SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from Ethylenediamine and Carbon Dioxide

Article abstract of DOI:10.1007/s10562-021-03728-z

In this work, a simple and facile approach is conducted for preparing many new SBA-15 supported dendritic imidazolium ILs heterogeneous catalysts SBA-15/IL(1–3) having high ionic density from SBA-15. SBA-15/IL(3) as a green heterogeneous catalyst can be used for synthesis of 2-imidazolidinone from ethylenediamine and carbon dioxide and considering solvent-free condition. SBA-15/IL(3) showed to have the highest catalytic activity besides a positive dendritic influence on the yields of the synthesis of 2-imidazolidinone in the presence of CO₂ is seen because of existing the high-density peripheral zwitterionic ionic liquid functional groups on the biobased SBA-15/IL(3) catalyst surfaces. Graphical Abstract: [Figure not available: see fulltext.]

Full text of DOI:10.1007/s10562-021-03728-z

Catalysis Letters
https://doi.org/10.1007/s10562-021-03728-z
SBA‑15 Supported Dendritic ILs as a Green Catalysts for Synthesis
of 2‑Imidazolidinone from Ethylenediamine and Carbon Dioxide
Qingwang Min1 · Penghua Miao1 · Jinghan Liu1 · Jianjun Ma1 · Meijuan Qi1 · Farzaneh Shamsa2
Received: 6 March 2021 / Accepted: 3 July 2021
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2021
Abstract
In this work, a simple and facile approach is conducted for preparing many new SBA-15 supported dendritic imidazolium
ILs heterogeneous catalysts SBA-15/IL(1–3) having high ionic density from SBA-15. SBA-15/IL(3) as a green heteroge-
neous catalyst can be used for synthesis of 2-imidazolidinone from ethylenediamine and carbon dioxide and considering
solvent-free condition. SBA-15/IL(3) showed to have the highest catalytic activity besides a positive dendritic infuence on
the yields of the synthesis of 2-imidazolidinone in the presence of CO2 is seen because of existing the high-density peripheral
zwitterionic ionic liquid functional groups on the biobased SBA-15/IL(3) catalyst surfaces.
Graphical Abstract
SBA-15 supported dendritic ILs as a green catalysts for
synthesis of 2-imidazolidinone from ethylenediamine and
carbon dioxide
O
O
O
O
O
O
S
S
N
N
N
N
N
N
N
N
O
O
O
O
N
N
N
N
S
S
O
N
N
N
N
O
N
N
N
N
N
N
N
N
H
N
H
N
N
N
H
N
H
N
O
S
N
N
O
O
N
N
N
N
H
N
N
H
H
O
S
H
O
N
N
N
N
O
O
O
HN
O
N
HN
S
N
N
N
O
O
O
N
S
Si
Si
N
N
N
N
O
S
O
O
O
N
O
O O
O
N
N
N
N
O
SBA-15/IL (2)
SBA-15/APTS/Imidazolium
HN
NH
O
S
O
N
H
O
NH
HN
N
N
N
H
H
N
N
N
N
N
N
N
N
N
N
N
H
N
H
N
N
N
H
H
N
N
N
N
H
N
H
N
N
N
HN
N
Cl
Cl
N
N
N
N
N
N
Cl
Cl
H
H
N
H
N
H
N
N
N
S
O
H2
N
NH2
N
H
N
H
O
N
N
N
Cl
N
Cl
O
Si
N
HN
N
N
HN
N
N
HN
N
O
O O
H2
N
Cl
NH2
Cl
N
N
SBA-15/IL(3)
(1) H2
N
N
N
N
Si
Si
Si
Si
Cl
NH2
SBA-15/APTS/CC/EA-2
OH OH
SBA-15
H2
N
O
O
O
O
O
O
O
O
O
Cl
N
Cl
O
O
O
Cl
Cl
APTS
EtOH
N
N
(2)
Cl
SBA-15/APTS
SBA-15/APTS/CC-2
SBA-15/APTS/CC-1
N
Cl
H
O
O
S
N
N
O
O
S
O
O
H
N
N
(3)
(4)
N
N
N
N
N
N
O
N
N
N
N
O
O
O
S
N
N
N
HN
N
HN
O
O
O
S
Si
Si
O
O
O
O
O
SBA-15/IL (1)
SBA-15/APTS/Imidazolium
Keywords Nanocatalyst · Green chemistry · SBA-15 · Ionic liquid · 2-imidazolidinone · CO2
1 Introduction
Usually, many diamines reactions having many types of rea-
* Qingwang Min
gents utilized as carbonyl sources like carbonyl selenide [1],
phosgene, urea, organic carbonates [2, 3], dithiocarbonate
[4] and carbonyldiimidazole [5]. The reaction process of
CO2 with a diamine is a direct eco-friendly procedure in the
synthesis of cyclic urea from the toxic point of mentioned
reagents. In the term of this reaction, scholars demonstrated
homogeneous catalysts like TBA2[WO4] [6] and Ph3SbO/
minqw@dlpu.edu.cn
* Farzaneh Shamsa
Farzaneh.Shamsa@gmail.com
1
School of Light Industry and Chemical Engineering, Dalian
Polytechnic University, Dalian 116034, PR China
2
Young Researchers and Elite Club, Neyshabur Branch,
Islamic Azad University, Neyshabur, Iran
Vol.:(0123456789)
1 3

