One-pot multicomponent green LED photoinduced synthesis of chromeno[4,3-b]chromenes catalyzed by a new nanophotocatalyst histaminium tetrachlorozincate

Article abstract of DOI:10.1039/d1ra00189b

Histaminium tetrachlorozincate nanoparticles are prepared, characterized and applied as an effective and recoverable photocatalyst in the one-pot, green and multi-component synthesis of various chromenes by the reaction of dimedone and/or 1,3-cyclohexaned

Full text of DOI:10.1039/d1ra00189b

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One-pot multicomponent green LED photoinduced
synthesis of chromeno[4,3-b]chromenes catalyzed
by a new nanophotocatalyst histaminium
tetrachlorozincate
Cite this: RSC Adv., 2021, 11, 19723
a
a
b
Behrooz Malekia and Alireza Salimi
*
Mahbube Jarrahi,
Reza Tayebee,
Histaminium tetrachlorozincate nanoparticles are prepared, characterized and applied as an effective and
recoverable photocatalyst in the one-pot, green and multi-component synthesis of various chromenes
by the reaction of dimedone and/or 1,3-cyclohexanedione, arylaldehyde and 4-hydroxycoumarin in high
yields under solventless conditions at ambient temperature. This new catalyst is characterized by FT-IR,
XRD, EDX, NMR, SEM and TEM techniques. The incorporation of histaminium ions into the framework of
2ꢀ
ZnCl4 significantly affected the photocatalytic activity of tetrachlorozincate such that good reusability
ꢀ
and recyclability are attained. Moreover, reactive species such as cO2 and hydroxyl radicals have proved
to be active species in the presented photocatalytic reaction. In addition, the hot filtration test confirms
enough stability of the photocatalyst and no significant leaching and destruction of the framework in the
course of the reaction. The major advantages of the presented methodology include easy work-up, cost
effectiveness, nontoxic nature, broad substrate scope, 100% atom economy, ease of separation, and
environment friendly reaction conditions. Finally, the catalyst could be reused many times without
significant loss of activity.
Received 9th January 2021
Accepted 19th May 2021
DOI: 10.1039/d1ra00189b
rsc.li/rsc-advances
many photochemical reactions and can effectively be consid-
ered as a green solution to reach a cleaner life. Therefore,
1 Introduction
chemists try to redesign the synthetic methods by focusing on
visible resources. Visible light has the potential to act as an
inexpensive, abundant, renewable, available source of energy,
and a non-polluting reagent for chemical synthesis. Therefore,
chemists have promoted photochemical reactions as an inter-
esting led in organic synthesis.8–10 Among many advantages of
photochemical reactions, traditional UV light sources have
signicant drawbacks including various technical complica-
tions, energy intensive nature, limited lifetime and consider-
able requirements due to dissipation of heat generated from the
light source. In addition, the energy of a UV photon is generally
in the range of carbon–carbon s bonds, which induces prob-
lematic complications and may result in various unwanted
photo induced decomposition reactions and the generation of
obscure optical polymeric materials on the reactor wall.11,12
However, most of these drawbacks can be solved by new
modications in reactor design and applying efficient LED
lights.13
The development of green and straightforward multi-
component reactions has attracted great deal of attention
from the environment point of view. Multi-component reac-
tions combine at least three reagents at the same time in
a single pot to generate intended products in a short reaction
time with enhanced atom economy. This interesting strategy
can serve as a preferred tool, which has gained attention for
traditional multi-step reactions and a new extension has
emerged in synthetic organic chemistry as well as in biological
scaffolds and the drug discovery eld.1–4 The principal reaction
parameters such as temperature, solvents and catalyst amount
strongly affect the selectivity, versatility and environmental
acceptability of a multi-component reaction.
Photochemical condensation reactions have been rst
explored in the early 20th century and opened useful strategies
in synthetic organic chemistry and extensive efforts are devoted
to various effective contributing experimental parameters
related to these types of transformations.5–7 There is no doubt
that light is a nonpolluting source of energy, which motivates
On the other hand, one fundamental impediment that limits
the development of photochemical processes is that most
organic molecules cannot absorb visible light. This issue
limited the application of photochemical reactions and moti-
vated the development of new effective visible light photo-
catalysts in chemical transformations.14 Commonly the applied
aDepartment of Chemistry, School of Sciences, Hakim Sabzevari University, Sabzevar,
96179-76487, Iran. E-mail: rtayebee@hsu.ac.ir
bDepartment of Chemistry, Faculty of Science, Ferdowsi University of Mashhad,
Mashhad, Iran
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visible-light driven photocatalysts have been classied into two histaminium tetrachlorozincate as an effective and recoverable
main families of organic and inorganic photosensitive mate- catalyst in the green, one-pot and multi-component synthesis of
rials. Organic visible light driven photocatalysts (sensitizers) are various chromene derivatives via the multi-component
commonly organic compounds, which involve aromatic rings or condensation of aromatic aldehydes with a suitable 1,3-dike-
conjugated unsaturated bonds that hold the irradiation energy tone and 4-hydroxycoumarin under solventless condition at
with the help of quantum vibrations.15 To achieve effective ambient temperature (Scheme 1). Herein, the used photo-
photocatalysts applicable in the visible spectrum of electro- catalyst can serve either as an electron-donor or acceptor in the
magnetic radiation, they should be colored and should consist catalytic route. The photoreactivity property originates from the
of common metal-free organic dyes, whereas the most repre- nature of the oxidized metal center and the reduced ligand.
sentative class of inorganic visible-light photocatalysts basically
involve metal oxide semiconductors, coordination complexes
2 Experimental section
2.1 Materials and methods
and some colored metal–organic frameworks.16
Chromene derivatives are essential oxygenated heterocyclic
Solvents and all materials were purchased from commercial
resources and utilized as received without any further puri-
cation. Histamine dihydrochloride (Sigma-Aldrich, >99%),
aromatic aldehydes (Merck, Fluka and Sigma-Aldrich, 98–99%),
dimedone (Sigma-Aldrich, >97%), 4-hydroxycoumarin (Fluka,
purum), and acetonitrile (Sigma-Aldrich, 99.8%) were used as
received. The performed LEDs were commercial and no cutoff
lter was used. Fourier transform infrared (FT-IR) spectra were
recorded on a Shimadzu 8700 Fourier transform spectropho-
tometer in the range 400 to 4000 cmꢀ1 with KBr pellets. UV-
visible spectra were recorded on a Photonix UV-visible array
spectrophotometer. X-ray diffraction (XRD) patterns were
acquired on a PHILIPS PW 1730 diffractometer with Cu Ka at 30
mA, 40 keV and a scanning rate of 3ꢁ minꢀ1 in the 2q domain
from 5 to 80ꢁ. Energy dispersive X-ray spectroscopy (EDS) was
performed with an Electron Probe Microanalyser JEOL JXA-8230
equipped with an energy dispersive spectrometer Bruker
QUANTAX 200. A Mira 3-MU eld emission scanning electron
microscope (FESEM) was used to investigate the morphology of
the synthesized nanomaterials. Particle size and further
morphology studies were performed on a TEM (Philips CM-200
and Titan Krios). NMR experiments were carried out on
a Bruker Avance DMX600 instrument operating at 400 MHz for
proton.
