (s, 1H,
OH), 8.37 (d, 4H, J = 8 Hz, aromatic), 8.17 (s, 2H, aro-
matic), 7.61 (t, 4H, J = 8 Hz, aromatic), 7.56–7.48 (m,
3H, aromatic), 7.44–7.42 (m, 2H, aromatic), 6.98 (d, 1H,
J = 8 Hz, aromatic). 13C NMR (101 MHz, DMSO, δ,
ppm): 158.0, 156.4, 149.8, 139.2, 138.8, 130.1, 129.2,
128.7, 126.9, 118.0, 116.5, 116.2, 114.0.
4‐(4‐Chlorophenyl)‐2,6‐di‐p‐tolylpyridine (1e). M.p.
142–145 °C. FT‐IR (KBr, ν, cm−1): 3028, 1655, 1599,
1491, 1407, 1224, 774. 1H NMR (400 MHz, DMSO, δ,
ppm) 8.14 (d, 2H, J = 8 Hz, aromatic), 8.05–7.99 (m, 4H,
aromatic), 7.78 (d, 2H, J = 16 Hz,aromatic), 7.69 (d, 3H,
J = 8 Hz,aromatic), 7.45 (d, 3H, J = 8 Hz,aromatic), 2.47
(s, 6H, Me). 13C NMR (101 MHz, DMSO, δ, ppm): 188.5,
143.7, 142.1, 135.0, 134.9, 133.7, 130.5, 129.4, 128.9,
128.7, 123.2, 21.2.
4.3 | General procedure for synthesis of
2,4,6‐Triarylpyridine derivatives
In a test tube containing a mixture of aromatic aldehydes
(1 mmol), acetophenone derivatives (2 mmol) and ammo-
nium acetate (5 mmol, 0.385 g), 10 mg of
Fe3O4@TiO2@O2PO2(CH2)2NHSO3H as a sulfonic acid‐
functionalized titana‐coated magnetic nanoparticle cata-
lyst was added. The obtained reaction mixture was stirred
under solvent‐free conditions at 110 °C according to the
appropriate times (Table 1). The progress of the reactions

ZOLFIGOL ET AL.
9 of 11
4‐(4‐Chlorophenyl)‐2,6‐bis(4‐methoxyphenyl)pyridine
133.81, 131.40, 126.65, 119.11, 110.76, 110.02, 54.98,
50.37, 31.95, 31.38, 29.31, 25.85.
(1f). M.p. 114–115 °C. FT‐IR (KBr, ν, cm−1): 2962, 1656,
1
1605, 1511, 1492, 1177, 817. H NMR (400 MHz, DMSO,
9‐(3‐Ethoxy‐4‐hydroxyphenyl)‐3,3,6,6‐tetramethyl‐
3,4,6,7,9,10‐hexahydroacridine‐1,8‐(2H,5H)‐dione (2i). M.
p. 282–284 °C. FT‐IR (KBr, ν, cm−1): 3276, 2966, 1646,
1620, 1478, 1365, 1221, 1144. 1H NMR (400 MHz, DMSO,
δ, ppm): 9.32 (s, 1H, NH), 8.60 (s, 1H, OH), 6.80–6.64 (m,
3H, aromatic), 4.82 (s, 1H, CH), 4.00 (br s, 2H, OCH2),
2.61–2.12 (m, 8H, CH2), 1.39 (br s, 3H, Me), 1.12 (s, 6H,
Me), 1.00 (s, 6H, Me). 13C NMR (101 MHz, DMSO, δ,
ppm): 194.43, 148.93, 145.72, 144.67, 138.40, 63.79, 50.30,
32.08, 31.81, 29.14, 26.34, 14.75.
δ, ppm): 8.23 (d, 2H, J = 8 Hz, aromatic), 8.05–7.97 (m,
4H, aromatic), 7.75 (d, 2H, J = 8 Hz, aromatic), 7.58 (d,
3H, J = 8 Hz, aromatic), 7.15 (d, 3H, J = 8 Hz, aromatic),
3.93 (s, 6H, OMe). 13C NMR (101 MHz, DMSO, δ, ppm):
187.2, 163.3, 141.6, 134.8, 133.8, 131.0, 130.4, 130.3,
128.9, 122.8, 114.0, 55.6.
