Boosting the catalytic performance of manganese (III)-porphyrin complex MnTSPP for facile one-pot green synthesis of 1,4-dihydropyridine derivatives under mild conditions

Article abstract of DOI:10.1002/aoc.6238

In this study, the metal complex (5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin manganese (III) chloride; denoted as MnTSPP) represents a promising efficient and reusable heterogeneous solid catalyst for facile and highly efficient one-pot synthesis of 1,4 dihydropyridine derivatives via three-component condensation reaction of aromatic aldehyde, ethyl acetoacetate, and ammonium acetate under green and mild reaction conditions. The simple operation, short reaction time (15 min), and the high efficiency (99%) are the special advantage of this protocol. Furthermore, the green aspects of this synthetic protocol were more studied by examination of the reusability of MnTSPP for four consecutive cycles without a significant loss of catalytic activity. Remarkably, the new synthesis presented advantages in terms of safety, commercially available catalyst, simplicity, stability, mild conditions, short reaction time, and excellent yields, using a mixture of H₂O and C₂H₅OH environmental-friendly solvent, operationally facile, wide tolerance of starting materials, and excellent recoverable of the catalyst.

Full text of DOI:10.1002/aoc.6238

Received: 24 December 2020
DOI: 10.1002/aoc.6238
Revised: 24 February 2021
Accepted: 8 March 2021
F U L L P A P E R
Boosting the catalytic performance of manganese
(III)-porphyrin complex MnTSPP for facile one-pot green
synthesis of 1,4-dihydropyridine derivatives under mild
conditions
Mahmoud Abd El Aleem Ali Ali El-Remaily1
| Hesham A. Hamad2,3
|
Ahmed M. M. Soliman1
| Omar M. Elhady1
1Department of Chemistry, Faculty of
Science, Sohag University, Sohag, Egypt
2Fabrication Technology Research
In this study, the metal complex (5,10,15,20-tetrakis-(4-sulfonatophenyl)-
porphyrin manganese (III) chloride; denoted as MnTSPP) represents a
promising efficient and reusable heterogeneous solid catalyst for facile and
highly efficient one-pot synthesis of 1,4 dihydropyridine derivatives via three-
component condensation reaction of aromatic aldehyde, ethyl acetoacetate,
and ammonium acetate under green and mild reaction conditions. The simple
operation, short reaction time (15 min), and the high efficiency (99%) are
the special advantage of this protocol. Furthermore, the green aspects of this
synthetic protocol were more studied by examination of the reusability of
MnTSPP for four consecutive cycles without a significant loss of catalytic
activity. Remarkably, the new synthesis presented advantages in terms of
safety, commercially available catalyst, simplicity, stability, mild conditions,
short reaction time, and excellent yields, using a mixture of H2O and C2H5OH
environmental-friendly solvent, operationally facile, wide tolerance of starting
materials, and excellent recoverable of the catalyst.
Department, Advanced Technology and
New Materials Research Institute
(ATNMR), City of Scientific Research and
Technological Applications (SRTA-City),
New Borg El-Arab City, Alexandria, Egypt
3Biological and Chemical Research
Centre, Faculty of Chemistry, University
of Warsaw, Warsaw, Poland
Correspondence
Mahmoud Abd El Aleem Ali Ali El-Remaily,
Department of Chemistry, Faculty of Science,
Sohag University-82524 Sohag, Egypt.
Email: msremaily@yahoo.com
Hesham A. Hamad, Fabrication
Technology Research Department,
Advanced Technology and New Materials
Research Institute (ATNMR), City of
Scientific Research and Technological
Applications (SRTA-City), New Borg El-
Arab City, Alexandria, Egypt.
K E Y W O R D S
1,4-dihydropyridines, benign protocol, manganese (III)-porphyrin complex, mild condensations;
recoverable catalyst, three-component reaction
Email: hhamad@srtacity.sci.eg
1 | INTRODUCTION
the field of homogeneous and heterogeneous catalysis.[2]
The strategy of immobilization of porous metal-porphyrin
Metal-porphyrins have attracted more attention for broad
applications in catalysis.[1] Among these reactions, metal-
porphyrins have a significant catalytic activity towards
the oxidative processes in organic synthesis. So the devel-
opment of catalysts is claiming huge attention due to
their wide applications of the produced organic com-
pounds with high selectivity and productivity.
(Figure 1) has already been developed by organic amor-
phous polymers, amorphous inorganic matrices, or crystal-
line inorganic materials such as silica,[3] zeolites,[4] clay
from the smectite group (montmorillonite),[5,6] layered
double hydroxides,[7,8] tubular and fibrous matrices,[9] and
silica matrix obtained by the sol–gel process. [10–16]
The search for broadly applicable metal catalysts
operating in the aqueous phase is a subject of high inter-
est.[17–19] Environmental applications of metal catalysis
It is well known that the porous metal-porphyrin net-
works have demonstrated to be an excellent technology in
Appl Organomet Chem. 2021;e6238.
wileyonlinelibrary.com/journal/aoc
© 2021 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.6238

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ALI EL-REMAILY ET AL.
particular, 1,4-dihydropyridine drugs are the most widely
used in the treatment of cardiovascular disease,[23] have a
broad range of pharmacological properties such as
antitumor, antimutagenic, neuroprotective, geroprotective,
heptaprotective, antimicrobial, anti-alzheimer, cytotoxic,
[24–26]
and antidiabetic agents,
1,4-Dihydropyridines have
also proved to be very important synthetic intermediates,
finding applications in the preparation of a large number
of nitrogen alkaloids.[27] The remarkable drug activity of
these compounds has not only attracted many chemists to
synthesize this heterocyclic nucleus but has also become
FIGURE 1 The structure of MnTSPP catalyst
in water are the treatment of aqueous waste effluents that
result from chemical production streams (e.g., obtained
from dyes production). The reactions of particular inter-
est for such applications are catalytic oxidations, prefera-
bly promoted by the consumption of molecular oxygen or
hydrogen peroxide as oxidizing agents. Until now, how-
ever, most metal-based catalytic applications have been
related to organic media, as the sensitivity of complexes
to moisture. Accordingly, the number of metal complexes
suitable for catalysis in in aqueous media remains lim-
ited. The need for such catalysts has resulted in detailed
studies with various metal complexes towards their suit-
ability for such applications in aqueous media.