compounds that have emerged as important ingredients of
many biological active materials in drug chemistry and phar-
macology.17–19 Chromenes exist in various avonoids, tocoph-
erols and alkaloids, which exhibit diverse biological,20 anti-
cancer,21 anti-HIV,22 antialzheimer,23 anti-tumor,24 anti-bacte-
rial,25 anti-viral,26 anti-leishmanial,27 anticoagulant,28 antitu-
bercular,29 anti-inammatory,30 and anti-tubulin activities.31 In
addition, chromenes can activate the potassium channels and
may prohibit some reductases and some phosphodiesterases
and these compounds have been utilized as cosmetics,
pigments, biodegradable agrochemicals, colored optical lasers,
brighteners, and uorescence biomarkers.32–34 There are many
reports to synthesize varieties of chromeno[4,3-b]chromenes by
the reaction of different arylaldehydes with 1,3-dicarbonyls and
4-hydroxycoumarin in the presence of various catalysts such as
Ni(II)–bis(oxazoline),35 Fe3O4@SiO2–sultone,36 WO3/ZnO@NH2-
EY,37 and Zn(L-proline)2.38 Although most of these protocols are
effective, some of them have some disadvantages such as side
reactions, lengthy reaction time, tedious workup, high reaction
temperature, moderate yields and non-reusable mediators.
Therefore, development of novel synthetic green procedures is
of great interest in synthetic organic chemistry because of
environmental and economic concerns.
As photoredox catalysis obeys the general property of an
excited state that is both more easily reducible and oxidizable
than its corresponding ground states, herein and in continua-
tion of our previous reports on the green multi-component
synthesis of heterocycles,39–42 we report our ndings on using
2.2 Synthesis of histaminium tetrachlorozincate
Pure histaminium zinctetrachloride was prepared under sol-
vothermal conditions by mixing of histamine dihydrochloride
Scheme 1 The general route describing the desired photocatalytic condensation reaction by the mediation of histaminium tetrachlorozincate as
a photocatalyst.
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(0.21 g, 1.1 mmol) with ZnCl2 (0.06 g, 0.05 mmol) in warm
methanol (65 ꢁC, 13 mL). Aer mixing, the mixture was kept at
room temperature for 24 h without disturbance. Finally, the
resulting white precipitate was isolated, washed with deion-
2.3 General route for the synthesis of chromeno[4,3-b]
chromenes
To a 25 mL ask container, histaminium tetrachlorozincate (2
mg), benzaldehyde (100 mg, 1 mmol), dimedone (140 mg, 1
mmol) and 4-hydroxycoumarin (162 mg, 1 mmol) were added.
In the case of reactions with the solvent, acetonitrile (3 mL) was
ꢁ
ized water and dried in air at 70 C.
Fig. 1 XRD patterns of histamine (a), tetrachlorozincate anion (b) and histaminium tetrachlorozincate (c).
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used. Then, the mixture was irradiated with a visible green light- latter clearly indicated that the material was pure and no
emitting diode (LED) at room temperature in an open air impurity peaks were observed.
condition. Production of the desired chromene was monitored
3.1.1 XRD analysis. The wide-angle XRD patterns of hista-
by TLC and aer completion of the reaction, the reaction mine (a), tetrachlorozincate (b) and histaminium tetra-
mixture was quenched with H2O (3 mL) and the remained chlorozincate (c) are shown in Fig. 1. Free histamine exhibited
precipitate was dissolved in EtOAc. Then, the ethyl acetate layer several peaks at the 2q of 12.4, 16.9, 19.7, 21.1, 23.4, 26.4, 28.3,
was removed and the aqueous phase was extracted with ethyl 29.5, 34.0, 34.8, 35.5, 39.9, 48.5 and 51.2ꢁ (Fig. 1a). In addition,
acetate (3 ꢂ 3 mL). Finally, the combined organic layer was anionic tetrachlorozincate revealed many peaks at 17.4, 17.7,
dried on Na2SO4 and concentrated in a vacuum. The crude 22.3, 25.8, 27.1, 28.0, 29.4, 30.5, 32.5, 33.1, 36.1, 38.6, 39.3, 41.0,
product could be further puried through column chromatog-
raphy (100–200 mesh silica gel; EtOAc/hexane) to obtain the
pure products.
3 Results and discussion
3.1 Physicochemical properties and characterization of
histaminium tetrachlorozincate
Histamine (2-aminoethylimidazole) is a familiar, biocompatible
and pharmacologically important material which can be suit-
able as a good ligand due to its unique characteristics under in
vivo conditions and readily binds to several metal ions such as
nickel(II), cobalt(II), zinc(II) and copper(II) to form complexes
with moderate stability. Histamine free base involves an imid-
azole ring with an aminoethyl side-chain, which accepts
a proton to give a histaminium dication. The chemical structure
and morphology of the histaminium tetrachlorozincate photo-
catalyst were explored by means of SEM, EDX, FT-IR, NMR and
XRD. FT-IR is used as the most informative technique to
determine the surface interactions in the nanomaterial. More-
over, powder X-ray diffraction (XRD) can conrm the formation
of the histaminium tetrachlorozincate framework. The
morphology and particle size of histaminium tetrachlorozincate
were further conrmed by TEM, SEM and EDX analyses. The
Fig. 3 Schematic representation of histamine (a) and 1H NMR (b) and
Fig.
2 FT-IR spectra of (a) histamine and (b) histaminium
13C NMR (c) spectra of histaminium tetrachlorozincate.
tetrachlorozincate.
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Fig. 4 EDS pattern of histaminium tetrachlorozincate.