Q. Min et al.
P4S10 [7] as efcient catalysts together with many limitations
such as recyclability, catalyst separation, and high cost of
catalyst production. In the Refs. [8] and [9], scholars have
suggested non-catalytic approaches to synthesis cyclic urea,
directly, from diamine and CO2. The related reactions are
done considering harsh conditions like temperature higher
than 200 °C, and a pressure higher than 6.0 MPa. For this
reaction, only a few studies are reported in the case of het-
erogeneous catalysts. In the Ref. [10], polyethylene-glycol-
supported potassium hydroxide is introduced as an efcient
catalyst to synthesis cyclic urea from carbon dioxide and
diamine, directly demonstrated a low yield of cyclic urea,
under 80 bar pressure of carbon dioxide and at the tempera-
ture of 150 °C. This catalyst showed a low yield of product,
at a pressure of 70 bar carbon dioxide and 140 °C. CeO2
synthesized by biopolymer template method gave low yield
for cyclic urea at 6 bar carbon dioxide pressure and 150 °C
[11]. Tomishige et., al have proposed pure commercial CeO2
as the most impressive catalyst among many diferent metal
oxides like Al2O, CaO, La2O3, TiO2, MgO, Pr6O11, ZnO and
ZrO2. However, the catalyst of CeO2 demonstrated appro-
priate catalytic activity in the case of CO2 as well as amine
reaction [10, 12–18].
of these compound. By the use of many functional groups
in cations and anions having distinct structures, the physical
and chemical attributes of ILs has been adjusted. Dendritic
ILs (DILs) that have the properties of both dendrimers and
ILs, were utilized in the felds of adsorption of heavy metal
cations, transporters and catalysis [37, 38].
In this paper, many novel SBA-15 supported dendritic
zwitterionic ionic liquid heterogeneous catalysts together
with high-density active sites SBA-15/IL(1), SBA-15/IL(2),
and SBA-15/IL(3) from SBA-15 (Scheme 1) are provided
and after that are used as highly efcient and recyclable het-
erogeneous catalysts for synthesis of 2-imidazolidinone from
CO2 and ethylenediamine under mild conditions, as can be
seen in Scheme 2. The high yields of appropriate 2-imi-
dazolidinone can be achieved. The heterogeneous catalytic
system is known to be reusable and stable for the synthesis
of 2-imidazolidinone.
2 Experimental Section
2.1 General Approach for the Synthesis of SBA‑15
NPs
Mesoporous silica materials can be used as a platform
for many applications in diagnosis, therapeutics and phar-
maceuticals [19]. SBA-15 as a mesoporous silica material,
is widely utilized as supports in the case of heterogeneous
catalysis due to the dispersity of active sites. In addition, for
increasing the efciency of mentioned materials, one can
cofunctionalize them by other functional groups [20–22].
Moreover, SBA-15 can be utilized in wastewater purifca-
tion, treatment and gas separation [23]. It is mesopore-rich
and showed to have considerable internal surface area, high
hydrothermal, plentiful surface hydroxyl groups and appro-
priate mechanical stability. Currently, in cases of catalyze
reactions, a substantial number of catalysts like ionic liquids
(ILs) [24, 25] as well as transition metal complexes [26, 27]
were evaluated to be immobilized on SBA-15. Moreover,
these immobilized catalysts demonstrated appropriate recy-
clability. SBA-15 is thought to be proper choice for stably-
supporting multi-site ILs due to having mesoporous channel
and plain loading [28–31].
SBA-15 is produced based on the Ref. [39]. TEOS is uti-
lized as Pluronic (P123) and silica source is utilized as tem-
plate. Firstly, 8.0 g of P123 and a constant amount of TEOS
equal to 14.0 g are slowly added to an aqueous solution of
HCl (3 mol/L, 180 ml) along with 70 g of water. For a day,
whole considered mixtures is stirred under the temperature
of 40 °C and after that was heated to the temperature of
120 °C for another 20 h considering static conditions. In the
next step, the mesoporous material is fltered, washed by
water up to when no Cl− is not detected. The result com-
pound is dried under the temperature of 45 °C considering
vacuum condition. After that, the dried sample is dissolved
in methanol and sonicated under the temperature of 45 °C
for 15 min, then was fltered and repeated for four times. In
the last step, the resulted compound is dried under vacuum
under the temperature of 40 °C for obtaining SBA-15.
2.2 The Synthesis of Amino‑Modifed SBA‑15
Dendrimers are widely utilized in the feld of catalysis
because of their highly branched tridimensional structures
and abundant peripheral groups as well as inimitable den-
dritic efects [32, 33]. Immobilization of dendrimer catalyst
on support materials is an appearing area which attracted
more consideration from chemists due to their simple and
easy recoverability and reusability [34–36]. ILs as green
chemistry compounds are utilized widely because of hav-
ing promising attributes such as low flammability, low
vapor pressure, good stability and so on. The adjustability
of structure is known as the most signifcant characteristic
(SBA‑15/APTS)
A small amount of SBA-15 equal to 5.0 g are released in
75 mL of NaOH solution (1.5 M). The obtained mixture is
refuxed by applying the temperature of 150 °C at 1 h for
improving its hydrophilicity. Then, the obtained fbers are
washed for more than three times by water up to when the
wash-water pH became neutral. Then, the activated fbers
are dried in a vacuum oven and under 70 °C at 7 h and the
activated lufa sponge fbers are functionalized by APTS for
the preparation of amino-modifed SBA-15/APTS. In detail,
1 3

SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from…
O
O
O
O
O
O
S
S
N
N
N
N
N
N
N
N
O
O
O
N
N
N
N
S
S
O
N
N
N
N
O
N
N
O
N
N
N
N
N
N
H
N
H
N
H
N
O
N
H
N
N
N
N
O
O
N
N
N
N
N
N
S
H
H
O
H
H
O
N
N
N
N
S O
O
O
HN
O
N
HN
S
N
N
O
O
O
N
S
N
Si
O O O
Si
O O O
N
N
N
N
O
S
N
O
N
N
N
N
O
O
SBA-15/IL (2)
SBA-15/APTS/Imidazolium
HN
NH
O
S
O S O
O
N
H
O
N
NH
HN
N
N
N
N
H
H
N
N
N
N
N
N
N
N
N
N
N
H
N
N
H
N
H
H
N
N
N
H
N
H
N
N
N
HN
N
N
N
Cl
Cl
N
N
N
N
N
N
N
Cl
Cl
H
H
N
H
N
H
N
N
N
S O
O
H2
N
NH2
N
H
N
O
N
N
O
S
N
Cl
N
Cl
H
O
Si
O O O
O
N
N
N
N
N
N
HN
H2N
HN
HN
Cl
N
N
NH2
Cl
SBA-15/IL(3)
(1) H2
N
N
N
N
Si
O O O
Si
O O O
Si
O O O
Si
O O O
Cl
NH2
OH OH
SBA-15
H2
N
Cl
Cl
Cl
N
Cl
APTS
EtOH
N
N
(2)
Cl
SBA-15/APTS/CC/EA-2
SBA-15/APTS
SBA-15/APTS/CC-2
SBA-15/APTS/CC-1
N
Cl
H
O
O
N
O
O
S O
O S
H
N
N
N
(3)
(4)
N
N
N
N
N
N
N
N
N
N
O
O
O
S
N
HN
N
N
N
HN
O
O
O
S
Si
O O O
Si
O O O
SBA-15/IL (1)
SBA-15/APTS/Imidazolium
Scheme 1 Synthesis of the SBA-15/IL(1), SBA-15/IL(2), and SBA-15/IL(3)
reaction is performed under 25 °C for 2.0 h. The resulting
mixture is then fltered, after that the fltrate is dried under
vacuum under the temperature of 50 °C after the solvent is
removed.
O
H2N
SBA-15/IL
NH2
+
HN
NH
CO2
Scheme 2 Synthesis of 2-imidazolidinone from carbon dioxide and
2.4 General Approach for the Synthesis of SBA‑15/
IL(2) and SBA‑15/IL(3)
ethylenediamine in the presence of SBA-15/IL
3.5 g of SBA-15/APTS/CC-1 in 60.0 mL of THF is released
inethylenediamine DIPEA (8.41 mL). The mixture of reac-
tion is stirred magnetically under the temperature of 85 °C
at1 day. The obtained ethylenediamine-modified SBA-
15/APTS/CC/EA-2 is fltered and then washed by using
5 mL×6 of EtOAc and lastly dried in in vacuum oven under
the temperature of 55 °C for 11 h. A mixture of 5.5 g of cya-
nuric chloride (CC) and ethylenediamine-modifed 3.5 g of
SBA-15/APTS/CC/EA-2 as well as 8.45 mL of diisopropyl-
ethylamine in 55 mL of THF is stirred under the temperature
of 25 °C for 12 h, magnetically. After that, the fltration
process in a proper way for separating the cyanuric chloride-
modifed fbers (SBA-15/APTS/CC-2). After each separation
process SBA-15/APTS/CC-2 is washed by utilizing 5 mL×6
of EtOAc and then dried in vacuo for a half of day. 3.5 g of
SBA-15/APTS/CC-2 is suspended in THF (60 mL), 2.5 g of
imidazole and 17.1 mL of DIPEA are released, and the mix-
ture is magnetically stirred under the temperature of 90 °C at
1 day. The bio-based heterogeneous catalyst SBA-15/APTS/
Imidazole (2) catalysis is washed by 5 mL×6 of EtOAc and
4.0 g of activated lufa sponge fbers mixture and 7.0 mL of
APTS, in 75 mL anhydrous ethanol is stirred under the tem-
perature of 80 °C at a day, magnetically. After that, SBA-15/
APTS is fltered and then washed by EtOH for three times
and dried under the temperature of 60 °C at a half of day.
2.3 General Approach for the Synthesis of SBA‑15/
IL(1)
A mixture containing 2.6 mL of DIPEA, 3.1 g of cyanuric
chloride (CC) and 3.2 g of SBA-15/APTS fbers is released
in 40.0 mL of THF and is stirred under the temperature of
25 °C at a half of day. The metnioendmixture is fltered and
the obtained fbers SBA-15/APTS/CC-1 are washed by using
5 mL×6 of EtOAc and then dried at 10 h. 2.7 g of SBA-15/
APTS/CC-1 is suspended in 55.0 mL of THF, 2.2 g of 1-imi-
dazole are released, and the obtained mixture is stirred, mag-
netically, under 65 °C for a day. 100 mg of SBA-15/APTS/
Imidazole is released in water: a mixture of ethanol (10:10
v/v, 100 mL) containing 2.5 g of 1,4-butanesultone. The
1 3

