Sulfonic acid supported on magnetic nanoparticle as an eco-friendly, durable and robust catalyst for the synthesis of β-amino carbonyl compounds through solvent free Mannich reaction

Article abstract of DOI:10.1002/aoc.3865

A simple, efficient and environmentally benign solid acid catalyst was prepared by anchoring a propyl sulfonic acid on the surface of silica-coated magnetic nanoparticles by low cost precursors. The catalyst has been then engaged in the efficient β-amino carbonyl compounds production via three component Mannich reaction under solvent free reaction condition at room temperature. After the completing the reaction, the catalyst was readily separated by external magnet and reused for 10 successive rounds of reaction, without any significant loss in catalytic efficiency. The solid acidic system presented reusable strategy for the efficient synthesis of β-amino carbonyl compounds, simplicity in operation, and green aspects by avoiding toxic conventional catalysts under solvent-free condition.

Full text of DOI:10.1002/aoc.3865

Received: 28 January 2017
DOI: 10.1002/aoc.3865
Revised: 26 March 2017
Accepted: 2 April 2017
F U L L PA P E R
Sulfonic acid supported on magnetic nanoparticle as an eco‐
friendly, durable and robust catalyst for the synthesis of β‐amino
carbonyl compounds through solvent free Mannich reaction
Farhad Kabiri Esfahani1 | Daryoush Zareyee2
| Ali Shokuhi Rad3 | Sima Taher‐Bahrami2
1 Department of Chemistry, Faculty of
Sciences, University of Zanjan, Zanjan
45371‐38791, Iran
2 Department of Chemistry, Islamic Azad
University, Qaemshahr Branch, Qaemshahr,
Iran
3 Department of Chemical Engineering,
Qaemshahr Branch, Islamic Azad University,
Qaemshahr, Iran
A simple, efficient and environmentally benign solid acid catalyst was prepared by
anchoring a propyl sulfonic acid on the surface of silica‐coated magnetic nanoparti-
cles by low cost precursors. The catalyst has been then engaged in the efficient β‐
amino carbonyl compounds production via three component Mannich reaction
under solvent free reaction condition at room temperature. After the completing
the reaction, the catalyst was readily separated by external magnet and reused for
10 successive rounds of reaction, without any significant loss in catalytic efficiency.
The solid acidic system presented reusable strategy for the efficient synthesis of β‐
amino carbonyl compounds, simplicity in operation, and green aspects by avoiding
toxic conventional catalysts under solvent‐free condition.
Correspondence
Daryoush Zareyee, Department of
Chemistry, Islamic Azad University,
Qaemshahr Branch, Qaemshahr, Iran.
Email: zareyee@gmail.com
KEYWORDS
compounds; Mannich reaction, heterogeneous catalyst, magnetic nanoparticles, solid acid, β‐amino
carbonyl
1 | INTRODUCTION
sulfuric acid. Although liquid sulfuric acid is used annually
in critical chemical processes, but it suffers from several dis-
β‐amino carbonyl compounds are fundamental building
blocks for the preparation of peptides, amino alcohols,
lactams and as precursors to synthesize amino acids and
many nitrogen‐containing biologically important com-
pounds.[1–4] In recent years, these materials have been pre-
pared by various significant methods,[5,6] but among them,
one‐pot three component Mannich reaction of aldehydes,
ketones and aryl amines are more desirable route to con-
structing β‐amino carbonyl units. In this context, several
approaches based on Lewis acids,[7–15] Lewis base,[16–20]
Brønsted acids,[21–28] and transition metal salts[29,30] have
been used for three component Mannich reaction. However,
despite promising improvements, recycling and reusing of
catalysts, toxic reagents and solvents, harsh reaction condi-
tions and difficulty in product separation are still important
issues that remain unresolved.
advantages such as neutralization of H2SO4 that produces a
large amount of waste, troublesome separation of sulfates
(from neutralization processing) and purification of the prod-
uct which also involves substantial energy and material use.
