Mesoporous silica SBA-15 functionalized with acidic deep eutectic solvent: A highly active heterogeneous N-formylation catalyst under solvent-free conditions

Article abstract of DOI:10.1002/aoc.3901

Mesoporous silica SBA-15 functionalized with N-methylpyrrolidonium-zinc chloride based deep eutectic solvent (DES) is found to be a more efficient and reusable catalyst for a convenient N-formylation of a variety of amines at room temperature. N-Formylation of primary, secondary as well as heterocyclic amines have been carried out in good to excellent yields by treatment with formic acid in low loading of DES/SBA-15 an environmentally benign catalyst for the first time. The DES/SBA-15 catalyst, which possesses both Br?nsted and Lewis acidities as well as an active SBA-15 support, makes this procedure quite simple, reusable, more convenient and practical. This catalyst was tolerant of a wide range of functional groups, and it can be reused for four runs without obvious deactivation.

Full text of DOI:10.1002/aoc.3901

Received: 14 February 2017
DOI: 10.1002/aoc.3901
Revised: 30 April 2017
Accepted: 1 May 2017
F U L L PA P E R
Mesoporous silica SBA‐15 functionalized with acidic deep eutectic
solvent: A highly active heterogeneous N‐formylation catalyst
under solvent‐free conditions
Najmedin Azizi
| Mahtab Edrisi | Faezeh Abbasi
Department of Green Chemistry, Chemistry
and Chemical Engineering Research Center
of Iran, P.O. Box 14335‐186 Tehran, Iran
Mesoporous silica SBA‐15 functionalized with N‐methylpyrrolidonium‐zinc chlo-
ride based deep eutectic solvent (DES) is found to be a more efficient and reusable
catalyst for a convenient N‐formylation of a variety of amines at room temperature.
N‐Formylation of primary, secondary as well as heterocyclic amines have been car-
ried out in good to excellent yields by treatment with formic acid in low loading of
DES/SBA‐15 an environmentally benign catalyst for the first time. The DES/SBA‐
15 catalyst, which possesses both Brønsted and Lewis acidities as well as an active
SBA‐15 support, makes this procedure quite simple, reusable, more convenient and
practical. This catalyst was tolerant of a wide range of functional groups, and it can
be reused for four runs without obvious deactivation.
Correspondence
Najmedin Azizi, Department of Green
Chemistry, Chemistry and Chemical
Engineering Research Center of Iran, P.O.
Box 14335‐186, Tehran, Iran.
Email: azizi@ccerci.ac.ir
KEYWORDS
acidic deep eutectic solvent, acidic support, amines, N‐formylation, SBA‐15
1 | INTRODUCTION
methods require harsh reaction conditions, large amounts of
expensive catalysts, difficulties in the preparation of catalyst,
Protecting groups play a pivotal role in organic synthesis,
particularly in the multi‐step synthesis of multifunctional tar-
gets and structurally complicated natural products.[1] Amines
as well as amino acids moieties represent the most abundant
functional groups in nature.[2] In this context, in the multi‐
step organic synthesis, the protection of reactive amino
groups is acute and unavoidable.[3] N‐formylation by the for-
myl (CHO) group was one of the most common protection
methods in organic synthesis due to their ease of formation.
The formylation products are valuable intermediates in the
construction of various important N‐heterocyclic com-
pounds. [4] Furthermore, they are useful reagents in Vilsmeier
formylation reactions and the most common reagent for the
preparation of isocyanide derivatives for isocyanide‐based
multicomponent reactions.[5] Owing to substantial capacity
of formamide derivatives, several methods or reagents for
the N‐formylation of amines in the presence of catalysts or
heating source have been reported during recent years.[6–15]
Despite their own merits, many existing N‐formylation
tedious purification, unstable reagents and inert atmosphere
using rigorously dried solvents.
According to the principles of green chemistry, organic
functional group transformation should be carried out at
room temperature in the presence of more environmentally
benign and efficient heterogeneous catalysts.[16–18] Nano-
structured mesoporous silica matrices, in particular, SBA‐
15 are attractive candidates as heterogeneous catalysts for
various organic transformations due to their large surface
area, narrow pore size distribution and a tunable pore diame-
ter.[19–24] On the other hands, adsorbed or covalently bonded
organic functional groups, especially ionic liquids at the sur-
face of nanostructured mesoporous silica matrices have been
widely researched because of the many applications of these
composite materials.[24–27] Deep eutectic solvents DESs are
the most attractive and effective precursor for immobilization
on the solid support for the several advantages such as ease of
preparation, available from bulk renewable resources, and
especially economic considerations.[28–35] DES is advanced
Appl Organometal Chem. 2017;e3901.
wileyonlinelibrary.com/journal/aoc
Copyright © 2017 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.3901