Q. Min et al.
after that dried in in vacuum oven under the temperature of
50 °C for 12 h. SBA-15/APTS/Imidazole (3) can be pro-
duced utilizing the similar approach presented previously. A
constant amount of SBA-15/APTS/Imidazole (2) or SBA-15/
APTS/Imidazole (3) equal to 100 mg is released in water:
a mixture of ethanol (10:10 v/v, 100 mL) containing 2.5 g
of 1,4-butanesulton. The reaction is performed at 25 °C for
2.0 h. The obtained mixture is fltered, after which the fltrate
is dried under vacuum under the temperature of 50 °C is the
solvent was removed.
to an appropriate temperature and also pressure. The reac-
tor is leaved in cold water. After that, the excess CO2 is
slowly released after occurring the reaction. 12 mL of EtOH
is added in the mixture of reaction. Then, the catalyst of
SBA-15/IL is recovered using fltration process. Lastly, the
fabricated catalyst is washed two times by using methanol
and dried under vacuum at room temperature.
3 Results and Discussion
2.5 Representative Approach for the Synthesis
of 2‑imidazolidinone Catalysed by Utilizing
SBA‑15/IL Catalysts
Moreover, SEM and TEM analysis are used to characterize
the morphology and also pore structure of the immobilized
ILs (3) catalysts. Figure 1a and b shows the SEM images
of immobilized ILs (3) catalysts. In addition, Fig. 1c and
d shows the TEM images of immobilized ILs (3) catalysts.
As seen, the strip sharp and regular appearance of SBA-15
and hexagonal structure of SBA-15 is clear, demonstrat-
ing the usual structure of SBA-15. Moreover, after loading
ILs (3), the SBA-15 structure have not varied. As can be
seen in Fig. 2, the decomposition conduct of the SBA-15
as well as dendritic ILs catalysts SBA-15/IL(1), SBA-15/
Whole the cycloaddition reactions of carbon dioxide by
ethylenediamine are performed in 20.0 mL of Tefon-lined
stainless-steel reactor. In the reaction, a magnetic stirrer and
a pressure gauge are attached. In the common approach,
appropriate amount of ethylenediamine (10.0 mmol), SBA-
15/IL catalyst, are added in the reactor. The reactor is purged
three times by using carbon dioxide and the reactor is heated
Fig. 1 SEM images of SBA-15
NPs (a); SBA-15 /IL(3) NPs
(b); and TEM images of SBA-
15 NPs (c); SBA-15/IL(3) NPs
(d)
1 3

SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from…
demonstrated small weight loss equal to 5.0% related to the
evaporation of physical adsorbed H2O from the samples.
Second one is between 300 °C and 450 °C demonstrated
clear reduces by large weight loss of around 20–30% related
to the lignin degradation.
Figure 3 shows the FT-IR spectroscopy pattern of the syn-
thesized catalyst and its surface modifcation. As can be seen
in Fig. 3a, for SBA-15, the bands at 1101 cm−1, 798 cm−1,
and 1627 cm−1 demonstrated is related to Si–O–Si vibra-
tions, the typical silanol group (Si–OH) stretching mode
and the water absorbed onto the surface of solid, respec-
tively. Many new appeared absorption peaks of 856 cm−1,
1042 cm−1 and 1696 cm−1 in comparison with the FT-IR
spectrum of lufa sponge (refer to Fig. 3a) is related to the
stretching vibration of Si–O bond and the bending vibra-
tions of C= N bond on the surface of SBA-15/IL, respec-
tively. In addition to the mentioned peaks, the broad peak at
1044 cm−1 is related to S=O stretching vibrations in the sul-
phonate functional groups. Bands at 1493 cm−1 are belonged
to N–H bending vibrations in the ammonium groups. It was
demonstrated that IL is immobilized onto SBA-15 NPs,
successfully.
Fig. 2 TGA of a SBA-15/IL(1); b SBA-15/IL(2); and c SBA-15/IL(3)
IL(2) and SBA-15/IL(3) is compared for understanding the
infuences of the grafted dendritic IL molecules. In Fig. 2,
the TGA analysis in the cases of SBA-15/IL(1), SBA-15/
IL(2), and SBA-15/IL(3) are shown. As seen, all three men-
tioned samples demonstrated same thermal stability. As seen
in the TGA curves, there are two processes of weight loss
that the frst process is determined among 25 °C and 100 °C
The N2 adsorption–desorption isotherms of SBA-15,
SBA-15/IL(1), SBA-15/IL(2), and SBA-15/IL(3) showed
a distinct type IV curve, which was consistent with past
Fig. 3 FTIR spectra of SBA-15
(a); and SBA-15/IL (b)
1 3

