Silver Nanoparticles Architectured HMP as a Recyclable Catalyst for Tetramic Acid and Propiolic Acid Synthesis through CO2 Capture at Atmospheric Pressure

Article abstract of DOI:10.1002/cctc.201901461

The recent advancement on the tailored synthesis of hypercrosslinked microporous polymer (HMP-2) has assembled significant concentration by the virtue of its adjustable porosity, operative design and absolutely ordering structure. This perfectly structured Ag NPs supported carbocatalyst (Ag-HMP-2) has been synthesized by Friedel-Crafts alkylation between 4,4′-Bis(bromomethyl)-1,1′-biphenyl and carbazole over anhydrous iron(III)chloride catalysis followed by the appending of the silver nanoparticles (Ag NPs) onto the material. The silver nanoparticle was decorated over the HMP-2 to prepare the corresponding catalyst (Ag-HMP-2). The characterization of the newly produced material has been conducted by N₂ adsorption/desorption studies, XPS, FE-SEM, transmission electron microscopy (TEM) and Powder X-ray diffraction (PXRD) methods. This microporous catalyst has spectacular activities for the production of tetramic acids from various types of propargylic amine derivatives at 60 °C under atmospheric carbon dioxide pressure. Parallel attempt on fixation of CO₂ was executed over terminal alkynes to synthesize propiolic acids under 1 atm pressure. The catalyst (Ag-HMP-2) exhibited sufficient recycling ability for the generation of tetramic acids and propiolic acids up to five catalytic runs without reduction in its catalytic activity.

Full text of DOI:10.1002/cctc.201901461

Accepted Article
Title: Silver nanoparticles architectured HMP as a recyclable catalyst
for tetramic acid and propiolic acid synthesis through CO2
capture at atmospheric pressure
Authors: Swarbhanu Ghosh, Aniruddha Ghosh, Sk Riyajuddin,
Somnath Sarkar, Arpita Hazra Chowdhury, Kaushik Ghosh,
and Sk. Manirul Islam
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: ChemCatChem 10.1002/cctc.201901461
Link to VoR: http://dx.doi.org/10.1002/cctc.201901461
A Journal of
www.chemcatchem.org

10.1002/cctc.201901461
ChemCatChem
FULL PAPERS
Silver nanoparticles architectured HMP as a recyclable catalyst for
tetramic acid and propiolic acid synthesis through CO2 capture at
atmospheric pressure
Swarbhanu Ghosha¥, Aniruddha Ghosha¥, Sk Riyajuddinb, Somnath Sarkara, Arpita Hazra Chowdhurya,
Kaushik Ghoshb*, Sk. Manirul Islama*
Abstract: The recent advancement on the tailored synthesis of
hypercrosslinked microporous polymer (HMP-2) has assembled
significant concentration by the virtue of its adjustable porosity,
operative design and absolutely ordering structure. This perfectly
structured Ag NPs supported carbocatalyst (Ag-HMP-2) has been
been conducted by N2 adsorption/desorption studies, XPS, FE-SEM,
transmission electron microscopy (TEM) and Powder X-ray diffraction
(PXRD) methods. This microporous catalyst has spectacular activities
for the production of tetramic acids from various types of propargylic
amine derivatives at 60oC under atmospheric carbon dioxide pressure.
Parallel attempt on fixation of CO2 was executed over terminal
alkynes to synthesize propiolic acids under 1 atm pressure. The
catalyst (Ag-HMP-2) exhibited sufficient recycling ability for the
generation of tetramic acids and propiolic acids upto five catalytic
runs without reduction in its catalytic activity.
synthesized
by
Friedel-Crafts
alkylation
between
4,4′-
Bis(bromomethyl)-1,1′-biphenyl and carbazole over anhydrous
iron(III)chloride catalysis followed by the appending of the silver
nanoparticles (Ag NPs) onto the material. The silver nanoparticle was
decorated over the HMP-2 to prepare the corresponding catalyst (Ag-
HMP-2). The characterization of the newly produced material has
In this regard some different procedures were examined to date
such as oxidative cyclization with hypervalent iodine
compounds,[11] reductive cyclization process with SmI2,[12]
cyclization of enantioselective nature through SmI2 mediated
coupling[13] and intramolecular aza-anti-Michael addition.[14] In
recent times the incorporation of the CO2 (responsible for global
warming, greenhouse gas) through incorporation it into reactive
organic compounds[15] has great potential to utilize the abundant
source of CO2 present in air. One such useful strategy in the CO2
fixation reactions has been reported describing the silver-
catalysed activation of alkyne followed by intramolecular
cyclization process.[16] The transformation of o-alkynylaniline
compounds into 4-hydroxyquinolin-2(1H)-one derivatives by
silver-catalyzed alkyne activation and cyclization of intramolecular
nature has been well-known.[15a]
Introduction
The incorporation of carbon dioxide and its catalytic conversion to
the valuable chemicals are extremely significant in the context of
reducing carbon dioxide (greenhouse gas),[1] green and economic
organic synthesis. Since carbon dioxide is an inexpensive, non-
hazardous and renewable abundant C1 source of valuable
organic chemicals.[2] Replacement of harmful and poisonous
carbon monoxide as a C1 source with CO2, is a sustainable and
greener movement towards the generation of carbonyl functional
group containing different essential chemicals.[3] Systematic
incorporation of CO2 on propargyl amine at atmospheric pressure
could provide one of the most vital constituent unit tetramic acid,
obtained from a group of naturally occurring products. The main
skeleton of tetramic acid moiety is derived from some significant
natural products, which is recognized to be important compound
for its efficiency in biological systems (Scheme 1). Decalin
comprises of tetramic acid frameworks and 4-hydroxy-2-
pyridones having good cytotoxic and antimicrobial activity were
isolated from the fungus Coniochaeta cephalothecoides collected
in Tibetan Plateau (Medog).[4] Spiroscytalin was separated from
the solid-phase cultures of the bioactive fungus Scytalidium
cuboideum.[5] For instance, discodermide retards the
development of Candida fungi,[6] and reutericyclin retards the
Unsaturated carboxylic acids are important substrates in
synthetic field of organic chemistry and are significant frameworks
in
a wide range of agrochemicals, natural products or
pharmaceutically relevant agents such as prandin, vancomycin,
lipitor, blopress, and many more compounds.[17] In this study,
Zhang et al. have published different schemes for CO2 capture of
alkyne derivatives.[18] Different metals was employed for these
methods reported in literature, among which Ag catalyzed paths
have established to be the most efficient for giving access to the
corresponding products in satisfactory conversions and huge
selectivity.[19-22]
But
these
procedures
have
different
development
of
Gram-positive
bacteria.[7] Additionally,
disadvantages because these reactions take place with
homogeneous catalysts making the purification or isolation and
recovery of the high-priced metal decorated catalysts very
complicated, or even unfeasible. The economic and
environmentally benign concerns related with the contamination
problems of biologically active agents are extremely vital when
dealing with huge scale-production and commercial methods.
Different catalytic systems of heterogeneous nature have been
developed for investigating organic transformations to solve
disadvantages related to the catalysts of homogeneous nature.[23-
spirotetramat was employed as an agricultural agent.[8] Majority of
the tetramic acids have been achieved by undergoing
rearrangement process through intramolecular Dieckmann
condensation[9] or amidation[10] in presence of base. Additionally,
a broad range of starting materials is essential and high
temperature is required in basic media.