4‐(4‐Methoxyphenyl)‐2,6‐di‐p‐tolylpyridine (1j). M.p.
183–185 °C. FT‐IR (KBr, ν, cm−1): 3061, 1609, 1597,
1509, 1424, 1180, 820. 1H NMR (400 MHz, DMSO, δ,
ppm): 8.27 (d, 4H, J = 8 Hz, aromatic), 8.13 (s, 2H, aro-
matic), 8.06 (d, 2H, J = 8 Hz, aromatic), 7.40 (d, 4H,
J = 8 Hz, aromatic), 7.16 (d, 2H, J = 8 Hz, aromatic),
3.90 (s, 3H, OMe), 2.44 (s, 6H, Me). 13C NMR (101 MHz,
DMSO, δ, ppm): 160.3, 156.3, 148.9, 138.6, 136.2, 130.7,
129.9, 129.3, 128.6, 126.8, 115.2, 114.4, 55.3, 20.9.
2,4,6‐Tris(4‐methoxyphenyl)pyridine (1k). M.p. 123–
127 °C. FT‐IR (KBr, ν, cm−1): 3003, 2836, 1608, 1583,
1509, 1427, 1174, 822. 1H NMR (400 MHz, DMSO, δ,
ppm): 8.33 (d, 4H, J = 8 Hz, aromatic), 8.07–8.04 (m,
4H, aromatic), 7.16 (t, 6H, J = 16 Hz, aromatic), 3.91 (s,
9H, OMe). 13C NMR (101 MHz, DMSO, δ, ppm): 160.2,
155.9, 148.8, 131.5, 130.1, 128.5, 128.2, 114.4, 114.3,
114.0, 55.2.
4′‐(4‐Chlorophenyl)‐2,2′:6′,2″‘‐terpyridine (1n). M.p.
160–164 °C. FT‐IR (KBr, ν, cm−1): 3058, 1602, 1583,
1549, 1471, 1091, 786. 1H NMR (400 MHz, DMSO, δ,
ppm): 9.09 (s, 1H, aromatic), 8.81–8.63 (m, 4H, aromatic),
8.38 (s, 3H, aromatic), 8.02 (s, 2H, aromatic), 7.62–7.53
(m, 4H, aromatic). 13C NMR (101 MHz, DMSO, δ, ppm):
155.9, 155.2, 155.0, 153.4, 149.9, 149.3, 148.1, 137.6,
137.4, 137.2, 134.2, 129.3, 128.8, 128.6, 124.5, 124.5,
121.5, 120.9, 120.8, 117.8, 117.3, 116.5.
9‐(3,5‐Difluorophenyl)‐3,3,6,6‐tetramethyl‐
3,4,6,7,9,10‐hexahydroacridine‐1,8‐(2H,5H)‐dione (2l). M.
p. 301–303 °C. FT‐IR (KBr, ν, cm−1): 3277, 2961, 1646,
1
1619, 1488, 1365, 1222, 1144, 987. H NMR (400 MHz,
DMSO, δ, ppm): 9.45 (s, 1H, NH), 6.91–6.79 (m, 3H, aro-
matic), 4.89 (s, 1H, CH), 2.45–2.13 (m, 8H, CH2), 1.00 (s,
6H, Me), 0.92 (s, 6H, Me). 13C NMR (101 MHz, DMSO,
δ, ppm): 194.45, 163.13, 160.71, 151.39, 150.01, 110.50,
110.27, 101.07, 50.05, 33.14, 32.12, 28.88, 26.44.
9‐(4‐Methoxyphenyl)‐3,3,6,6‐tetramethyl‐3,4,6,7,9,10‐
hexahydroacridine‐1,8‐(2H,5H)‐dione
(2o).
M.p.