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AZIZI ET AL.
ionic liquids in terms of a low vapor pressure and low flam-
mability with additional advantages such as biodegradability,
non‐toxicity, and being inexpensive. Moreover, unlike ionic
liquids, these green solvents do not require a preliminary
purification step since one only has to mix natural and readily
available starting materials.[36–42]
Based on the above information, our research group has
been engaged mainly on the development of environmentally
friendly organic synthesis in green reaction media such as
water and DESs.[43–45] In our development efforts towards
this important class of DESs, herein we report an alternative,
recyclable, mild and highly effective catalytic system based
DES that immobilized on nanoporous silica SBA‐15 for the
N‐formylation of amine derivatives with formic acid under
solvent‐free conditions. Our key objective is to design novel
SBA‐15 nanocomposite with DES supported linear side
chains with the simple manner without tedious synthetic
procedure.
a
two‐step synthesis process.[25] First, N‐methyl‐2‐
pyrrolidinone (NMP) reacted with hydrochloric acid (HCl)
to form [HNMP]Cl, then ZnCl2 was added to form the final
DES following the procedure outlined in literature.[20]
[HNMP]ZnCl3 based DES was immobilized on calcined
SBA‐15 by dissolving certain amount of the prepared DES
in ethanol with constant stirring at 60 °C overnight. The
resulting suspension was then used to immobilize SBA‐15
with DES content of 50 wt %. After the immobilization, the
sample was dried at 60 °C under vacuum for 12 h and the cat-
alyst was labeled as DES/SBA‐15. The new concept of sup-
ported DES catalysis (Figure 1) is very simple and easy
preparation which does not require tethering or complicated
synthetic modification of SBA‐15 and therefore, the charac-
teristics of the material are dependent solely on the DES
and SBA‐15 dopant. The addition of an additional linker for
immobilization is not required, and the catalyst was prepared
by dissolving the biodegradable DES after immobilization on
the SBA‐15 at room temperature.
First, DES/SBA‐15 composite was synthesized by simple
and rapid two‐step method based on physical adsorption of
DES onto the surface of SBA‐15 as shown in Figure 1.[43]
[HNMP]ZnCl3‐based DES was prepared using a reported
procedure from the literature with some modifications via
The morphology and crystalline properties of the DES/
SBA‐15 nanocomposites were characterized by the thermal
gravimetric analysis (TGA), fourier transform infrared spec-
troscopy (FT‐IR), scanning electron microscopy (SEM),
energy dispersive X‐ray spectroscopy (EDX), and
Brunauer–Emmett–Teller (BET) surface analysis.
The SEM image used in this experiment is shown in
Figure 2. The SEM image of mesoporous SBA‐15 shows a
uniform particle distribution and morphology with some
structural twisting (Figure 2a). Considering the BET surface
analysis data and the distribution of pore size, this spatial tor-
sion does not have substantial effect on the mesostructure in
terms of surface area, pore size and pore diameter. It should
be noted that after the immobilization of DES on the SBA‐
15 surface, the irregular small and large particles shaped
(Figure 2b). However, there is not a clear explanation for
the deep eutectic solvent effect on the SBA‐15 surface but
according to the N2 adsorption/desorption isotherms for
DES/SBA‐15, the mesostructures still remained in the cata-
lyst but the surface area and the morphological structure
altered dramatically.
According to infrared spectrum of SBA‐15 (Figure 3)
there is an asymmetric stretching vibration of Si‐O‐Si
bond in 1078 cm−1. Moreover, the peaks at 463 cm−1
and 801 cm−1 both were attributes to symmetric stretching
vibration of Si‐O‐Si bonds. The observed broad absorption
in the region of 3445 cm−1 represents silanol groups at
the surface of mesoporous structure. In addition to sym-
metric and asymmetric fluctuations stretching associated
with the Si‐O‐Si bonds and silanol surface groups on
SBA‐15 mesostructure, in DES/SBA‐15 infrared spectrum
the stretching vibrations in 1638 cm−1 and 2967 cm−1
are associated with the carbonyl group and methyl alkanes
respectively.
FIGURE 1 Simple procedure for immobilization of DES on SBA‐15

