Preparation of Well-Ordered Mesoporous-Silica-Supported Ruthenium Nanoparticles for Highly Selective Reduction of Functionalized Nitroarenes through Transfer Hydrogenation

Article abstract of DOI:10.1002/ejoc.201701228

MCM-41-type mesoporous silica (OMS-IL) was prepared by using an ionic liquid (1-hexadecyl-3-methylimidazolium bromide) as a template. The XRD and TEM results demonstrated that OMS-IL was more stable than the MCM-41 material. Ru nanoparticles were supported on OMS-IL (Ru/OMS-IL) by impregnating OMS-IL with a RuCl₃ aqueous solution, and the resulting material was used for the selective reduction of nitroarenes. The effects of the components of the catalysts and the reaction conditions on the catalytic behavior of the prepared catalysts were investigated in detail. Ru/OMS-IL exhibited high catalytic activity and chemoselectivity for the reduction of various substituted nitroarenes to the corresponding aromatic amines in ethanol with hydrazine hydrate as a hydrogen donor under mild conditions. The Ru/OMS-IL catalysts were highly stable and could easily be recovered by simple filtration over at least six recycling reactions without any observable loss in catalytic performance.

Full text of DOI:10.1002/ejoc.201701228

DOI: 10.1002/ejoc.201701228
Full Paper
Nanoparticles | Very Important Paper |
Preparation of Well-Ordered Mesoporous-Silica-Supported
Ruthenium Nanoparticles for Highly Selective Reduction of
Functionalized Nitroarenes through Transfer Hydrogenation
[
a,b]
[a,b]
[a,b]
[a,b]
Weizhong Ding,[a,b]
Ning Wei,
Xiujing Zou,*
Haigen Huang,
Xueguang Wang,*
and Xionggang Lu[
a,b]
Abstract: MCM-41-type mesoporous silica (OMS-IL) was pre- pared catalysts were investigated in detail. Ru/OMS-IL exhibited
pared by using an ionic liquid (1-hexadecyl-3-methylimid- high catalytic activity and chemoselectivity for the reduction of
azolium bromide) as a template. The XRD and TEM results dem- various substituted nitroarenes to the corresponding aromatic
onstrated that OMS-IL was more stable than the MCM-41 mate- amines in ethanol with hydrazine hydrate as a hydrogen donor
rial. Ru nanoparticles were supported on OMS-IL (Ru/OMS-IL) under mild conditions. The Ru/OMS-IL catalysts were highly sta-
by impregnating OMS-IL with a RuCl aqueous solution, and ble and could easily be recovered by simple filtration over at
3
the resulting material was used for the selective reduction of least six recycling reactions without any observable loss in cata-
nitroarenes. The effects of the components of the catalysts and lytic performance.
the reaction conditions on the catalytic behavior of the pre-
Introduction
Functionalized aromatic amines are important intermediates in
the production of a range of pharmaceuticals, agrochemicals,
cosmetics, herbicides, dyes, and polymers.
obtained through the catalytic hydrogenation of the corre-
sponding aromatic nitro compounds by using reducing agents
high-surface-area heterogeneous catalyst supports, are recog-
nized as promising catalysts for the catalytic hydrogenation of
nitro compounds because of their high catalytic activity and
[
15,25,26]
low cost.
So, it is a challenge to develop cost-effective
[
1–4]
Amines can be
and highly efficient heterogeneous noble-metal catalysts for
the green chemoselective reduction of nitroarenes.
[
5]
[6]
It is generally believed that the high surface area of hetero-
geneous catalysts results in their high catalytic activity. The
mesoporous material MCM-41 is a good candidate for a solid
support, as it has a regular pore diameter of ca. 5 nm and a
such as hydrosilanes, sodium borohydride, hydrazine deriva-
[
7,8]
[9]
[10,11]
tives,
formic acid, and molecular hydrogen.