[a]S. Ghosh, Dr. A.Ghosh, S. Sarkar, A. Hazra Chowdhury, Prof. S. M. Islam
Department of Chemistry, University of Kalyani ,Kalyani, Nadia, 741235, W.B.,
India. E-mail: manir65@rediffmail.com
28]
[b]Sk Riyajuddin, Dr. K. Ghosh
Although different Ag(I) salt catalyzed carbon dioxide
Institute of Nano Science and Technology, Mohali, Punjab-160062, India
E-mail: kaushik@inst.ac.in
Supporting information for this article is given via a link at the end of the
document. ((Please delete this text if not appropriate))
incorporation of alkynes are previously reported in literature but
there are just some publications on silver-catalysts of
heterogeneous nature in this regard.[29]
1
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
Furthermore, the design and generation of porous
Power X-ray diffraction analysis
functionalized catalytic systems having high surface area,
enormous capacity of CO2 uptake and porosity is a significant
part of quality research. A versatile range of microporous
substances, e.g. zeolites,[30] metal-organic frameworks (MOFs),[31]
imidazole based zeolitic frameworks[32] and porous organic
polymers (POPs)[33] have been broadly applied in CO2 fixation of
organic molecules to develop industrial and medicinal target
compounds. Potentially a group of functionalized microporous
organic polymers (HMP-1) can be build up by simple
polymerization of rigid monomeric unit by condensation, coupling
and followed by cyclization reactions. Later these carbon-based
microporous organic polymer catalysts has caught our eyes in the
Powder XRD pattern of Ag-HMP-2 catalyst has been revealed in
Figure 1. Microporous HMP-2 exhibited its unique wide diffraction
peaks appeared at 2=18-23 degree which demonstrated the
amorphous nature of the polymer. Magnificent surface area of the
nanomaterial is efficient to combine the NPs at surface of the
polymer with the assistance of N donor sites. The powder XRD
pattern of silver nanoparticles of Ag-HMP-2 is attributable to the
peak for face-centered cubic structure (Figure 1). Consequently,
Ag-HMP-2 nanomaterials displayed four extra diffraction peaks at
38.2°, 44.6°, 64.5° and 77.5o, it could be attributable to the (111),
(200), (220) and (311) sets of Miller indices respectively, and
could be assigned to fcc nanoparticle structures of silver.
Accordingly, the powder XRD pattern definitely confirmed that the
NPs of silver in Ag-HMP-2 are crystalline.[35]
context
of
catalytic
application
in
green
organic
transformations.[34]
This work elaborates a detail report on synthesis of well-
designed silver nanoparticle embedded modified carbocatalyst
HMP-2 by direct Friedel-Crafts alkylation between carbazole and
4,4′-Bis(bromomethyl)-1,1′-biphenyl using anhydrous FeCl3,
followed by the appending of highly sticky silver nanoparticles (Ag
Np) to achieve Ag-HMP-2 nanomaterial (Scheme 2). The tailored
material has been positively applied as a nanocatalyst in carbon
dioxide incorporation into propargylic amines and terminal
alkynes at atmospheric pressure.
Figure 1. Powder XRD pattern of modified HMP-2 and Ag-HMP-2 nanomaterial.
Scheme 1. Bioactive agents having tetramic acid skeletons.
Results and discussion
Characterization of Ag-HMP-2 nanomaterial
The loading of silver in Ag-HMP-2 has been analyzed via the AAS
analysis and the observed loading of silver in the catalyst was
3.12 weight %. Elemental studies of Ag-HMP-2 by ICP-AES
experiments afforded Ag loading of 3.21 wt%. We have
conducted CHN analysis to check the content of hydrogen,
carbon and nitrogen in Ag-HMP-2 catalyst, where observed C =
79.43 %, H = 6.11 % and N = 4.19 %. The content of hydrogen,
carbon and nitrogen has been analyzed theoretically to be
88.41 %, 5.92 %, and 3.21 %, respectively.
Figure 2. The N2 adsorption/desorption isotherms of modified HMP-2, Ag-HMP-
2 and reused Ag-HMP-2. The diagram of distributions of pore size utilizing
NLDFT technique is demonstrated.
N2 adsorption/desorption analysis
The N2 adsorption/desorption isotherm of Ag-HMP-2 material is
demonstrated in Figure 2. As noticed from the plot that the N2
adsorption/desorption isotherm may be identified as combination
Scheme 2. Synthetic representation of the generation of modified HMP-2 and
Ag-HMP-2.
2
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
of type I and IV isotherms according to IUPAC convention.[36,37]
Firstly the slow uptake of nitrogen at 0 to 0.1 partial pressure P/P0
range implies the existence of micropores in Ag-HMP-2
nanomaterial, followed by regular rise in uptake of N2 in the partial
pressure P/P0 range 0.20 to 0.90 indicated the existence of
mesopores. These types of mesopores correspond to the porosity
of inter-particle system in the range of nanoscale. Surface area
obtained from BET (Brunauer, Emmett and Teller) and the entire
pore volume were 418 m2g-1 and 0.321 ccg-1, respectively for Ag-
HMP-2. With the help of NLDFT technique (non-local density
functional theory) the plot of distribution of pore size has been
depicted in Figure 2, where the diameter of pore for Ag-HMP-2
nanomaterial is 1.9 nm. The pore diameter of modified HMP-2
was appeared near the peak at 1.9 nm and has been fixed after
Ag loading in Ag-HMP-2.[34] The contribution of both mesoporosity
and microporosity to the entire surface area of Ag-HMP-2
nanomaterial using De Boer statistical thickness (t-plot) are
determined as 352 and 47.360 m2g-1, respectively.
(442), (600), (620) and (533) or more (hkl) in accordance with the
selection rule for the different kinds of fcc crystal models.
X-ray photoelectron spectroscopy analysis
A certain degree of chemical interaction including coordination
between the polymers and metal NPs can surely enhance the
catalytic activity and stability of metal NPs thereby evading
agglomeration and leaching from the polymeric networks. Further
insights into the evaluation of oxidation state and metal support
interaction were revealed from XPS measurements.To make
clear about the oxidation state of active silver centre and binding
sites with organic moiety XPS analysis has been conducted.
Figure 3 demonstrates the XPS spectrum of Ag-HMP-2 material
in narrow range, which implied the existence of different elements
C 1s (a), N 1s (b), and Ag 3d (c). Figure 3c exhibits the XPS
spectrum of silver 3d with two different binding energy values at
368.2 eV and 374.2 eV, related to two splitting components 3d5/2
and 3d3/2, respectively. This outcome indicated the existence of
zero oxidation state of Ag in Ag-HMP-2 material. The N 1s band
at 399.8 eV could be attributable to the existence of carbazole
moiety, which can bind through coordinate bond with the silver
centres. Figure 3d demonstrates the valence band (VB) XPS
spectra of silver-core, i.e., Ag 4d and Ag 5s bands. The XPS
spectrum of the N-1s core level of the Ag NPs architectured HMP
(Ag-HMP-2) indeed showed a positive displacement by 0.6, in
comparison with the as-prepared HMP, demonstrating strong
interaction between the N-rich HMP support and Ag-NPs.37b
Scanning electron microscopy (SEM) images and energy
dispersive X-Ray (EDX) analysis
Figure 3. Narrow range XPS spectra of Ag-HMP-2 nanomaterial containing
elements C 1s of Ag-HMP-2 (a), N 1s (b), Ag 3d (c), XPS valence band
spectrum (d) and full scale XPS survey spectrum of Ag-HMP-2 and HMP-2 (e
and f respectively)
In order to realize the morphology of Ag-HMP-2 nanomaterial,
field emission scanning electron microscopic study has been
performed. The SEM images of modified HMP-2 material are
demonstrated in figures S1. From figure S1 (d, e and f) it is
obvious that the Ag-HMP-2 have almost spherical particulate
materials with diameter of ca. 1-2 m. These particles of round
shaped are agglomerated to generate particles with larger
diameter and it results in inter-particle porosity as noticed from
the BET study. Moreover, the analysis of EDX (energy dispersive
spectroscopy of X-rays) also demonstrated the attachment of
silver nanoparticles on the solid matrix in Figure 5. High
resolution transmission electron microscopic (HR TEM)
analysis
HR-TEM images of Ag-HMP-2 nanomaterial are demonstrated in
Figure 4. The HR-TEM images suggest a comprehensive insight
on the morphology of the Ag NPs within the nanomaterial.