AZIZI ET AL.
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hysteresis loop similar to the standard type IV isotherm
for mesoporous materials (Figure 5). The surface area for
SBA‐15 was 520 m2/g with the total pore volume of
0.50 g/cm3, and an average pore diameter of 5 nm. Based
on the BJH chart in the region of 1 to 100 nm, after
impregnation of DES on to the mesoporous SBA‐15 mate-
rial, the surface area and the total pore volume consider-
ably decreased to 150 m2/g and 0.21 cm3/g respectively
and the average pore diameter obtained to about 4.5 nm
(Figure 6). In this regard it can be concluded that the
mesoporous structure of SBA‐15 and DES/SBA‐15 in
terms of morphology and pores distribution are similar
to each other.
The thermal stability and compositional analysis of the
DES/SBA‐15 was further investigated using TGA and is
shown in Figure 7. TGA studies suggested that an abrupt
weight loss occurs from 210 to 500 °C due to decompo-
sition of DES part of catalyst. There is a 2% weight loss
around 200 °C which can be attributed to water elimina-
tion from the DES/SBA‐15. Therefore, the DES/SBA‐15
is stable around this temperature and could be
show catalytic activity.
After preparation and characterization of DES/SBA‐15
nanocomposites, the applicability and efficiency of the
nanocomposite in the N‐formylation was validated by ani-
line and formic acid as a model reaction (Table 1). First,
our investigation focused on finding the best reaction con-
dition to maximize the yield in a model system and a set
of reactions were carried out under different catalytic con-
ditions (catalyst loading, reaction time, and solvent). Due
to the environmentally friendly benefit of the solvent free
reactions, the model reaction was first carried out under
solvent‐free condition. As shown in Table 1, when the
reaction was carried out with 1.5 equiv. of formic acid
in the presence of DES/SBA‐15 (20 mg) at room temper-
ature within 50 min., a single product was obtained in
97% isolated yield after simple workup without flash
chromatography (Table 1, entry 5). Encouraged with this
initial result, we decided to monitor the time required
for completion of model reaction (Figure 8). After varying
time we found that the model reaction did not proceed for
completion at short reaction times. Upon lowering the cat-
alyst loading to 10 mg, the yield decreased to 76%,
(Table 1, entry 7) whereas an increasing in catalyst con-
centration to 50 mg did not shorten the reaction time. Fur-
thermore, results showed that no desired product could be
detected when the model reaction was conducted in the
absence of DES/SBA‐15, and only the starting materials
were recovered (Table 1, entry 9), indicating that DES/
SBA‐15 were absolutely necessary for this procedure.
However, it is worth noting that the use of SBA‐15 for
N‐formylation affords 35% yield after 50 min. (Table 1,
entry 10), while the N‐formylation in the presence of large
FIGURE 2 The SEM image of mesoporous SBA‐15 (a) and DES/
SBA‐15 (b)
Elemental analysis data of mesoporous silica SBA‐15
indicates the presence of oxygen (57.51%) and Silicon
(42.49%) percentage by weight in the mesoporous structure.
Based on the obtained results for DES/SBA‐15 in Figure 4,
the zinc, chlorine, silicon, nitrogen, oxygen, and carbon
atoms percentage by weight are in agreement with those used
for the preparation of the mesoporous SBA‐15 immobilized
with deep eutectic solvent.
The N2 adsorption–desorption isotherms for both SBA‐
15 and DES/SBA‐15 obtained by BET analysis showed

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AZIZI ET AL.
FIGURE 3 The FT‐IR spectra of SBA‐15, DES, and DES/SBA‐15
FIGURE 4 The EDS analysis for mesoporous silica SBA‐15 and DES/SBA‐15