However,
selectivity in the targeted reduction of the –NO group in the
presence of other reactive function groups (e.g., alkenes,
nitriles, esters, and halogen groups) remains a big challenge
for the production of aromatic amines. Homogeneous metal
catalysts, especially Ru and Ir complexes, are usually used for
the catalytic hydrogenation of nitro compounds.
2
2
–1 [27]
high surface area (> 1000 m g ).
Its large pore size allows
[
12]
the passage of large molecules such as organic reactants and
metal complexes through the pores so that they may reach the
[
28–30]
[
13–15]
surfaces of the channels.
Nevertheless, MCM-41 is re-
However,
ported to have high thermal stability and hydrothermal stability
in air and oxygen-containing water vapor. However, it has low
the homogeneous catalytic process is generally unaccepted as
a preferential alternative, as recovery and reuse of the expen-
sive metals are difficult and most of the reactions do not pro-
ceed without the use of expensive ligands. Heterogeneous cata-
[
31,32]
hydrothermal stability in water and aqueous solutions.
To
enlarge the application range of MCM-41, it is important to
[
1,16,17]
[18–21]
[22,23]
[33]
lysts (noble metal catalysts such as Au,
Pd,
Pt,
improve its hydrothermal stability.
It was reported that by
[
13,25,26]
and Ru
) have many advantages over their homogeneous adapting the synthesis parameters, such as the type of silicium
counterparts, including easy removal from reaction mixtures source, type of template, pH, and temperature, different materi-
and recyclability. Ru catalysts, especially those supported on als could be synthesized with varying porosity and crystalli-
[
32]
nity.
[
[
a] State Key Laboratory of Advanced Special Steel, Shanghai University
Shanghai 200072, China
b] Shanghai Key Laboratory of Advanced Ferrometallurgy,
School of Materials Science and Engineering, Shanghai University,
Shanghai 200072, China
In the present study, ordered mesoporous silica (OMS-IL)
with good hydrothermal stability was synthesized by using 1-
hexadecyl-3-methylimidazolium bromide (C mimBr) as a tem-
16
plate. OMS-IL-supported Ru catalysts (Ru/OMS-IL) were pre-
pared by the impregnation method. Ru species were uniformly
dispersed in the mesoporous silica without changes in the or-
dered mesoporous structure. Their behavior in the reduction of
nitroarenes to the corresponding aromatic amines with hydra-
E-mail: xjzou@shu.edu.cn
wxg228@shu.edu.cn
http://www.sklass.shu.edu.cn/
Supporting information for this article is available on the WWW under
https://doi.org/10.1002/ejoc.201701228.
Eur. J. Org. Chem. 2018, 209–214
209
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zine hydrate (N H ·H O) in ethanol without any other additive (Figure 2). The TEM images show that the pore walls are thicker
2
4
2
(
acid or base) was intensively investigated. The Ru/OMS-IL cata- in the OMS-IL sample than in MCM-41, which is in accordance
lysts exhibited excellent catalytic activity and chemoselectivity with the XRD results. Considering the indiscernible Ru particle
for the reduction of nitroarenes to the corresponding aromatic size in 0.5Ru/OMS-IL, Ru/OMS-IL samples with higher Ru load-
amines. Noticeably, hydrazine hydrate as a hydrogen donor ing were prepared and characterized by TEM. Figure 3 shows
generated only N as a byproduct.
that for all of the xRu/OMS-IL samples (x = 1, 2, and 3), ultrafine,
dark Ru nanoparticles are homogeneously distributed through-
out the silica matrices. The size of the Ru nanoparticle increases
slightly upon increasing the Ru loading.