Material of spherical shape with particular morphology which is
interconnected is made clear in Fig. 4a. The dark coloured dots
present at the surface of the spherical shaped polymeric material
are owing to the existence of the Ag NPs on the surface of
modified HMP-2. It provided its lattice fringes with the inter-fringe
distance (0.236 nm) related to Ag (111) planes which
corresponds to silver crystalline nanomaterial of fcc model (Fig.
4b). Figure 4d indicates SAED pattern of Ag-HMP-2
nanomaterials. The possible indices (hkl) related to a fcc
structure of particular (hkl) indices, usually (111), (200), (220),
(311), (222), (400), (311), (420), (422), (333), (511), (440), (531),
Figure 4. The UHR-TEM images of Ag-HMP-2 at different scales (a) 0.2 m, (b)
2 nm, (c) 10 nm and (d) SAED pattern of Ag-HMP-2.
3
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
The circles of (111), (200), (220) and (311) indices are exactly
assigned and tried to correlate with the PXRD pattern (Figure 1).
The SEAD patterns are undoubtedly in agreement with the XRD
data despite the factor that the limit range of the XRD
measurement was less than 90o.
is favoured between N site of the chelating type polymer ligand
and Ag NPs which may promote the suitable binding of Ag NPs
on the HMP-2 polymer surface.37c
Figure 5. The EDAX pattern of Ag-HMP-2.
Figure 7. FT IR spectra of HMP-2.
UV-Vis DRS analysis
The UV-Vis diffuse reflectance spectrum of Ag-HMP-2 is
demonstrated in Figure
6 employing coatings of barium
sulphate (BaSO4) disk as a white reflecting diffusive agent. As
seen from this pattern that the adsorption hump of
hypercrosslinked microporous polymer in the UV-visible range
implied the transitions ofσ→σ* and π→π* for the presence of
aromatic rings.
Figure 8. FT IR spectra of Ag-HMP-2.
Thermal analysis
o
The thermogravimetric (TGA) study has been executed at 10 C
temperature ramp under the application of nitrogen flow up to
700 °C to explore the thermal stability of Ag-HMP-2 nanomaterial.
Figure
9
suggests the TG/DTA diagram for Ag-HMP-2
nanomaterial. The first loss of weight at ca. 80-110 oC
corresponds to the disappearance of adsorbed water from Ag-
HMP-2 polymeric surface. Additionally, the second loss of weight
was found in the temperature range of 250 to 430 °C owing to the
disintegration of functional substituents from the spherical shaped
particulate skeleton. The final loss of weight appeared at 490 °C
on account of the dissociation of remaining part of the catalyst.
The data of thermal analysis suggested the remarkable thermal
stability of Ag-HMP-2 nanomaterial upto 250 °C.
Figure 6. The DRS-UV-visible absorption spectrum of Ag-HMP-2 and reused
Ag-HMP-2.
FT-IR spectroscopy
The Fourier transform infrared spectroscopy of HMP-2 is quite
identical with those previously reported data. The prominent
1
peaks at ∼2911 cm− (phenyl −C−H) and ∼3438 cm-1 (carbazole –
N-H) apparently substantiate the generation of the
hypercrosslinked microporous polymer (Figure 7). The FT-IR
spectrum of the Ag-HMP-2 is demonstrated in Figure 8. The FT-
IR spectrum of Ag-HMP-2 showed a hump-shaped stretching
vibration at 3432 cm-1 due to carbazole N–H bonds (Figure 8).
The Ag-HMP-2 showed the important vibrational peak at 2910
cm-1 for phenyl –C-H bonds. The designed HMP-2 has a
microporous structure enriched with large number of nitrogen
atoms within the cavity generated by the hypercrosslinked
polymer. This modified heterogeneous polymer has an intensive
tendency to interact with the nm sized metal nanoparticles,
consequently it becomes favourable and compatible for fitting
silver nanoparticles, as shown in Scheme 2, Figure 4. The
carbazole –NH groups on the surface of HMP-2 may play an
important role in the adsorption and embedding of silver
nanoparticles. As manifested by the FTIR spectra of HMP-2 and
Ag-HMP-2 (Fig.7 and Fig. 8), the significant lowering of –NH
Figure 9. TGA-DTA profile diagrams of Ag-HMP-2 nanomaterial: (a) TGA and
(b) DTA.
Catalytic Activity
Tetramic acids synthesis catalyzed by Ag-HMP-2
stretching vibration approximately
6
cm-1 elucidating the
Conventional methods of tetramic acids synthesis are reported as
cyclization of intramolecular nature through amidation (Scheme 3,
eq. 1) or Dieckmann condensation (Scheme 3, eq. 2). These
techniques are well-known to generate tetramic acids.
Alternatively, different derivatives of starting agents come into
microporous structure of HMP-2 favours the non covalent type
interaction of –NH groups with Ag NPs. The spectra appeared in
Fig. 8, was a drop in stretching frequency for the N peak upon
nanoparticle grafting, while all the other peaks remain almost
unchanged. The coordination interaction within the nanocatalyst
4
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
play as a vital function and the method needs higher temperature
under the application of basic condition.
Firstly we have kept 2.6 mmol of 1-Phenylethynyl-
cyclohexylamine, 40 mg of Ag-HMP-2, 5 ml of MeCN and 5.2
mmol of NaOH at 0.1 MPa CO2 pressure. The end of the outcome
was lucrative as the achievement of 85 % oxazolidinone from
starting derivatized primary propargylic amines (Scheme 6).
Scheme 6. Generation of tetramic acid derivatives from carbon dioxide and
various functionalized propargylic amine derivatives by Ag-HMP-2.
Scheme 3. Conventional production of tetramic acid derivatives.
The required reaction parameters were optimized individually to
achieve the corresponding product optimization. Transformation
of the initial substrate depends entirely on the alkaline nature of
the reaction medium. Some common strong bases e.g. t-BuOK,
Na2CO3 and NaOH were not much successful for the generation
of tetramic acid, rather the resultant oxazolidinone was generated
in satisfactory conversion (Table 1, entries 1, 3 and 4). When
Et3N (poor alkai) was used, the corresponding tetramic acid was
not produced, but corresponding oxazolidinone was generated in
92% conversion (Table 1, entries 2). When DBU (organic alkali)
was utilized, the CO2 incorporation of propargylic amine was
carried out and resultant oxazolidinone transformed into the
desired product (tetramic acid) via intramolecular rearrangement
(Table 1, entries 5-9).
We have generated hypercrosslinked microporous polymeric (Ag-
HMP-2) nanomaterial and this has been suitably employed for the
CO2 fixation of several derivatized propargylic amine compounds
to prepare the corresponding tetramic acids.