AZIZI ET AL.
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FIGURE 5 The N2 adsorption–desorption isotherms for SBA‐15 and
DES/SBA‐15
amount of DES (100 mg) gives 85% yield (Table 1 entry 11).
In addition, the DES/SBA‐15 nanocomposite showed supe-
rior activities compared to DES or SBA‐15 alone due to the
synergistic effect and facilitates the separation of the high vis-
cose DES from the reaction mixture and reducing the cost
and the amount of DES.
Having identified the most effective optimized reaction
conditions, to demonstrate the versatility of the method,
the N‐formylation reactions between formic acid and a
variety of aromatic and aliphatic amines were screened,
and the results are shown in Table 2. Structurally diverse
anilines containing both electron‐donating and electron‐
withdrawing groups underwent N‐formylation with formic
acid under mild reaction conditions and the products were
isolated in good to excellent yields. Anilines containing
electron‐donating groups underwent the conversion
smoothly and give the excellent yields at short reaction
times. Anilines containing electron‐withdrawing groups
such as chloro, fluoro, bromo and iodo gave the good
yields with longer reaction times. In contrast, strong elec-
tron‐withdrawing group such as nitro and carbonyl and
deactivated amines (Table 2, entries 15, 16) gave the
slightly lower yield with longer reaction times. Further-
more, different functional groups in the aromatic amines
such as alkyl, nitro, halogens and carbonyl remained
intact (Table 2). The procedure is equally effective for
secondary aromatic amines and N‐ethyl aniline that gave
good yields. For a variety of sterically hindered amines
and heterocyclic amines, the catalyst showed good results
without any significant influence of their structures on the
product yields. Primary and secondary aliphatic amines
can also be used as starting components to synthesize
FIGURE 6 The BJH chart in the region of 1 to 100 nm for SBA‐15
and impregnated DES/SBA‐15
corresponding n‐formylamine under optimized reaction
conditions. When 1,2‐phenylenediamine as aromatic
diamine was used, instead of N‐formylation reaction,
benzimidazole as a sole cyclization product was obtained.
Chemoselectivity of the DES/SBA‐15 catalyst was also
investigated by performing formylation of amines with a
hydroxy group in the side chain as a bifunctional com-
pound (Table 2, entry 13). Excellent chemoselectivity
was observed for substrates with hydroxy functionalities,
providing selective N‐formylation in high yields without
side reactions.
In order to test the robustness and practical applicability of
this procedure, a relatively large‐scale reaction of aniline
(20 mmol) and formic acid (30 mmol) in the presence of
DES/SBA‐15 (200 mg) was performed. The reaction was
completed in 60 min. With 86% isolated yield after simple
work‐up. After completion of the reaction, the mixture was

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AZIZI ET AL.
FIGURE 7 Thermogravimetric analysis (TGA) of DES/SBA‐15
extracted with ethyl acetate (20 ml) and purified with the stan-
dard procedure to give the pure products.
DES/SBA‐15 catalyst was separated. The recovered DES/
SBA‐15 was dried under vacuum washed with ethyl acetate
(10 ml) used for another cycle of reaction. After four times
no appreciable loss in its catalytic activity was observed
(Scheme 1).
The possible reaction mechanism was proposed in
Figure 6. We presume that the reaction proceeds via
acid–base complexation of catalyst with the formic acid,
and the SBA‐15 part of catalyst could provide an excellent
cooperative capability in the case of creating stability and
bringing aniline and formic acid closer due to the high
pore volume and narrow pore size distribution. The nucle-
ophilic attack of aniline to the activated carbonyl carbon
of formic acid and then dehydration gives the
final products (Figure 9).
The recycling of the catalyst is substantial in the large‐
scale industrial application. The reusability of DES/SBA‐
15 in the model reaction of aniline with formic acid in
10 mmol scale was examined. After completion, the product
was extracted with ethyl acetate (15 ml) and the insoluble
TABLE 1 Optimization of N‐formylation model reaction between
aniline and formic acid
Finally, comparison of the DES/SBA‐15 catalyzed n‐
formylation of amines under solvent free conditions with
a range of other methodologies demonstrated the high
Entry
Catalyst (20 mg)
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
Des/SBA‐15
‐
Time (min)
Yield (%)a
1
10
20
30
40
50
60
50
40
50
50
50
45
60
65
80
97
97
76
97
10
35
85
2
3
4
5
6
7b
8c
9
10d
11e
SBA‐15
DES
aIsolated yields.
b10 mg DES/SBA‐15.
c50 mg DES/SBA‐15.
d20 mg SBA‐15.
e100 mg DES.
FIGURE 8 The effect of reaction time on the N‐formylation reaction