According to the green chemistry from both environ-
mental and economic viewpoints, developments of efficient
and environmentally benign heterogenous processes with
green energies, and lowest-level waste, as well as stability
in reaction media are the priorities. The performance with
5,10,15,20-tetrakis-(4-sulfonato-phenyl)-porphyrin manga-
nese (III) chloride (MnTSPP; Figure 1) fulfills the prerequi-
sites of water solubility,[20] low toxicity, commercially
available catalyst, and high stability of the complexes, even
in oxidation reaction.[21] In addition, this catalyst is com-
mercially available from several suppliers up to gram scale.
Further advantages are its high stability and its ability for
prevention the aggregation in an aqueous solution.
Multicomponent reactions (MCRs) allow the creation
of several bonds in one-step process in synthetic chemistry.
MCRs also are attracting the interest as one of the most
powerful emerging synthetic tools for the creation of
molecular complexity and diversity due to their intrinsic
atom economy, selectivity, simplicity, and energy
efficiency.[22] Although MCRs have many advantages, it
has still suffered from several drawbacks, such as harsh
reaction conditions, requiring long reaction time, and
usage of excessive number of reagents and toxic solvents.
The most important one among them is the one-pot
four-component synthesis of 1,4-dihydropyridines and
hexahydroquinolines reported by Hantzsch in 1882. In the
past few decades, much interest has been focused on the
synthesis of 1,4-dihydropyridine compounds owing to their
various pharmacological and therapeutic features. In
an active research area of continuing interest [28] [29]
Aromatization of Hantzsch esters compounds has been
reported by several catalysts such as cellulose sulfuric acid[30]
,
.
,
solid acid[31], silica supported 12-tungstophosphoric acid[32]
,
Iron (III) trifluoroacetate,[33] ionic liquid [tbmim]Cl2/
AlCl3,[34] organo catalyst,[35] cerric ammonium nitrate,[36] Ni
nanoparticle,[37] aluminum phosphate,[38] bismuth nitrate,[39]
gadolinium triflate,[40] TiO2 nanoparticles,[41] FeF3,
silica
[42]
sulfuric acid,[43] MgO nanoparticles,[44] visible light[45]
,
chitosan[46], sulfated polyborate,[47] and protic pyridinium
ionic liquid[48] have been reported. The industrial and biolog-
ical importance of 1,4-dihydropyridine derivatives is the rea-
son to improve the several routes for synthesis of these
compounds. Although these techniques suffer from several
drawbacks drawbacks such as extended reaction times,
unsatisfactory yields, elevated temperatures, tedious work-
up, relatively expensive reagents, formation of numerous side
products, and difficult recovery process of catalyst, the devel-
opment, however, of simple, efficient, and environmental
benign protocols of 1,4 dihydropyridine using reusable heter-
ogenous solid acid catalyst is highly demanded.
To the best of our knowledge, 1,4-dihydropyridine
derivatives catalyzed by MnTSPP under mild reaction
conditions have not been reported. In line with outlined
strategies and continuation of our interest towards the
development of new routes to the role of metal-porphyrin
catalyst for synthesis bio-active heterocyclic compounds
by MCRs.[49] With the merits of environment benign,
readily accessibility, and cost-benefit, manganese
(III)-porphyrin complex MnTSPP seems to be a promis-
ing reusable catalyst in the facile one-pot synthesis of
hybrid molecules 1,4-dihydropyridine compounds 4a-o
through Hantzsch, a three-component coupling reaction
of aromatic aldehyde, ethyl acetoacetate, and ammonium
acetate under mild conditions. All products have been
deposited in excellent yields in short reaction time.
2 | EXPERIMENTAL
All starting materials and solvents were used as
received from Sigma Aldrich or Alfa Aesar. Thin-layer

ALI EL-REMAILY ET AL.
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chromatography was conducted using TLC silica gel
60F254 (Merck Co.), visualized with ultraviolet light. All
melting points were recorded on Melt-Temp II melting
point apparatus. IR spectra were measured as KBr pellets
on a Shimadzu DR-8001 spectrometer. 1H,13C spectra
were recorded on a Bruker DRX 400 MHz using TMS as
an internal reference and CDCl3 as a solvent. All com-
pounds were checked for their purity on TLC plates.
2CH3). 13C NMR (100 MHz, CDCl3) δ: 168.1, 148.2,
145.7, 132.3, 128.6, 126.1, 103.6, 59.9, 39.87, 19.1, 14.0.
IR (KBr) cm−1 = 3342, 1701, 1650, 1483, 1210.
• Compound 4b: M.P = 150–152ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.15–7.25 (dd, 4H, ArH), 5.68
(br, 1H, NH), 4.99 (s, 1H, CH), 4.09 (q, J = 7.1 Hz, 4H,
2CH2), 2.32 (s, 6H, 2CH3), 1.23 (t, J = 7.1 Hz, 6H,
2CH3). 13C NMR (100 MHz, CDCl3) δ: 167.6, 147.0,
143.9, 131.3, 129.4, 128.1, 104.1, 60.0, 39.1, 19.6, 14.4.
IR (KBr) cm−1 = 3344, 1698, 1650, 1489, 1212.
2.1 | General procedure for the synthesis
of 1,4-Dihydropyridine derivatives 4a–o
• Compound 4c: M.P = 130–132ꢀC, 1H NMR (400 MHz,
CDCl3) δ: 7.05–7.26 (m, 4H, ArH), 5.67 (s, 1H, NH),
5.30 (s, 1H, CH), 4.10 (q, J = 7.1 Hz, 4H, 2CH2), 2.32
(s, 6H, 2CH3), 1.23 (t, J = 7.1 Hz, 6H, 2CH3). 13C NMR
(100 MHz, CDCl3) δ: 168.1, 145.3, 143.9, 132.8, 130.4,
128.0, 127.1, 126.8, 103.5, 59.8, 37.1, 20.0, 14.1. IR
(KBr)cm−1 = 3331, 1699, 1670, 1491, 1208.
In a round bottom flask manganese (III)-porphyrin com-
plex MnTSPP 10 mol % was dissolved in 30 ml H2O at
room temperature by magnetic stirrer. Then aromatic
aldehyde 1a-o (1 mmol), ethyl acetoacetate 2 (2 mmol),
and ammonium acetate 3 (2 mmol) were added. Due to
the partial solubility of some aromatic aldehyde in water,
we used to use a mixed solvent of H2O and ethanol (v/v)
(3/1). The reaction mixture was refluxed for the appropri-
ate time see (Scheme 1). The reaction mixture was
allowed to cool to room temperature. The organic mate-
rial was extracted twice with ethyl acetate; the
1,4-dihydropyridine derivatives 4a–o combined organic
• Compound 4d: M.P = 158–160ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.12–7.31 (dd, 4H, ArH), 5.71
(s, 1H, NH)), 5.33 (s, 1H, CH), 4.11 (q, J = 7.1 Hz, 4 H,
2CH2), 2.35 (s, 6 H, 2CH3), 1.23 (t, J = 7.1 Hz, 6 H,
2CH3), 13C NMR (100 MHz, CDCl3) δ: 167.7, 148.3,
142.3, 130.2, 131.0, 128.1, 104.0, 59.9, 39.3, 19.3, 14.2.