43.3, 44.1, 44.8, 45.1, 46.2 and 47.1ꢁ (Fig. 1b). Eventually, the C–H stretching of the alkyl group was detected by the peaks at
target composite nanomaterial showed the main peaks at the 2q 2895 and 2848 cmꢀ1. The bands at 1622 and 1517 cmꢀ1 are due
values of 16.5, 17.3, 18.8, 21.0, 23.8, 24.9, 25.0, 26.8, 28.1, 29.6, to the N–H bending and C–N stretching vibrations of the
30.2, 31.6, 34.1, 35.6, 36.8, 38.8, 41.6, 44.3 and 46.0ꢁ (Fig. 1c). imidazole ring, respectively.43 The FT-IR spectrum of hista-
Repeating XRD of this material under lower magnication minium tetrachlorozincate (Fig. 2b) is not signicantly different
showed the main peaks of 16.3, 24.8, 30.0 and 41.7ꢁ (inset of from that of histamine and only the peak at 717 cmꢀ1 conrmed
Fig. 1c). Comparison of these XRD patterns showed that the the incorporation of zinc into the material, which is related to
XRD of the new nanocomposite is mainly similar to that of Zn–Cl stretching.
tetrachlorozincate and histaminium ions had no signicant
3.1.3 NMR spectroscopy. There are three sites in histamine
effect on the crystal structure of anionic ZnCl42ꢀ. In addition, dihydrochloride, which can act as proton donating/accepting
the average crystallite size of histaminium tetrachlorozincate is
estimated by the use of Debye–Scherrer's equation (eqn (1)).
L ¼ 0.98 l/b cos q
(1)
where b is the excess width-line at the half-maximum of the
diffraction peak in radians, q is the Bragg angle in degrees, and
l is the wavelength. By calculation, an average crystallite size of
about 24 nm was attained for this nanophotocatalyst.
3.1.2 FT-IR spectroscopy. FT-IR spectroscopy was used to
dene the structure of the synthesized catalyst. As shown in
Fig. 2a, the peak at 3101 cmꢀ1 is assigned to the C–H stretching
of the imidazole ring in the histamine fragment. Secondary
amine N–H stretching mode was observed at 3012 cmꢀ1. The
Fig. 6 (a) UV-Vis absorption spectrum and (b) the corresponding Tauc
Fig. 5 SEM (a) and TEM (b) images of histaminium tetrachlorozincate. plot of histaminium tetrachlorozincate.
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(C3), 134.64 (C2) and 134.96 (C1). The 1H NMR spectrum of
histaminium tetrachlorozincate in D2O also revealed compa-
rable peaks at 3.11 (2H, t, CH2), 3.30 (2H, t, CH2), 7.35 (1H, s,
ring CH), and 8.61 (1H, d, ring CH) (Fig. 3b). The small up-eld
shi would be due to metal coordination. The 13C NMR of this
compound also exhibited 5 peaks at 22.24 (C5), 38.13 (C4),
117.13 (C3), 128.35 (C2) and 133.93 (C1) (Fig. 3c). The little line-
broadening would be due to a slow internal uctuation with
a timescale close to the NMR frequency.45
3.1.4 SEM/EDS analysis. Scanning electron micrography
and energy dispersive X-ray spectroscopy were used as bene-
cial methods to determine the morphology and chemistry of the
individual particles and bulk materials (Fig. 4 and 5). EDS
analysis claried the included elements and brought a quanti-
tative assessment of each element. This study conrmed the
atomic concentration% of carbon (44.7), nitrogen (16.6), chlo-
rine (29.3) and zinc (7.9) as the main elements of histaminium
tetrachlorozincate and the molecular formula of C5H11Cl4N3Zn
was recommended. In addition, the SEM image of this photo-
catalyst showed that the particles have an angular tile-shape
with a wide range of sizes (Fig. 5a). The TEM image of hista-
minium tetrachlorozincate revealed a mean particle size of
about 15–30 nm in most cases, which is in good agreement with
XRD results (Fig. 5b).
Table
1 Optimization of the light source in the condensation
reactiona
Entry Light source Light specication
Time (h) Yieldb (%)
1
2
3
4
5
6
Dark
—
2.5 W
2.5 W, lmax ¼ 535 nm
2.5 W, lmax ¼ 431 nm
2.5 W, lmax ¼ 695 nm
2.5 W, lmax ¼ 455 nm
3
3
3
3
3
3
Trace
24
57
46
43
White LED
Green
Blue
Red
Violet
42
a
Reaction conditions: benzaldehyde (1 mmol), dimedone (1 mmol),
and 4-hydroxycoumarin (1 mmol) with the photocatalyst (1 mg) under
an open atmosphere at RT in 3 mL acetonitrile. Yields refer to the
isolated product in all cases.
b
3.1.5 UV-visible spectroscopy. The UV-Vis absorption
spectrum of the photocatalyst was analyzed in order to inves-
tigate the viable mechanism involved in the effective visible
light absorption. The UV-Vis absorption spectrum of hista-
minium tetrachlorozincate in the region of 200–300 nm (Fig. 6a)
provided the band-gap edge, which may be ascribed to the
photo-excitation occurring from the valence band to the
conduction band. The optical band-gap of this sample was
estimated using the Tauc plot based on the extrapolation of the
linear slope to photon energy. The calculated band-gap energy
of histaminium tetrachlorozincate was found to be 2.8 eV. The
extrapolation plot of hv vs. (ahv)2 was applied to get the optical
energy band-gap (Eg) as shown in Fig. 6b. In this relation, the
analysis is performed based on the equation ahv ¼ A(hv ꢀ Eg)n,
where a, hv, Eg, and A refer to the absorption coefficient, light
frequency, band-gap, and a constant, respectively.46
Fig. 7 Effect of catalyst amount on the condensation reaction. The
reaction conditions are described in Table 1. The reaction time was 3 h
under solvent conditions (acetonitrile, 3 mL).
centers (Fig. 3a). The 1H NMR spectrum of histamine in CDC13
shows peaks at 3.21 (2H, t, CH2), 3.39 (2H, t, CH2), 7.43 (1H, s,
ring CH), and 8.70 (1H, d, ring CH).44 The 13C NMR of this
compound also shows 5 peaks at 30.40 (C5), 41.73 (C4), 118.00
3.2 Catalytic tests
3.2.1 Impact of the light source on the catalytic conden-
sation reaction. In order to derive the best conditions, a model
reaction was conducted using benzaldehyde (1 mmol), dime-
done (1 mmol), and 4-hydroxycoumarin (1 mmol) with the
photocatalyst (0.001 g) under solvent conditions (acetonitrile, 3
mL) against irradiation with a green LED (lmax ¼ 535 nm) (Table
1). The reaction mixture was set at room temperature in an open
air test tube equipped with a magnet. The desired product
chromeno[4,3-b]chromene was formed in good yield aer 3 h.
This experiment demonstrated that if we perform the reaction
under the dark conditions, only a trace amount of the product
would be obtained under the same conditions. In addition,
a green LED was effective and resulted in 57% yield. Moreover,
this condensation reaction was really a photocatalytic one
Fig. 8 Impact of temperature on the condensation reaction. The
reaction conditions are described in Table 1. The reaction time was 3 h
and 0.002 g of photocatalyst was used under solvent conditions
(acetonitrile, 3 mL).
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Fig. 9 Effect of time on the reaction progress. Benzaldehyde (1 mmol), dimedone (1 mmol), and 4-hydroxycoumarin (1 mmol) were reacted in
the presence of the photocatalyst (2 mg) under an open atmosphere at room temperature with a green LED in the absence of a solvent.
