Imidazolium chloride immobilized SBA-15 as a heterogenized organocatalyst for solvent free Knoevenagel condensation using microwave

Article abstract of DOI:10.1016/j.apcata.2011.11.008

Heterogeneous organocatalyst, 1-methyl-3-[(3-triethoxysilyl) propyl] imidazolium chloride [MTESPImCl] immobilized SBA-15 (ILS) was synthesized by co-condensation method using microwave irradiation in which 1-methylimidazole (Im) was modified by organosila

Full text of DOI:10.1016/j.apcata.2011.11.008

Applied Catalysis A: General 413–414 (2012) 205–212
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Applied Catalysis A: General
journal homepage: www.elsevier.com/locate/apcata
Imidazolium chloride immobilized SBA-15 as a heterogenized organocatalyst for
solvent free Knoevenagel condensation using microwave
Mst. Nargis Parvina, Hua Jina, Mohd. Bismillah Ansaria, Soon-Moon Ohb,∗∗, Sang-Eon Parka,∗
a Lab of Nano-Green Catalysis and Nano Center for Fine Chemicals Fusion Technology, Department of Chemistry, Inha University, Incheon, 402-751, South Korea
b Department of Sanitary and Environmental System Engineering, Gachon University of Medicine and Science, Incheon, 406-799, South Korea
a r t i c l e i n f o
a b s t r a c t
Article history:
Heterogeneous organocatalyst, 1-methyl-3-[(3-triethoxysilyl) propyl] imidazolium chloride [MTE-
SPImCl] immobilized SBA-15 (ILS) was synthesized by co-condensation method using microwave
irradiation in which 1-methylimidazole (Im) was modified by organosilane (3-chloropropyl triethoxysi-
lane). The ILS was thoroughly characterized by small angel XRD, N2 adsorption desorption isotherms,
TEM, SEM, TGA and FT-IR. The ILS showed 2D hexagonal short channeled disk type mesostructure which
can provide facile to-and-from diffusion of substrates and products with enhanced activity. This hetero-
genized organocatalyst ILS had been investigated for the Knoevenagel condensation reaction of different
aromatic and heteroaromatic aldehyde with ethyl cyanoacetate in solvent free conditions. The catalyst ILS
was found to be efficient to catalyze the condensation effectively leading the completion of the reaction
within 6 min using single mode microwave irradiation.
Received 17 September 2011
Received in revised form 4 November 2011
Accepted 7 November 2011
Available online 16 November 2011
Keywords:
Ionic liquid
1-Methyl-3-[(3-triethoxysilyl) propyl]
imidazolium chloride
Mesoporous SBA-15
Heterogeneous organocatalyst
Green method
© 2011 Elsevier B.V. All rights reserved.
1. Introduction
materials with various active sites had been extensively investi-
gated in recent decade [18]. The organo-functional modification of
Ionic liquids have achieved great attention as a green solvent [1]
in the fields of organic synthesis [2], nanoporous materials’ synthe-
sis [3,4], enzyme activation and catalysis [5] because of their unique
properties such as non-volatility, non-flammability, polarity, solu-
bility, and high thermal and chemical stabilities [6]. In the field of
catalysis, ionic liquids (ILs) play the role of solvents and organocat-
alysts. In general, organocatalysis uses small organic molecules,
composed of C, H, N, O, S and P atoms which play role as active
site however, their high cost, and difficulty in recyclability and in
the separation of products, cause limitations for their further appli-
cations at the industrial scale [7]. To overcome these shortcomings,
supporting or immobilizing of organocatalyst ILs onto the solid sup-
ports termed as heterogenized IL organocatalysts have become as
a green approach in their catalytic applications [8–15].