269–271 °C. FT‐IR (KBr, ν, cm−1): 3279, 2958, 1644, 1634,
1606, 1483, 1368, 1145, 834. 1H NMR (400 MHz, DMSO, δ,
ppm): 9.25 (s, 1H, NH), 7.06–6.73 (m, 4H, aromatic), 4.77
(s, 1H, CH), 3.67 (s, 3H, OMe), 2.19–2.02 (m, 8H, CH2),
1.00 (s, 6H, Me), 0.90 (s, 6H, Me). 13C NMR (101 MHz,
DMSO, δ, ppm): 194.34, 157.06, 149.00, 139.49, 128.49,
112.89, 111.67, 54.79, 50.25, 32.10, 31.86, 29.09, 26.47.
3,3,6,6‐Tetramethyl‐9‐(thiophen‐2‐yl)‐3,4,6,7,9,10‐
hexahydroacridine‐1,8‐(2H,5H)‐dione
(2q).
M.p.
313–315 °C. FT‐IR (KBr, ν, cm−1): 3277, 2956, 1638,
1
1626, 1605, 1482, 1371, 1217, 716. H NMR (400 MHz,
DMSO, δ, ppm): 9.25 (s, 1H, NH), 6.95–6.55 (m, 3H,
aromatic), 4.95 (s, 1H, CH), 2.01–2.28 (m, 8H, CH2), 0.76
(s, 12H, Me). 13C NMR (101 MHz, DMSO, δ, ppm):
194.3, 192.4, 149.6, 126.2, 123.0, 122.8, 110.8, 50.2, 32.7,
32.42, 28.78, 27.1, 26.5.
9‐(3‐Hydroxy‐4‐methylphenyl)‐3,3,6,6‐tetramethyl‐
3,4,6,7,9,10‐hexahydroacridine‐1,8‐(2H,5H)‐dione
(2d).
M.p. 317–319 °C. FT‐IR (KBr, ν, cm−1): 3538, 2958, 1650,
1
1607, 1489, 1367, 1143, 759. H NMR (400 MHz, DMSO,
δ, ppm): 8.99 (s, 1H, NH), 8.38 (s, 1H, OH), 6.43–6.29
(m, 3H, aromatic), 4.45 (s, 1H, CH), 3.12 (s, 3H, Me),
2.25–1.77 (m, 8H, CH2), 0.76 (s, 6H, Me), 0.66 (s, 6H,
Me). 13C NMR (101 MHz, DMSO, δ, ppm): 194.33,
148.88, 145.53, 140.12, 118.05, 115.47, 111.69, 111.47,
55.50, 50.31, 32.09, 31.82, 29.10, 26.57.
9‐(2‐Methoxyphenyl)‐3,3,6,6,tetramethyl‐3,4,6,7,9,10‐
hexahydroacridine‐1,8‐(2H,5H)‐dione (2e). M.p. 298–
300 °C. FT‐IR (KBr, ν, cm−1): 3285, 2955, 1645, 1605,
1489, 1224, 1143, 747. 1H NMR (400 MHz, DMSO, δ,
ppm): 8.97 (s, 1H, NH), 6.94–6.56 (m, 4H, aromatic),
4.69 (s, 1H, CH), 3.43 (s, 3H, OMe), 2.26–1.66 (m, 8H,
CH2), 0.76 (s, 6H, Me), 0.58 (s, 6H, Me). 13C NMR
(101 MHz, DMSO, δ, ppm): 194.02, 157.57, 149.59,
ACKNOWLEDGEMENTS
We thank Bu‐Ali Sina University and Iran National Sci-
ence Foundation (INSF) (The grant Number: 95831207)
and National Elites Foundation for financial support to
our research groups.
ORCID
Mohammad Ali Zolfigol http://orcid.org/0000-0002-4970-
8646
Meysam Yarie http://orcid.org/0000-0002-7129-0776

10 of 11
ZOLFIGOL ET AL.