Q. Min et al.
Table 1 Structural parameters of SBA-15, SBA-15/IL(1), SBA-15/
IL(2), and SBA-15/IL(3) materials determined from nitrogen sorption
experiments
researches on standard fibrous silica spheres (Fig. 4).
Table 1 illustrates that the produced SBA-15 possessed
similar properties as commercial the SBA-15 and SBA-15,
before and after grafting demonstrates a considerable large
diference. In cases of SBA-15/IL(1), SBA-15/IL(2), and
SBA-15/IL(3), the surface areas of BET are determined to
be 331 m2g−1, 302 m2g−1, and 254 m2g−1; pore diameters are
equal to 6.58 nm, 6.55 nm, and 6.51 nm; and pore volumes
0.55 cm3g−1, 0.52 cm3g−1, and 0.41 cm3g−1, respectively.
Compared to pristine SBA-15, the SBA-15/IL nitrogen sorp-
tion analysis has demonstrated a regular and uniform meso-
structure having a reduction of surface area, pore diameter
and pore volume parameters. The related pore volumes were
considerably decreased by the functionalization using X-Si
(X=IL(1), IL(2), and IL(3)). As seen, ILs are immobilized
onto SBA-15 that is related to reducing surface area as well
as total pore volume, (refer to Table 1). The BET surface
area, pore diameter, and total pore volume of BJH of the
used catalyst were compared with those of the fresh catalyst.
It was found that the anatomy of the used catalyst remained
undamaged after three recycles.
Catalysts
SBET (m2 g−1
)
Vt (cm3 g−1
)
DBJH (nm)
SBA-15
536
331
302
254
0.97
0.55
0.52
0.41
0.43
6.67
6.58
6.55
6.51
6.64
SBA-15/IL(1)
SBA-15/IL(2)
SBA-15/IL(3)
SBA-15/IL(3) after 261
three reuses
The catalytic activity of the SBA-15/IL(3) NPs are exam-
ined by synthesis of 2-imidazolidinone from carbon dioxide
and ethylenediamine (refer to Table 3). Moderate to good
to excellent yields were obtained under diferent solvent
conditions (refer to Table 3). We have demonstrated that
the solvent-free condition caused to obtaining better results
compared to using organic solvents by taking into consid-
eration of the yield of the synthesis of 2-imidazolidinone.
After wards, in the cases of subsequent reactions, we
investigated the SBA-15/IL(3) catalyst for obtaining the
optimized reaction conditions. The efect of temperature,
reaction time and CO2 pressure as well as amount of SBA-
15/IL(3) catalyst on the reaction of cycloaddition is evalu-
ated. As seen in Fig. 5, the temperature of reaction possessed
a dramatic efect on the 2-imidazolidinone yield. The 2-imi-
dazolidinone yield can enhance by the enhancement of reac-
tion temperature ranging from 30 °C to 70 °C (94%, 70 °C)
and levels of upon more enhancing temperature equal to
100 °C.
The catalytic activity of the diferent kinds of dendritic
imidazolium ILs catalysts (i.e., SBA-15/IL(1), SBA-15/
IL(2), and SBA-15/IL(3)) are examined by synthesis of
2-imidazolidinone from carbon dioxide and ethylenediamine
(refer to Table 2). The reaction performed deploying SBA-
15 showed that no amount of the 2-imidazolidinone was
formed (Table 2, row 2). Product yields equal to 76–94%
are achieved utilizing the 25 mg of SBA-15/IL(1), SBA-15/
IL(2), or SBA-15/IL(3) as catalysis after 10 h. It is found
that, by the increase in the generation of the dendritic ILs,
the catalytic activity enhanced. To improve the reaction situ-
ations, the synthesis of 2-imidazolidinone in the presence of
SBA-15/IL(3) was selected.
Table 4 shows that the enhancement of the catalyst
amount from 5 mg to 10 mg, 15 mg, 20 mg, and 25 mg can
enhance the yield of cycloaddition from 22 to 53, 71, 94, and
94, respectively. It is clear that, the 2-imidazolidinone by the
enhancement of catalyst amount. With using 20 mg of SBA-
15/IL(3), a yield about 94% is achieved. Noted that, more
enhancement of catalyst amount cannot change the 2-imi-
dazolidinone yield considerably. Figures 6 demonstrate the
efect of reaction time at the presence of CO2 under the tem-
perature of 70 °C and 1.5 bar. The 2-imidazolidinone yield
Table 2 Synthesis of 2-imidazolidinone by diferent of SBA-15/IL
NPs
Entry
Catalyst
Yield (%)a
1
2
3
4
5
None
SBA-15
SBA-15/IL(1)
SBA-15/IL(2)
SBA-15/IL(3)
-
-
76
85
94
Fig. 4 Adsorption–desorption isotherms of a SBA-15, b SBA-15/
IL(1), c SBA-15/IL(2), and d SBA-15/IL(3)
aIsolated yields
1 3

SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from…
Table 3 Synthesis of 2-imidazolidinone from carbon dioxide and eth-
ylenediamine by SBA-15/IL(3) in diferent solventsa
Table 4 Efect of amount of catalyst on yield of synthesis of 2-imida-
zolidinonea
Entry
Entry
Solvent
Yield (%)b
Amount of SBA-15/
IL (mg)
Yield (%)
TON
1
2
3
4
5
6
7
8
Solvent-free
DMF
DMSO
Dioxane
CH3CN
EtOAc
94
31
44
52
40
56
38
41
56
42
8
10
13
19
72
64
41
52
1
2
3
4
5
5
22
53
71
94
94
36.6
88.3
118.3
156.6
156.6
10
15
20
25
THF
aReaction conditions: ethylenediamine (5.0 mmol), and CO2 (2.5
Mpa) at 70 °C for 12 h
Toluene
CH2Cl2
CHCl3
bIsolated yields
9
10
11
12
13
14
15
16
17
18
CCl4
100
90
80
70
60
50
40
30
20
10
0
n-Hexane
Benzene
Cyclohexane
H2O
EtOH
i-PrOH
MeOH
aReaction conditions: ethylenediamine (5.0 mmol), CO2 (2.5 Mpa)
and SBA-15/IL(3) (20 mg) at 100 °C for 12 h
bIsolated yields
0
2
4
6
8
10
Time (h)
100
90
80
70
60
50
40
30
20
10
0
Fig. 6 Efect of time on yield of synthesis of 2-imidazolidinone.
Reaction conditions: ethylenediamine (5.0 mmol), CO2 (2.5 Mpa) and
SBA-15/IL(3) (20 mg) at 70 °C
CO2 to ethylenediamine. The efect of pressure is specifed,
experimentally, in the range of 0.5 MPa to 2.5 MPa pressure.
The SBA-15/IL(3) NPs function forcefully enhanced when
the pressure of CO2 increased from 0.5 MPa to 1.5 MPa
pressure. Then, it is supportable for the pressure in the range
of 1.5 MPa to 2.5 MPa demonstrated in Fig. 7. These out-
comes demonstrated the requirement considering an opti-
mum pressure about the pressure of 1.5 bar for the desired
products of 2-imidazolidinone. Also, the efects of concen-
tration of ethylenediamine was investigated. The reaction
order with respect to ethylenediamine concentration was
almost zero, which indicates that the diamine is strongly
adsorbed on catalyst. [12, 40]
20
30
40
50
60
70
80
90
100
Temperature (oC)
Fig. 5 Efect of temperature on yield of synthesis of 2-imidazoli-
dinone. Reaction conditions: ethylenediamine (5.0 mmol), CO2 (2.5
Mpa) and SBA-15/IL(3) (20 mg) for 12 h
possessed a gradual enhancing from 2 h to 8 h (94%, 8 h).
After that, remaining unvaried in all time approximately. It
is obvious that ethylenediamine is almost converted in the
target product only in 8 h.
Product syntheses from CO2, and diamines were examined
comprehensively (Table 5). 1,2-propanediamine, 2-methyl-
1,2-propanediamine, and ethylenediamine (Table 5, entries
1–3) reacted to aford the corresponding cyclic ureas in
excellent yields (92–95%). N-Alkyl ethylenediamines
(Table 5, entry 4) were also converted selectively. However,
N,N′-dimethylethylenediamine was converted in good yield
(89%) (Table 5, entry 5). The amplitude of substrate scope
was investigated with diferent aminoalcohols over SBA-15/
Moreover, the pressure of CO2 is investigated to increase
the production of 2-imidazolidinone. The promised CO2
pressure to obtain the most appropriate preparation of SBA-
15/IL(3) NPs can be determined in the meantime the kinetics
related to the mass transfer reactions can be varied by tak-
ing into considerations of both difusion and the reaction of
1 3