Since the discovery of ordered mesoporous silicates, a vari-
ety of ordered mesoporous materials with high surface area, large
pore volume and large pore size have been synthesized using dif-
ferent surfactant templating methods to expand their practical
applications in the area of heterogeneous organocatalysis by immo-
bilizing organic functionalities [16,17]. The modified mesoporous
mesoporous silica permits to tailor the surface properties, useful
for various applications in the heterogeneous catalysis [19]. Gen-
erally the synthesis of functionalized mesoporous materials have
two approaches: (1) the direct synthesis approach where in a silane
containing functional group of ionic liquid was added to the syn-
thetic mixture during the synthesis of mesoporous materials (2)
the second approach is by post grafting wherein the organosilane
is grafted after synthesis of mesoporous support [20,21].
Among the siliceous supports SBA-15 is promising candidate
for the immobilization of organocatalyst due to its high surface
area, porosity, uniform pore size distributions, and thermal sta-
bility [22]. In recent year our group reported several organic
functional groups such as primary and quaternary amine, sulfonic
acid, and amino acid (l-proline) functionalized mesoporous sil-
ica for organocatalytic applications in various reactions such as
Knoevenagel, Henry reaction, Claisen-Schmidt condensation and
diethyl malonate addition [23]. SBA-15 supported ionic liquids
such as 1-methyl-3-propylimidazolium chloride (MPImCl) and 1-
propylpyridinium chloride (PPyCl) ionic liquids have also been used
as heterogeneous catalysts providing high yields in Knoevenagel
condensation under solvent free conditions; however these are
associated with longer reaction times due to conventionally, con-
vective heating over heat baths or electric heating mantles, which
have major adverse effect to the environment as well as consump-
tion of energy for heating and cooling [24].
∗
Corresponding author.
Corresponding author. Tel.: +82 32 860 7675, fax: +82 32 872 8670.
E-mail addresses: smoh@gachon.ac.kr (S.-M. Oh), separk@inha.ac.kr (S.-E. Park).
∗∗
0926-860X/$ – see front matter © 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.apcata.2011.11.008

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Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
Over the past few years, the concept of speeding up ionic liquid-
bound chemistry by microwave irradiation has created a lot of
interest, for both academic as well as industrial communities [25].
In a number of publications, significant rate accelerations and very
high loadings for several solid-phase protocols have been reported,
with reaction times being reduced in some cases from hours to
few minutes. Despite these initial reports, the benefits associated
with this new technology have not been rigorously established,
since in many cases domestic household microwave ovens have
been employed, that do not allow the monitoring of temperature
or pressure profiles during irradiation experiments [26]. We have
demonstrated here the microwave flash heating, i.e., the very rapid
heating of the reaction mixture in combination with high reac-
tion temperatures. The initial studies on the microwave irradiation
are reported for its application toward synthetic chemistry and to
demonstrate the feasibility of carrying out such transformations
in a controlled and reproducible parallel fashion by using dedi-
cated reactor systems [27–30]. In continuation of our earlier studies
we here report our recent investigation on microwave mediated
morphosynthesis of MTESPImCl immobilized SBA-15 (ILS) as het-
erogeneous organocatalyst and its potential catalytic applications
toward Knoevenagel condensation under solvent free conditions.
Fig. 1. The powder XRD patterns of 2.5% ILS, 5% ILS, 7.5% ILS and 10% ILS.
were recorded by Nicolet 5700. The product was analyzed by gas
chromatography (GC) (Agilent 6890N, HP-5 capillary column, FID
detector) and GC–MS (Agilent technologies, GC6890N, MS5975).
2. Experimental
2.1. Materials
Chemicals 1-methylimidazole (99%), 3-chloropropyl tri-
ethoxysilane (95%), sodium metasilicate nonahydrate (98%) and
P123 (MW 5800) were purchased from Aldrich USA. Hydrochlo-
ric acid (37.6%) was purchased from DAE JUNG South Korea.
Dichloromethane and ethanol were purchased from Duksan South
Korea.