2
Results and Discussion
Physical and Chemical Properties of the Catalysts
XRD was first used to study the crystalline phases of the pre-
pared materials. Figure 1 displays the small- and wide-angle
XRD patterns of the prepared samples. The results of the small-
angle XRD patterns (Figure 1a) show that both MCM-41 materi-
als prepared possess a strong diffraction peak at around 2θ =
2.1–2.4° and two other weak peaks at 2θ = 3.7–4.1 and 4.3–
4.8°, which can be assigned to the lattice faces (100), (110), and
(
200), respectively, indicating a quasiregular arrangement of the
[
35]
mesopores with hexagonal symmetry. Relative to the diffrac-
tion peaks of MCM-41 in Figure 1, the diffraction peaks repre-
senting the ordered mesoporous structure of OMS-IL are shifted
to smaller angles. This indicates that the pore walls are thicker
in the OMS-IL samples than in MCM-41
C mimBr (used as a template) having longer molecular chains
[
36]
likely as a result of
1
6
than cetyltrimethylammonium bromide (CTAB). For 0.5Ru/MCM-
1, the intensity of the diffraction deceases gradually relative
4
to that of MCM-41, which indicates that the initially ordered
pore channels of MCM-41 are destroyed once Ru is supported.
In the case of the 0.5Ru/OMS sample, there are also clear dif-
fractions at 2θ = 2.4, 4.1, and 4.8°, and the intensities of the
diffractions do not change distinctly relative to those of the
OMS-IL support, which indicates that the quasiregular arrange-
ment of the mesopores with hexagonal symmetry is not de-
stroyed after supporting Ru by using the impregnation method.
It is speculated that the good stability of OMS-IL can be attrib-
Figure 2. TEM images of the prepared samples: (a) OMS-IL, (b) MCM-41, (c) Ru/
OMS-IL, and (d) Ru/MCM-41.
[
37,38]
uted to thicker pore walls, as reported previously.
The
wide-angle XRD patterns of all the samples in Figure 1b show
typical broad bands for the amorphous silica walls of solid
mesoporous MCM-41. Diffraction peaks for Ru species are not
observed in the 0.5Ru/MCM-41 and 0.5Ru/OMS-IL samples,
which indicates that Ru is highly dispersed in these mesomate-
rials. These results are consistent with the TEM observations
Figure 1. (a) Low-angle and (b) wide-angle XRD patterns of the prepared
samples.
Figure 3. TEM images of (a) 1Ru/OMS-IL, (b) 2Ru/OMS-IL, and (c) 3Ru/OMS-IL.
(d) X-ray photoelectron spectrum of 0.5Ru/OMS-IL.
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2
–1
3
–1
The Ru X-ray photoelectron spectrum (Figure 3d) of 0.5Ru/ (SBET) of 1242 m g , a pore volume (V ) of 0.90 cm g , and
p
OMS-IL shows that the Ru 3d spectral bands at binding energies a pore size (D ) of 2.9 nm, whereas those of 0.5Ru/MCM-41 are
p
2
–1
3
–1
(
BEs) of 284.4 and 280.2 eV are dominant, and they can be 771 m g , 0.47 cm g , and 2.4 nm, respectively. These results
0
[26]
attributed to Ru ; they indicate that metallic Ru is formed as may be related to destruction of the initial ordered pore chan-
the major phase on the surfaces. BJH analysis (not shown) indi- nels of MCM-41. Compared with OMS-IL, 0.5Ru/OMS-IL has a
cates that both OMS-IL and MCM-41 present uniform pore-size smaller specific surface area, pore volume, and average pore
distributions. Table 1 displays the textural properties of the pre- size owing to partial coating of the OMS-IL surface by Ru and
pared materials. Compared with the MCM-41 support, 0.5Ru/ variation in the mass density of the catalysts.
MCM-41 exhibits a clear decrease in the BET surface area, pore
volume, and pore size. MCM-41 shows a specific surface area
Catalytic Reaction
Table 1. Textural properties of the prepared materials.
The reduction of 4-methoxylnitrobenzene was examined as a
2
[cm g–1]
3
Sample
S
BET [m g–1]
V
p
D
p
[nm]
model reaction over the prepared catalysts to optimize the
components of the samples, and the results are shown in
Table 2. Ru catalysts with various supports were prepared, and
their catalytic performances were evaluated (Table 2, entries 1–
MCM-41
OMS-IL
1242
1051
771
0.90
1.03
0.47
0.85
2.9
3.9
2.4
3.6
0
.5Ru/MCM-41
.5Ru/OMS-IL
0
940
8
). Both of the SiO -supported Ru catalysts presented much
2
Table 2. Performance of the prepared catalysts for the chemoselective reduction of 4-methoxynitrobenzene to 4-methoxyaniline.[a]
.