AZIZI ET AL.
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TABLE 2 N‐formylation of a variety of aromatic and aliphatic amines in the presence of DES/SBA‐15
Entry
Substrate
Yielda(%)
References
[46]
1
97
[47]
2
78
[48]
[46]
[46]
[46]
3
4
5
6
97
90
97
90
[49]
[46]
7
8
98
74
[47]
[46]
[49]
[47]
9
88
92
82
80
10
11
12
[50]
[51]
13
78
74
14b
[51]
[46]
15
16
72
78
aIsolated yields.
bbenzimidazole as product

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AZIZI ET AL.
monitored by GC or thin layer chromatography (TLC) with
UV light as detecting agents.
SCHEME 1 The reusability of DES/SBA‐15 catalyst
2.2 | Preparation of DES/SBA‐15
nanocomposite
In a separate 100‐mL, three‐necked flask equipped with a
magnetic stirring bar and a reflux condenser was charged
with a N‐methyl‐2‐pyrrolidone (7.22 ml, 75 mmol). After
cooling down the reaction mixture to 0 °C in ice bath, the
equimolar HCl 32% was added dropwise over a 1 h period
and subsequently the reaction temperature was raised to
45 °C and was stirred for 24 h. Then, the water was removed
by rotary evaporation and the white solid product was washed
several times with ethyl acetate to remove any unreacted
starting materials and dried under vacuum by rotary evapora-
tor. In the next step, [HNMP]Cl mixed with equimolar ZnCl2
and heated under constant stirring at 100 °C for 12 h under
N2 atmosphere. The [HNMP]ZnCl3 was then dried under
vacuum for 12 h and honey like brown viscose liquid was
obtained. Finally, in 100 ml flask containing 2 g calcined
SBA‐15 in 20 ml ethanol, HNMP/ZnCl3 (2 g) was added
and the reaction mixture was stirred at 60 °C overnight.
The final DES/SBA‐15 nanocomposite was obtained by
removing the solvent under vacuum by rotary
evaporator.[25,43]
FIGURE 9 The proposed reaction mechanism for N‐formylation of
aniline with formic acid
yields, short reaction times, low loading of catalyst and
eco‐friendly nature of the protocol (Table 3).
2 | EXPERIMENTAL
2.1 | General
Melting and boiling points were determined on a Buchi melt-
ing point B‐545 apparatus. FTIR spectra were taken on a
Bruker Vector‐22 spectrometer in KBr pellets and reported
2.3 | General procedure
In the dried test tube with a magnetic stir bar, amine
(1 mmol), formic acid (1.5 mmol) and DES/SBA‐15
(20 mg) were added. The mixture was stirred vigorously
at room temperature and the progress of the reaction was
monitored by TLC or GC. After completion, the mixture
was extracted with ethyl acetate (10 ml) and washed with
water (10 ml), and then dried over anhydrous Na2SO4.
After evaporation of the ethyl acetate with a rotary
1
in cm−1. H NMR spectra were recorded at 500 MHz on a
Bruker Avance‐500 spectrometer in CDCl3 as solvent with
chemical shifts given in ppm relative to TMS as an internal
standard. All chemicals such as amine, formic acid, DES
and SBA‐15 components were obtained from commercial
suppliers and used without further purification. Water and
Other solvent were distilled before use. All the reactions were
TABLE 3 Comparison of DES/Sba‐15 catalyst with previous procedure in the n‐formylation reaction
Entry
Catalyst
Thiazolium carbine (7.5 mol%)
ZnCl2 (10 mol%)
Solvent
DMA
Temp. (°C)
Time (h)
15
Yields (%)
Ref.
[52]
1
2
3
4
5
6
7
8
9
10
50
70
53
96
96
97
93
86
97
69
99
97
[9]
Solvent‐free
CH3CN
0.16
11
[11]
[46]
[47]
[48]
[49]
[50]
[51]
‐
Reflux
70
Nano‐Fe3O4 (10 mol%))
Pd(OAC)2/bpy,PivOH/BF3.Et2O (0.01 mmol)
FSG‐Hf(NPf2)4 (1 mol%)
SBA‐15/PrEn‐NHSO3 (1 mol%)
[Cp*RhCl2]2, KI (1.6 mmol)
[Ch‐SO3H]3W12PO40 (20 mg)
DES/SBA‐15 (20 mg)
PEG400
0.5
Toluene
120
70
24
Solvent‐free
Solvent‐free
DMSO
1
50
4
100
Rt
20
Solvent‐free
Solvent‐free
0.08
0.66
Rt
This work