Q. Min et al.
100
90
80
70
60
50
40
30
20
10
0
can remarkably enhance the availability of the active sites of
the SBA-15. For this reason, the SBA-15 was more efcient
than MCM-41 and nano-SiO2 (Table 6, rows 3 and 5).
Table 7 presents information about catalysts and reagents
for the direct reaction of diamines with carbon dioxide [43].
As mentioned in the section on cyclic carbamates synthesis,
the reaction system consisting of the DPPA and PhTMG was
efcient for the synthesis of 2-imidazolidinone (Table 7, row
1). TBA2[WO4] and Ph3SbO/P4S10 were introduced as cata-
lysts (Table 7, rows 2 and 3). The reaction by Ph3SbO/P4S10
continued in the same reaction pathway mentioned in the
synthesis of carbamate by catalysts. The TBA2[WO4] intro-
duced by Mizuno was an efective homogeneous substance
for the synthesis of 2-imidazolidinone from atmospheric car-
bon dioxide and diamines. The activity of the TBA2[WO4]
catalyst was done by the activation of carbon dioxide by the
weak Lewis basic feature and the absorption of diamineby-
hydrogen bonding [4, 5]. CeO2 and KOH/PEG1000 were
reported as catalysts (Table 7, rows 4 and 5) [8, 40]. CeO2
NPs synthesized by biopolymer template techniques and the
employment of mesoporous alginate aerogel was an efec-
tive catalyst at 433 K and 0.7 MPa carbon dioxide pressure.
This catalyst sufered from disadvantages such as a narrow
bed of substrates and low product efciencies. In contrast, it
has recently been shown that pure CeO2 acted as an efcient
heterogeneous catalyst in isopropyl alcohol (IPA) solvent,
even at a low carbon dioxide pressure of 0.3 MPa, to provide
high-yield cyclic urea [12].
0
0.5
1
1.5
2
2.5
3
CO2 Pressure (MPa)
Fig. 7 The efect of carbon dioxide pressure on the synthesis of
2-imidazolidinone. Reaction conditions: ethylenediamine (5.0 mmol),
and SBA-15/IL(3) (20 mg) at 70 °C for 8 h
IL(3), the results of which are illustrated in Table 5. Ami-
noethanols (Table 5, rows 6–8) were quantitatively converted
to the corresponding fve-membered-ring cyclic carbamates
at high efciencies [41, 42]. The use of o-phenylenediamines
with electron receptor groups was resulted in good efcien-
cies due to a decrease of the electron density of the nitro-
gen atom (Table 5, rows 9–11). On the other hand, only a
trace of aniline was observed, which might be due to the
fact that CO2 reactions with these substrates are equilibrium
restricted. Aniline reacted with difculty (Table 5, entry 12),
which was due to the low nucleophilicity of aniline [11].
For a deeper evaluation of the efciency of the catalyst,
various control experiments were conducted (Table 6).
The reaction performed deploying SBA-15 showed that
no amount of the 2-imidazolidinone was formed after 12 h
(Table 6, row 1). Also, no reaction was perceived when
SBA-15/APTS was employed as a catalyst (Table 6, row
2). APTS is not able to show catalytic activity. Due to these
unfavorable results, we continued research to increase ef-
ciency by adding ionic liquid (Table 6, row 3). Our results
show that the reaction is primarily catalyzed using ionic
liquid in the SBA-15/APTS nanostructure. Nanoparticles
increase the activity of the catalyst due to the increase in
surface area to volume, so they signifcantly increase the
sensitivity between the reactants and the catalyst and act as
a homogeneous catalyst (Table 6, rows 3 and 4). In addi-
tion, the activity and selectivity of nano-catalysts can be
controlled by adjusting the chemical and physical character-
istics such as size, form, composition, and morphology. To
evaluate the real infuence of the existence of SBA-15 in the
catalyst, the SBA-15/IL(3) NPs were compared with MCM-
41/IL(3) and nano-SiO2/IL(3) (Table 6, rows 5 and 6). The
use of MCM-41/IL(3) and nano-SiO2/IL(3) as the catalyst
led to a good efciency of the desired product; however, the
efciency for SBA-15/IL(3) was superb. The tangible activ-
ity of the silica was assigned to its form, composition, and
morphology. Furthermore, the large space between the pores
In green chemistry, the catalyst reusability state is consid-
ered a signifcant property. Therefore, the reuse of the SBA-
15/IL(3) NPs was investigated with respect to the optimal
state of synthesis of 2-imidazolidinone. SBA-15/IL(3) NPs
were easily isolated from the liquid reaction zone after a
few seconds. The solvent can be used quickly after clean-
ing. As Fig. 8 illustrates, the catalyst was recycled for ten
consecutive cycles. Product yield in the tenth run was 89%,
showing merely a 5% decrease in performance compared to
the fresh catalyst.
Finally, we carried out a leaching experiment to explore
the homogeneity of the catalyst system. This reaction was
initially done deploying optimized circumstances, in the
participation of the ten-times recycled catalyst. After 4 h
of reaction, the catalyst was separated by hot fltration and
the solution was mixed for 4 h. Figure 9 illustrates the syn-
thesis of 2-imidazolidinone as a function of time with the
ten-times recycled catalyst (black curve). As Fig. 10 shows,
the employment of the reagent was no longer observed after
the isolation of the catalyst (red curve).
The obtained analyzes of SEM and TEM demonstrated the
more data in the case of the fbrous NPs of SBA-15/IL(3). In
the case of new fbrous NPs of SBA-15/IL(3), the analyzes
of SEM and TEM for, and the 10th fbrous NPs SBA-15/
IL(3) reused were determined as shown in Fig. 10a and b,
1 3

SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from…
Table 5 Scope of diamines for
Entry
Diamine
Cyclic urea
Conversion (%)
Yield (%)b
Cyclic urea
synthesis of the cyclic ureaa
N-Alkylated
amine
1
2
3
98
98
97
94
95
92
Trace
Trace
2
H
N
H2N
NH2
O
N
H
H
N
O
H2N
H2N
NH2
NH2
N
H
H
N
O
N
H
4
5
98
96
90
89
Trace
4
H
N
NH NH2
O
N
NH HN
N
N
O
6
7
8
94
97
97
96
95
96
2
O
H2N
OH
O
N
H
3
H
N
HO
NH2
OH
O
O
O
O
Trace
H2N
N
H
H
9
99
92
Trace
1
NH2
NH2
N
O
F
N
H
F
10
11
12
H
97
95
NH2
N
O
N
H
Cl
NH2
NH2
NH2
Cl
Br
H
N
98
93
Trace
Trace
O
N
H
Br
Trace
Trace
NH2
O
N
N
H
H
aReaction conditions: ethylenediamine (5.0 mmol), CO2 (1.5 Mpa) and SBA-15/IL(3) (20 mg) at 70 °C for
8 h
bIsolated yields
respectively. After being 10th reusing of the catalyst, the tube-
like structure of the catalyst is still obvious. The desired power
in recyclability is specifed because of existing the identical
structure of fresh fbrous NPs of SBA-15/IL(3) and SBA-15/
IL(3) 10th reused. Moreover, after 10 runs recycling, the ther-
mal stability of mentioned catalysis is not appropriate as the
1 3

Q. Min et al.
Table 6 Infuence of diferent catalysts for the synthesis of 2-imida-
zolidinonea
Entry
Catalyst
Yield (%)b
1
2
3
4
5
6
SBA-15
–
–
94
95
88
72
SBA-15/APTS
SBA-15/IL(3)
IL(3)
MCM-41/IL(3)
nano-SiO2/IL(3)
aReaction conditions: ethylenediamine (5.0 mmol), CO2 (1.5 Mpa) at
70 °C for 12 h
bIsolated yield
Table 7 2-imidazolidinone syntheses from diamine and carbon diox-
Fig. 9 Leaching test for the catalyst of the synthesis of 2-imidazoli-
ide
dinone
Entry
Catalyst
Yield (%)
References
1
2
3
4
5
6
DPPA/ PhTMG
TBA2[WO4]
Ph3SbO/P4S10
KOH/PEG1000
CeO2
86
91
85
82
96
94
[43]
[4]
[5]
[8]
[40]
This work
fresh catalyst casued by the loss of IL in SBA-15 fbers in the
process of recycling (refer to Fig. 11). However, it has not
afect its practicability while utilized under the temperature
of 100 °C.
SBA-15/IL(3)
4 Conclusions
In this study, the synthesis of SBA-15 supported dendritic
ILs catalysts SBA-15/IL(1), SBA-15/IL(2), and SBA-15/
IL(3) possessing high ionic density and distinct generations
are reported for the frst time. We observed that there exists a
positive dendritic impact of the dendritic ILs catalysts SBA-
15/IL(1), SBA-15/IL(2), and SBA-15/IL(3) onto the prod-
uct yield of the synthesis of 2-imidazolidinone from carbon
dioxide and ethylenediamine. Between the introduced cata-
lysts, SBA-15/IL(3) showed to have the optimal heterogene-
ous catalytic conduct and have appropriate catalytic activity
in the case of the synthesis of 2-imidazolidinones, provid-
ing excellent yields. SBA-15/IL(3) can be recycled until 10
consecutive runs without any dramatic reduction in catalytic
activity. SBA-15/IL(3) demonstrated many promising ben-
efts than the reported heterogeneous catalysts, like low cost,
easy preparation and higher catalytic potential as well as
renewable nature in the case of the synthesis of 2-imidazo-
lidinones that introduced it a proper candidate for diferent
practical usages.
100
90
80
70
60
50
40
30
20
10
0
1
2
3
4
5
6
7
8
9
10
Reuse
Fig. 8 Recyclability of the catalyst. Reaction conditions: ethylen-
ediamine (5.0 mmol), CO2 (1.5 Mpa) and SBA-15/IL(3) (20 mg) at
70 °C for 8 h
1 3