Table 2 Comparison of the catalytic activity of histaminium tetrachlorozincate with some reported catalysts in the synthesis of chromeno[4,3-b]
chromenea
Catalyst
Time (h)
Temp (ꢁC)
Solvent
Yield (%)
Ref.
Histaminium tetrachlorozincate (2 mg)
Eozin Y (2 mol%)
ZrO2 (10 mol%)
Fe(DS)3 (10 mol%)
CuFe2O4@SO3H (0.05 g)
Fe3O4@SiO2@(CH2)3OMoO3H (2 mg)
40 min
3.5
25 min
2
2.5
45 min
r.t.
r.t.
80
70
70
80
—
93
77
91
87
90
90
This work
CH3CN
H2O
H2O
EtOH
—
47
48
49
50
51
a
Benzaldehyde was used in all cases.
because of the trace yield obtained under the dark conditions.
Table 1 also shows that a green LED (lmax ¼ 535 nm) achieved
the best yield in comparison with other colors illuminating at
the same power and under similar reaction conditions.
3.2.2 Studying the impact of catalyst amount on the
condensation reaction. The condensation reactions were
carried out with different amounts of the photocatalyst in order
to optimize the exact quantity of the needed photocatalyst
under solvent conditions (Fig. 7). It was observed that 0.002 g of
the photocatalyst is appropriate to achieve the best yield of 83%.
However, a further increase in the catalyst amount had no clear
effect on the yield% and reaction time.
3.2.3 Role of reaction temperature. To improve the yield
and accomplish the best conditions, the effect of temperature
was also studied on the selected standard reaction of dimedone,
benzaldehyde and 4-hydroxycoumarin (Fig. 8). As shown,
yield% was a little decreased when the temperature increased
Fig. 10 Effect of some familiar scavengers on the reaction progress
under the standard reaction conditions (benzaldehyde (1 mmol),
dimedone (1 mmol), and 4-hydroxycoumarin (1 mmol) were reacted in
the presence of the photocatalyst (2 mg) under an open atmosphere at
room temperature with a green LED under solvent-free conditions
after 40 min). In all cases 1 ꢂ 103ꢀ M solution of the scavenger is used.
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Table 3 Substrate scope for the condensation of dimedone, benzaldehyde, and 4-hydroxycoumarina
Mp
Entry
Benzaldehyde
Diketone
Product
Yield (%)
Found
Reported56–58
1
94
211
208–210
2
93
222–224
220–222
3
73
134–135
133–135
4
5
72
76
190–191
219–220
187–189
218–220
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Table 3 (Contd.)
Mp
Entry
Benzaldehyde
Diketone
Product
Yield (%)
Found
Reported56–58
6
78
231–232
230–232
a
Reaction conditions: aldehyde (1 mmol), diketone (1 mmol), and 4-hydroxycoumarin (1 mmol) with the photocatalyst (2 mg) under an open
atmosphere at room temperature by irradiation with a green LED (2.5 W, lmax ¼ 535 nm). The reaction time was set at 40 min under solvent
free conditions. Yields refer to the isolated product in all cases.
from 25 to 55 ꢁC. Also, a further increase of temperature did not used for the preparation of chromeno[4,3-b]chromenes under
alter the yield. Therefore, the temperature of 25 ꢁC was kept as different conditions. Herein, the reaction yield of the performed
the best in all runs.
condensation reaction contrasted with those reported (Table 2).
3.2.4 Role of reaction time under solvent-free conditions. Compared to all mentioned catalysts, the presented method-
The impact of time was also researched to explore the minimum ology is a special case that offers a successful route for one-pot
time needed to reach the best yield under solvent-free condi- single-step synthesis of the intended products under very mild
tions. It is evident that the photocatalyst had shown good conditions under an open atmosphere at room temperature by
activity because of 65% yield attained aer 30 min. As shown in means of a green LED irradiation source. The comparison was
Fig. 9, 93% yield was reached aer 40 min under the above made based on the catalyst concentration, reaction time and
optimum conditions in the absence of a solvent.
yield%. Clearly, the present report gives rise to a few advantages
3.2.5 Superiority of the presented protocol over some re- like using an environmentally benign photocatalyst under
ported methodologies. As we know, some protocols have been ambient reaction conditions to achieve different chromenes.
3.2.6 Active species scavenging experiments. To identify
the principal active species involved in the photocatalytic route,
a number of scavenging experiments were conducted. p-Ben-
zoquinone (BQ) as an O2cꢀ scavenger,52 dichromate as an eꢀ
scavenger,53 EDTA as an h+ scavenger,54 and isopropyl alcohol
(IPA) as a scavenger for the hydroxyl free radicals55 were used
during the standard photocatalytic reactions. These series of
experiments established that all the used scavengers show
a signicant scavenging power with the order of BQ > IPA >
EDTA > potassium dichromate > no scavenger (Fig. 10).
However, it seems that the superoxide anion (O2cꢀ) is one of the
major involved components because of its crucial role in the
photocatalytic process. As a result, the superoxide radical-anion
and hydroxyl radical would be the main species involved in the
photocatalytic process.
Fig. 11 Yield% vs. reusability of histaminium tetrachlorozincate.
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Fig. 12 FT-IR spectra of (a) fresh histaminium tetrachlorozincate and (b) the reused material after the 5th run.
structure of histaminium tetrachlorozincate remained intact
(Fig. 12). Typical experiments were repeated to conrm the
reproducibility of the condensation reaction and the acquired
yields were repeatable within ꢄ5% alteration.
3.2.7 Synthesis of different chromeno[4,3-b]chromenes by
histaminium tetrachlorozincate. The versatility of the current
methodology was identied through the synthesis of a series of
chromeno[4,3-b]chromene derivatives using some aromatic
aldehydes (Table 3). Aromatic aldehydes with different electron
withdrawing/donating groups created the desired products in
acceptable yields. However, in agreement with previous reports,
aldehydes bearing electron withdrawing groups reacted a little
better than those with electron donating groups.
3.2.8 Studying the stability and reusability of histaminium
tetrachlorozincate. To study the stability and reusability of
histaminium tetrachlorozincate, the catalyst was detached from
the reaction mixture aer completion of the rst run via
a simple ltration. Then, the ltered catalyst was washed with
a copious amount of toluene and dried at room temperature
before the next run. The catalyst was examined for ve subse-
quent runs and good reusability was detected (Fig. 11). The yield
efficiency decreased from ꢃ93% in the rst run to ꢃ86% aer
the h run that indicates only a small deactivation. Moreover,
comparison of the infrared spectra of fresh histaminium tet-
rachlorozincate with that of the regenerated one aer the 5th
run proved the existence of principal characteristic bands
around 1200–1800 cmꢀ1, which clearly conrmed that the
3.2.9 Hot ltration test. A hot ltration experiment was
also performed to prove that the catalytic activity of the photo-
catalyst originates from histaminium tetrachlorozincate in the
reaction mixture and not from the leached or decomposed
fragments. For this purpose, 2 mg of histaminium tetra-
chlorozincate was added to a mixture of dimedone, 4-hydrox-
ycoumarin and benzaldehyde in acetonitrile and the reaction
was started for 1.5 h. In this part, the product yield was 52%.