2.4. Knoevenagel condensation reaction
The Knoevenagel condensation reaction was carried out under
solvent free conditions at 120 ◦C using single mode microwave
(CEM). In a typical procedure, 1 mmol of aldehyde was added to
1 mmol of the active methylene compound, ethyl cyanoacetate
and 10 mg of the catalyst was mixed to the reactant mixture and
allowed to react for an appropriate time of 3–6 min at 120 ◦C under
microwave irradiation power 300 W. After completion of the reac-
tion, the reaction mixture was cooled at room temperature and
diluted by dichloromethane and then precipitated for quantita-
tive analysis. From the aqueous layer the catalyst was recovered
by filtration and dried at 100 ◦C on an oven for reuse. The reaction
product analysis was done by GC and further confirmed by GC–MS.
2.2. Synthesis procedure
The synthesis of 1-methyl-3-[(3-triethoxysilyl) propyl] imida-
zolium chloride (MTESPImCl) was carried out by reported method
[31]. This ionic liquid was synthesized by taking 1-methylimidazole
and chloropropyl silane in 1:1 molar ratio by keeping it at 70 ◦C
for 48 h under nitrogen atmosphere. 2.5 g P123 amphilic triblock
copolymer (EO20PO70EO20) was dissolved in 64 g of water at room
temperature followed by addition of 6.835 g of sodium metasilicate
and certain amount of MTESPImCl (IL) (IL to SiO2 molar ratio was
2.5%, 5%, 7.5% and 10%) under vigorous stirring until clear solution is
obtained. To this clear mixture 20.25 g of concentrated hydrochlo-
ric acid (37%) was added and the final mixture was stirred for 1 h at
40 ◦C. The resultant solution mixture was transferred to the teflon
vessel and aged at 100 ◦C for 2 h in microwave irradiation (300 W,
100%) under static conditions, Scheme 1. After microwave irradia-
tion the solid products were filtered, washed with distilled water
and finally dried at 60 ◦C. The template was removed by soxhlet
extraction using acidic ethanol for 24 h [31,32].
3. Results and discussion
3.1. Powder X-ray diffraction pattern
The ionic liquid functionalized SBA-15 were synthesized by co-
condensation under microwave irradiation with different ratios of
ionic liquid to SiO2 and small angle X-ray diffraction patterns are
recorded (Fig. 1) in order to understand the amount of ionic liq-
uid effecting orderness. The PXRD patterns showed well-resolved
peaks with very intense diffraction peaks at 2ꢁ = 0.8–0.9 and two
ordering peaks at higher degrees, which were indexed to the
1 0 0, 1 1 0, and 2 0 0 planes, characteristic of the long range order
and excellent textural uniformity of mesoporous materials with a
mesostructure of hexagonal space group symmetry (p6mm). It was
observed that the ratios of ionic liquid to silica affect the inten-
sity of the peaks corresponding to hexagonal orderness (1 1 0 and
2 0 0). The intensity of the order peaks decreased with an increase
in the ratios from 2.5% to 10% ILS. It is presumed that the increase
in MTESPImCl ratio may lead to minimize the interaction between
inorganic silica and organic surfactant due to the hydrophobic
nature of organosilane. It is well documented that during cooper-
ative self-assembly such weak interactions decreases the ordering
of the hexagonal geometry of the mesostructure [31].
2.3. Sample characterization
The low angle powder X-ray diffraction (XRD) patterns were
recorded on
a rigaku diffractometer using Cu K␣ radiation
˚
(ꢀ = 0.154 A). N2 adsorption desorption isotherms studies were con-
ducted on a Tri-Star at −196 ◦C. The surface area was calculated by
BET method and the pore parameters were calculated from adsorp-
tion branches by BJH methods. Scanning electron microscopy (SEM)
images were taken with Hitachi S-4200 at 15–20 kV. Transmission
electron microscopy (TEM) images were taken using a Philips CM
200 at 200 kV. The thermogravimetric analysis (TGA) was done
by Bruker 2010SA. The Fourier transformation IR (FT-IR) spectra

Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
207
P123 + H2O + Na2SiO3
OH
O
Cl-
N
Direct synthesis
MW, 2h, 100 oC
+
Si
N
Me
O
Cl-
N
O
(EtO)3Si
N
Me
Scheme 1. The synthesis route of ionic liquid functionalized SBA-15.