AZIZI ET AL.
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[20] J. Wei, H. Wang, Y. Deng, Z. Sun, L. Shi, B. Tu, M. Luqman, D.
evaporator, the residue was purified by column chromatog-
raphy on silica gel to obtain the pure N‐formyl amine deriv-
atives. All compounds were known and were confirmed by
Zhao, J. Am. Chem. Soc. 2011, 133, 20369.
[21] V. T. Hoang, Q. Huang, M. Eić, T. O. Do, S. Kaliaguine, Langmuir
2005, 21, 2051.
1
FTIR, H NMR and melting point.
[22] F. Tang, L. Li, D. Chen, Adv. Mater. 2012, 24, 1504.
In summary, the greener protocol developed in this paper
offers an efficient catalytic system for N‐formylation of
amines in the presence of DES/SBA‐15 as a novel heteroge-
neous catalyst under solvent‐free conditions at room temper-
ature. The application of DES/SBA‐15 to the N‐formylation
of a wide variety of primary and secondary amines provides
a green method for the synthesis of formamide derivatives
in good to excellent yields. The methodology was shown to
be fast, economic and environment friendly, and it involved
a simple work‐up.
[23] Q. Tang, Y. Wang, J. Zhang, R. Qiao, X. Xie, Y. Wang, Y. Yang.
Appl. Organomet. Chem. 2016, 30, 435.
[24] H. Cao, X. H. Zhu, D. Wang, Z. Sun, Y. Deng, X. F. Hou, D. Zhao,
ACS Catal. 2015, 5, 27.
[25] X. Chen, H. Guo, A. A. Abdeltawab, Y. Guan, S. S. Al‐Deyab, G.
Yu, L. Yu, Energy Fuels 2015, 29, 2998.
[26] P. Wang, F.‐P. Ma, Z.‐H. Zhang, J. Mol. Liq. 2014, 198, 259.
[27] I. del Hierro, Y. Pérez, M. Fajardo. Appl. Organomet. Chem. 2016,
30, 208.
[28] E. L. Smith, A. P. Abbott, K. S. Ryder, Chem. Rev. 2014, 114,
11060.
REFERENCES
[29] P. Liu, J.‐W. Hao, L.‐P. Mo, Z.‐H. Zhang, RSC Adv. 2015, 6,
[1] A. J. Pearson, W. R. Roush, Handbook of Reagents for Organic
Synthesis, Activating Agents and Protecting Groups, John Wiley
and Sons Ltd, Dublin, Ireland, 1999.
48675.
[30] D. A. Alonso, R. Chinchilla, I. M. Pastor, D. J. Ramón, Eur. J. Org.
Chem. 2016, 612.
[2] J. Martinez, J. Laur, Synthesis 1982, 979.
[31] M. Hayyan, F. S. Mjalli, M. A. Hashim, I. M. AlNashef, Fuel Pro-
cess. Technol. 2010, 91, 116.
[3] T. W. Green, P. G. M. Wuts, Protective Groups in Organic Synthe-
sis, 4th ed., Wiley Interscience, New York, 1991.
[32] M. Hayyan, M. A. Hashim, M. A. Al‐Saadi, A. Hayyan, I. M.
AlNashef, M. E. S. Mirghani, Chemosphere 2013, 93, 455.
[4] S. Das, F. D. Bobbink, S. Bulut, M. Soudani, P. J. Dyson, Chem.
Commun. 2016, 2497.
[33] A. Abo‐Hamad, M. Hayyan, M. A. AlSaadi, M. A. Hashim, Chem.
Eng. J. 2015, 273, 551.
[5] A. Jackson, O. Meth‐cohnt, J. Chem. Soc., Chem. Commun. 1995,
1319.
[34] A. S. Amarasekara, Chem. Rev. 2016, 116, 6133.
[6] F. F. Blicke, C.‐J. Lu, J. Am. Chem. Soc. 1952, 74, 3933.
[7] M. Waki, J. Meienhofer, J. Org. Chem. 1977, 42, 2019.
[8] F. M. F. Chen, N. L. Benoiton, Synthesis 1979, 709.