Entry
Catalyst
Reducing agent
equiv.]
Solvent
[mL]
Conversion
[%]
Selectivity
[%]
[
1
2
3
4
5
6
7
8
9
0.5Ru/OMS-IL
0.5Ru/MCM41
0.5Ru/SBA-15
0.5Ru/C
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
–
69
28
32
8
5
4
<1
<1
<1
3
22
17
67
57
50
41
36
<1
<1
<1
<1
28
59
71
59
29
43
23
17
52
60
43
32
>99
>99
>99
>99
>99
>99
–
0.5Ru/TiO
0.5Ru/Al
0.5Ru/CeO
0.5Ru/ZrO
2
2
O
3
2
2
–
–
0.5Au/OMS-IL
0.5Ag/OMS-IL
0.5Pt/OMS-IL
0.5Pd/OMS-IL
0.25Ru/OMS-IL
1.0Ru/OMS-IL
2.0Ru/OMS-IL
3.0Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
0.5Ru/OMS-IL
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
>99
>99
>99
>99
>99
>99
>99
64
–
–
–
–
[
[
[
[
b]
c]
d]
e]
4
NaBH (6)
HCOOH (6)
HCOOK (6)
[
f]
H
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
N
2
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
H
4
(0)
(2)
(4)
(8)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
(6)
EtOH (2)
EtOH (2)
EtOH (2)
EtOH (2)
iPrOH (2)
THF (2)
98
>99
>99
>99
>99
>99
98
toluene (2)
EtOAc (2)
distilled H
EtOH (0)
EtOH (1)
EtOH (4)
EtOH (6)
2
O (2)
76
>99
>99
>99
>99
[
[
a] Reaction conditions: catalyst (10 mg), 4-methoxynitrobenzene (2 mmol), 40 °C, 30 min. [b] Catalyst (20 mg). [c] Catalyst (5 mg). [d] Catalyst (2.5 mg).
e] Catalyst (1.7 mg). [f] PH2 = 2 MPa.
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higher conversions of 4-methoxynitrobenzene than all of the collapsed structure led to aggregation of the ruthenium parti-
other support catalysts. Specifically, 0.5Ru/OMS-IL showed a cles, and a decrease in the number of active sites was the main
much higher conversion of 4-methoxynitrobenzene (69 %) than reason for the low reaction activity. The conversion of
the 0.5Ru/MCM-41 (28 %) and 0.5Ru/SBA-15 (32 %) samples. Al- 4-methoxynitrobenzene was lower on the Au-, Ag-, Pt-, and Pd-
though both OMS-IL and SBA-15 were hydrothermally stable, supported OMS-IL catalysts (Table 2, entries 9–12) than on the
the excellent activity of 0.5Ru/OMS-IL might result from readily 0.5Ru/OMS-IL catalyst. The effect of the Ru loading was investi-
accessible and uniform catalytic sites within the appropriate gated (Table 2, entries 1 and 13–16), and the highest conversion
[
39]
pore structure of OMS-IL.
In the case of 0.5Ru/MCM-41, the was obtained with 0.5Ru/OMS-IL. The effects of the hydrogen
Table 3. Chemoselective reduction of various nitroarenes over 0.5Ru/OMS-IL.[a]
[
a] Reaction conditions: catalyst (10 mg), 4-methoxylnitrobenzene (2 mmol), N
2 4 2
H ·H O (12 mmol), ethanol (2 mL), 40 °C. [b] TOF: turnover frequency; calculated
on the basis of total metal and substrate conversions at 10 %. [c] The product was 1,2,4-benzenetriamine. [d] The product was 1,3-diaminobenzene.