SBA-15 Supported Dendritic ILs as a Green Catalysts for Synthesis of 2-Imidazolidinone from…
Fig. 10 a FE-SEM, and b TEM
images of the recovered SBA-
15/IL(3) NPs after the 10 th run
for the synthesis of 2-imidazo-
lidinone
8. Kong D-L, He L-N, Wang J-Q (2010) Synlett 2010:1276–1280
9. Primo A, Aguado E, Garcia H (2013) ChemCatChem
5:1020–1023
10. Hwang J, Han D, Oh JJ, Cheong M, Koo H-J, Lee JS, Kim HS
(2019) Adv Synth Catal 361:297–306
11. Tomishige K, Tamura M, Nakagawa Y (2019) Chem Rec
19:1354–1379
12. Tamura M, Honda M, Nakagawa Y, Tomishige K (2014) J Chem
Technol Biotechnol 89:19–33
13. Honda M, Sonehara S, Yasuda H, Nakagawa Y, Tomishige K
(2011) Green Chem 13:3406–3413
14. Truong CC, Mishra DK (2020). Environ Chem Lett. https://doi.
org/10.1007/s10311-020-01121-7
15. Tamura M, Miura A, Honda M, Gu Y, Nakagawa Y, Tomishige
K (2018) ChemCatChem 10:4821–4825
16. Gu Y, Miura A, Tamura M, Nakagawa Y, Tomishige K (2019)
ACS Sustainable Chem Eng 7:16795–16802
17. Kulal N, John C, Shanbhag GV (2020) Appl. Catal. A
598:117550
18. Alferov KA, Fu Z, Ye S, Han D, Wang S, Xiao M, Meng Y (2019)
ACS Sustain Chem Eng 7:10708–10715
Fig. 11 TGA of the fresh SBA-15/IL(3) catalyst (a) and the reused
SBA-15/IL(3) catalyst after 10 times recycling (b)
19. Popat A, Hartono SB, Stahr F, Liu J, Qiao SZ, Lu GQ (2011)
Nanoscale 3:2801–2818
20. Doustkhah E, Rostamnia S, Hassankhani A (2016) J Porous Mater
23:549–556
21. Doustkhah E, Rostamnia S (2016) Mater Chem Phys 177:229–235
22. Doustkhah E, Lin J, Rostamnia S, Len C, Luque R, Luo X, Bando
Y, Wu KCW, Kim J, Yamauchi Y, Ide Y (2019) Chem Eur J
25:1614–1635
Acknowledgements This work was sponsored in part by Natural Sci-
ence Foundation of Liaoning Province (No. 20170520296)
23. Ji G, Zhang Y, Shen J (2015) Nat Gas Chem Indust 40:84–88
24. Rostamnia S, Golchin Hossieni H, Doustkhah E (2015) J Orga-
nomet Chem 791:18–23
References
25. Rostamnia S, Doustkhah E, Bulgar R, Zeynizadeh B (2016)
Microporous Mesoporous Mater 225:272–279
1. Kondo K, Yokoyama S, Miyoshi N, Murai S, Sonoda N (1979)
Angew Chem 18:691–691
26. Hosseini HG, Doustkhah E, Kirillova MV, Rostamnia S,
Mahmoudi G, Kirillov AM (2017) Appl Catal A Gen 548:96–102
27. Rostamnia S, Doustkhah E, Zeynizadeh B (2016) Microporous
Mesoporous Mater 222:87–93
2. Flosi WJ, DeGoey DA, Grampovnik DJ, Chen H-J, Klein LL,
Dekhtyar T (2006) Bioorg Med Chem 14:6695–6712
3. Leung M-k, Lai J-L, Lau K-H, Yu H-h, Hsiao H-J (1996) J Org
Chem 61:4175–4179
28. Kruk M, Jaroniec M, Ko CH, Ryoo R (2000) Chem Mater
12:1961–1968
4. Nomura R, Hasegawa Y, Ishimoto M, Toyosaki T, Matsuda H
(1992) J Org Chem 57:7339–7342
29. Yue MB, Chun Y, Cao Y, Dong X, Zhu JH (2006) Adv Funct
Mater 16:1717–1722
5. Kimura T, Kamata K, Mizuno N (2012) Angew Chem
51:6700–6703
30. Karimi B, Vafaeezadeh M (2012) Chem Commun 48:3327–3329
6. Bhanage BM, Fujita S-I, Ikushima Y, Arai M (2003) Green
Chem. 5:340–342
31. Zhong S, Liang L, Liu M, Liu B, Sun J (2015) J. CO2
9:58–65.
Util.
7. Wu C, Cheng H, Liu R, Wang Q, Hao Y, Yu Y, Zhao F (2010)
Green Chem 12:1811–1816
1 3

Q. Min et al.
32. Astruc D, Boisselier E, Ornelas C (2010) Chem Rev
110:1857–1959
39. Shi Z, Su Q, Ying T, Tan X, Deng L, Dong L, Cheng W (2020) J.
CO2 Util. 39:101162.
33. Tomalia DA (2012) New J Chem 36:264–281
34. Giacalone F, Campisciano V, Calabrese C, Parola VL, Syrgiannis
Z (2016) Prato M 10:4627–4636
40. Tamura M, Noro K, Honda M, Nakagawa Y, Tomishige K (2013)
Green Chem 15:1567–1577
41. Tamura M, Ito K, Nakagawa Y, Tomishige K (2016) J Catal
343:75–85
35. Sadjadi S, Malmir M, Heravi MM (2019) Appl Clay Sci
168:184–195
42. Tamura M, Honda M, Noro K, Nakagawa Y, Tomishige K (2013)
J Catal 305:191–203
36. Murugan E, Jebaranjitham JN, Raman KJ, Mandal A, Geethalak-
shmi D, Kumarc MD, Saravanakumarc A (2017) New J Chem
41:10860–10871
43. Paz J, Perez-Balado C, Iglesias B, Munoz L (2010) J Org Chem
75:3037–3046
37. Qin TY, Li XY, Chen JP, Zeng Y, Yu TJ, Yang GQ, Li Y (2014)
Chem Asian J 9:3641–3649
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional afliations.
38. Hayouni S, Robert A, Maes C, Conreux A, Marin B, Mohamadou
A (2018) New J Chem 42:18010–18020
1 3