[35] M. K. Alomar, M. Hayyan, M. A. Alsaadi, S. Akib, A. Hayyan, M.
A. Hashim, J. Mol. Liq. 2016, 215, 98.
[36] G. Yu, X. Li, X. Liu, C. Asumana, X. Chen, Ind. Eng. Chem. Res.
2011, 50, 2236.
[9] A. Chandra Shekhar, A. Ravi Kumar, G. Sathaiah, V. Luke Paul,
M. Sridhar, P. Shanthan Rao, Tetrahedron Lett. 2009, 50, 7099.
[37] Q. H. Zhang, K. D. Vigier, S. Royer, F. Jerome, Chem. Soc. Rev.
2012, 41, 7108.
[10] M. Mihara, Y. Ishino, S. Minakata, M. Komatsu, Synthesis 2003,
2317.
[38] Z.‐H. Zhang, X.‐N. Zhang, L.‐P. Mo, Y.‐X. Li, F.‐P. Ma, Green
Chem. 2012, 14, 1502.
[11] P. Ganapati Reddy, G. D. Kishore Kumar, S. Baskaran, Tetrahe-
dron Lett. 2000, 41, 9149.
[39] A. P. Abbott, G. Capper, D. L. Davies, R. K. Rasheed, V.
[12] L. De Luca, G. Giacomelli, A. Porcheddu, M. Salaris, Synlett 2004,
Tambyrajah, Chem. Commun. 2003, 99, 70.
2570.
[40] J. Lu, X. T. Li, E. Q. Ma, L. P. Mo, Z. H. Zhang, ChemCatChem
2014, 6, 2854.
[13] N. Azizi, B. Mirmashhori, M. R. Saidi, Catal. Commun. 2007, 8,
2198.
[41] A. Hayyan, M. A. Hashim, M. Hayyan, F. S. Mjalli, I. M. Alnashef,
[14] L. Zhang, Z. Han, X. Zhao, Z. Wang, K. Ding, Angw. Chem. Int.
Ed. 2015, 54, 6186.
J. Cleaner Prod. 2014, 65, 246.
[42] Z. Maugeri, Z. P. Domínguez de María, ChemCatChem 2014, 6,
[15] Y. Wei, C. Keke, Z. Xiaofang, K. Yingying, T. Xiujuan, H.
1535.
Xiaoxiang, J. Ind. Eng. Chem. 2015, 29, 185.
[43] N. Azizi, M. Edrisi, Microporous Mesoporous Mater. 2017, 240,
[16] P. T. Anastas, J. C. Warner, The Pollution Prevention Act (PPA)
states: Principles of Green Chemistry, Theory and Practice, Oxford
University Press, New York, 1998.
130.
[44] N. Azizi, E. Gholibeglo, RSC Adv. 2012, 2, 7413.
[45] N. Azizi, S. Dezfooli, M. Khajeh, M. M. Hashemi, J. Mol. Liq.
2013, 186, 76.
[17] B. Tanwar, P. Purohit, B. N. Raju, D. Kumar, D. N. Kommi, A. K.
Chakraborti, RSC Adv. 2015, 5, 11873.
[46] Z.‐G. Wang, M. Lu, RSC Adv. 2014, 4, 1234.
[18] D. N. Kommi, D. Kumar, K. Seth, A. K. Chakraborti, Org. Lett.
2013, 15, 1158.
[47] S. Rostamnia, E. Doustkhah, J. Mole. Catal. A: Chem. 2016, 411,
317.
[19] M. Kruk, M. Jaroniec, C. H. Ko, R. Ryoo, Chem. Mater. 2000, 12,
1961.
[48] D.‐W. Gu, X.‐X. Guo, Tetrahedron 2015, 71, 9117.

10 of 10
AZIZI ET AL.
[49] Y. Wei, J. Wu, D. Xue, C. Wang, Z. Liu, Z. Zhang, G. Chen, J.
Xiao, Synlett 2014, 25, 1295.
How to cite this article: Azizi N, Edrisi M, Abbasi F.
Mesoporous silica SBA‐15 functionalized with acidic
deep eutectic solvent: A highly active heterogeneous
N‐formylation catalyst under solvent‐free conditions.
Appl Organometal Chem. 2017;e3901. https://doi.org/
10.1002/aoc.3901
[50] M. Hong, G. Xiao, J. Fluorine Chem. 2013, 146, 11.
[51] S. P. Satasia, P. N. Kalaria, D. K. Raval, J. Mol. Catal. A: Chem.
2014, 391, 41.
[52] S. Das, F. D. Bobbink, S. Bulut, M. Soudani, P. J. Dyson, Chem.
Commun. 2016, 52, 2497.