IR (KBr)cm−1 = 3340, 1696, 1650, 1494, 1210.
• Compound 4e: M.P = 163–165ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 8.02–7.32 (m, 4H, ArH), 5.74
(br, 1H, NH), 5.10 (s, 1H, CH), 4.10 (q, J = 7.1 Hz, 4H,
2CH2), 2.33 (s, 6H, 2CH3), 1.24 (t, J = 7.1 Hz, 6H,
2CH3). 13C NMR (100 MHz, CDCl3) δ: 167.6, 149.9,
148.3, 144.9, 134.4, 129.0, 123.1, 121.2, 103.9, 59.8, 38.1,
19.3, 14.1. IR (KBr) cm−1 = 3342, 1701, 1645, 1487,
1212.
phases were washed with water, dried over anhydrous
[30–43]
Na2SO4, and concentrated under reduced pressure
.
After completion of reaction as indicated by thin layer
chromatography (TLC), the resulting solid product was
filtered and recrystallized with 5 ml ethanol to give the
pure product and characterized by their melting point,
FT-IR. NMR spectra were recorded on a 400 MHz Bruker
spectrometer using TMS as an internal reference and
CDCl3 as solvent (See Supporting Information).
• Compound 4f: M.P = 129–131ꢀC, 1H NMR (400 MHz,
CDCl3) δ: 8.01–7.35 (m, 4H, ArH), 5.71 (br, 1H, NH),
5.07 (s, 1H, CH), 4.10 (q, J = 7.1 Hz, 4H, 2CH2), 2.24
(s, 6H, 2CH3), 1.23 (t, J = 7.1 Hz, 6H, 2CH3). 13C NMR
(100 MHz, CDCl3) δ: 168.1, 150.3, 146.7, 145.0, 126.3,
122.6, 103.6, 59.9, 38.7, 19.3, 14.2. IR (KBr)
cm−1 = 3331, 1699, 1644, 1483, 1212.
2.2 | Catalyst recovery and reuse
The catalyst was recovered by adding drop wise (5 ml) of
acetone to the aqueous layer while stirring at room tem-
perature giving it a precipitated manganese-porphyrin
catalyst which was cooled to 3ꢀC. MnTSPP was recovered
by filtration, dried, which could be reused without losing
catalytic activity.
• Compound 4g: M.P = 158–160ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.18–6.81(dd, 4H, ArH), 5.71
(s, 1H, NH), 5.05 (s, 1H, CH), 4.09 (q, J = 7.1 Hz, 4H,
2CH2), 3.75 (s, 3H, CH3), 2.32 (s, 6H, 2CH3), 1.22
(t, J = 7.1 Hz, 6H, 2CH3). 13C NMR (100 MHz, CDCl3)
δ: 167.8, 158.0, 146.5, 136.3, 131.1, 113.6, 103.5, 59.8,
53.7, 39.3, 19.2, 14.3.
2.3 | Spectral data for the synthesized
compounds
• IR (KBr) cm−1 = 3341, 1691, 1649, 1491, 1211.
• Compound 4h: M.P = 139–141ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.40–6.80 (m, 4H, ArH), 5.73
(s, 1H, NH), 5.11 (s, 1H, CH), 4.07 (q, J = 7.1 Hz, 4H,
2CH2), 3.90 (s, 3H, CH3), 2.34 (s, 6H, 2CH3), 1.24
(t, J = 7.1 Hz, 6H, 2CH3). 13C NMR (100 MHz, CDCl3)
δ: 167.7, 158.3, 146.5, 131.2, 127.9, 122.1, 121.7, 112.7,
• Compound 4a.: M.P = 157–159ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.10–7.31 (m, 5H, ArH), 5.59
(br, 1H, NH), 5.01 (s, 1H, CH), 4.10 (q, J = 7.1 Hz, 4H,
2CH2), 2.34 (s, 6H, 2CH3), 1.24 (t, J = 7.1 Hz, 6H,

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ALI EL-REMAILY ET AL.
SCHEME 1 1,4-Dihydropyridine derivatives 4a-o time of reaction (min) and Yield(%)
103.9, 59.8, 54.3, 32.6, 19.3, 14.1. IR (KBr)
cm−1 = 3334, 1698, 1650, 1491, 1210.
2CH3). 13C NMR (100 MHz, CDCl3) δ: 167.4, 155.3,
146.6, 135.7, 131.4, 115.4, 104.1, 59.9, 39.4, 19.5, 14.1.
IR (KBr) cm−1 = 3342, 1689, 1641, 1491, 1221.
• Compound 4i: M.P = 230–232ꢀC, 1H NMR (400 MHz,
CDCl3) δ: 7.21–6.78 (dd, 4H, ArH), 5.64 (s, 1H, NH),
5.21 (s, 1H, OH), 5.02 (s, 1H, CH), 4.07 (q, J = 7.1 Hz,
4H, 2CH2), 2.34 (s, 6H, 2CH3), 1.24 (t, J = 7.2 Hz, 6H,
• Compound 4j: M.P = 137–139ꢀC, 1H NMR (400 MHz,
CDCl3) δ: 7.19–7.02 (m, 4H, ArH), 5.73 (s, 1H, NH),
5.02 (s, 1H, CH), 4.07 (q, J = 7.1 Hz, 4H, 2CH2), 2.32

ALI EL-REMAILY ET AL.
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(s, 6H, 2CH3), 2.22 (s, 3H, CH3), 1.21 (t, J = 7.1 Hz,
6H, 2CH3). 13C NMR (100 MHz, CDCl3) δ: 168.1,
146.3, 143.9, 135.4, 128.3, 127.7, 104.1, 59.7, 39.4, 21.3,
19.5, 14.2. IR (KBr) cm−1 = 3348, 1699, 1650, 1487,
1212.
103.6, 60.1, 37.3, 19.9, 14.1. IR (KBr) cm−1 = 3311,
1696, 1615, 1488, 1201, 861.