Then, toluene was added, the photocatalyst was separated and
the reaction was continued for another 1.5 h with the ltrate.
Yield% was increased to only 57%; therefore, no signicant
increase in yield% proved the stability of the photocatalyst
during the reaction progress. Clearly, this experiment
conrmed that a 5% increase in yield% would be due to the
leached or decomposed fragments from the mother active
nanocomposite.
3.2.10 Suggesting a plausible reaction pathway. A feasible
mechanism is disclosed for the generation of chromenes cata-
lyzed by histaminium tetrachlorozincate, as shown in Fig. 13.47
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Fig. 13 A probable reaction pathway for the condensation reaction.
Formation of chromeno[4,3-b]chromene (i) occurs by conden- be converted into (g) by the mediation of the photocatalyst.
sation of the Knoevenagel product (d) attained from diketone Finally (h) undergoes a simple dehydration reaction and leads
and aromatic aldehyde. Thereaer, chromeno[4,3-b]chromene to the targeted molecule (i).
can be formed by the intra-molecular cyclization of the activated
Finally, to demonstrate the applicability of the presented
carbonyl group via elimination of a water molecule. 4-Hydrox- protocol, an experiment was planned on a gram scale under the
ycoumarin (c) is converted into a radical-cation (e) through optimized conditions (Scheme 2). Benzaldehyde (a) was reacted
a single electron transfer path. The radical-cation (e) undergoes with dimedone (b) and 4-hydroxycoumarin (c) to give the
a Michael type addition with b-dicarbonyl-enone (d) to furnish desired chromeno[4,3-b]chromene (d) in ꢃ85% under solvent
compound (f). Again at the same time, the intermediate (f) can free conditions in about 60 min.
Scheme 2 Demonstration of the practicality of the presented protocol.
© 2021 The Author(s). Published by the Royal Society of Chemistry
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CDCl3): 28.3, 29.3, 30.5, 34.7, 39.4, 51.3, 107.0, 113.3, 114.0,
115.7, 122.6, 124.2, 127.0, 128.2, 128.8, 130.9, 132.7, 136.4,
138.3, 149.5, 155.1, 163.2, 196.2.
3.3 Spectral data of some synthesized chromenes
3.3.1 10,10-Dimethyl-7-(4-nitrophenyl)-10,11-dihy-
drochromeno[4,3-b]chromene-6,8(7H,9H)-dione (Table 3, entry
ꢁ
1). Mp 208–210 C, FT-IR: 2932, 1718, 1650, 1605, 1528, 1459,
1342, 1177, 1098, 1031, 863, 761 cmꢀ1 1H-NMR (400 MHz,
.
4 Conclusions
CDCl3): 1.10 (s, 3H); 1.11 (s, 3H); 2.17 (d, J ¼ 16.3 Hz, 1H); 2.24
(d, J ¼ 16.3 Hz, 1H); 2.66 (d, J ¼ 18.2 Hz, 1H); 2.73 (d, J ¼ 18.2 Hz,
1H); 4.94 (s, 1H); 6.91 (d, J ¼ 8.8 Hz, 2H); 7.05 (d, J ¼ 8.8 Hz, 2H);
7.32–7.42 (m, 2H); 7.59 (t, J ¼ 8.3 Hz, 1H); 7.88 (dd, J ¼ 8.2 Hz, J
¼ 1.5 Hz 1H). 13C-NMR (100 MHz, CDCl3): 27.3, 29.4, 31.2, 32.7,
40.8, 50.6, 114.8, 115.0, 115.2, 115.3, 115.4, 117.0, 122.4, 124.4,
129.7, 129.9, 130.1, 130.3, 132.3, 162.0, 162.2, 163.0, 196.5.
3.3.2 10,10-Dimethyl-7-phenyl-10,11-dihydrochromeno
In conclusion, histaminium tetrachlorozincate is disclosed as
an effective and recoverable photocatalyst in the synthesis of
various chromeno[4,3-b]chromenes to achieve high yields under
solvent-less conditions at ambient temperature. This new pho-
tocatalyst is characterized by FT-IR, XRD, EDX, NMR, SEM and
TEM. It is found that incorporation of histaminium ions into
2ꢀ
the framework of ZnCl4
signicantly affected the photo-
catalytic activity of tetrachlorozincate and led to a recyclable
nanomaterial. The major advantages of the presented meth-
odology include easy and cheap preparation of the photo-
catalyst, simple work-up, nontoxic nature, broad substrate
scope and complete atom economy under environmental
friendly conditions in the presence of a simple green LED light.
We believe that this protocol will play an important role in
medicinal synthetic organic chemistry using a potent and
economic alternative to the preparation of target materials. This
protocol can be scaled up easily under mild conditions without
needing to add further additives; thus, this photocatalyst can
occupy a vital role among various introduced photocatalysts in
organic synthesis.
[4,3-b]chromene-6,8(7H,9H)-dione (Table 3, entry 2). Mp 220–
222 C, FT-IR: 2961, 1711, 1663, 1604, 1492, 1452, 1362, 1324,
ꢁ
1289, 1182, 1165, 1051, 1032, 892, 765 cmꢀ1. 1H-NMR (400 MHz,
CDCl3): 1.08 (s, 3H); 1.12 (s, 3H); 2.22 (d, J ¼ 16.3 Hz, 2H); 2.63
(d, J ¼ 16.3 Hz, 2H); 4.98 (s, 1H); 7.16 (t, J ¼ 7.3 Hz, 1H); 7.25 (t, J
¼ 7.5 Hz, 2H); 7.29 (d, J ¼ 7.7 Hz, 2H); 7.35–7.46 (m, 2H); 7.63 (t,
J ¼ 8.0 Hz, 1H); 7.85 (dd, J ¼ 8.0 Hz, J ¼ 1.9 Hz, 1H). 13C-NMR
(100 MHz, CDCl3): 27.2, 28.8, 32.0, 33.3, 40.3, 50.8, 105.0, 114.1,
115.3, 115.8, 120.1, 123.1, 125.3, 127.5, 128.5, 131.1, 140.3,
153.2, 153.7, 161.8, 196.2.