Table 1
Physicochemical properties of the extracted functionalized SBA-15 with ionic liquid
concentration in the initial mixture.
Catalysts
SBET (m2/g)
Total pore
Average pore
size (nm)
volume (m3/g)
2.5% ILS
5% ILS
7.5% ILS
10% ILS
664
535
468
418
0.98
0.91
0.64
0.42
8.6
8.51
8.12
5.72
Table 2
The thermogravimetric analysis of ionic liquid functionalized SBA-15.
Catalysts
Weight loss
(H2O, %)
Weight loss
(IL, %)
Amount of ILs
(mmol/g)
2.5% ILS
5% ILS
7.5% ILS
10% ILS
5.7
5.5
9.9
7.2
4.4
6.7
12.7
15.5
0.27
0.42
0.78
0.95
(BJH) method from the adsorption branches. It is observed that on
increasing the IL amount, the BET surface area, pore volume and
pore size were decreased due to presence of ionic liquid (Table 1).
In the case of 7.5% ILS (Fig. 2a), two steps desorption branches were
observed indicating the pore plugging effect. Plugging effect can
increase the stability of mesoporous silica and can provide con-
finement effect which has very superior catalytic activity [33,34].
3.3. TEM and SEM images analysis
The morphological features of IL immobilized SBA-15 were stud-
ied by TEM and SEM (Figs. 3 and 4) respectively. The SEM images of
ILS (Fig. 4) indicated a uniform particle size with hexagonal shape
for the directly synthesized organosilane modified ionic liquid
functionalized SBA-15 under microwave irradiation. The hexago-
nal shape depended on the different loading amount of ionic liquid
functionalized SBA-15. The shapes were changed from prism to
platelet like morphologies from 2.5%, 5%, 7.5% and 10% ILS. But the
platelet morphology became unclear and particles stacked heav-
ily when the amounts of IL were increased to 10%. Increasing
the amount of IL in the initial mixture of SBA-15, also decreased
the thickness from 500 nm to 300 nm, which controlled the mor-
phology of ILS and confirmed the formation of short channeled
mesoporous silica [31,35].
Fig. 2. The N2 adsorption–desorption isotherms (a) and pore size distributions (b)
of 2.5% ILS, 5% ILS, 7.5% ILS, and 10% ILS.
The TEM images revealed that the short channeled SBA-15 with
different loading of IL (Fig. 3) showed the high mesoscopic order.
This hybrid material displayed the hexagonal array of well ordered
one dimensional pore structure and honeycomb. The TEM images
of ILS also indicate the short channels are parallel to the thickness
which let to access the molecules easily [36].
3.2. N2 adsorption–desorption analysis
The mesoporous nature of the synthesized samples based upon
concentration of organosilane were studied by N2 adsorption des-
orption isotherms (Fig. 2). All samples showed type IV isotherms
with H1 hysteresis loop being characteristic for highly ordered
hexagonal mesostructures with uniform cylindrical channels. All
the isotherms presents a sharp adsorption step in the P/P0 region
from 0.4 to 0.8 which implied that the materials possess large
pore size with narrow distributions. This was further confirmed by
the pore size distributions calculated by Barrett–Joyner–Halenda
3.4. TG analysis
The amount of MTESPImCl in SBA-15 was determined without
air flow by the TGA. TGA of ionic liquid functionalized SBA-15 (ILS)
is depicted in Fig. 5 and the content of ionic liquid (MTESPImCl)
is given Table 2. The first step appeared at <150 ◦C because of the

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Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
Fig. 3. Transmission electron micrographs of the extracted SBA-15 short channeled mesoporous silica functionalized with different concentrations of MTESPImCl in the
initial mixture (a) 2.5% (b) 5% and (c) 7.5%.
loss of water, i.e., adsorbed water on the inner and outer surfaces
of ILS. The second step weight loss at 250–500 ◦C is probably due
to the decomposition of the immobilized ionic liquid (MTESPImCl)
moieties in SBA-15 (Table 2).
reaction. The base catalyzed Knoevenagel condensation reaction of
aromatic aldehyde and ethyl cyanoacetate (Scheme 2) was inves-
tigated in solvent free conditions through single mode microwave.