3 | RESULTS AND DISCUSSION
• Compound 4 k: M.P = 160–162ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.23(s, 1H, CH), 6.34 (m, 1H,
CH), 6.01 (d, J = 3.7 Hz, 1H, CH), 5.72 (s, 1H, NH),
5.00 (s, 1H, CH), 4.08 (q, J = 7.1 Hz, 4H, 2CH2), 2.33
(s, 6H, 2CH3), 1.22 (t, J = 7.2 Hz, 6H, 2CH3). 13C NMR
(100 MHz, CDCl3) δ: 167.6, 151.9, 146.3, 141.9, 110.2,
107.7, 103.4, 59.8, 29.6, 18.3, 14.1. IR (KBr)
cm−1 = 3344, 1701, 1651, 1485, 1209.
3.1 | Synthesis of various
1,4-dihydropyridine derivatives
The catalytic activity of MnTSPP catalyst was
evaluated towards the Hantzsch synthesis of bioactive
1,4-dihydropyridines. In this context, the facile one-pot
and three-component condensation reaction of aromatic
aldehyde 1a-o (1 mmol), ethyl acetoacetate 2 (2 mmol),
and ammonium acetate 3 (2 mmol) was designated as a
model reaction. Through the present experiments, the
growth of the condensation reaction was systemically
studied the influence of catalyst dose, reaction-solvent, as
well as the different Lewis acid catalysts on the catalytic
activity. In the absence of catalyst, the product got at lon-
ger reaction time. In the presence of MnTSPP, it
improves the yield of the products as clarified at
Scheme 1. The series of aromatic aldehydes that undergo
electrophilic substitutions reactions are successfully syn-
thesized in excellent yields that illustrated in Scheme 1.
• Compound 4l: M.P = 173–175ꢀC, 1H NMR (400 MHz,
CDCl3) δ: 7.19–7.08 (m, 1 H), 6.98–6.80 (m, 2 H), 5.81
(s, 1H, NH), 5.11 (s, 1H, CH), 4.11 (q, J = 7.1 Hz, 4 H,
2CH2), 2.33 (s, 6 H, 2CH3),1.28 (t, J = 7.1 Hz, 6 H,
2CH3), 13C NMR (100 MHz, CDCl3) δ: 167.8, 151.3,
144.9, 143.3, 126.3, 123.1, 103.7, 59.7, 34.3, 19.3,14.1. IR
(KBr) cm−1 = 3343, 1699, 1651, 1488, 1370, 1211.
• Compound 4m: M.P = 230–232ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.79–7.26 (m, 3H, Ar), 5.88
(s, 1H, NH), 4.99 (s, 1H, CH), 4.13–4.08 (q, J = 7.1 Hz,
4H, 2CH2), 2.37 (s, 6H, 2CH3),1.25–1.22 (t, J = 7.1 Hz,
6H, 2CH3); 13C NMR (100 MHz, CDCl3) δ: 166.8,
148.6, 147.5, 145.0, 133.3, 131.4, 131.3, 130.7, 102.9,
60.3, 39.6, 19.6, 14.1. IR (KBr) cm−1 = 32,462, 3101,
2979, 1680, 1530, 872.
3.1.1 | Effect of catalyst loading
• Compound 4n: M.P = 103–105ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.71–7.40 (m, 4 H, ArH), 5.86
(s, 1H, NH), 5.14 (s, 1H, CH), 4.11–4.08 (q, J = 7.1 Hz,
4 H, CH2), 2.39 (s, 6 H,CH3), 1.11–1.08 (t, J = 7.1 Hz,
6 H, CH3), 13C NMR (100 MHz, CDCl3) δ: 166.9,
156.23, 144.5, 141.4, 132.0, 129.1, 126.3, 118.6, 112.5,
61.7, 23.2, 14.0. IR (KBr) cm−1 = 3246, 2930, 2223,
1710, 1559, 1444, 868.
The relationship between catalyst dosages toward the
product yields is shown in Table 1. In particular, the
loading of the catalyst from 2 to 10 mol% was improved
yield from 22% to 99% of the product (Table 1). The
improvement of the yield by increasing the amount of
MnTSPP can be rationalized to the possible increase in
the number of available active sites, as well as increasing
the amount of contact and collision chance between the
surface of MnTSPP with the molecules of the starting
materials. Note, that with a further increase of the loaded
catalyst from 10 mol% to 11 mol%, the yields and reaction
times did not change significantly (Table 1). Thus, 10 mol
% of catalyst is the optimal catalyst loading.
• Compound 4o: M.P = 148–150ꢀC, 1H NMR
(400 MHz, CDCl3) δ: 7.29–7.11 (m, 3 H, ArH), 5.71
(brs, 1H, NH), 5.29 (s, 1H, CH), 4.13–4.09
(q, J = 7.1 Hz, 4 H, CH2), 2.33 (s, 6 H,CH3), 1.19–1.16
(t, J = 7.1 Hz, 6 H, CH3), 13C NMR (100 MHz, CDCl3)
δ: 167.2, 144.3, 143.9, 133.1, 132.7, 132.1, 129.0, 127.3,
TABLE 1 The amount of MnTSPP
Entry
Cat. mol%
Yield %b
Entry
Cat. mol%
Yield %b
catalyst for the synthesis of
1,4-dihydropyridine derivative 4aa
1
2
3
4
2
4
6
7
22
39
54
72
5
6
7
8
8
86
93
99
99
9
10
11
aReaction conditions 1a(1 mmol), 2 (2 mmol), 3 (2 mmol), and Catalyst (0.1 mmol) in mixture of water and
ethanol (3:1 ratio) were refluxed 15 min.
bIsolated yields based on 4a.

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ALI EL-REMAILY ET AL.
3.1.2 | Effect of solvents
the catalyst and the reagents in the polar solvents. From
Table 2, it is evident that this reaction under mixture of
solvents (water and ethanol (v/v) (3/1)) is obviously the
best choice for the synthesis of 1,4-dihydropyridines 4a
proceeded rapidly with the highest yield. The authors pre-
ferred this mixture because it is green, safe, and cheap in
comparison with organic solvents.
In the recent years, metal ions-polyphyrin complexes
have received considerable attention as a mild Lewis acid
catalyst for an array of organic transformation. The reac-
tion of benzaldehyde 1a, ethyl acetoacetate 2, and ammo-
nium acetate 3 in the absence of the catalyst at the same
condition, trace product, was obtained (Table 3, entry 1).