Therefore, due to the stringent environmental standards and
economic pressures, much attention has been directed toward
to immobilized sulfuric acid on solid support to reducing of
waste, effective separation of catalyst and simple purification
of the products. Toward this aim, many support materials
such as polymers,[31,32] amorphous and mesoporous car-
bon,[33–36] mesoporous silica[37–41] and amorphous silica[42]
are often used for immobilization of sulfuric acid, which
can be separated by conventional separation techniques such
as centrifugation and filtration.
Over the last few years, magnetic nanomaterials have
developed as good alternatives to conventional support mate-
rials as readily available heterogeneous catalyst supports with
high surface area. It is noteworthy that one of the salient
As a matter of fact, one of the best Brønsted acid cata-
lysts, which is highly active in acid‐catalyzed reactions, is
Appl Organometal Chem. 2017;e3865.
wileyonlinelibrary.com/journal/aoc
Copyright © 2017 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.3865

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KABIRI ESFAHANI ET AL.
facets of magnetically supports is their separation properties
because they can be easily recovered with an external mag-
net.[43–47] Due to the unique properties of magnetic
nanomaterials, it appears that they are good candidates for
consolidation of homogeneous catalysts such as sulfuric acid.
On the other hand, in the view of the stringent environ-
mental issues and green chemistry, a growing consensus is
directed toward the carrying out organic reactions in solvent
free reaction conditions.[48–52] These reactions are becoming
more popular because they have many advantages such as
cost savings, decreased energy consumption, reduced reac-
tion times, a large reduction in reactor size and capital invest-
ment, and make the reactions cleaner, safer, and easier to
perform. It is noteworthy that “the best solvent is no solvent
and if a solvent (diluent) is needed it should preferably be
water” as clearly stated by R. A. Sheldon.[53] Furthermore,
the E factor of solvent‐free reactions is also reducing that is
very suitable for clean technology.[54] Consequently, there
FIGURE 1 Sulfonated core‐shell magnetic nanoparticles (SMNPs)
(Fe3O4@SiO2@PrSO3H)
TABLE 1 Screening of catalyst amount on model reaction of benzaldehyde, aniline and acetophenon
Entry
Fe3O4@SiO2@PrSO3H (mol%)
Time (h)
Yield[a] (%)
1
2
3
4
5
0
1
2
3
4
24
4
NR
55
92
95
96
4
4
4
[a] Isolated yields.
TABLE 2 Synthesis of different β‐aminocarbonyl compounds under solvent free condition at room temperature using SMNPs as catalyst[a]
Entry
Aldehyde
Amine
Ketone
Product
Time (h)
Yield [b] (%)
1
4
92
2
3.5
92
(Continues)

KABIRI ESFAHANI ET AL.
3 of 8
TABLE 2 (Continued)
Entry
Aldehyde
Amine
Ketone
Product
Time (h)
Yield [b] (%)
3
7
90
4
5
6
7
8
9
4
4
4
6
6
6
90
90
89
90
88
90
10
11
4
4
91
92
(Continues)

4 of 8
KABIRI ESFAHANI ET AL.
TABLE 2 (Continued)
Entry
Aldehyde
Amine
Ketone
Product
Time (h)
Yield [b] (%)
12
5
90
13
14
6
7
83
90
15
16
7
7
89
85
[a] Reaction condition: aldehyde (1 mmol), amine (1 mmol), ketone (1 mmol), Fe3O4@SiO2@PrSO3H (2 mol%), solvent free, room temperature. [b] Isolated yields after
recrystallization.
are great demands for development of environmentally
benign reaction systems that operate in a safe media and with
2 | EXPERIMENTAL
efficient and easily recoverable heterogeneous catalysts.
Toward these aims, herein we wish to report a simple,
efficient and green procedure for the synthesis of β‐amino
2.1 | General procedure for the preparation of
β–amino carbonyl compounds:
carbonyl compounds under solvent free condition by using
sulfonated core‐shell magnetic nanoparticles (SMNPs)
(Fe3O4@SiO2@PrSO3H) as a renewable and reusable strong
solid acid catalyst (Figure 1).