The reaction mixture was cooled at room temperature and diluted
by dichloromethane and then precipitated. Product analysis was
done by GC and GC–MS for conversion and selectivity. For recy-
cling of the catalyst, the catalyst was recovered from the aqueous
layer by filtration and was dried at 100 ◦C in an oven.
3.5. FT-IR
The FT-IR spectra of imidazolium based ionic liquid immobi-
lized mesoporous silica SBA-15 is depicted (Fig. 6.) characteristic
IR bands at 1380, 978, 798 and 615 cm−1 due to the Si–O stretch-
ing in Si–O–Si structure. The spectrum displayed vibration peaks
3.6.1. Influence of ionic liquid loading in SBA-15
at 1634 cm−1 and 1508 cm−1 which are attributed to C C and C
N
The condensation reaction between benzaldehyde and ethyl
cyanoacetate depicted that with an increase in the loading ratio of
ionic liquid to silica, increase in conversion with increase in selec-
tivity was observed (Table 3). The highest conversion was observed
in 7.5% ILS (81% conversion and 96% selectivity). The higher conver-
sion with higher selectivity in case of 7.5% ILS may be due to ordered
hexagonal short length platelet morphology which allows free flow
of reactant and products. The conversions and selectivities associ-
ated with 10% ILS were less in comparison with that of 5% and 7.5%
bonds of the aromatic ring of imidazole respectively. The adsorp-
tion band around 2978 cm−1 assigned to C–H stretching vibration
which confirms the presence of propyl groups of ionic liquid.
3.6. Activity test of the catalysts
It is aimed to evaluate the catalytic properties of ILS as an
environment friendly base catalyst for typical organic synthetic
Table 3
The effect of the loading amount of ionic liquid.
Catalyst
Time (min)
Temperature (◦C)
a,bConversion of
benzaldehyde %
bSelectivity of Ethyl
2-cyano-3-phenylacrylate %
2.5% ILS
5% ILS
7.5% ILS
10% ILS
Conventional-SBA-15
Blank
3
3
3
3
3
3
120
120
120
120
120
120
50
63
81
60
12
2
45
90
96
84
99
–
a
Reaction conditions: benzaldehyde (1 mmol), ethyl cyanoacetate (1 mmol), Catalyst weight: 10 mg, Time: 3 min, Temperature: 120 ◦C.
C analysis.
b

Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
209
Fig. 4. Scanning electron micrographs of the extracted SBA-15 short channeled mesoporous silica functionalized with different concentrations of MTESPImCl in the initial
mixture (a) 2.5% (b) 5% (c) 7.5% and (d) 10%.
Table 4
The effect of reaction temperature.
Catalyst
Temperature Time
a,bConversion of
Benzaldehyde %
bSelectivity of
Ethyl 2-cyano-3-
phenylacrylate
%
(◦C)
(min)
7.5% ILS
7.5% ILS
7.5% ILS
7.5% ILS
30
60
90
120
6
6
6
6
4.8
23
59
97
18
70
91
98
a
Reaction condition: Benzaldehyde (1 mmol), ethyl cyanoacetate (1 mmol), cat-
alyst weight: 10 mg, temperature: 30–20 ◦C, time: 6 min.
b
GC analysis.
3.6.2. The effect of reaction temperature
The effect of reaction temperature on the Knoevenagel conden-
sation was studied in the range of 30–120 ◦C for a representative
substrate, benzaldehyde using 7.5% ILS (Table 4). The rise in tem-
Fig. 5. The thermogravimetric analysis (TGA) of 2.5% ILS, 5% ILS, 7.5% ILS, and 10%
Table 5
ILS.