Various types of Lewis acids such as AlCl3, MgCl2, Mg
To handle the procedure more easily, we then continued
to optimize the model process mentioned above by
detecting the efficiency of several classic solvents chosen
as the medium for comparison (Table 2). The role of the
solvents was evaluated with the model reaction 4a. As
indicated in Table 2, the polar protic solvents (MeOH,
EtOH, AcOH, and H2O) were much better than aprotic
solvents (DCM, DMF, THF, CH3CN, and CHCl3). The
results could be interpreted with much better solubility of
TABLE 2 Effect of solvent for the synthesis of
1,4-dihydropyridines 4a
Solventa
Time (min)
Yield (%)b
DCM
180
180
180
180
180
50
35
46
49
53
50
76
69
94
84
99
DMF
THF
CH3CN
CHCl3
MeOH
ACOH
EtOH
60
25
H2O
20
H2O/EtOH
15
Note: Effect of various Lewis acid catalysts.
aReaction conditions 1a (1 mmol), 2 (2 mmol), 3 (2 mmol), and catalyst
(0.1 mmol) in mixture of water and ethanol (3:1 ratio) were refluxed 15 min.
bIsolated yields based on 4a.
FIGURE 2 Recyclability of MnTSPP in the model reaction
TABLE 3 Use of different Lewis acid for the reaction 4aa
Entry
Cat (mol%)
Conditionsa
Yield (%)b
1
No catalyst
water/ethanol, 1 day
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
water/ethanol, 15 min
Trace
58
45
34
53
61
66
72
54
60
47
60
63
99
2
AlCl3 (10)
3
MgCl2 (10)
4
Mg (OTf)2 (10)
FeCl3.6H2O (10)
Fe (OTf)3 (10)
MnCl2.4H2O (10)
MnO2 (10)
5
6
7
8
9
(10) ZnBr2
10
11
12
13
14
Zn (OTf)2 (10)
CuCl2(10)
TiCl4 (10)
p-TsOH (10)
MnTSPP (10)
aReaction conditions 1a(1 mmol), 2 (2 mmol), 3 (2 mmol), and catalyst (0.1 mmol) in mixture of water and ethanol (3:1 ratio) were refluxed 15 min.
bIsolated yields based on 4a.

ALI EL-REMAILY ET AL.
7 of 11
(OTf)2, FeCl3.6H2O, Fe (OTf)3, MnCl2.4H2O, MnO2,
ZnBr2, Zn (OTf)2, CuCl2, TiCl4, and p-TsOH are tested in
the selected reaction conditions. It was confirmed that
the iron soluble porphyrin catalyst was much better in
comparison with all the other Lewis acids stable in water
(Table 3, entries 2–13). MnTSPP was found to be the most
effective catalyst and afforded the desired product 4a in
99% yield (Table 3, entry 14).
of MnTSPP catalyst for reusing at the next runs of the
Hantzsch condensation reaction. To do this, progress
of the model reaction (aromatic aldehyde, ethyl
acetoacetate, and ammonium acetate, water/ethanol (3:1
ratio), refluxed 15 min.) in the presence of MnTSPP was
studied four times for the synthesis of compound 4a and
there was an inevitable loss of catalyst during the recov-
ery process. The summarized results in Figure 2 show
that the MnTSPP was reused for four consecutive cycles
without the significant loss of catalytic activity, when we
tried the next runs (five to seven) that gave low catalytic
activity under the similar conditions.
3.1.3 | Recycling of MnTSPP catalyst
The green and economic aspect of this synthetic
protocol was further studied by examining the possibility
The Hantzsch 1,4 dihydropyridine mechanism has
been Studied with NMR (Katritzky et al.).[50] The
TABLE 4 The comparison of the catalytic activity of MnTSPP with formerly reported catalysts
Time
(min.)
Catalyst
amount
Entry catalyst
Solvent
Temperature Yield (%) Ref.
Yb (OTf)3
Gd (OTf)3
H5BW12O40
300
300
45
5 mol.%
5 mol.%
10 mol.%
6 mg
EtOH
EtOH
EtOH
DMF
r.t
90
91
94
93
51
26
52
53
Reflux
Reflux
70ꢀC
PdRuNi nanoparticles furnished
with graphene oxide (PdRuNi@
GO NPs)
45
Alumina sulfuric acid (ASA)
120
180
0.2 g
MeOH
70ꢀC
92
95
54
55
Hafnium (IV) bis
1 mol.%
perfluorodecalin 60ꢀC
(perfluorooctanesulfonyl)imide
Hf (NPf2)4
Tetrabutylammonium
20
7 mmol%
Solvent free
110ꢀC
95
56
hexatungstate [TBA]2[W6O19]
PPh3
120
140
60
20 mol.%
-
EtOH
Reflux
Reflux
80ꢀC
94
90
92
81
45
95
90
90
93
78
98
95
93
94
95
95
85
90
99
57
[PS-IM (CH2)4SO3H][HSO4]
CeO2
EtOH
58
50 mg
EtOH
59
Cellulose sulfuric acid
Chitosan-CuSO4
Montmorillonite K10
TiO2 NPs
300
24
15 mol.%
20 mg
Solvent free
CH3CN
EtOH
100ꢀC
Reflux
80
60
61
20
20 wt.%
-
62
105
160
120
120
40
EtOH
80
63
MgO NPs
0.04 g
EtOH
Reflux
60ꢀC
64
Hydrotalcite
AlCl3. 6H2O
20 mg
Water
65
10 mol.%
20 mol.%
20 mg
Solvent free
EtOH
60ꢀC
66
Alginic acid
NiFe2O4@SiO2@SO3H
LiBr
Reflux
70ꢀC
67
20
H2O
68
180–360
30
10 mol.%
40 mg
CH3CN
EtOH
Reflux
40ꢀC
69
Zr-ZSM-5
70
Magnetic dextrin
La2O3
15
3.5 wt.%
10 mol.%
2 mol.%
0.04 gm
10 mol.%
EtOH
Reflux
Reflux
Reflux
r.t
71
60
TFE
72
BiBr3
120
70
EtOH
73
magnetite/chitosan
MnTSPP
EtOH
74
15
H2O/EtOH
Reflux
Present work

8 of 11
ALI EL-REMAILY ET AL.
known mechanism for this reaction consists of three
reaction paths: the MnTCPP catalyzed between
benzaldehyde with an ethyl acetoacetate yields an
arylidene compound by Knoevenagel condensation;
the MnTSPP catalyzed condensation between NH4
and an ethyl acetoacetate to give the α-amino
α,β-unsaturated carbonyl compound; and the condensa-
tion products between arylidene compound and
α-amino α,β-unsaturated carbonyl compound formation
of 1,4-dihydropyridine derivatives.
As can be seen in Table 4, the catalytic activity of
MnTSPP was compared with diverse catalysts such
as which have been previously employed as
catalysts in our model reaction. In terms of reaction
times and the yield of the products, the present work
exhibited the perfect efficiency than the other
promoters.