To the mixture of aldehyde (1 mmol), ketone (1 mmol) and
amine (1 mmol) under solvent free reaction condition
(Table 1), Fe3O4@SiO2@PrSO3H (0.03 g, 2 mol%) was
added. The mixture was stirred at room temperature for
FIGURE 2 Recyclability of the SMNPs
catalyst for the Mannich reaction of
benzaldehyde, aniline and acetophenone
after 4 h

KABIRI ESFAHANI ET AL.
5 of 8
appropriate time indicated in Table 2 until the reaction was
completed as monitored by thin‐layer chromatography. The
analytical sample was obtained by recrystallization of crude
product from ethanol. Spectroscopic data for selected exam-
ples listed below.
performance of catalyst studied in the three component
Mannich reaction, because this reaction is usually carried
out in high catalyst loading and hence the reactivity and reus-
ability of the catalyst can be studied under this reaction
conditions.
To determine the optimal experimental conditions, the
impact of various loading of SMNPs were examined and it
was found that 2 mol% of catalyst was better suited for this
purpose under solvent free condition at room temperature
(Table 1). It should be noted that decreasing of the catalyst
loading resulted in significantly lower yield. Notably,
increasing the amount of SMNPs to more than 2 mol%
resulted in slightly higher yields. Thus, because of small
Table 2, Entry 2: 1H NMR (400 MHz; CDCl3): δH = 2.34
(s, 3H), 3.48–3.60 (m, 2H), 5.01 (t,
3
3J = 8 Hz, 1H), 6.65 (d, J = 8 Hz,
3
2H), 6.73 (t, J = 8 Hz, 1H), 7.11–7.20
(m, 3H), 7.35–7.37 (d, 3J = 8.4 Hz,
3
2H), 7.47 (t, J = 8 Hz, 2H), 7.57–7.61
3
(m, 1H), 7.96 (d, J = 8.4 Hz, 2H).
Table 2, Entry 3: 1H NMR (400 MHz; CDCl3): δH = 3.50–
3.58 (m, 2H), 3.80 (s, 3H), 5.00 (t,
3
3J = 6.4 Hz, 1H), 6.63 (d, J = 8 Hz,
3
2H), 6.72 (t, J = 7.6 Hz, 1H), 6.88 (d,
3J = 8.4 Hz, 2H), 7.11–7.15 (m, 2H),
7.39 (d, 3J = 8.4 Hz, 2H), 7.47 (t,
3
3J = 7.2 Hz, 2H), 7.59 (t, J = 7.2 Hz,
1H), 7.93 (t, 3J = 7.2 Hz, 2H),
13C NMR (100 MHz, CDCl3): δC = 46.1,
54.8, 55.3, 114.2, 114.4, 118.4, 127.7,
128.2, 128.5, 128.7, 129.2, 133.5,
134.4, 136.7, 158.9, 198.4.
Table 2, Entry 5: 1H NMR (400 MHz; CDCl3): δH = 3.46–
3
3.57 (m, 2H), 5.00 (t, J = 6.4 Hz, 1H),
6.61 (d, 3J = 8 Hz, 2H), 6.75 (t,
3
3J = 8 Hz, 1H), 7.14 (t, J = 8 Hz, 2H),
7.37 (d, 3J = 8.4 Hz, 2H), 7.46–7.53
3
(m, 4H), 7.61 (t, J = 7.2 Hz,1H), 7.93
(t, 3J = 7.2 Hz, 2H), 13C NMR
(100 MHz, CDCl3): δC = 45.8, 54.8,
114.4, 118.7, 121.2, 128.2, 128.4,
128.8, 129.2, 131.9, 133.6, 136.5,
141.6, 197.8.