Tapaswi, R. J. Butcher, Tetrahedron Lett. 2010, 51, 1797; d)
A. R. Moosavi‐Zare, M. A. Zolfigol, S. Farahmand, A. Zare,
A. R. Pourali, R. Ayazi‐Nasrabadi, Synlett 2014, 25, 193; e) S.
Tu, T. Li, F. Shi, Q. Wang, J. Zhang, J. Xu, X. Zhu, X. Zhang,
S. Zhu, D. Shi, Synthesis 2005, 18, 3045.
REFERENCES
[1] R. Mrowczynski, A. Nan, J. Liebscher, RSC Adv. 2014, 4, 5927.
[2] T. Cheng, D. Zhang, H. Li, G. Liu, Green Chem. 2014, 16, 3401.
[3] R. J. White, R. Luque, V. L. Budarin, J. H. Clark, D. J.
Macquarrie, Chem. Soc. Rev. 2009, 38, 481.
[18] M. Adib, N. Ayashia, P. Mirzaei, Synlett 2016, 27 417 And refer-
[4] M. Mokhtary, J. Iran. Chem. Soc. 2016, 13, 1827.
ences therein.
[5] V. F. Puntes, K. M. Krishnan, A. P. Alivisatos, Science 2001, 291,
[19] H. Alinezhad, M. Tajbakhsh, N. Ghobadi, Res. Chem. Intermed.
2015, 41 9113 And references therein.
2115.
[6] a) V. Polshettiwar, R. Luque, A. Fihri, H. Zhu, M. Bouhrara,
J. M. Basset, Chem. Rev. 2011, 111, 3036; b) B. Karimi, F.
Mansouri, H. M. Mirzaei, ChemCatChem 2015, 7, 1736; c) D.
Zhang, C. Zhou, Z. Sun, L. Z. Wu, C. H. Tung, T. Zhang, Nano-
scale 2012, 4, 6244.
[20] E. Tabrizian, A. Amoozadeh, S. Rahmani, E. Imanifar, S.
Azhari, M. Malmir, Chin. Chem. Lett. 2015, 26, 1278.
[21] M. R. Mohammad Shafiee, R. Moloudi, M. Ghashang, APCBEE
Procedia 2012, 1, 221.
[22] A. R. Moosavi‐Zare, M. A. Zolfigol, Z. Rezanejad Can. J. Chem.
2016, 94 626 And references therein.
[7] a) S. Shylesh, V. Schunemann, W. R. Thiel, Angew. Chem. Int.
Ed. 2010, 49, 3428; b) A. H. Lu, E. L. Salabas, F. Schuth, Angew.
Chem. Int. Ed. 2007, 46, 1222; c) R. Hudson, Y. Feng, R. S.
Varma, A. Moores, Green Chem. 2014, 16, 4493; d) S. Laurent,
D. Forge, M. Port, A. Roch, C. Robic, L. V. Elst, R. N. Muller,
Chem. Rev. 2008, 108, 2064.
[23] A. Shaabani, M. B. Boroujeni, M. S. Laeini, RSC Adv. 2016, 6,
27706.
[24] a) P. Murugan, P. Shanmugasundaram, V. T. Ramakrishnan, B.
Venkatachalapathy, N. Srividya, P. Ramamurthy, K.
Gunasekaran, D. Velmurugan, J. Chem. Soc. Perkin Trans. 2
1998, 999; b) S. J. Tu, C. B. Miao, Y. Gao, F. Fang, Q. Y. Zhuang,
Y. J. Feng, D. Q. Shi, Synlett 2004, 255.
[8] C. K. Banerjee, J. D. Umarye, P. R. Kanjilal, Synth. Commun.
2013, 43, 2208.
[9] a) B. Y. Kim, J. B. Ahn, H. W. Lee, S. K. Kang, J. H. Lee, J. S.
Shin, S. K. Ahn, C. I. Hong, S. S. Yoon, Eur. J. Med. Chem.
2004, 39, 433; b) R. Karki, P. Thapa, M. J. Kang, T. C. Jeong,
J. M. Nam, H.‐L. Kim, Y. Na, W. J. Cho, Y. Kwon, Bio. Med.
Chem. 2010, 18, 3066; c) I. J. Enyedy, S. Sakamuri, W. A.