The presented rearrangement was observed to be
appropriate for the cyclic agents composed of five atoms to
generate the desired tetramic acid derivatives from the
derivatized propargylic amines easily. As evident from the
previous reported works, fixation of CO2 into several propargylic
amine derivatives leads to the resultant oxazolidinone with Ag
catalyst under the application of base free condition (Scheme 4,
eq. 3). Ag(I) catalyst was reported to be an efficient catalyst for
cyclic CO2 capture of propargylic amine to desired tetramic acid
(Scheme 4, eq. 4 and eq. 5).15b,c The reaction was executed
under the application of a strong organic base medium and Ag
catalyst. The reaction mixture containing easily available and
common starting materials could undergo to generate a derivative
Table 1. Optimization of bases for the synthesis of tetramic acida
of
oxazolidinone
intermediates
later experiencing an
intramolecular rearrangement process to yield the corresponding
desired tetramic acid derivatives under ambient reaction
conditions (Scheme 5). The current work is an endeavour to
produce tetramic acids by means of an environmentally green
pathway involving CO2 capture in presence of Ag-catalyst and
after that an intramolecular rearrangement step.
Entry
Base
Solvent
Yieldb (%)
of 2a
Yieldb (%)
of 3a
1
2
3
4
5
NaOH
Et3N
MeCN
MeCN
MeCN
MeCN
MeCN
trace
trace
trace
trace
95
86
92
tBuOK
95
Na2CO3
DBU (1 equiv)
95
Negligible
6
7
8
9
DBU
DBU
DBU
DBU
MeCN
THF
97
86
91
97
Negligible
Negligible
Negligible
Negligible
Scheme 4. Fixation of carbon dioxide into several alkynyl amines.
DMF
Recently, we have started the CO2 capture of several derivatized
propargylic amines in the presence of Ag-HMP-2 with DBU
(strong organic base).
DMSO
aReaction condition: 1-Phenylethynyl-cyclohexylamine (2.6 mmol), carbon
dioxide (0.1 MPa), Alkali (5.2 mmol, 2 equiv.), temperature (60 0C), 20 h.
bIsolated yield.
The detail investigation of various solvents was carried out during
synthesis of tetramic acid (Table 1). The reaction was taken place
in THF solvent thereby leading to the product in 86% yield (Table
1, entry 8). Besides that the reaction was undergone at
atmospheric CO2 pressure in easily available dimethyl sulfoxide
(DMSO) instead of MeCN and devoid of any significant loss of
tetramic acid yield (Table 1, entries 9). Performance of the
reaction was smooth in DMSO, MeCN or DMF (polar aprotic
Scheme 5. Generation of tetramic acid derivatives from CO2 and various
functionalized propargylic amine derivatives.
5
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
solvent) to achieve the product in excellent amount. MeCN was
the ultimate prefer for solvent since it got separated from the
reaction mixture after keeping the pressure low.
3
4
5
6
1
1
2
2
20
20
20
6
50
60
60
60
64
96
97
90
26
Negligible
Negligible
Negligible
The crucial factor of Ag-HMP-2 on the synthesis of desired
products is demonstrated in Fig.10. When the reaction took place
in presence of Ag-HMP-2 (40 mg, 0.011903 mmol based on silver
metal), yield of the product was 97%. The reactions took place in
presence of 10 mg, 20 mg and 30 mg of Ag-HMP-2, and the
tetramic acid was generated in moderate conversion in 20 hours.
30 mg of Ag-HMP-2 could actively increase the rate of reaction to
produce the desired product in 78% conversion in 20 hours. The
reaction without Ag-HMP-2 provided the desired tetramic acid in
low yield despite longer reaction time. In conclusion, these data
would suggest Ag-HMP-2 should highly accelerate the reaction
and suppose to be significant to achieve the tetramic acid.
aReaction condition: 1-Phenylethynyl-cyclohexylamine (2.6 mmol), MeCN (5
ml), Ag-HMP-2 (40 mg, 0.011903 mmol based on silver metal), CO2 (0.1 MPa),
20 h. bIsolated yield.
The propargylic amine was converted into the corresponding
tetramic acid in 97% yield under the application of CO2 pressure
(1 atm) in presence of DBU in acetonitrile solvent (Table 3, 2a).
The propargylic amine bearing terminal alkyne provided product
in 54% yield (Table 3, 2b). The affecting factors of different
functional substituent on the ring in group R have been examined.
When aromatic ring was attached with an electron-attracting
group such as a nitro functional substituent at the para-position,
the reaction was quickly carried out to achieve the desired
tetramic acid in 95% yield (Table 3, 2c). An electron repelling
methyl substituent or methoxy substituent was employed as a
para substituent on the aromatic ring. Fixation of carbon dioxide
on these substrates was taken place and both were converted
into the final products, in satisfactory conversions (Table 3, 2d
and 2e).
Table 3. Generation of tetramic acid over Ag-HMP-2 under the
application of optimized conditionsa
Figure 10. Affecting factor of amount of catalyst on the generation of
corresponding tetramic acid from 1-Phenylethynyl-cyclohexylamine.
Additionally, optimization of important variables such as
temperature and time was investigated (Table 3). When
temperature of the medium was attempted to drop from 60 °C to
30 °C, the oxazolidinone was generated in satisfactory
conversion with tetramic acid, despite enhanced time of the
reaction and a higher proportion of DBU (Table 2, entries 1, 2 and
3). Consequently, carbon dioxide capture was come about at
60 °C to produce desired corresponding product in magnificent
yield in presence of 1 equivalent base (Table 2, entry 4). These
results recommend us to explain the intramolecular
rearrangement process of oxazolidinone is the rate determining
step, triggered by the elimination of amide proton. Finishing point
of the reaction was achieved in 20 h with 2 equiv of DBU under
the application of 60oC (Table 2, entry 5).
In order to conduct the proton elimination of the amide
system, the proportion of DBU was enhanced (Table 2). When
DBU (1.0 equiv) was employed in the medium, yield of the
corresponding tetramic acid was 96% (Table 2, entry 4). When
DBU (2.0 equivalents) was employed, the corresponding tetramic
acid was obtained in excellent amount (Table 2, entry 5 and 6).
By consuming 2 equiv. of DBU, time of the reaction was
shortened to 5 hours and 91% yield was achieved.
Table 2. Optimization of reaction for the synthesis of tetramic
aReaction conditions: Starting material (2.6 mmol), DBU (2.0 equiv), CO2
(0.1Mpa), Ag-HMP-2 (40 mg, 0.011903 mmol based on silver metal), MeCN (5
ml). bIsolated yields.
acida
Propargylic amines having no substitution on the propargylic
position could not provide the final product; instead the mixture of
complexes were produced. Under the application of optimized
condition as mentioned in Table 4, the different substituted
propargyl amines were examined with strong base DBU (1
equivalent) for various reaction time of the reaction at 25 oC
temperature. The transformation of starting agent into
oxazolidinone (intermediate) was carried out by catalytic CO2
capture in the presence of Ag-HMP-2 without DBU base.
Degassing is mandatory to undergo this procedure with the help
of freeze-deaeration process to eliminate the excess dissolved
CO2. Addition of DBU (1.0 equivalent) was performed to the
reaction mixture at 25 °C. This procedure was carried out by
subjecting the starting agent into the reaction system to achieve
the product in 93% conversion (Table 4, 2f). Propargylic amines
Entry
alkali
(equiv)
time
(h)
temperature
(oC)
Yieldb
(%)
(2a)
(3a)
1
2
1
1
42
42
30
40
39
52
31
66
6
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
bearing an electron repelling methyl substituent in either para-,
meta-, or ortho- position, conducted the reaction to give rise the
corresponding products in higher amount (Table 4, 2h, 2i and 2j).
amines in presence of Ag catalyst which produce the intermediate
(oxazolidinone) without any basic environments.
Propiolic acids synthesis catalyzed by Ag-HMP-2
Table 4. Generation of tetramic acid by employing Ag-HMP-2
catalyst under optimized reaction conditionsa
Later,
a
detailed and effective procedure for the
carbonylation[39-41] of aryl halides was developed utilizing CO as a
C1 source. On the other hand, CO is a poisonous gas and
subsequently investigation of the activity of the Ag-HMP-2
catalyst was performed for the CO2 capture of terminal alkynes
employing carbon dioxide as the C1 source. Preliminary
experiments were concentrated on speculative possibility of the
generation of 3-phenylpropiolic acid from carbon dioxide and
ethynylbenzene by optimizing several parameters of the reaction
that could be valuable to different kinds of derivatized terminal
alkynes. Chemoselectivity of the carboxylation depends on
conditions of the reaction, i.e. base, solvent, amount of the
catalyst, the nucleophilic character, and significantly CO2
pressure.
Scheme 7. Ag-HMP-2 catalyzed CO2 capture of terminal alkynes
In order to investigate the catalytic performance of Ag-HMP-2
nanomaterial, the carboxylation of terminal alkynes has been
examined (Scheme 8). In presence of atmospheric CO2 (balloon),
phenyl acetylene has been transformed into 3-phenylpropiolic
acid. Preliminary observation has been monitored on the
carboxylation reaction of phenyl acetylene in existence of Cs2CO3
basic medium in DMF solvent.
aReaction conditions: Starting agent (2.4 mmol), DBU (1.0 equiv), Ag-HMP-2
(40 mg, 0.011903 mmol based on silver metal), MeCN (5 ml), CO2 (1 atm).
bisolated product.
Scheme 8. Ag-HMP-2 catalyzed CO2 capture of 1-ethynylbenzene
Different kinds of solvents and bases are screened to achieve the
most appropriate conditions of the reaction (Table 5). In order to
identify the suitable environment of the reaction for facilitating the
carbon dioxide capture of terminal alkynes, the carboxylation is
accomplished under different reaction time and temperature
(Table 6). Additionally, the existence of an alkali could definitely
activate CO2 capture of terminal alkynes. Different kinds of
organic and inorganic bases were utilized to check the affecting
factor of alkali on the activity of the catalyst. Some category of
bases, such as K2CO3 and DBU were less important for this
carbon dioxide fixation of terminal alkynes. But tBuOK and
Cs2CO3 played a crucial role in the CO2 capture of terminal
t
alkynes. For BuOK the conversion is moderate (73%), whereas
for Cs2CO3 maximum conversion is found. We observed that Ag-
HMP-2 exhibited 98% conversion of the desired product through
CO2 capture of 1-ethynylbenzene at 80 C by employing Cs2CO3
Figure 11. Plausible mechanistic model for the generation of tetramic acid over
Ag-HMP-2.
0
as alkali in the solvent (DMF) (Table 5, entry 4).
With the help of earlier literature survey the Plausible mechanistic
model for the production of the tetramic acids is given in figure
11.[15b,38] The reaction was performed with a specific base and
Ag-HMP-2 would be expected to generate an intermediate
species (oxazolidinone) followed by an intramolecular
rearrangement to produce the tetramic acids at mild conditions
from easily available starting agents. The present work suggests
a novel procedure for the production of tetramic acids, which
relies on Ag-catalyzed carbon dioxide capture, followed by a
rearrangement of intramolecular pathway. This rearrangement
was typically appropriate to cyclic systems composed of five
atoms to assist the generation of corresponding tetramic acids
from different types of the propargylic amines of primary class.
CO2 capture has previously been known to involve the propargylic
Table 5. Screening of solvent and base on CO2 capture of 1-
ethynylbenzene
Entry
Solvent
Base
Yielda(%)
1
2
3
4
DMF
dioxane
DMF
tBuOK
Cs2CO3
DBU
73
59
41
98
DMF
Cs2CO3
7
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
5
6
7
DMF
DMSO
Toluene
K2CO3
Cs2CO3
Cs2CO3
27
Until now, the exploration on the effect of the AgNPs diameter on
the activity of the catalyst has mainly been limited to particles that
are larger than diameter of 10 nm. Nanoparticles of small
diameter (<10 nm) are most efficient compared to the
nanoparticles of large diameter owing to the quantum size effects.
It is restricted mainly to the complexity in the generation of AgNPs
of small diameter. Ag nanoclusters with controlled size of the core
have efficiently been produced so far which make it easy to
examine the activity of the silver-nanoclusters towards carbon
dioxide fixation of terminal alkynes. We have generated 10-25 nm
AgNPs and utilized HMP-2 as the solid support, which is
extremely porous in nature. So, very minute AgNPs can be lightly
decorated on the surface of the catalyst. This designed AgNPs
are observed to be extremely effective than its homogeneous
form. Additionally, HMP-2 cannot facilitate the process by
activating the terminal proton of alkynes and very trace
conversion was achieved. We have embedded AgNPs on the
HMP-2 and Ag-HMP-2 was found to be more efficient catalyst
since existence of very active AgNPs of smaller diameter. Thus,
Ag-HMP-2 catalyst could extremely be efficient and reusable for
the CO2 fixation reaction of terminal alkynes. The microporous
nature of HMP-2 material enhanced the uniqueness of the
catalyst. In order to ensure the extent of CO2 capture of terminal
alkynes, a variety of terminal alkynes were encountered with
carbon dioxide in solvent (DMF) in presence of Ag-HMP-2
catalyst. The experimental outcomes are listed in Table 7. As
exposed in Scheme 7, the reaction method may tolerate several
electronic and steric groups in the terminal alkynes, ensuing all in
satisfactory to excellent conversions.
56
Trace
Reaction conditions: 1-ethynylbenzene (1.0 mmol), Ag-HMP-2 (40 mg,
0.011903 mmol based on silver metal), Alkali (1.5 mmol), Carbon dioxide (0.1
MPa), temperature of the reaction (80 0C), solvent (5 mL), 12 h, aGC yield.
Several solvents are screened to verify the effect of solvent while
considering the CO2 capture of 1-ethynylbenzene as the model
carboxylation reaction. The carboxylation is carried out in different
solvents bearing polar character e.g. DMSO, dioxane and DMF.
DMF is most efficient among them (Table 5). Toluene as a
solvent did not participate well for this CO2 fixation reaction (Table
5, entry 7). Consequently, DMF is selected as a suitable solvent
for the CO2 capture of terminal alkynes. DMF (a mild base) is
recognized as an effective medium for Cs2CO3 as well as good
medium for capturing CO2.[42] Very low to satisfactory conversion
is observed at the temperature range of 30-50 0C (Table 6,
entries 1-3). In the present reaction, 800C temperature was
adjusted to be the most effective for the carboxylation reaction
(Table 6, entry 5). The conversion was reduced at the
0
temperature of 90 C. This is owing to fact that the intermediate
(Ag-propynoate) is unstable at higher temperature. The
decomposition of Ag-propynoate is due to decarboxylation at
higher temperature range. Additionally, the carboxylation reaction
was performed for several times adjusting from 5 h to 14 h and it
was observed that 98% conversion was achieved under the
application of given reaction conditions at 12 h.
Table 6. Screening of reaction time and temperature on CO2
capture of 1-ethynylbenzene
Table 7. Ag-HMP-2 catalyzed CO2 capture of terminal alkynes
with carbon dioxidea.