3.1.4 | Plausible mechanism for the
synthesis of 1,4-dihydropyridines
derivatives
We propose that the possible following mechanism for
the synthetic protocol (Scheme 2) could be outlined for
the role of MnTSPP catalyzing the synthesis of
1,4-dihydropyridines derivatives. (4-sulfonatophenyl)-
porphyrin manganese (III) chloride (a) primarily acti-
vates the carbonyl moiety of aromatic aldehyde that
acts as appropriate electrophile using protonation of
carbonyl group and then one molecule of ethyl
acetoacetate condenses with activated aldehyde to form
Knoevenagel intermediate (aldol condensation) (b). At
the next, through the catalyst activation of intermedi-
ate (c) with the second molecule of ethyl acetoacetate
material (Michael addition), intermediate (d) is
SCHEME 2 Suggested
mechanism for synthesis of
1,4-dihydropyridines derivatives
and the catalytic role of MnTSPP

ALI EL-REMAILY ET AL.
9 of 11
produced. Nucleophilic attack of the NH2 group of
ammonia to carbonyl group leads to achieve intermedi-
ate (e). Finally, the ring closing of intermediate (f),
then removal of one molecule of H2O, owing to the
driving force of conjugation of double bonds with car-
bonyl groups, the derivatives of 1,4-dihydropyridines
will be produced.[75] This proposed mechanism was
confirmed with the literature.[68]
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are avail-
able from the corresponding author upon reasonable
request.
FUNDING INFORMATION
No funding.
ORCID
Mahmoud Abd El Aleem Ali Ali El-Remaily https://
orcid.org/0000-0002-3591-0077
4 | CONCLUSION
Hesham A. Hamad https://orcid.org/0000-0002-2434-
8904
Ahmed M. M. Soliman https://orcid.org/0000-0003-
2541-638X
In conclusion, we successfully developed a facile and
efficient method for synthesis
a
variety of
1,4-dihydropyridine derivatives from the reaction of aro-
matic aldehyde 1, ethyl acetoacetate 2 and ammonium
acetate in the presence of MnTSPP catalyst in mild condi-
tions. The catalytic activity of Hantzsch three-component
reaction approach for the synthesis of aromatization of
1,4-dihydropyridine derivatives using MnTSPP catalyst is
remarkable, and the use of environmentally benign, and
commercially available. We have investigated the
advantages of MnTSPP to form precipitates in a mul-
ticomponent system in water for the enhancement of the
Aromatization of 1,4-dihydropyridines. The higher cata-
lytic activity of MnTSPP is ascribed to its high acidity and
water tolerance. Also, the superiority of use MnTSPP
towards the synthesis of 1,4-dihydropyridine is compared
with other Lewis acids; the mildness of the conversion,
compatibility with various functional groups, makes this
procedure attractive to synthesize variety of these deriva-
tives. All reactions were carried out in mixture of H2O
and C2H5OH within 15–80 min. to afford the products
from high to excellent yields. The current protocol offers
several significant advantages, in terms of the avoidance
of discharging harmful organic solvents, experimental
simplicity, the high yield of products, commercially
available catalyst, short reaction times, easy workup pro-
cedures, low cost and nontoxicity of the catalyst, wide tol-
erance of starting materials, benefits of green and
economic solvents, as well as excellent reusability of the
catalyst. The simple, economical, and green procedure
may be applied to the industry in the future.
Omar M. Elhady https://orcid.org/0000-0003-1702-2495
REFERENCES
[1] S. Nakagaki, K. A. D. F. Castro, G. S. Machado, M. Halma,
S. M. Drechsel, F. Wypych, J. Braz. Chem. Soc. 2006, 17, 1672.
[2] K. S. Suslick, P. Bhyrappa, J. H. Chou, M. E. Kosal, S.
Nakagaki, D. W. Smithenry, S. R. Wilson, Acc. Chem. Res.
2005, 38, 283.
[3] F. L. Benedito, S. Nakagaki, A. A. Saczk, P. G. Peralta-Zamora,
M. C. M. Costa, Appl. Catal. A 2003, 250, 1.
[4] S. Nakagaki, C. R. Xavier, A. J. Wosniak, A. S. Mangrich, F.
~
Wypych, M. P. Cantao, I. Denicoló, L. T. Kubota, Colloids
Surf. A 2000, 168, 261.
[5] A. M. Machado, F. Wypych, S. M. Drechsel, S. Nakagaki,
J. Colloid Interface Sci. 2002, 254, 158.
[6] A. L. Faria, T. O. C. M. Leod, V. P. Barros, M. D. Assis, J. Braz.
Chem. Soc. 2009, 20, 895.
[7] S. Nakagaki, M. Halma, A. Bail, G. G. C. Arízaga, F. Wypych,
J. Colloid Interface Sci. 2005, 281, 417.
[8] F. Wypych, A. Bail, M. Halma, S. Nakagaki, J. Catal.
2005, 234, 431.
[9] S. Nakagaki, F. Wypych, J. Colloid Interface Sci. 2007, 315, 145.
[10] E. A. Vidoto, M. S. M. Moreira, F. S. Vinhado, K. J. Ciuffi,
O. R. Nascimento, Y. Iamamoto, J. Non-Cryst. Solids
2002, 304, 151.
[11] H. C. Sacco, K. J. Ciuffi, J. C. Biazzotto, M. R. Zuccki, C. A. M.
Leite, O. R. Nascimento, O. A. Serra, Y. Iamamoto, J. Non-
Cryst. Solids 2000, 273, 150.
[12] D. C. Oliveira, H. C. Sacco, O. R. Nascimento, Y. Iamamoto,
K. J. Ciuffi, J. Non-Cryst. Solids 2001, 284, 28.
[13] A. T. Papacídero, L. A. Rocha, B. L. Caetano, E. Molina, H. C.
Sacco, E. J. Nassar, Y. Martinelli, C. Mello, S. Nakagaki, K. J.
Ciuffi, Colloids Surf. A 2006, 275, 27.
ACKNOWLEDGMENTS
The authors are deeply grateful, and thanks to Sohag
University in Egypt for supporting and facilitating for this
study.
[14] H. Podbielska, A. Ulatowska-Jarza, G. Müller, I. Holowacz, J.
Bauer, U. Bindig, Biomol. Eng. 2007, 24, 425.
[15] H. Tanaka, T. Yamada, S. Sugiyama, H. Shiratori, R. Hino,
J. Colloid Interface Sci. 2005, 286, 812.
[16] a) I. Dror, D. Baram, B. Berkowitz, Environ. Sci. Technol. 2005,
39, 1283; b) H. Wang, Y. Song, Z. Wang, C. J. Medforth, J. E.
Miller, L. Evans, P. Li, J. A. Shelnutt, Chem. Mat.
2008, 20, 7434.