Zaman, K. M. Johnson, S. Wang, Bioorg. Med. Chem. Lett.
2003, 13, 513.
[25] a) A. Albert, The Acridines, St Martin's Press, New York 1966,
403504; b) L. Guetzoyan, X.‐M. Yu, F. Ramiandrasoa, S. Pethe,
C. Rogier, B. Pradines, T. Cresteil, M. Perrée‐Fauvet, J.‐P.
Mahy, Bioorg. Med. Chem. 2009, 17, 8032; c) D. P. Spalding, E.
C. Chapin, H. S. Mosher, J. Org. Chem. 1954, 19, 357; d) S. A.
Gamega, J. A. Spicer, G. J. Atwell, G. J. Finlay, B. C. Baguley,
W. A. Deny, J. Med. Chem. 1999, 42, 2383; e) I. Antonini, P.
Polucci, L. R. Kelland, E. Menta, N. Pescalli, S. Martelli, J.
Med. Chem. 1999, 42, 2535; f) L. Ngadi, A. M. Galy, J. P. Galy,
J. Barbe, A. J. Cremieux, J. Chevalier, D. Sharples, Eur. J.
Med. Chem. 1990, 25, 67; g) O. Berkan, B. Sarac, R. Simsek, S.
Yildirim, Y. Sarioglu, C. Safak, Eur. J. Med. Chem. 2002, 37, 519.
[10] a) P. Thapa, R. Karki, M. Yun, T. M. Kadayat, E. Lee, H. B.
Kwon, Y. Na, W. J. Cho, N. D. Kim, B. S. Jeong, Y. Kwon,
E. S. Lee, Eur. J. Med. Chem. 2012, 52, 123; b) G. Lowe, A. S.
Droz, T. Vilaivan, G. W. Weaver, J. J. Park, J. M. Pratt, L.
Tweedale, L. R. Kelland, J. Med. Chem. 1999, 42, 3167.
[11] a) P. R. Andres, U. S. Schubert, Adv. Mater. 2004, 16, 1043; b)
B. G. G. Lohmeijer, U. S. Schubert, J. Polym. Sci., Part A: Polym.
Chem. 2003, 41, 1413; c) B. G. G. Lohmeijer, U. S. Schubert,
Angew. Chem. Int. Ed. 2002, 41, 3825; d) S. Kelch, M. Rehahn,
Macromolecules 1999, 32, 5818.
[26] a) Z. Topcu, J. Clin. Pharm. Ther. 2001, 26, 405; b) T. J. Van
Mouwerik, P. M. Caines, R. Ballentine, Drug Intell. Clin. Pharm.
1987, 21, 330.
[27] a) K. B. Ramesh, M. A. Pasha, Bioorg. Med. Chem. Lett. 2014, 24,
3907; b) Y.‐B. Shen, G.‐W. Wang, ARKIVOC 2008, 1; c) M.
Kidwai, D. Bhatnagar, Tetrahedron Lett. 2010, 51, 2700. d) M.
V. Reddy, Y. T. Jeong, Synlett 2012, 23, 2985; e) E. Rafiee, S.
Eavani, M. Khodayari, Chin. J. Catal. 2013, 34, 1513; f) M. A.
Ghasemzadeh, J. Safaei‐Ghomi, H. Molaei, C. R. Chim. 2012,
15, 969; g) S. Balalaie, F. Chadegani, F. Darviche, H. R.
Bijanzadeh, Chin. J. Chem. 2009, 27, 1953; h) W. Shen, L. M.
Wang, H. Tian, J. Tang, J. J. Yu, J. Fluorine Chem. 2009, 130,
522; i) D.‐Q. Shi, S.‐N. Ni, F. Yang, J. W. Shi, G. L. Dou, X. Y.
Li, X. S. Wang, J. Heterocycl. Chem. 2008, 45, 653; j) X. Fan, Y.
Li, X. Zhang, G. Qu, J. Wang, Heteroatom Chem. 2007, 18,
786; k) S. M. Vahdat, S. Khaksar, M. Akbari, S. Baghery, Arab.