3.3.3 7-(4-Bromophenyl)-10,10-dimethyl-10,11-dihy-
drochromeno[4,3-b]chromene-6,8(7H,9H)-dione (Table 3, entry
ꢁ
3). Mp 133–135 C, FT-IR: 3077, 2961, 2873, 1707, 1687, 1614,
1
1572, 1487, 1266 cmꢀ1. H-NMR (400 MHz, CDCl3): 1.21 (2H,
CH3), 1.35 (t, 2H, CH2), 2.2 (t, 2H, CH2), 2.3 (t, 1H, CH), 7.15–
7.21 (m, 4H, aromatic), 7.2–7.8 (m, 4H, aromatic). 13C-NMR (100
MHz, CDCl3): 13.1, 19.5, 23.5, 58.4, 103.5, 104.9, 114.1, 118.7,
122.4, 123.9, 128.1, 129.1, 130.4, 130.4, 130.6, 131.0, 132.3,
138.4, 144.1, 152.7, 162.8, 165.8, 204.9.
Conflicts of interest
There are no conicts to declare.
Acknowledgements
3.3.4 10,10-Dimethyl-7-(4-methoxyphenyl)-10,11-dihy-
drochromeno[4,3-b]chromene-6,8(7H,9H)-dione (Table 3, entry
The work was supported by Hakim Sabzevari University.
ꢁ
4). Mp 187–189 C, FT-IR: 2957, 1726, 1661, 1607, 1508, 1455,
1359, 1301, 1252, 1183, 1168, 1140, 1034, 893, 765 cmꢀ1 1H-
.
References
NMR (400 MHz, CDCl3): 1.14 (s, 3H), 1.16 (s, 3H), 2.22 (m,
2H), 2.35 (m, 2H), 4.87 (s, 1H), 7.25 (d, J ¼ 7.6 Hz, 2H), 7.44 (d, J
¼ 7.6 Hz, 2H), 7.56 (m, 2H), 7.78 (t, J ¼ 8.0 Hz, 1H), 7.97 (d, J ¼
8.0 Hz, 1H). 13C-NMR (100 MHz, CDCl3): 27.0, 27.1, 28.4, 30.2,
37.0, 54.6, 106.3, 114.1, 114.1, 115.3, 123.0, 123.9, 128.3, 135.8,
136.2, 138.3, 143.9, 150.7, 153.1, 156.6, 158.1, 161.1, 195.9.
3.3.5 9,10-Dihydro-7-(3-nitrophenyl)-7H,11H-benzopyrano
[3,2-c]chromene-6,8-dione (Table 3, entry 5). Mp 218–220 ꢁC FT-
1 D. Insuasty, J. Castillo, D. Becerra, H. Rojas and R. Abonia,
Synthesis of Biologically Active Molecules through
Multicomponent Reactions, Molecules, 2020, 25(3), 505.
2 C. G. Neochoritis, T. Zarganes-Tzitzikas, K. Katsampoxaki-
¨
Hodgetts and A. Domling, Multicomponent Reactions,
“Kinderleicht”, J. Chem. Educ., 2020, 97(10), 3739–3745.
3 S. Zhi, X. Ma and W. Zhang, Consecutive multicomponent
reactions for the synthesis of complex molecules, Org.
Biomol. Chem., 2019, 17(33), 7632–7650.
IR: 3100, 2935, 1734, 1525, 1364 cmꢀ1 1H-NMR (400 MHz,
.
CDCl3): 2.07–2.22 (m, 2H), 2.40–2.55 (m, 2H), 2.77–2.86 (m, 1H),
2.92–2.98 (m, 1H), 5.08 (s, 1H), 7.37 (d, 1H), 7.42 (t, 1H), 7.46 (t,
1H), 7.64 (t, 1H), 7.96 (m, 2H), 8.05–8.07 (m, 2H).
´
4 C. S. Graebin, F. V. Ribeiro, K. R. Rogerio and
¨
A. E. Kummerle, Multicomponent Reactions for the
3.3.6 10,10-Dimethyl-7-(3-nitrophenyl)-10,11-dihy-
Synthesis of Bioactive Compounds, A Review, Curr. Org.
Syn., 2019, 16(6), 855–899.
drochromeno[4,3-b]chromene-6,8(7H,9H)-dione (Table 3, entry
ꢁ
6). Mp 230–232 C, FT-IR: 2973, 1718, 1657, 1608, 1526, 1352,
¨
5 B. Konig, Photocatalysis in Organic Synthesis-Past, Present,
1182, 1142, 1094, 1034, 1032, 818, 765 cmꢀ1. 1H-NMR (400 MHz,
CDCl3): 1.11 (s, 3H), 1.14 (s, 3H), 2.24 (d, J ¼ 15.6 Hz, 2H), 2.42
(d, J ¼ 16.3 Hz, 2H), 4.97 (s, 1H), 7.22 (t, J ¼ 7.6 Hz, 1H), 7.29 (d, J
¼ 7.5 Hz, 1H), 7.42 (d, J ¼ 7.7 Hz, 2H), 7.62–7.68 (m, 2H), 7.87 (t,
J ¼ 7.9 Hz, 1H), 8.06 (d, J ¼ 7.7 Hz, 1H). 13C-NMR (100 MHz,
and Future, Eur. J. Org. Chem., 2017, 1979–1981.
6 R. Tayebee, E. Esmaeili, B. Maleki, A. Khoshniat,
M. Chahkandi and N. Mollania, Photodegradation of
methylene blue and some emerging pharmaceutical
micropollutants with an aqueous suspension of WZnO-
19734 | RSC Adv., 2021, 11, 19723–19736
© 2021 The Author(s). Published by the Royal Society of Chemistry

View Article Online
Paper
RSC Advances
NH2@H3PW12O40 nanocomposite, J. Mol. Liq., 2020, 317,
13928.
avone derivatives preparation method and therapeutic
use, US Pat., 6965039B2, 2005.
7 Q. Q. Zhou, Y. Q. Zou, L. Q. Lu and W. J. Xiao, 21 S. F. Razavi, M. Khoobi, H. Nadri, A. Sakhteman, A. Moradi,
Visible-light-induced organic photochemical reactions
through energy-transfer pathways, Angew. Chem. Int. Ed.,
2019, 58(6), 1586–1604.
S. Emami, A. Foroumadi and A. Shaee, Synthesis and
evaluation of 4-substituted coumarins as novel
acetylcholinesterase inhibitors, Eur. J. Med. Chem., 2013,
64, 252–259.
8 B. Li, R. Tayebee, E. Esmaeili, M. S. Namaghi and B. Maleki,
Selective photocatalytic oxidation of aromatic alcohols to 22 Z. Q. Xu, M. G. Hollingshead, S. Borgel, C. Elder, A. Khilevich
aldehydes with air by magnetic WO3ZnO/Fe3O4. In situ
photochemical synthesis of 2-substituted benzimidazoles,
RSC Adv., 2020, 10(67), 40725–40738.
and M. T. Flavin, In Vivo anti-HIV activity of (+)-calanolide
a in the hollow ber mouse model, Bioorg. Med. Chem.