AUTHOR CONTRIBUTIONS
hesham hamad: Supervision. Ahmed M. M. Soliman:
Supervision. omar elhady: Supervision.

10 of 11
ALI EL-REMAILY ET AL.
[17] For reviews about metal catalysis in water, see: a) W. A.
Herrmann, C. W. Kohlpaintner, Angew. Chem. Int. Ed. Engl.
1993, 32, 1524–1544; Angew. Chem 1993, 105, 1588–1609;
b) P. Dixneuf, V. Cadierno (Eds), Metal-Catalyzed Reactions in
Water, Wiley-VCH, Weinheim 2013.
[43] E. Kolvari, M. A. Zulfigol, N. Koukabi, B. Shirmardi-
Shaghasemi, Chem. Pap. 2011, 65(6), 898.
[44] H. Mirzaei, A. Davoodnia, Chin. J. Catal 2012, 33, 1502.
[45] S. Ghosh, F. Saikh, J. Das, A. K. Pramanik, Tetrahedron Lett.
2013, 54, 58.
[18] a) C. J. Li, Acc. Chem. Res 2002, 35, 533.
[19] P. Dixneuf, V. Cadierno (Eds), Metal-Catalyzed Reactions in
Water, Wiley-VCH, Weinheim 2013.
[20] L. Stefan, H.-J. Xu, C. P. Gros, F. Denat, D. Monchaud, Chem.
Eur. J. 2011, 17, 10857.
[21] E. Rose, B. Andreoletti, S. Zrig, M. Quelquejeu-Etheve, Chem.
Soc. Rev. 2005, 34, 573.
[46] J. Safari, F. Azizi, M. Sadeghi, New J. Chem. 2015, 39, 1905.
[47] a) D. S. Rekunge, C. K. Khatri, G. U. Chaturbhuj, Tetrahedron
Lett 2017, 58, 1240; b) S. Mondal, B. C. Patra, A. Bhaumik,
Chem. Cat. Chem. 2017, 9, 1469.
[48] a) M. Tajbakhsh, H. Alinezhad, M. Norouzi, S. Baghery, M.
Akbari, J. Mol. Liq. 2013, 177, 44; b) S. K. Das, S.
Mondal, S. Chatterjee, A. Bhaumik, Chem. Cat. Chem. 2018,
10, 2488.
[22] S. Beigly, S. Ghiaee, S. A. Ebrahimi, M. Mahmoudian, Acta
Physiologica Hungarica 2004, 91, 111.
[49] a) M. A. A. El-Remaily, M. Elhady, Appl.Organometal.Chem.
2019, 33, 4989; b) M. A. A. El-Remaily, O. M. Elhady, Tetrahe-
dron Lett. 2016, 57, 435; c) M. A. A. El-Remaily, H. A. Hamad,
J. Mol. Catal. A: Chem. 2015, 404, 148; d) M. A. A. El-Remaily,
A. M. Abu-Dief, Tetrahedron 2015, 71, 2579; e) M. A. A.
El-Remaily, Tetrahedron 2014, 70, 2971; f) M. A. A.
El-Remaily, Chin. J. Catal. 2015, 36, 1124; g) A. M. M.
Soliman, S. K. Mohamed, M. A. A. El-Remaily, H.
Abdel-Ghany, Eur. J. Med. Chem. 2012, 47, 138; h) M. A. A.
El-Remaily, S. K. Mohamed, Tetrahedron 2014, 70, 270;
i) M. A. A. El-Remaily, A. M. Abu-Dief, O. M. Elhady, Appl.
Organometal. Chem. 2019, 33, 5005; j) M. A. A. El-Remaily,
A. M. Abu-Dief, M. Rafat, El-Khatib. Appl. Organometal.
Chem. 2016, 30, 1022; k) M. A. A. El-Remaily, A. M. M.
Soliman, O. M. Elhady, ACS Omega 2020, 5, 6194; l) A. M.
Abu-Dief, N. M. El-Metwaly, S. O. Alzahrani, F. Alkhatib,
M. M. Abualnaja, T. El-Dabea, M. A. A. El-Remaily, J. Mol.
Liq. 2021, 326, 115277; m) M. A. A. El-Remaily, O. M. Elhady,
Chemistry Select 2020, 5(39), 12098; n) E. A. Ahmed, A. M. M.
Soliman, A. M. Ali, M. A. A. El-Remaily, Appl. Organometal.
Chem. 2021, 35, e6197. https://doi.org/10.1002/aoc.6197
[50] A. R. Katritzky, D. L. Ostercamp, T. I. Yousaf, Tetrahedron
1986, 42, 5729.
[23] M. Faizi, M. Janahmadi, M. Mahmoudian, Acta Physiolo Gica
Hungarica 2003, 90, 243.
[24] a) S. Sheik Mansoor, K. Aswin, K. Logaiya, S. P. N. Sudhan,
Arab. J. Chem 2017, 10, S546. https://doi.org/10.1016/j.arabjc.
2012.10.017 b) V. K. Sharma, S. K. Singh, RSC Adv. 2017, 7,
2682; c) M. George, L. Joseph, C. Joseph, Pharm. Innov.
2017, 6, 165.
[25] a) G. W. Zamponi, Nat. Rev. Drug Discov 2016, 15, 19; b) P. A.
Datar, P. B. Auti, J. Saudi Chem. Soc 2016, 20, 510; c) S. A.
Khedkar, P. B. Auti, Mini-Rev. Med. Chem 2014, 14, 282;
d) R. S. Kumar, A. Idhayadulla, A. J. A. Nasser, J. Selvin,
J. Serb. Chem. Soc. 2011, 76, 1.
[26] a) R. S. Kumar, A. Idhayadulla, A. J. A. Nasser, K. Murali,
Indian J. Chem. 2011, 50B, 1140; b) G. Swarnalatha, G.
Prasanthi, N. Sirisha, C. Madhusudhana Chetty, Int.
J. ChemTech. Res. 2011, 3, 75.
[27] D. L. Comins, S. O'Connor, Advances in Heterocyclic Chemistry
1988, 44, 199. https://doi.org/10.1016/S0065-2725(08)60263-9
[28] R. Kumar, R. Chandra, Advances in Heterocyclic Chemistry
2001, 78, 269. https://doi.org/10.1016/S0065-2725(01)78005-1
[29] R. Lavilla, J. Chem. Soc., Perkin Transactions 2002, 1, 1141.
https://doi.org/10.1039/B101371H
[30] J. Safari, S. H. Banitaba, S. D. Khalili, J. Mol. Catal. A: Chem.
2011, 335, 46.