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donor, solvent, and substrate concentration were investigated
To investigate the reusability of the 0.5Ru/OMS-IL catalyst
in detail to optimize the reaction conditions, and the results are for the chemoselective reduction of nitroarenes, the selective
summarized in Table 2 (entries 17–33). Initially, we explored the reduction of 2,4-dichloronitrobenzene was examined as an ex-
reduction of 4-methoxynitrobenzene in the presence of 0.5Ru/ ample. The selective reduction of 2,4-dichloronitrobenzene with
OMS-IL with five different hydrogen donors: hydrazine hydrate, ca. 74 % conversion in the first cycle (Figure 4), at which the
sodium borohydride, formic acid, potassium formate, and reduction of 2,4-dichloronitrobenzene was controlled by chemi-
hydrogen (Table 2, entries 17–21). The use of hydrazine hydrate cal kinetics, was evaluated under the optimum conditions. After
(
Table 2, entry 1) in ethanol as the solvent resulted in the high- every run, the catalyst was recovered by simple filtration, which
est conversion of 4-methoxynitrobenzene (69 %) with >99 % se- was followed by washing with ethanol. The conversion of 2,4-
lectivity to 4-methoxyaniline. Upon using sodium borohydride dichloronitrobenzene decreased only slightly from 75 to 65 %
in ethanol, the conversion of 4-methoxynitrobenzene was 36 % after six cycles, whereas the selectivity to 2,4-dichloroaniline
and the selectivity to 4-methoxyaniline was 64 %. The use of was maintained at >99 % (Figure 3). After the sixth run, the
formic acid or potassium formate in ethanol or hydrogen as spent catalyst was characterized by XRD. No observable
the hydrogen donor did not show any conversion. The catalytic changes in the ordered mesoporous structure or Ru particle
activity increased upon increasing the hydrazine content and size were detected. Inductively coupled plasma atomic emission
approached a stable value if the molar ratio of hydrazine to spectrometry (ICP-AES) analyses showed that the amount of Ru
in the filtrate was negligible (< 1 ppm), which indicated that
leaching of the metal components did not occur during the
reaction procedure.
substrate reached 6:1 (Table 2, entries 1 and 22–24); all of the
solvents, including ethanol, isopropyl alcohol, THF, toluene,
ethyl acetate, and distilled water, resulted in excellent catalytic
performances, but ethanol [4-methoxynitrobenzene/ethanol =
–
1
2:1 (mmol mL )] allowed the highest conversion of 4-methoxy-
nitrobenzene (Table 2, entries 1 and 25–33).
The selective hydrogenation protocol of the 0.5Ru/OMS-IL
catalyst was further extended to the conversion of various sub-
stituted nitroarenes into the corresponding amines to demon-
strate the generality of this reaction under the optimized condi-
tions, and the results are summarized in Table 3. 0.5Ru/OMS-IL
presented high intrinsic activity and excellent selectivity in the
hydrogenation reactions to the corresponding aromatic amines
under the given conditions. Nitroarenes with nonreducible
groups such as –CH , –OH, –NH , and –CF (Table 3, entries 1–
Figure 4. Reusable profiles of the 0.5Ru/OMS-IL catalyst for the selective re-
duction of 2.4-dichloronitrobenzene to 2,4-dichloroaniline. Reaction condi-
3
2
3
9), were quantitatively transformed into the corresponding
tions: catalyst (20 mg), 2,4-dichloronitrobenzene (4 mmol),
24 mmol), ethanol (3 mL), 40 °C.
2 4 2
N H ·H O
amines in yields >99 %. Furthermore, we were pleased to find
that halo (F, Cl, Br)-substituted nitroarenes could be reduced to
the corresponding anilines with no discernible dehalogenation
(
(
Table 3, entries 10–20). A number of other reducible functional
Conclusions
groups (e.g., carboxy, ester, nitrile, amide, and sulfanilamide)
were tolerated in the reduction reaction (Table 3, entries 21–
2
ing diaminobenzenes (Table 3, entries 25 and 26). Interestingly,
chemoselective reduction of N-heterocyclic nitroarenes could
In summary, OMS-IL- with stable structures was prepared by
using 1-hexadecyl-3-methylimidazolium bromide as a template.