Table 2, Entry 6: 1H NMR (400 MHz; CDCl3): δH = 3.44–
3
3.56 (m, 2H), 5.02 (t, J = 6.8 Hz, 1H),
3
3
6.59 (d of d, J = 10 Hz, J = 0.8 Hz,
2H), 6.71 (t, 3J
=
10 Hz, 1H),
7.11–7.16 (m, 2H), 7.30–7.33 (m, 2H),
7.41–7.44 (m, 2H), 7.47–7.51 (m, 2H),
7.59–7.63 (m, 1H), 7.92–7.95 (m, 2H),
13C NMR (100 MHz, CDCl3): δC = 46.0,
54.4, 114.1, 118.4, 127.9, 128.2, 128.8,
129.0, 129.2, 133.1, 133.6, 136.6,
141.3, 146.4, 197.9.
3 | RESULTS AND DISCUSSION
Very
recently,
we
prepared
Now,
magnetic
the
catalyst
catalytic
FIGURE 3 TEM images of catalyst before (left) and after (right) the
10th reaction cycle
Fe3O4@SiO2@PrSO3H.[55,56]

6 of 8
KABIRI ESFAHANI ET AL.
difference in the yield of product, 2 mol% of catalyst selected
as optimum amount.
entries 10–13). Additionally, SMNPs also shows excellent
tolerance for a broad range of substituted aromatic amine
and converted these substrates to their corresponding prod-
ucts (Table 2, entries 14–16). These results demonstrate the
high performance and activity of the designed catalyst for
the preparation of a wide range of Mannich products bearing
different functional groups, which are important in the syn-
theses of amino acids and many nitrogen‐containing biologi-
cally important compounds.
From academic and industrial point of view, the most
important issue that should be considered for practical appli-
cations of heterogeneous catalyst systems is the lifetime of
the catalyst and the easy separation of catalyst from the reac-
tion media. In this regard, we investigated the recycling per-
formance of the catalyst in the Mannich reaction of
benzaldehyde, aniline, and acetophenone. After the comple-
tion of the first run, the SMNPs were effortlessly separated
from the reaction mixture with an external magnet. The
recovered catalyst was then directly reused under the same
conditions for at least ten reaction cycles without significant
loss of activity (Figure 2), indicating the high stability and
reusability of the catalyst during the reaction process. This
can be attributed to the efficient immobilizing of the SO3H
groups on silica coated magnetic nanoparticles. Comparison
With the optimal reaction conditions to hand, the activity
of the catalyst was then investigated in the three component
Mannich reaction of numerous electron‐rich and electron‐
poor benzaldehydes with different ketones and amines
(Table 2). The aromatic aldehydes bearing electron‐donating
groups, namely, 4‐methylbenzaldehyde (Table 2, entry 2), 4‐
methoxybenzaldehyde (Table 2, entry 3), and 4‐
hydroxybenzaldehyde (Table 2, entry 4), also afforded high
yields of the corresponding coupling adducts. Furthermore,
the other aromatic aldehydes bearing electron‐withdrawing
groups, such as 4‐boromobenzaldehyde (Table 2, entry 5),
4‐chlorobenzaldehyde (Table 2, entry 6), and 4‐
nitrobenzaldehyde (Table 2, entry 7), also gave excellent
yields of Mannich products under the same reaction condi-
tions. It is also noteworthy that in Mannich reaction of more
sterically demanding ortho‐substituted substrates, which are
usually less reactive compounds in organic transformations,
the corresponding β‐amino carbonyl compounds were
obtained in good yields (Table 2, entries 8 and 9). Notably,
this method was equally applicable to the reaction of both lin-
ear and cyclic aliphatic enolizable ketones, giving the respec-
tive carbonyl compounds in good to excellent yields (Table 2,
TABLE 3 Comparison of activity of some homogeneous and heterogeneous sulfonic acid catalysts in Mannich reaction of benzaldehyde, aniline
and acetophenon
Entry
Catalyst
Mol %
Time (h)
Yield[a] (%)
Ref.
[b]
1
Fe3O4@SiO2@PrSO3H
None
2
‐
4
92
NR
5
‐
‐
‐
‐
‐
2
24
3
H2SO4
2
4
4
p‐TSOH
2
4
30
5
KHSO4
2
4
Trace
10
6
CH3SO3H
2
4
4
‐
[23]
7
SBA‐15‐Ph‐PrSO3H
5
92
[57]
[58]
[24]
[59]
[27]
[26]
[21]
8
5/1‐butyl‐1‐aza‐[18‐C‐6KSO3H][TFA]2
PS‐SO3H[c]
10
1
5
83
9
24
75
[d]
10
11
12
13
14
PS‐PTSA
0.65 g
16
10
10
20
45 min
12
96.7
85
[Hmim]+Tfa‐[e]
[f], [i]
H3BO3
44
80
[DOPA][Tos][j],[i]
Alginic acid aerogel (AG 1)[h],[i]
6
89
18–20
90
[a] Isolated yields. [b] catalyst (2 mol%, 0.03 g). [c] ethanol, room temperature [d] 30°C, H2O. [e] benzaldehyde: aniline: acetophenone, 1:1:1 (mole ratio), ionic liq-
uid = PS‐PTSA (0.65 g). Two drops of water (0.06 g) was added to the ionic liquid. [f] [Hmim]+TFA− = 3.11 g. [g] benzaldehyde, aniline and cyclohexanone, glycerol
(1–2 drops), 45°C, H2O. [h] benzaldehyde, aniline and cyclohexanone, H2O. [i] benzaldehyde, aniline and cyclohexanone, CH3CN–H2O 8:2, R.T. [j] Compare with entry
10, Table 2.

KABIRI ESFAHANI ET AL.
7 of 8
[9] J. Xia, R. Qiu, S. Yin, X. Zhang, S. Luo, C.‐T. Au, K. Xia, W.‐Y.
Wong, J. Organomet. Chem. 2010, 695, 1487.
of the TEM images of catalyst before and after ten times
recovery showed that the size distribution of 30–60 nm (aver-
age ~ 40 nm) unchanged after recovery (Figure 3). Addition-
ally, the loading of the SO3H function in recovered SMNPs
calculated again from elemental analysis and ion exchange
pH analysis, showed intact loading of approximately
[10] H. Li, H. Y. Zeng, H. W. Shao, Tetrahedron Lett. 2009, 50, 6858.
[11] Z. Li, X. Ma, J. Liu, X. Feng, G. Tian, A. Zhu, J. Mol. Catal. A:
Chem. 2007, 272, 132.
[12] M. F. Jacobsen, L. Ionita, T. Skrydstrup, J. Org. Chem. 2004, 69,
0.9 mmol g−1
.
4792.
For a better comparison of the catalytic performance of
Fe3O4@SiO2@PrSO3H, a set of individual catalytic experi-
ments were conducted by employing H2SO4, p‐TSOH,
KHSO4 and CH3SO3H under the same reaction condition
(Table 3, entries 3–6). These results compared with some
homogeneous and heterogeneous Brønsted acid catalysts
under different conditions (Table 3, entries 7–14). It should
be noted that Fe3O4@SiO2@PrSO3H with lower catalyst load-
ing and under solvent free condition exhibits higher activity in
Mannich reaction. In comparison with other heterogeneous
catalysts (Table 3). SMNPs can recycle more easily from the
reaction mixture with an external magnet and reuse for several
times without decrease in catalytic activity.
[13] S. Kobayashi, R. Matsubara, H. Kitagawa, Org. Lett. 2002, 4, 143.
[14] I. Komoto, S. Kobayashi, Chem. Commun. 1842, 2001.
[15] S. V. Goswami, P. B. Thorat, A. V. Chakrawar, S. R. Bhusare, Mol.
Divers. 2013, 17, 33.
[16] M. Rueping, C. Vila, R. M. Koenigs, K. Poscharny, D. C. Fabry,
Chem. Commun. 2011, 47, 2360.
[17] S. E. Denmark, G. L. Beutner, Angew. Chem. Int. Ed. 2008, 47,
1560.
[18] H. Fujisawa, E. Takahashi, T. Mukaiyama, Chem. Eur. J. 2006, 12,
5082.