[51] L.-M. Wang, J. Sheng, L. Zhang, J.-W. Han, Z.-Y. Fan, H.
Tiana, C.-T. Qian, Tetrahedron 2005, 61, 1539.
[31] A. Bamoniri, S. Fouladgar, RSC Adv. 2015, 5, 78483.
[32] E. Rafiee, S. Eavani, S. Rashidzadeh, M. Joshaghani, Inorg.
Chim. Acta 2009, 362, 3555.
[33] H. Adibi, H. A. Samimi, M. Beygzadeh, Catal. Commun 2007,
8, 2119.
[34] B. P. Reddy, K. Rajesh, V. Vijayakumar, Arab. J. Chem. 2011,
11. https://doi.org/10.1016/j.arabjc.2011.01.027
[35] S. M. Baghbanian, S. Khaksar, S. M. Vahdat, M. Farhang, M.
Tajbakhsh, Chin. Chem. Lett 2010, 22, 563.
[36] C. S. Reddy, M. Raghu, Chin. Chem. Lett 2008, 19, 775.
[37] L. Saikia, D. Dutta, D. K. Dutta, Catal. Commun. 2012, 19, 1.
[38] K. Purandhar, V. Jyothi, P. P. Reddy, M. A. Chari, K.
Mukkantid, J. Heterocycl. Chem. 2012, 49, 232.
[52] T. Momeni, M. M. Heravi, T. Hosseinnejad, M. Mirzaei, V.
Zadsirjan, J. Mol. Strut. 2020, 1199. 127011
[53] T. Demirci, B. Çelik, Y. Yıldız, S. Eris, M. Arslan, F. Sen, B.
Kilbas, RSC Adv. 2016, 6, 76948.
[54] M. M. Heravi, V. Zadsirjan, B. Fattahi, N. Nazari, Curr. Org.
Chem. 2016, 20, 1676.
[55] M. Hong, C. Cai, W.-B. Yi, Hafnium J. Fluorine Chem 2010,
131, 111.
[56] A. Davoodnia, M. Khashi, N. Tavakoli-Hoseini, Chin. J. Catal.
2013, 34, 1173.
[57] A. Debache, W. Ghalem, R. Boulcina, A. Belfaitah, S. Rhouati,
B. Carboni, Tetrahedron Lett. 2009, 50, 5248.
[58] B. Jahanbin, A. Davoodnia, H. Behmadi, N. Tavakoli-Hoseini,
[39] D. Bandyopadhyay, S. Maldonado, B. K. Banik, Molecules
2012, 17, 2643.
Bull. Korean Chem. Soc. 2012, 33, 2140.
ꢀ
[59] O. D'alessandro, A. G. Sathicq, J. E. Sambeth, H. J. Thomas,
[40] S. S. Mansoor, S. S. Shafi, S. Z. Ahmed, Arab. J. Chem. 2011.
https://doi.org/10.1016/j.arabjc.2011.09.018
[41] M. Tajbakhsh, E. Alaee, H. Alinezhad, M. Khanian, F. Jahani,
S. Khaksar, Chin. J. Catal. 33, 1517.
G. P. Romanelli, Catal. Commun. 2015, 60, 65.
[60] Y. L. N. Murthy, A. Rajack, M. T. Ramji, J. J. Babu, C.
Praveen, K. A. Lakshmi, Bioorg. Med. Chem. Lett. 2012, 22,
6016.
[42] R. Surasani, D. Kalita, A. V. D. Rao, K. Yarbagi, K. B.
Chandrasekha, J. Fluo. Chem. 2012, 135, 91.
[61] M. G. Dekamin, E. Kazemi, Z. Karimi, M. Mohammadalipoor,
M. R. Naimi-Jamal, Int. J. Biol. Macromol. 2016, 93, 767.

ALI EL-REMAILY ET AL.
11 of 11
[62] G. Song, B. Wang, X. Wu, Y. Kang, L. Yang, Synth. Commun.
2005, 35, 2875.
[63] M. Tajbakhsh, E. Alaee, H. Alinezhad, M. Khanian, F. Jahani,
S. Khaksar, P. Rezaee, M. Tajbakhsh, Chin. J. Catal. 2012, 33,
1517.
[74] A. Maleki, M. Kamalzare, M. Aghaei, J. Nanostruct. Chem.
2015, 5(1), 95. https://doi.org/10.1007/s40097-014-0140-z
[75] S. M. Vahdat, M. A. Zolfigol, S. Baghery, Appl. Organometal.
Chem. 2016, 30, 311.
[64] H. Mirzaei, A. Davoodnia, Chin. J. Catal. 2012, 33, 1502.
[65] P. Ramakanth, S. Maddila, V. D. B. C. Dasireddy, S. B.
Jonnalagadda, Catal. Commun. 2014, 45, 148.
[66] S. D. Sharma, P. Hazarika, D. Konwar, Catal. Commun.
2008, 9, 709.
[67] M. G. Dekamin, S. Ilkhanizadeh, Z. Latifidoost, H. Daemi, Z.
Karimi, M. Barikani, RSC Adv. 2014, 4, 56658.
[68] B. Zeynizadeh, S. Rahmani, E. Eghbali, Polyhedron.
2019, 168, 57.
[69] D. K. Yadav, R. Patel, V. P. Srivastava, G. Watal, L. D. S.
Yadav, Chin. J. Chem. 2011, 29, 118.
[70] U. Kusampally, N. Dhachapally, R. Kola, C. R. Kamatal,
Mater. Chem. Phys. 2020, 242, 122497.
SUPPORTING INFORMATION
Additional supporting information may be found online
in the Supporting Information section at the end of this
article.
How to cite this article: Ali El-
Remaily Mahmoud Abd El Aleem Ali, Hamad HA,
Soliman AMM, Elhady OM. Boosting the catalytic
performance of manganese (III)-porphyrin
complex MnTSPP for facile one-pot green synthesis
of 1,4-dihydropyridine derivatives under mild
conditions. Appl Organomet Chem. 2021;e6238.
https://doi.org/10.1002/aoc.6238
[71] A. Maleki, F. Hassanzadeh-Afruzi, Z. Varzi, M. S. Esmaeili,
Mater. Sci. Eng. C 2020, 109, 110502.
[72] S. U. Tekale, V. P. Pagore, S. S. Kauthale, R. P. Pawar, Chin.
Chem. Lett. 2014, 25(8), 1149. https://doi.org/10.1016/j.cclet.
2014.03.037
[73] J. S. Yoo, T. J. Laughlin, J. J. Krob, R. S. Mohan, Tetrahedron
Lett. 2015, 56(27), 4060. https://doi.org/10.1016/j.tetlet.2015.
04.121