The Ru/OMS-IL catalysts, prepared by the impregnation
method, efficiently and quantitatively reduced various function-
4). Notably, dinitrobenzenes were reduced to the correspond-
also be performed to give the corresponding amines in yields alized nitroarenes to the corresponding anilines with yields
99 % (Table 3, entries 27–30). In these reactions, sufficiently >99 % by using hydrazine hydrate. Recycling tests and charac-
>
high chemoselectivity for reduction of the nitro group in the terization revealed that 0.5Ru/OMS-IL was highly stable and
benzene ring can likely be attributed to the fact that the nitro could be reused for the reduction of nitroarenes.
group is more reactive than other reducible groups over the
catalyst, and this is strongly supported by intermolecular
competitive reductions that were performed separately.
Upon reducing mixtures of nitrobenzene and other reducible-
group-substituted benzenes (e.g., benzoic acid, ethyl benzoate,
Supporting Information: Complete experimental details, charac-
terization data.
Acknowledgments
benzonitrile, benzamide, styrene, quinoline) with hydrazine in This research was supported by the Open Project of the State
ethanol at 40 °C, nitrobenzene was completely converted into Key Laboratory of Advanced Special Steel of Shanghai Univer-
aniline, whereas the other reactants did no undergo any reac- sity (SKLASS2015-Z052), National Basic Research Program of
tion. These results indicate that the 0.5Ru/OMS-IL catalyst has China (973 Program, No. 2014CB643403), the National Natural
both high activity and high selectivity for the chemoselective Science Foundation of China (No. 51574164), and Basic Major
reduction of various functionalized nitroarenes under mild con- Research Program of Science and Technology Commission
ditions.
Foundation of Shanghai (No. 14JC1491400).
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Full Paper
[
21] Y. Lu, H. Zhu, W. Li, B. Hu, S. Yu, J. Mater. Chem. A 2013, 1, 3783–3788.
Keywords: Ordered mesoporous silica · Ruthenium ·
Reduction · Nanoparticles · Nitroarenes
[22] L. Cisneros, P. Serna, A. Corma, Angew. Chem. Int. Ed. 2014, 53, 9306–
9310; Angew. Chem. 2014, 126, 9460–9464.
[
23] S. Byun, Y. Song, B. M. Kim, ACS Appl. Mater. Interfaces 2016, 8, 14637–
4647.
1
[
[
[
[
[
[
1] D. Wang, D. Astruc, Chem. Rev. 2015, 115, 6621–6686.
2] P. Lara, K. Philippot, Catal. Sci. Technol. 2014, 4, 2445–2465.
3] S. Gladiali, E. Alberico, Chem. Soc. Rev. 2006, 35, 226–236.
4] P. Serna, A. Corma, ACS Catal. 2015, 5, 7114–7121.
5] D. Porwal, M. Oestreich, Eur. J. Org. Chem. 2016, 3307–3309.
6] P. Zhou, D. Li, S. Jin, S. Chen, Z. Zhang, Int. J. Hydrogen Energy 2016, 41,
[
[
[
[
24] A. J. A. Watson, A. J. Fairbanks, Eur. J. Org. Chem. 2013, 6784–6788.
25] R. B. N. Baig, R. S. Varma, ACS Sustainable Chem. Eng. 2013, 1, 805–809.
26] Y. Gao, S. Jaenicke, G. Chuah, Appl. Catal. A 2014, 484, 51–58.
27] J. S. Beck, J. C. Vartuli, W. J. Roth, M. E. Leonowicz, C. T. Kresge, K. D.
Schmitt, C. T.-W. Chu, D. H. Olson, E. W. Sheppard, S. B. McCullen, J. B.
Higgins, J. L. Schlenker, J. Am. Chem. Soc. 1992, 114, 10834–10843.