Entry
Time (h)
Temperature
(0C)
Conversion(%)a
1
2
3
12
12
12
30
40
50
32
61
71
4
5
6b
7c
8
12
12
12
12
12
70
80
80
80
90
78
98
38
trace
85
9
5
7
80
80
80
61
72
87
10
11
10
12
14
80
98
Reaction conditions: 1-ethynylbenzene (1.0 mmol), Cs2CO3 (1.5 mmol), DMF
(5 mL), Ag-HMP-2 (40 mg, 0.011903 mmol based on silver metal), CO2 (1.0
atm). aGC yields, bAg-NPs used instead of Ag-HMP-2, cHMP-2 (40 mg) used
instead of Ag-HMP-2.
The variation of conversion with respect to the amount of Ag-
HMP-2 has been examined (Figure 12). A rise in the amount of
Ag-HMP-2 from 10 mg to 50 mg results in a rise in the conversion
up to 98%. Further rise in amount of Ag-HMP-2 catalyst had no
reasonable influence on the conversion of the desired product.
aReaction conditions: substrate (1.0 mmol), Cs2CO3 (1.5 mmol), CO2 (0.1
MPa), Ag-HMP-2 (40 mg, 0.011903 mmol based on silver metal), DMF (5 mL),
80 0C.
Figure 12. Influence of quantity of the catalyst on CO2 capture of 1-
ethynylbenzene
The electron attracting and electron releasing groups on the
phenyl ring of substituted 1-ethynylbenzene had significant effect
on the substrate conversion and yield of the reaction.
Reaction conditions: 1-ethynylbenzene (1.0 mmol), Cs2CO3 (1.5
mmol), DMF (5 mL), Carbon dioxide (0.1 MPa), 80 0C, 12 h.
8
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
Phenylacetylene having either electron releasing or electron
attracting groups provided the corresponding caboxylative
products with excellent conversations. Both methyl and methoxy
as the electron releasing group or nitro as electron-attracting
group on the phenyl ring of phenylacetylene resulted in somewhat
lower yields than that of the conversion from 1-ethynylbenzene
(Table 7, 4b, 4c, 4e and 4g). Almost comparable conversions
were achieved with 1-ethynyl-4-nitrobenzene and 1-ethynyl-4-
methoxylbenzene. Generally, aromatic terminal alkynes bearing
an electron attracting substituent are deactivated and very inert
towards many conversions. With the electron attracting
substituent on the aryl ring, the reduced nucleophilicity at C1
carbon of the alkynes was achieved. Consequently, the
conversion of 4-nitro-1-ethynylbenzene was poor than that of 1-
ethynylbenzene (Table 7, 4e and 4a). The whole reaction is
dependent on three main steps; (i) Generation of the intermediate
(Ag-acetylide) from terminal alkynes in the existence of alkali and
this path is more favoured when excellent electron attracting
functional group is substituted on phenyl ring. (ii) Carbon dioxide
capture into the intermediate (Ag-acetylide) is the second path.
(iii) The 3rd path concerned with the attack of nucleophile at
intermediate (Ag-propynoate) to afford the corresponding
carboxylative product (after treatment with acid) and another
intermediate (Ag-acetylide) to finish the reaction cycle. Nowadays,
third path is slowed down when strong electron attracting
functional group is substituted on phenyl ring; alternatively, the
rate of the step 1 is reduced when excellent electron releasing
group is substituted on phenyl ring. Therefore, in our case
considerably releasing functional group (i.e. -Me) afforded the
higher product compared to strong releasing or attracting
substituent. For derivatized terminal alkynes this conversions
proceeded effortlessly without any by-product production.
Surprisingly, this procedure was applied to the 1,4-
diethynylbenzene (Table 7, 4d).
Heterogeneity test of Ag-HMP-2 catalyst
To check the heterogeneous nature of Ag-HMP-2 catalyst, we
have performed hot filtration test in this CO2 fixation reaction.
From this leaching limit study by AAS instrument we can
conclude that after the first reaction cycle, leaching of silver was
observed in negligible amount in ppm scale. The AAS analysis
recorded that after several reaction runs, a very negligible
quantity of silver was leached out in our experiment compared to
the other reported systems. For further confirmation we have
done ICP-AES analysis of the filtrate and the recovered catalyst.
We did not get any considerable metal trace in the filtrate and in
Ag-HMP-2 catalyst got same metal loading as that of fresh
catalyst (≈2.28 %). All these experimental data clearly confirmed
the heterogeneous nature of the Ag-HMP-2 together with one-pot
design in the catalyst synthesis.
Catalyst recycling
After the completion of the process the isolation of Ag-HMP-2
from the mixture was done with the help of centrifugation method.
Subsequently, washing of Ag-HMP-2 was conducted with distilled
water and propanone to remove impurities from Ag-HMP-2. It is
subjected to dry at 75 0C in air oven for 10 h. After that,
continuation of the next run was conducted under the application
of mild conditions. Ag-HMP-2 can be simply reused and
recovered for five times without any significant decay in
conversions which definitely suggests that Ag-HMP-2 is
completely heterogeneous in nature (Fig. 14). This outcomes
suggested excellent recycling ability of Ag-HMP-2 for the
generation of desired tetramic acids and propiolic acids.
The entire plausible mechanistic study for this carbon dioxide
capture has not been demonstrated yet. On the other hand,
based on reported works, a proposed mechanism of the reaction
is shown in Figure 13.43,44 For Ag-catalyzed activation of terminal
proton in terminal alkynes, Ag-acetylide is the key intermediate.
The activity of the Ag-carbon bond is high for CO2 capture
reaction. The intermediate (Ag-acetylide) (1) is generated via the
reaction of Ag-HMP-2 catalyst and the terminal alkyne in the
presence of alkali. The introduction of CO2 into the Ag-C bond of
polar nature will generate propynoate intermediate (2), in which it
will undergo metathesis with the alkyne under the application of
the alkaline conditions. This path would release desired propiolic
acid and regenerate Ag-acetylide (1). However, the intermediate
(2) is disintegrated at the temperatures of higher range. In this
system, Ag-propynoate (2) may be unstable over heat thereby
Figure 14. Recyclability chart of Ag-HMP-2 catalyst under the optimization
conditions.
Conclusion
In conclusion, Silver nanoparticles are efficiently decorated on a
hypercrosslinked microporous polycarbazole (Ag-HMP-2) and the
resulting catalyst can outstandingly facilitate the production of
tetramic acids and propiolic acids utilizing CO2. The crosslinked
polymer bearing nitrogen sites can bind the AgNPs at the surface
of the microporous polymer very tightly. The Ag-HMP-2 catalyst
can be recycled and reused several times without much decay in
its performance. Consequently, the procedure reported herein for
the generation of AgNPs-HMP-2 catalyst and its efficient
utilization in the CO2 capture under green conditions for the
production of tetramic acids from propargylic amine derivatives
and propiolic acid production from several terminal alkynes under
the application of atmospheric pressure may unlock new paths in
catalysis and environmental study in near future.
leading to regenerate the intermediate (1) during
decarboxylation.
a
Experimental
Synthesis of 4,4’-Bis(bromomethyl)-1,1’-biphenyl
20.04 g of Biphenyl and paraformaldehyde (15.6 g) were kept in a round-
bottom flask (500 mL), and 48% HBr (45.3 mL), 85% H3PO4 (25.9 mL),
and 33% HBr (51.75 mL) in acetic acid were then poured. The solution
was heated to 70 OC for 1 h under the application of nitrogen atmosphere.