[19] E. Takahashi, H. Fujisawa, T. Mukaiyama, Chem. Lett. 2004, 33,
1426.
[20] K. Miura, T. Nakagawa, A. Hosomi, J. Am. Chem. Soc. 2002, 124,
536.
[21] A. Pettignano, L. Bernardi, M. Fochi, L. Geraci, M. Robitzer, N.
4 | CONCLUSIONS
Tanchoux, F. Quignard, New J. Chem. 2015, 39, 4222.
[22] T. Kano, Y. Aota, D. Asakawa, K. Maruok, Chem. Commun. 2015,
51, 16472.
In summary, covalent functionalization of propylsulfonic
acid on core‐shell magnetic nanoparticle gives a heteroge-
neous, green and reusable catalyst for the solvent‐free syn-
thesis of β‐amino carbonyl compounds through Mannich
reaction at room temperature. The advantages of this method
include low catalyst loading, easy separation of catalyst by
external magnet, recyclability of catalyst, simple procedure,
excellent yields and short reaction times. This results reveals
suitable environment for production of β‐amino carbonyl
compounds and this system represents a recyclable solid
acid catalyst.
[23] D. Zareyee, H. Alizadeh, RSC Adv. 2014, 4, 37941.
[24] S. Sahoo, T. Joseph, S. B. Halligudi, J. Mol. Catal. A: Chem. 2006,
244, 179.
[25] T. Akiyama, K. Matsuda, K. Fuchibe, Synlett 2005, 322.
[26] T. Chang, L. He, L. Bian, H. Han, M. Yuana, X. Gao, RSC Adv.
2014, 4, 727.
[27] C. Mukhopadhyay, A. Datta, R. J. Butcher, Tetrahedron Lett. 2009,
50, 4246.
[28] R. O. Duthaler, Angew. Chem. Int. Ed. 2003, 42, 975.
[29] M. O. Ratnikov, M. P. Doyle, J. Am. Chem. Soc. 2013, 135, 1549.
[30] R. K. Sharma, D. Rawat, G. Gaba, Catal. Commun. 2012, 19, 31.
REFERENCES
[31] C. S. Caetanoa, L. Guerreirob, I. M. Onsecab, A. M. Ramosb, J.
[1] Z. Zhang, Y. Zhu, C. Zhou, Q. Liu, H. Lu, Y. Ge, M. Wang, Acta
Pharmacol. Sin. 2014, 35, 664.
Vitalb, J. E. Castanheiro, Appl. Catal. A: General 2009, 359, 41.
[32] Q. Li, F. Meng, B. Zhang, M. Tian, J. Lian, J. Appl. Polym. Sci.
2008, 110, 791.
[2] R. Muller, H. Goesmann, H. Waldmann, Angew. Chem. Int. Ed.
1999, 38, 184.
[33] D. Zareyee, M. Serehneh, J. Mol. Catal. A: Chem. 2014, 391, 88.
[3] N. Risch, M. Arend, B. Westermann, Angew. Chem. Ind. Ed. 1998,
37, 1044.
[34] K. Fukuhara, K. Nakajima, M. Kitano, H. Kato, S. Hayashi, M.
Hara, ChemSusChem 2011, 4, 778.
[35] S. Suganuma, K. Nakajima, M. Kitano, D. Yamaguchi, H. Kato, S.
[4] M. Tramontini, L. Angiolini, Mannich Bases. Chemistry and Uses,
CRC, Boca Raton, FL 1994.
Hayashi, M. Hara, J. Am. Chem. Soc. 2009, 131, 12787.
[36] M. Toda, A. Takagaki, M. Okamura, J. N. Kondo, S. Hayashi, K.
[5] A. Ying, Z. Li, J. Yang, S. Liu, S. Xu, H. Yan, C. Wu, J. Org.
Chem. 2014, 79, 6510.
Domen, M. Hara, Nature 2005, 438, 178.
[37] D. Zareyee, S. M. Moosavi, A. Alaminezhad, J. Mol. Catal. A:
Chem. 2013, 378, 227.