J. Chem. 2014, https://doi.org/10.1016/j.arabjc.2014.10.026; l)
P. Mahesh, K. Guruswamy, B. S. Diwakar, B. R. Devi, Y. L. N.
Murthy, P. Kollu, S. V. N. Pammi, Chem. Lett. 2015, 44, 1386;
m) A. Amoozadeh, S. Rahmani, M. Bitaraf, F. Bolghan Abadi,
E. Tabrizian, New J. Chem. 2016, 40, 770; n) A. Bamoniri, S.
Fouladgar, RSC Adv. 2015, 5, 78483; o) A. K. Dutta, P. Gogoi, R.
[12] S. Yan, W. Chen, X. Yang, C. Chen, M. Huang, Z. Xu, K. W. K.
Yeung, C. Yi, Polym. Bull. 2011, 66, 1191.
[13] H. J. Jiang, Z. Q. Gao, F. Liu, Q. D. Ling, W. Wei, W. Huang,
Polymer 2008, 49, 4369.
[14] A. G. Fang, J. V. Mello, N. S. Finney, Tetrahedron 2004, 60,
11075.
[15] a) A. R. Katritzky, J. Adamson, E. M. Elisseou, G. Musumarra,
R. C. Patel, K. Sakizadeh, W. K. Yeung, J. Chem. Soc. Perkin
Trans. 2 1982, 1041; b) A. R. Katritzky, Tetrahedron 1980, 36,
679.
[16] a) J. Quiroga, J. Portilla, B. Insuasty, M. Nogueras, M. Sortino,
S. Zacchino, J. Heterocycl. Chem. 2005, 42, 61; b) G. W. V. Cave,
M. J. Hardie, B. A. Roberts, C. Raston, Eur. J. Org. Chem. 2001,
3227.
[17] a) P. V. Shinde, V. B. Labade, J. B. Gujar, B. B. Shingate, M. S.
Shingare, Tetrahedron Lett. 2012, 53, 1523; b) J. Li, P. He, Y.
Yu, Tetrahedron 2012, 68, 4138. c) C. Mukhopadhyay, P. K.

ZOLFIGOL ET AL.
11 of 11
Borah, RSC Adv. 2014, 4, 41287; p) C. A. Navarro, C. A. Sierra, C.
Ochoa‐Puentes, RSC Adv. 2016, 6, 65355.
Koorbanally, J. Iran. Chem. Soc. 2016, 13, 2239; d) M. Daraei,
M. A. Zolfigol, F. Derakhshan‐Panah, M. Shiri, H. G. Kruger,
M. Mokhlesi, J. Iran. Chem. Soc. 2015, 12, 855.
[28] M. A. Zolfigol, N. Bahrami‐Nejad, S. Baghery, J. Mol. Liq. 2016,
218, 558 and cited reference herein.
[46] a) M. Kiafar, M. A. Zolfigol, M. Yarie, A. Taherpour, RSC Adv.
2016, 6, 102280; b) M. A. Zolfigol, M. Yarie, Appl. Organometal.
Chem. 2017, 31 e3598; c) M. A. Zolfigol, M. Kiafar, M. Yarie, A.
Taherpour, M. Saeidi‐Rad, RSC Adv. 2016, 6, 50100; d) M. A.
Zolfigol, A. Khazaei, S. Alaie, S. Baghery, F. Maleki, Y. Bayat,
A. Asgari, RSC Adv. 2016, 6, 58667; e) M. A. Zolfigol, F.
Afsharnadery, S. Baghery, S. Salehzadeh, F. Maleki, RSC Adv.
2015, 5, 75555; f) J. Rakhtshah, S. Salehzadeh, E. Gowdini, F.