Lett., 1999, 9, 133–138.
9 S. Aguado, L. Casarrubios, C. R. de Arellano and M. A. Sierra, 23 C. Bruhlmann, F. Ooms, P. Carrupt, B. Testa, M. Catto,
Revisiting the photochemical synthesis of [FeFe]-
hydrogenase mimics, reaction optimization, mechanistic
study and electrochemical behaviour, RSC Adv., 2020,
10(50), 29855–29867.
F. Leonetti, C. Altomare and A. Cartti, Coumarins
Derivatives as Dual Inhibitors of Acetylcholinesterase and
Monoamine Oxidase, J. Med. Chem., 2001, 44, 3195–3198.
24 M. Suzuki, K. Nakagawa-Goto, S. Nakamura, H. Tokuda,
S. L. Morris-Natschke, M. Kozuka, H. Nishino and
K. H. Lee, Cancerpreventive agents. Part 5. Anti-tumor-
promoting effects of coumarins and related compounds on
epstein-barr virus activation and two-stage mouse skin
carcinogenesis, Pharm. Biol., 2006, 44, 178–182.
´
´
10 M. Hricovıni, J. Asher and M. Hricovıni, Photochemical anti–
syn isomerization around the–N–N [double bond, length as
m-dash] bond in heterocyclic imines, RSC Adv., 2020,
10(10), 5540–5550.
11 T. P. Yoon, Visible light photocatalysis, The development of
photocatalytic radical ion cycloadditions, ACS Catal., 2013, 25 S. Emami, A. Foroumadi, M. A. Faramarzi and N. Samadi,
3(5), 895–902.
Synthesis and antibacterial activity of quinolone-based
compounds containing a coumarin moiety, Arch. Pharm.,
2008, 341, 42–48.
12 C. George, M. Ammann, B. D'Anna, D. J. Donaldson and
S. A. Nizkorodov, Heterogeneous photochemistry in the
atmosphere, Chem. Rev., 2015, 115(10), 4218–4258.
13 K. Zeitler, Photoredox Catalysis with Visible Light, Angew.
Chem., Int. Ed., 2009, 48, 9785–9789.
26 J. Mori, M. Iwashima, M. Takeuchi and H. Saito, A synthetic
study on antiviral and antioxidative chromene derivative,
Chem. Pharm. Bull., 2006, 54, 391–396.
14 X. Yumeng, Y. Hong and L. Aiwen, Synthetic applications of 27 L. Firoozpour, N. Edraki, M. Nakhjiri, S. Emami, M. Safavi,
photoredox catalysis with visible light, Org. Biomol. Chem.,
2013, 11, 2387–2403.
15 M. R. N. Jagan and R. J. S. Corey, Visible light photoredox
catalysis applications in organic synthesis, Chem. Soc. Rev.,
2011, 40, 102–113.
16 B. Swagata, C. P. Suresh, F. Polycarpos, E. O. Kevin,
A. B. John and D. Dionysios, New Insights into the
Mechanism of Visible Light Photocatalysis, J. Phys. Chem.
Lett., 2014, 5, 2543–2554.
17 A. K. Sharma, J. Tiwari, D. Jaiswal, S. Singh, J. Singh and
J. Singh, Organophotoredox catalysis, Visible-light-induced
multicomponent synthesis of chromeno [4,3-b] chromene
and hexahydro-1h-xanthene derivatives, Curr. Organocatal.,
2019, 6, 222–230.
S. K. Ardestani, M. Khoshneviszadeh, A. Shaee and
A. Foroumadi, Cytotoxic activity evaluation and QSAR
study of chromene-based chalcones, Arch. Pharmacal Res.,
2012, 35(12), 2117–2125.
28 K. N. Venugopala, V. Rashmi, B. Odhav and
K. N. Venugopala, Review on natural coumarin lead
compounds for their pharmacological activity, Biomed. Res.
Int., 2013, e963248.
29 R. K. Nimesh, D. H. Dhaval, T. M. Prashant and
K. P. Saurabh, Synthesis and evaluation of in vitro
antitubercular activity and antimicrobial activity of some
novel 4H-chromeno[2,3-d]pyrimidine via 2-amino-4-phenyl-
4H-chromene-3-carbonitriles, Med. Chem. Res., 2011, 20,
854–864.
18 R. Tayebee, A. Pejhan, H. Ramshini, B. Maleki, N. Erfaninia, 30 K. Nitin, K. Sushil, G. Himanshu and P. K. Sharma, 3-
Z. Tabatabaie and E. Esmaeili, Equisetum arvense As an
abundant source of silica nanoparticles. SiO2/H3PW12O40
nanohybrid material as an efficient and environmental
Hydroxy-2-(substituted
derivatives- synthesis, spectral characterization and
pharmacological screening, WRJB, 2012, 1, 1–5.
phenyl)-4H-chromen-4-one
benign catalyst in the synthesis of 2-amino-4H-chromenes 31 K. Haider, S. Rahaman, M. S. Yar and A. Kamal, Tubulin
under solvent-free conditions, Appl. Organomet. Chem.,
2018, 32(1), 3924.
19 F. Javadi and R. Tayebee, TiO2/nanoclinoptilolite,
inhibitors as novel anticancer agents, An overview on
patents (2013-2018), Expert Opin. Ther. Pat., 2019, 29, 623–
641.
a recyclable and high efficient heterogeneous nanocatalyst, 32 N. Thomas and S. M. Zachariah, Asian J. Pharm. Clin. Res.,
for the synthesis of 2-amino-4H-chromene derivatives, Iran.
J. Catal., 2017, 7(4), 283–292.
20 J. P. Gesson, N. Fonteneau, M. Mondon, S. Charbit,
H. Ficheux and F. Schutze, Negma-Lerads, 7-carboxy-
2013, 6, 11–15.
33 M. K. Hussain, M. F. Khan, S. Khatoon, A. G. Al-Sehemi and
M. Saquib, Chromenes, Phytomolecules with Immense
Therapeutic Potential, InPlant-derived Bioactives, Springer,
Singapore, 2020, pp. 185–204.
© 2021 The Author(s). Published by the Royal Society of Chemistry
RSC Adv., 2021, 11, 19723–19736 | 19735

View Article Online
RSC Advances
Paper
34 V. Raj and J. Lee, 2H/4H-Chromenes-A Versatile Biologically
copper-doped Bi2WO6-induced sulfate radical-based visible
Attractive Scaffold, Fron. Chem., 2020, 8, 623.
light-Fenton reaction, RSC Adv., 2020, 10, 38024.
35 X. Yu, W. Lan, J. Li, H. Bai, Z. Qin and B. Fu, Enantioselective 47 A. K. Sharma, J. Tiwari, D. Jaiswal, S. Singh, J. Singh and
one-pot synthesis of 4H-chromene derivatives catalyzed by
a chiral Ni (ii) complex, RSC Adv., 2020, 10(72), 44437–44441.