[6] C. Huang, Y. Yin, J. Guo, J. Wang, B. Fan, L. Yang, RSC Adv.
2014, 4, 10188.
[38] G. Morales, M. Paniagua, J. A. Melero, G. Vicente, C. Ochoa, Ind.
Eng. Chem. Res. 2011, 50, 5898.
[7] Y. Zhang, J. Han, Z. Liu, RSC Adv. 2015, 5, 25485.
[8] R. Qiu, Y. Chen, S. Yin, X. Xua, C. Au, RSC Adv. 2012, 2, 10774.
[39] B. Karimi, D. Zareyee, J. Mater. Chem. 2009, 19, 8665.

8 of 8
KABIRI ESFAHANI ET AL.
[40] B. Karimi, D. Zareyee, Org. Lett. 2008, 10, 3989.
[54] R. A. Sheldon, Chem. Ind. 1992, 23, 903.
[41] D. Margolese, J. A. Melero, S. C. Christiansen, B. F. Chmelka, G.
[55] For further experimental details see the Supporting Information.
D. Stucky, Chem. Mater. 2000, 12, 2448.
[56] F. Kabiri Esfahani, D. Zareyee, R. Yousefi, ChemCatChem 2014,
6, 3333.
[42] Y. Gu, A. Karam, F. Jerome, J. Barrault, Org. Lett. 2007, 9, 3145.
[43] B. Karimi, F. Mansouri, H. M. Mirzaei, ChemCatChem 2015, 7,
[57] C. Cheng, H. Jing, RSC Adv. 2014, 4, 34325.
1736.
[58] S. Iimura, D. Nobutou, K. Manabe, S. Kobayashi, Chem. Commun.
2003, 39, 1644.
[44] A. Schätz, O. Reiser, W. J. Stark, Chem. Eur. J. 2010, 16, 8950.
[45] A. Lu, E. L. Salabas, F. Schuth, Angew. Chem. Int. Ed. 2007, 46,
1222. Angew. Chem. 2007, 119, 1242.
[59] G. Zhao, T. Jiang, H. Gao, B. Han, J. Huang, D. Sun, Green Chem.
2004, 6, 75.
[46] D. Wang, D. Astruc, Chem. Rev. 2014, 114, 6949.
[47] J. Lee, Y. Lee, J. K. Youn, H. B. Na, T. Yu, H. Kim, S. M. Lee, Y.
M. Koo, J. H. Kwak, H. G. Park, H. N. Chang, M. Hwang, J. G.
Park, J. Kim, T. Hyeon, Small 2008, 4, 143.
SUPPORTING INFORMATION
Additional Supporting Information may be found online in
the supporting information tab for this article.
[48] J. Zeng, Y. Liu, P. Hsieh, Y. Huang, C. Yi, S. S. Badsara, C. Lee,
Green Chem. 2014, 16, 2644.
[49] M. G. Al‐Shaal, P. J. C. Hausoul, R. Palkovits, Chem. Commun.
2014, 50, 10206.
How to cite this article: Kabiri Esfahani F, Zareyee D,
Shokuhi Rad A, Taher‐Bahrami S. Sulfonic acid
supported on magnetic nanoparticle as an eco‐friendly,
durable and robust catalyst for the synthesis of β‐amino
carbonyl compounds through solvent free Mannich
reaction. Appl Organometal Chem. 2017;e3865. https://
doi.org/10.1002/aoc.3865
[50] L. Chen, B. E. Lemma, J. S. Rich, J. Mack, Green Chem. 2014, 16,
1101.
[51] S. Vidyacharan, A. H. Shinde, B. Satpathi, D. S. Sharada, Green
Chem. 2014, 16, 1168.
[52] W. Zhou, L. Fang, Z. Fan, B. Albela, L. Bonneviot, F. De Campo,
M. Pera‐Titus, J. Clacens, J. Am. Chem. Soc. 2014, 136, 4869.
[53] R. A. Sheldon, J. Mol. Catal. A. 1996, 107, 75.