The effect of reaction time.
Catalyst Time (min) Temperature
(◦C)
a,bConversion of bSelectivity of Ethyl
Benzaldehyde %
2-cyano-3-
phenylacrylate
%
ILS. This may be due to the destruction of orderness and change
in morphology. In order to understand the effect of morphology
we have also tested conventional SBA-15 having long channel. The
conventional SBA-15 gave 12% conversions with 99% selectivity of
ethyl 2-cyano-3-phenylacrylate indicating that morphology of the
catalyst also plays an important role. A blank reaction of benzalde-
hyde and ethyl cyanoacetate conducted under identical reaction
condition did not show significant conversion (2%).
7.5% ILS 1.5
7.5% ILS
7.5% ILS 4.5
120
120
120
120
56
81
78
97
73
96
95
98
3
7.5% ILS
6
a
Reaction conditions: Benzaldehyde (1 mmol), ethyl cyanoacetate (1 mmol), cat-
alyst weight: 10 mg, time: 3 min, temperature: 120 ◦C.
b
GC analysis.

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Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
Table 6
Knoevenagel condensation reaction of aromatic aldehydes and ethyl cyanoacetate catalyzed by ILS (ionic liquid functionalized SBA-15).a
Entry
Substrate
Product
Time (min)
a,bConversion %
bSelectivity %
H
H
COOC2H5
O
1
6
97
99
CN
H
H
COOC2H5
O
2
3
3
6
83
98
99
99
CN
H
H
COOC2H5
CN
O
OH
OH
H
H
COOC2H5
CN
O
4
5
3
3
91
97
99
92
HO
HO
H
O
H
O
COOC2H5
O
CN
CH3
CH3
H
H
COOC2H5
O
6
7
3
6
82
89
87
99
CN
O
O
H3C
H3C
H
H
COOC2H5
O
CN
H
H
COOC2H5
O
8
9
3
3
90
80
86
99
CN
H
Cl
Cl
H
COOC2H5
O
CN
Cl
Cl
H
H
COOC2H5
O
10
3
99
98
CN
NO2
NO2
H
H
COOC2H5
O
11
12
3
99
96
99
70
CN
O2N
O2N
H
H
O
O
COOC2H5
O
1.5
CN

Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
211
Table 6 (Continued)
Entry
Substrate
Product
Time (min)
3
a,bConversion %
bSelectivity %
H
H
COOC2H5
O
13
14
92
91
CN
H
H
O
S
COOC2H5
COOC2H5
O
S
3
3
94
73
99
99
O
CN
CN
H
H
15
O
a
Reaction conditions: aldehyde (1 mmol), ethyl cyanoacetate (1 mmol), Catalyst weight: 10 mg, Temperature: 120 ◦C.
GC and GC–MS analysis.
b
It is presumed that the strong basic sites offered by modified imida-
zolium chloride groups and the rapid heating of reaction mixture by
the microwave could directly activate the reactants to form prod-
ucts. As the reaction time increased (1.5–6 min), the conversion
of benzaldehyde increased upto 97% (Table 5) 6 min was found
to be the best considerable time for higher conversion and higher
selectivity under the employed reaction conditions.
The study of Knoevenagel condensation reaction was then
extended to the several substituted aromatic and heteroaromatic
aldehydes using the ILS catalyst through microwave irradiation.
All the reactions occurred in solvent free conditions within 6 min
and gave ␣, ␤-unsaturated carbonyl compounds with selectivities
in range of 90–99% (Table 6). The Knoevenagel condensation of
aromatic aldehydes with both electron-withdrawing groups (such
as nitro –NO2) (entries 8–11) and electron-donating groups (such
as hydroxyl (–OH), methoxy (–OCH3)) (entries 3–7), gave higher
conversions (≥80%) with short time of 3–6 min with good selectiv-
ity. The heteroaromatic aldehyde like furfural, thiophenaldehyde
also provided appreciable conversions with 99% selectivity within
1.5–3 min.