After that, the temperature was increased to 110-130 OC for another 5 h,
after which the mixture was brought to RT. The solid materials were
separated through filtration, followed by washing with hexanes, and
subsequently subjected to crystallization from benzene/hexanes to provide
13.7 g (31%) of 4,4’-Bis(bromomethyl)-1,1’-biphenyl.45
Figure 13. Plausible mechanistic model for the production of
propiolic acid over Ag-HMP-2.
9
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
(f) J. H. Spatz, S. J. Welsch, D.-E. Duhaut, N. J. T. Boursier, M. Fredrich, L.
Allmendinger, G. Ross, J. Kolb, C. Burdack, M. Umkehrer, Tetrahedron Lett.
2009, 50, 1705-1707. (g) D. C. Dittmer, D. V. Avilov, V. S. Kandula, M. T.
Purzycki, Z. J. Martens, E. B. Hohn, M. W. Bacler, Arkivoc, 2010, 6, 61-83.
[10] (a) O. Igglessi-Markopoulou, and C. Sandris, J. Heterocycl. Chem. 1982,
19, 883-890. (b) P. G. Williard, S. E. de Laszlo, J. Org. Chem. 1984, 49, 3489-
3493. (c) O. Igglessi-Markopoulou, C. Sandris, J. Heterocycl. Chem. 1985, 22,
1599-1606. (d) W. R. Li, S. T. Lin, N. M. Hsu, M. S. Chern, J. Org. Chem. 2002,
67, 4702-4706.
Production of modified hypercrosslinked microporous polycarbazole
supported Silver nanomaterial (Ag-HMP-2):
The Friedel-Crafts alkylation reaction was conducted for generating
organic microporous polycarbazole.34 4,4′-Bis(bromomethyl)-1,1′-biphenyl
and carbazole conducts the Friedel-Crafts alkylation employing iron(III)
chloride as catalyst. In general 4,4′-Bis(bromomethyl)-1,1′-biphenyl (50
mmol) and carbazole (4.16 gm, 25 mmol) and FeCl3 (8.5 gm) were poured
in anhydrous DCE (dichloroethane) and allowed to stirr for 6 h under the
application of nitrogen atmosphere at RT. The temperature of the solution
was raised to 70 0C and allowed to reflux for 12 h. A precipitate (brown
color) was collected and to get rid of iron entirely the precipitate was then
subjected to wash with ethanol with the help of soxhlet apparatus, followed
by washing with acetone and hexane consecutively and then allowed to
dry out under the application of vacuum condition for overnight to achieve
modified HMP-2.
[11] L. Mao, Y. Li, T. Xiong, K. Sun, Q. Zhang, J. Org. Chem. 2013, 78, 733-737.
[12] W. J. Bai, S. K. Jackson and T. R. R. Pettus, Org. Lett. 2012, 14, 3862-
3865.
Impregnation of the Ag NPs were conducted by adding AgNO3 (100
mg) into water (10 ml) employing TRIS buffer (0.5 mmol). It was then
allowed to stir for 10 min after which dropwise addition of NaBH4 (0.25 ml,
0.08%) was performed. The resultant solution was allowed to stir for 10
min. The synthesized nanocolloid was cooled to 4 °C. Modified HMP-2
(500 mg) was dispersed in 10 ml solution of Ag NPs stabilized in TRIS.
After that, It was brought to normal temperature for 30 min under the
application of constant stirring. Ag-HMP-2 catalyst was separated after
performing centrifugation employing methanol as the washing solvent
(Scheme 2).
[13] C. P. Xu, P. Q. Huang, S. Py, Org. Lett. 2012, 14, 2034-2037.
[14] a) X. Bi, J. Zhang, Q. Liu, J. Tan, B. Li, Adv. Synth. Catal. 2007, 349, 2301-
2306. (b) Y. Li, X. Xu, J. Tan, P. Liao, J. Zhang, Q. Liu, Org. Lett. 2010, 12, 244-
247.
[15] (a) T. Ishida, S. Kikuchi, T. Yamada, Org. Lett. 2013, 15, 3710-3713; (b) T.
Ishida, R. Kobayashi, T. Yamada, Org. Lett. 2014, 16, 2430-2433; (c) H. Yang,
X. Zhang, G. Zhang, H. Fei, Chem. Commun. 2018, 54, 4469-4472; (d) S.
Ghosh, R. A. Molla, U. Kayal, S. M. Islam, Dalton Trans. 2019, 48, 4657-4666;
(e) K. Sekinea, T. Yamada, Chem. Soc. Rev. 2016, 45, 4524-4532.
[16] (a) M. Mikkelsen, M. Jorgensen, F. C. Krebs, Energy Environ. Sci. 2010, 3,
43-81; (b) M. S. Liu, K. Q. Gao, L. Liang, J. M. Sun, L. Sheng, M. Arai, Catal.
Sci. Technol. 2016, 6, 6406-6416; (c) V. B. Saptal, B. Nanda, K. M. Parida, B. M.
Bhanage, ChemCatChem. 2017, 9, 4105-4111; (d) M. M. Taherimehr, B. Van
de Voorde, L. H. Wee, J. A. Martens, D. E. De Vos, P. P. Pescarmona,
ChemSusChem. 2017, 10, 1283-1291; (e) P. Bhanja, A. Modak, A. Bhaumik,
Chem. Eur. J., 2018, 24, 7278-7297; (f) N. A. Tappe, R. M. Reich, V. D'Elia, F.
E. Kuehn, Dalton Trans. 2018, 47, 13281-13313.
Acknowledgement
SMI acknowledges Department of Science and Technology
(DST-SERB, project reference no. EMR/2016/004956) New Delhi,
Govt. of India, Board of Research in Nuclear Sciences (BRNS),
Project reference No: 37(2)/14/03/2018-BRNS/37003, Govt. of
India and Council of Scientific and Industrial Research (CSIR, Ref.
No. 02(0284)/16/EMR-II) New Delhi, Govt. of India for financial
support. AG is grateful to the funding agency SERB-NPDF, DST,
New Delhi, India (File No. PDF/2017/000478) for his National
Post Doctoral Fellowship. AHC is thankful to University of Kalyani,
India for her URS fellowship. We acknowledge the Department of
Science and Technology (DST) and University Grant Commission
(UGC) New Delhi, India for providing financial assistance to the
Department of Chemistry, the University of Kalyani under PURSE,
FIST and SAP program.
[17] C. X. Guo, B. Yu, J. N. Xie, L. N. He, Green Chem. 2015, 17, 474-479.
[18] D. Y. Yu, Y. G. Zhang, Proc. Natl. Acad. Sci. USA 2010, 107, 20184-20189.
[19] F. Manjolinho, M. Arndt, K. Goossen, L. J. Goossen, ACS Catal. 2012, 2,
2014-2021.
Keywords: Hypercrosslinked microporous polymer; Carbon
dioxide fixation reaction; Tetramic acids; Propiolic acids;
Heterogeneous catalysis.
[20] C. Liu, Y. Luo, W. Zhang, J. Qu, X. Lu, Organometallics 2014, 33, 2984-
2989.
[21] X. Zhang, W. Z Zhang, L. L. Shi, C. Zhu, J. L. Jiang, X. B. Lu, Tetrahedron,
2012, 68, 9085-9089.
References:
[1] J. Hu, J. Ma, Q. Zhu, Q. Qian, H. Han, Q. Mei, B. Han, Green Chem. 2016,
18, 382-385.
[22] K. Inamoto, N. Asano, K. Kobayashi, M. Yonemoto, Y. Kondo, Org. Biomol.
Chem. 2012, 10, 1514-1516.
[2] (a) Z. Ying, Y. Dong, J. Wang, Y. Yu, Y. Zhou, Y. Sun, C. Zhang, H. Cheng,
F. Zhao, Green Chem. 2016, 18, 2528-2533; (b) H. Cho, W. D. Kim, J. Yu, S.
Lee, D. C. Lee, ChemCatChem, 2018, 10, 5679-5688.
[23] M. K. Bhunia, S. K. Das, P. Pachfule, R. Banerjee, A. Bhaumik, Dalton
Trans. 2012, 41, 1304-1311.
[24] A. Modak, M. Pramanik, S. Inagaki, A. Bhaumik, J. Mater. Chem. A 2014, 2,
11642-11650.
[3] T. Fujihara, K. Nogi, T. Xu, J. Terao, Y. Tsuji, J. Am. Chem. Soc. 2012, 134,
9106-9109.
[25] A. K. Patra, A. Dutta, M. Pramanik, M. Nandi, H. Uyama, A. Bhaumik,
ChemCatChem. 2014, 6, 220-229.
[4] J. Han, C. Liu , L. Li, H. Zhou, L. Liu, L. Bao, Q. Chen, F. Song, L. Zhang, E.
Li, L. Liu, Y. Pei, C. Jin, Y. Xue, W. Yin, Y. Ma, H. Liu, J. Org. Chem. 2017, 82,
11474-11486.
[26] M. Pramanik, A. Bhaumik, ACS Appl. Mater. Interfaces 2014, 6, 933-941.
[27] K. Ghosh, R. A. Molla, M. A. Iqubal, S. M. Islam, Green Chem. 2015, 17,
3540-3551.
[5] K. Kempf, O. Kempf, M. Orozco, U. Bilitewski, R. Schobert, J. Org. Chem.
2017, 82, 7791-7795.
[28] (a) R. A. Molla, M. A. Iqubal, K. Ghosh, Kamaluddin, S. M. Islam, Dalton
Trans. 2015, 44, 6546-6559; (b) F. Xu, K. Meng, B. Cheng, J. Yu, W. Ho,
ChemCatChem, 2019, 11, 465-472.
[6] S. P. Gunasekera, M. Gunasekera, P. McCarthy, J. Org. Chem. 1991, 56,
4830-4833.
[7] A. Höstel, M. G. Gänzle, G. J. Nicholson, W. P. Hammes, G. Jung, Angew.
Chem., Int. Ed. 2000, 39, 2766-2768.
[29] X. H. Liu, J. G. Ma, Z. Niu, G. M. Yang, P. Cheng, Angew. Chem. Int. Ed.
2015, 54, 988-991.
[8] E. Brück, A. Elbert, R. Fischer, S. Krueger, J. Kühnhold, A. M. Klueken, R.
Nauen, J. F. Niebes, U. Reckmann, H.-J. Schnorbach, R. Steffens, X.
Waetermeulen, Crop Prot. 2009, 28, 838-844.
[30] C. S. Cundy, P. A. Cox, Chem. Rev. 2003, 103, 663-702.
[31] I. Senkovska, S. Kaskel, Chem. Commun. 2014, 50, 7089-7098.
[32] R. Z. Chen, J. F. Yao, Q. F. Gu, S. Smeets, C. Baerlocher, H. X. Gu, D. R.
Zhu, W. Morris, O. M. Yaghi, H. T. Wang, Chem. Commun. 2013, 49, 9500-
9502.
[9] (a) J. A. King, F. H. McMillan, J. Am. Chem. Soc. 1950, 72, 1236-1240. (b) S.
Larsen, J. Bernstein, J. Am. Chem. Soc. 1950, 72, 4447-4452. (c) R. N. Lacey,
J. Chem. Soc. 1954, 850-854. (d) S. V. Ley, S. C. Smith, P. R. Woodward,
Tetrahedron, 1992, 48, 1145-1174. (e) P. C. B. Page, A. S. Hamzah, D. C.
Leach, S. M. Allin, D. M. Andrews, G. A. Rassias, Org. Lett. 2003, 5, 353-355.
[33] Q. L. Zou, L. Zhang, X. H. Yan, A. H. Wang, G. H. Ma, J. B. Li, H.
Moehwald, S. Mann, Angew. Chem. Int. Ed. 2014, 53, 2366-2370.
10
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
[34] S. Bhunia, B. Banerjee, A. Bhaumik, Chem. Commun. 2015, 51, 5020-5023.
[35] A. Monshi, M. R. Foroughi, M. R. Monshi, Wjnse 2012, 2, 154-160.
[36] D. Chandra, N. Mukherjee, A. Mondal, A. Bhaumik, J. Phys. Chem. C.
2008, 112, 8668-8674.
[37] (a) A. Dutta, A. K. Patra, A. Bhaumik, Mircoporous Mesoporous Mater.
2012, 155, 208-214; (b) R. Singuru, K. Dhanalaxmi, S. C. Shit, B. M. Reddy, J.
Mondal, ChemCatChem, 2017, 9(13), 2550-2564; (c) G. Dutta, A. K. Jana, D. K.
Singh, M. Eswaramoorthy, S. Natarajan, Chem. Asian J. 2018, 13 (18), 2677-
2684.
[38] P. García-Domínguez, L. Fehr, G. Rusconi C. Nevado, Chem. Sci. 2016,
,
7, 3914-3918.
[39] S. M. Islam, K. Ghosh, A. S. Roy, R. A. Molla, RSC Adv. 2014, 4, 38986-
38999.
[40] S. M. Islam, K. Ghosh, A. S. Roy, R. A. Molla, N. Salam, T. Chatterjee, M.
A. Iqubal, J. Organomet. Chem. 2014, 772, 152-160.
[41] R. A. Molla, K. Ghosh, A. S. Roy, S. M. Islam, J. Mol. Catal. A: Chem.
2015, 396, 268-274.
[42] S. N. Riduan, Y. Zhang, J. Y. Ying, Angew. Chem., Int. Ed. 2009, 48, 3322-
3325.
[43] X. Zhang, W. Z. Zhang, X. Ren, L. L. Zhang, X. B. Lu, Org. Lett. 2011, 13,
2402-2405.
[44] B. Yu, Z. F. Diao, C. X. Guo, C. L. Zhong, L. N. He, Y. N. Zhao, Q. W.
Song, A. H. Liua, J. Q. Wang, Green Chem. 2013, 15, 2401-2407.
[45] A. Helms, D. Heiler, G. McLendon, J. Am. Chem. SOC. 1992, 114, 6227-
6238.
11
This article is protected by copyright. All rights reserved.

10.1002/cctc.201901461
ChemCatChem
Table of Contents
FULL PAPER
Swarbhanu Ghosh, Aniruddha Ghosh, Sk
Riyajuddin, Somnath Sarkar, Arpita Hazra
Chowdhury, Kaushik Ghosh, Sk. Manirul
Islam
Silver nanoparticles architectured HMP
as a recyclable catalyst for tetramic acid
and propiolic acid synthesis through CO2
capture at atmospheric pressure
CO2 fixation through the synthesis of tetramic acids from variety of
tetramic acids and propiolic acids: propargylic amines derivatives at
o
Ag NPs are decorated at the surface of 60 C and production of propiolic
a
modified
hypercrosslinked acids from terminal alkynes at 80
microporous polymer HMP-2 and oC under atmospheric CO2
resulting Ag-HMP-2 acts as a very pressure.
efficient catalyst for the synthesis of
12
This article is protected by copyright. All rights reserved.