36 M. P. Lati, F. Shirini, M. Alinia-Asli and M. A. Rezvani,
Fe3O4@SiO2-Sultone, A Novel and Recyclable Magnetic
J. Singh, Organophotoredox catalysis, Visible-light-induced
multicomponent synthesis of chromeno [4,3-b] chromene
and hexahydro-1h-xanthene derivatives, Curr. Organocatal.,
2019, 246, 222–230.
Nanocatalyst for the Efficient Synthesis of 3,
4
48 A. Saha, S. Payra and S. Banerjee, On water synthesis of
Dihydropyrano [c] Chromenes and 2-Amino-4H-Chromene
Derivatives, J. Nanosci. Nanotechnol., 2020, 20(2), 973–982.
37 R. Chen, Z. Jalili and R. Tayebee, UV-visible light-induced
pyran-chromenes via
catalyzed by uorescent t-zro2 nanoparticles, RSC Adv.,
2015, 5, 101664–101671.
a
multicomponent reactions
photochemical synthesis of benzimidazoles by coomassie 49 K. Pradhan, S. Paul and A. R. Das, Fe(DS)3, an efficient Lewis
brilliant blue coated on W–ZnO@NH2 nanoparticles, RSC
Adv., 2021, 11(27), 16359–16375.
38 B. Maleki, S. Babaee and R. Tayebee, Zn(L-proline)2 as
a powerful and reusable organometallic catalyst for the
acid-surfactant-combined catalyst(LASC) for the one pot
synthesis of chromeno[4,3-b]chromene derivatives by
assembling the basic building blocks, Tetrahedron Lett.,
2013, 54, 3105–3110.
very fast synthesis of 2-amino-4H-benzo [g] chromene 50 S. Vajar and M. Mokhtary, Nano-CuFe2O4@SO3H catalyzed
derivatives under solvent-free conditions, Appl. Organomet.
Chem., 2015, 29(6), 408–411.
39 N. Erfaninia, R. Tayebee, M. Dusek and M. M. Amini,
efficient one-pot cyclo-dehydration of dimedone and
synthesis of chromeno [4,3-b] chromenes, Polycyclic
Aromat. Compd., 2019, 39, 111–123.
Ethylene diamine graed nanoporous UiO-66 as an 51 F. Khosravian, B. Karami and M. Farahi, Synthesis and
efficient basic catalyst in the multi-component synthesis of
2-aminithiophenes, Appl. Organomet. Chem., 2018, 32(5),
e4307.
characterization of molybdic acid immobilized on
modied magnetic nanoparticles as a new and recyclable
catalyst for the synthesis of chromeno [4,3-b] chromenes,
New J. Chem., 2017, 41, 11584–11590.
40 R. Tayebee, A. F. Lee, L. Frattini and S. Rostami, H3PW12O40/
SBA-15 for the Solventless Synthesis of 3-Substituted 52 Z. Yin, M. Han, Z. Hu, L. Feng, Y. Liu, Z. Du and L. Zhang,
Indoles, Catalysts, 2019, 9(5), 409. Chem. Eng. J., 2020, 390, 124532.
41 R. Tayebee and M. Ghadamgahi, Solvent free one-pot multi- 53 S. Naraginti, Y. Li, Y. Wu, Ch. Zhang and A. Raj Upreti,
component synthesis of 3, 4-dihydropyrimidin-2(1H)-ones
catalyzed by mesoporous NH4H2PO4/MCM-41 as an
environmentally friendly, cheap, and effective catalyst,
Arab. J. Chem., 2017, 10, S757–S764.
Mechanistic study of visible light driven photocatalytic
degradation of EDC 17a-ethinyl estradiol and azo dye acid
black–phytotoxicity assessment of Intermediates, RSC Adv.,
2016, 6, 87246.
42 N. M. Ghohe, R. Tayebee and M. M. Amini, Synthesis and 54 X. Zheng, J. Yuan, J. Shen, J. Liang, J. Che, B. Tang, G. He and
characterization of mesoporous NbZr/KIT-6 as a productive H. Chen, J. Mater. Sci.: Mater. Electron., 2019, 30, 5986–5994.
catalyst for the synthesis of benzylpyrazolyl coumarins, 55 R. K. Sharma, B. Arora, S. Sharma, S. Dutta, A. Sharma,
Mater. Chem. Phys., 2019, 223, 268–276.
S. Yadav and K. Solanki, Mater. Chem. Front., 2020, 4, 605–
43 J. A. Collado and F. J. Ramfrez, Infrared and Raman Spectra
620.
of Histamine-Nh4 and Histamine-Nd4 Monohydrochlorides, 56 H. Emtiazi and M. A. Amrollahi, An Efficient and Rapid
J. Raman Spectrosc., 1999, 30, 391–397.
44 R. B. Stephen, W. G. Constance and L. M. Sharon,
Comparison of the Solid and Solution Conformations of
Access to the Synthesis of Tetrahydrochromeno[4,3-b]
chromene-6,8-dione Derivatives by Magnesium Perchlorate,
S. Afr. J. Chem., 2014, 67, 175–179.
Methapyriline,
Tripelennamine,
Diphenhydramine, 57 Y. K. Al-Majedy, A. A. Al-Amiery, A. A. H. Kadhum and
Histamine, and Choline. The 'Infrared-X-Ray Method for
Determination of Solution Conformations, J. Org. Chem.,
1976, 41, 2283–2288.
A. B. Mohamad, Efficient Catalyst One-Pot Synthesis of 7-
(Aryl)-10,10-dimethyl-10,11-dihydrochromeno[4,3-b]
chromene-6,8(7H,9H)-dione Derivatives Complemented by
Antibacterial Activity, BioMed. Res. Inter., 2016, 5891703.
45 M. B. Inoue, P. Oram, M. Inoue and Q. Fernando, Solution
1H NMR and X-ray crystal structures of Ca2+, Zn2+ and Cd2+ 58 R. Motamedi, S. Baghbani and F. F. Bamoharram, Catalytic
complexes with 12- and 13-membered macrocycles,
dioxotetraazacycloalkanediacetic acids, Inorg. Chim. Acta,
1996, 246, 401.
Method for Synthesis of Benzopyrano[3,2-c]chromene-6,8-
dione Derivatives by Heteropoly Acids, Syn. Commun.,
2012, 42(11), 1604–1612.
46 X. Zhong, W. T. Wu, H. N. Jie, W. Y. Tang, D. Y. Chen,
T. Ruan and H. P. Bai, Degradation of noroxacin by
19736 | RSC Adv., 2021, 11, 19723–19736
© 2021 The Author(s). Published by the Royal Society of Chemistry