3.6.4. Reusability studies of ILS
Fig. 6. The FT-IR spectra of ionic liquid functionalized SBA-15 with different con-
Reusability of the catalyst was tested by carrying out repeated
runs of the reaction of benzaldehyde using the catalyst, 7.5% ILS.
After each cycle the catalyst was filtered, washed with methylene
chloride and dried at 100 ◦C and then reused for the succes-
sive cycles. The reusability studies (Table 7) revealed that the
catalyst could recycle without any significant loss in its activity and
selectivity.
centrations 2.5% ILS, 5% ILS, 7.5% ILS and 10% ILS.
H
H
COOEt
COOEt
CN
120 oC, 10 mg cat
6 min
O
+
CN
(E)-ethyl 2-cyano-3-phenylacrylate
1 mmol
1 mmol
3.6.5. Plausible mechanism
Scheme 2. Knoevenagel condensation catalyzed by ILS.
Based on the above experimental results and with reference to
previous report [37], the following mechanism for ILS catalyzed
perature was found to be highly effective for the performance
of the catalyst for enhancing both conversion and selectivity.
At lower temperature 30 ◦C, the conversion of benzaldehyde
was 4.8% with 18% selectivity. There was regular increase in
conversion of benzaldehyde upto 97% and selectivity of ethyl 2-
cyano-3-phenylacrylate upto 98% with 6 min using microwave.
The higher temperature favored the formation of ethyl 2-cyano-
3-phenyacrylate with subsequent condensation of benzadehyde.
Table 7
The reusability test of 7.5% ILS.
Catalyst
Test
Time (min)
a,bConversion of
Benzaldehyde %
bSelectivity of Ethyl
2-cyano-3-
phenylacrylate
%
7.5% ILS
7.5% ILS
7.5% ILS
fresh
1 reuse
2 reuse
6
6
6
97
98
96
98
98
94
3.6.3. The effect of reaction time
The influence of reaction time over conversion and selectivity
was also studied (Table 5). The conversion of benzaldehyde (79%)
was found to be significant even with very short irradiation 1.5 min.
a
Reaction condition: benzaldehyde (1 mmol), ethyl cyanoacetate (1 mmol), tem-
perature: 120 ◦C, time: 6 min.
b
GC analysis.

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Mst.N. Parvin et al. / Applied Catalysis A: General 413–414 (2012) 205–212
H
Acknowledgements
COOEt
B-
Authors thank for financial support from National Research
CN
Foundation of Korea (NRF) grant funded by the Korea government
(MEST) (no. 2011-0001321) and MKE (Ministry of Knowledge Econ-
omy) for Nano Center for Fine Chemicals Fusion Technology.
COOEt
CN
H
B-H+
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4. Conclusions
In the present study ordered organo functionalized SBA-15 (ILS)
were synthesized by the co-condensations of MTESPImCl ionic liq-
uid and sodium metasilicate was carried out in the presence of
amphilic triblock co-polymer (P123) as a structure directing agent
under the acidic conditions. The morphologies of prepared sam-
ples were hexagonal short channeled with platelet type instead of
fibrous. The high loading ratio of ionic liquid to silica led to decrease
the ordered hexagonal mesoporousity of ILS. The performance of
the catalyst depended on loading ratio of the ionic liquid to silica.
ILS catalyst of 7.5% loading showed the optimum catalytic activity
for Knoevenagel condensation under the employed reaction con-
ditions. The catalyst has wide substrate scope from substituted
aromatic to heteroaromatic aldehydes within short reaction times
of 6 min in solvent free conditions. The reaction methodology of
this heterogenized organocatalyst was elegant, fast and efficient.
Further this protocol avoided the use of expensive, harsh chemi-
cals, and leads to high yields of products with very fast reaction
time in solvent free media. The catalyst can be easily recovered and
reused without loss of its catalytic activity and selectivity.
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