Maleki, S. Baghery, M. A. Zolfigol, RSC Adv. 2016, 6, 104875;
g) M. A. Zolfigol, M. Safaiee, F. Afsharnadery, N. Bahrami‐
Nejad, S. Baghery, S. Salehzadeh, F. Maleki, RSC Adv. 2015, 5,
100546; h) M. A. Zolfigol, M. Kiafar, M. Yarie, A. Taherpour,
T. Fellowes, A. N. Hancok, A. Yari, J. Mol. Struct. 2017, 1137,
674; i) M. A. Zolfigol, M. Safaiee, B. Ebrahimghasri, S. Baghery,
S. Alaie, M. Kiafar, A. Taherpour, Y. Bayat, A. Asgari, J. Iran.
Chem. Soc. 2017, 14, 1839; j) M. Yarie, Iran. J. Catal. 2017, 7, 85.
[29] A. Chanda, V. V. Fokin, Chem. Rev. 2009, 109, 725.
[30] C. Lamberth, A. Jeanguenat, F. Cederbaum, A. De Mesmaeker,
M. Zeller, H. J. Kempf, R. Zeun, Bioorg. Med. Chem. 2008, 16,
1531.
[31] D. Tejedor, F. Garcia‐Tellado, Chem. Soc. Rev. 2007, 36, 484.
[32] W. H. Moos, C. R. Hurt, G. A. Morales, Mol. Diversity 2009, 13,
241.
[33] C. C. A. Cariou, G. J. Clarkson, M. Shipman, J. Org. Chem. 2008,
73, 9762.
[34] P. Slobbe, E. Ruijter, R. V. A. Orru, Med. Chem. Commun. 2012,
3, 1189.
[35] R. C. Cioc, E. Ruijter, R. V. A. Orru, Green Chem. 2014, 16, 2958.
[36] R. Kakuchi, Angew. Chem. Int. Ed. 2014, 53, 46.
[47] a) M. A. Zolfigol, M. Safaiee, Synlett 2004, 0827; b) M. A.
Zolfigol, P. Salehi, M. Safaiee, Lett. Org. Chem. 2006, 3, 153.
[37] B. B. Touré, D. G. Hall, Chem. Rev. 2009, 109, 4439.
[38] M. A. Zolfigol, M. Yarie, RSC Adv. 2015, 5, 103617.
[39] M. A. Zolfigol, M. Yarie, S. Baghery, A. Khoshnood, D. A.
Alonso, Res. Chem. Intermed. 2017, 43, 3291.
SUPPORTING INFORMATION
[40] M. Yarie, M. A. Zolfigol, Y. Bayat, A. Asgari, D. A. Alonso, A.
Additional Supporting Information may be found online
in the supporting information tab for this article.
Khoshnood, RSC Adv. 2016, 6, 82842.
[41] M. Aghayee, M. A. Zolfigol, H. Keypour, M. Yarie, L.
Mohammadi, Appl. Organometal. Chem. 2016, 30, 612.
[42] M. A. Zolfigol, M. Yarie, S. Baghery, Synlett 2016, 27, 1418.
How to cite this article: Zolfigol MA, Karimi F,
Yarie M, Torabi M. Catalytic application of sulfonic
acid‐functionalized titana‐coated magnetic
[43] M. A. Zolfigol, M. Navazeni, M. Yarie, R. Ayazi‐Nasrabadi,
Appl. Organometal. Chem. 2017, 31, e3633.
[44] M. A. Zolfigol, M. Yarie, S. Baghery, J. Mol. Liq. 2016, 222, 923.
nanoparticles for the preparation of 1,8‐
[45] a) M. A. Zolfigol, M. Navazeni, M. Yarie, R. Ayazi‐Nasrabadi,
RSC Adv. 2016, 6, 92862; b) M. A. Zolfigol, H. Ghaderi, S.
Baghery, L. Mohammadi, J. Iran. Chem. Soc. 2017, 14, 121; c)
M. Shiri, M. M. Heravi, H. Hamidi, M. A. Zolfigol, Z.
Tanbakouchian, A. Nejatinezhad‐Arani, S. A. Shintre, N. A.
dioxodecahydroacridines and 2,4,6‐triarylpyridines
via anomeric‐based oxidation. Appl Organometal
Chem. 2017;e4063. https://doi.org/10.1002/aoc.4063