28] T. Maschmeyer, F. Rey, G. Sankar, J. M. Thomas, Nature 1995, 378, 159.
29] C. J. Liu, S. G. Li, W. Q. Pang, C. M. Che, Chem. Commun. 1997, 2397–
1
5218–15224.
7] H. Sun, Y. Ai, D. Li, Z. Tang, Z. Shao, Q. Liang, Chem. Eng. J. 2017, 314,
28–335.
8] H. Huang, X. Wang, X. Li, C. Chen, X. Zou, W. Ding, X. Lu, Green Chem.
017, 19, 809–815.
9] L. Gong, Y. Cai, X. Li, Y. Zhang, J. Sun, J. Chen, Green Chem. 2014, 16,
746–3751.
10] Z. Shao, S. Fu, M. Wei, S. Zhou, Q. Liu, Angew. Chem. Int. Ed. 2016, 55,
4653–14657; Angew. Chem. 2016, 128, 14873–14877.
[
[
[
[
[
3
2
398.
[
30] W. Zhou, J. M. Thomas, D. S. Shephard, B. F. G. Johnson, D. Ozkaya, T.
Maschmeyer, R. G. Bell, Q. Ge, Science 1998, 280, 705–708.
2
[
[
31] R. Ryoo, S. Jun, J. Phys. Chem. B 1997, 101, 317–320.
32] T. Linssen, K. Cassiers, P. Cool, E. F. Vansant, Adv. Colloid Interface Sci.
3
[
2003, 103, 121–147.
1
[
[
[
[
33] J. R. Dodson, E. C. Cooper, A. J. Hunt, A. Matharu, J. Cole, A. Minihan,
J. H. Clark, D. J. Macquarrie, Green Chem. 2013, 15, 1203–1210.
34] C. T. Kresge, M. E. Leonowicz, W. J. Roth, J. C. Vartuli, J. S. Beck, Nature
[
[
[
11] S. Furukawa, K. Takahashi, T. Komatsu, Chem. Sci. 2016, 7, 4476–4484.
12] C. Jiang, Z. Shang, X. Liang, ACS Catal. 2015, 5, 4814–4818.
13] N. Marozsán, H. Horváth, A. Erdei, F. Joó, J. Mol. Catal. A 2016, 425, 103–
1992, 359, 710–712.
109.
35] M. Zhang, W. Zhu, H. Li, S. Xun, W. Ding, J. Liu, Z. Zhao, Q. Wang, Chem.
Eng. J. 2014, 243, 386–393.
36] J. Qin, B. Li, W. Zhang, W. Lv, C. Han, J. Liu, Microporous Mesoporous
Mater. 2015, 208, 181–187.
[
[
[
14] P. P. Sarmah, D. K. Dutta, Appl. Catal. A 2014, 470, 355–360.
15] P. Kluson, L. Cerveny, Appl. Catal. A 1995, 128, 13–31.
16] N. Perret, X. Wang, T. Onfroy, C. Calers, M. A. Keane, J. Catal. 2014, 309,
333–342.
[37] R. Mokaya, J. Phys. Chem. B 1999, 103, 10204–10208.
[38] D. Das, C. Tsai, S. Cheng, Chem. Commun. 1999, 5, 473–474.
[39] C. del Pozo, A. Corma, M. Iglesias, F. Sanchez, Green Chem. 2011, 13,
[17] W. Guo, R. Pleixats, A. Shafir, Chem. Asian J. 2015, 10, 2437–2443.
[18] J. Tuteja, S. Nishimura, K. Ebitani, RSC Adv. 2014, 4, 38241–38249.
[19] M. Vilches-Herrera, S. Werkmeister, K. Junge, A. Börner, M. Beller, Catal.
Sci. Technol. 2014, 4, 629–632.
2
471–2481.
[
20] D. Zhang, F. Ye, T. Xue, Y. Guan, Y. Wang, Catal. Today 2014, 234, 133–
138.
Received: September 4, 2017
Eur. J. Org. Chem. 2018, 209–214
www.eurjoc.org
214
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim