Magnetic manganese catalyst for selective oxidation of alcohols
Table 3. Comparison of Mn@MNP with some other catalysts for the
oxidation of benzyl alcohol
Entry
Catalyst
Solvent Oxidant Time Yield
Ref.
(h)
(%)
1
2
3
4
5
CoO-CeO
Cr(salen)-NH
[Mn(bp)(N
2
n-Hexane
TBHP
8
4
4
6
4
55
53
42
57
[26]
[27]
[28]
[29]
2
-MCM-41 Solvent free
H
H
2
O
O
2
3
3 3
)(CH OH)] CH CN
2
2
SBA-15Co-Si
Mn@MNP
n-Hexane
TBHP
TBHP
DMSO
90 This work
Conclusions
We have developed a new MNP-supported Mn catalyst via a ‘click’
route. The catalyst shows high activity in the selective oxidation of
alcohols to afford aldehydes or ketones. Furthermore, the catalyst
can be simply recovered from the reaction system using magnetic
separation and can be reused several times without a significant
loss in activity.
Figure 6. Recycling experiment of the MNP-supported Mn catalyst (6).
a
Table 2. Oxidation of various alcohols
Acknowledgment
We are grateful for financial support from the Natural Science Foun-
dation of Jiangsu Province of China (no. BK2010485) and the Zijin
Star Project of NUST.
b
Entry
R
R′
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
9
4-Methoxyphenyl
4-Methylphenyl
4-Chlorophenyl
4-Nitrophenyl
2-Methoxyphenyl
2-Methylphenyl
2-Chlorophenyl
2-Bromophenyl
2-Pyridyl
H
4
4
92
94
92
51
90
91
79
76
91
86
58
8
H
H
4
References
H
8
[
[
1] D. Bogdał, M. Łukasiewicz, Synlett 2000, 143.
2] M. B. Gawande, A. Rathi, I. D. Nogueira, C. A. A. Ghumman,
N. Bundaleski, O. M. N. D. Teodoro, P. S. Branco, ChemPlusChem
2012, 77, 865.
H
4
H
4
H
4
H
4
[3] A. S. Burange, S. R. Kale, R. Zboril, M. B. Gawande, R. V. Jayaram, RSC Adv.
2014, 4, 6597.
H
methyl
H
4
[
[
[
4] A. R. Judy-Azar, S. Mohebbi, J. Mol. Catal. A 2015, 397, 158.
5] J. H. Tong, Z. Li, C. G. Xia, J. Mol. Catal. A 2005, 231, 197.
6] R. Gava, A. Olmos, B. Noverges, T. Varea, E. Alvarez, T. R. Belderrain,
A. Caballero, G. Asensio, P. J. Perez, ACS Catal. 2015, 5, 3726.
7] M. E. Hanhan, C. Cetinkaya, M. P. Shaver, Appl. Organometal. Chem.
2013, 27, 570.
10
11
12
Phenyl
4
Cyclohexyl
24
24
n-Nonyl
H
[
a
Reaction conditions: alcohol (1 mmol), TBHP (1.5 mmol), DMSO (3 ml),
0
.2 mol% catalyst.
[8] R. R. Fernandes, J. Lasri, M. F. C. G. D. Silva, J. A. L. D. Silva,
b
GC yields.
J. J. R. F. D. Silva, A. J. L. Pombeiro, Appl. Catal. A 2011, 402, 110.
[
9] a) P. Pattanayak, J. L. Pratihar, D. Patra, P. Brandao, D. Mal, V. Felix,
Polyhedron 2013, 59, 23; b) A. M. Kirillov, M. V. Kirillova, L. S. Shul’pina,
P. J. Figiel, K. R. Gruenwald, M. F. C. G. D. Silva, M. Haukka,
A. J. L. Pombeiro, G. B. Shul’pin, J. Mol. Catal. A 2011, 350, 26; c)
S. E. Balaghi, E. Safaei, L. Chiang, E. W. Y. Wong, D. Savard,
R. M. Clarke, T. Storr, Dalton Trans. 2013, 42, 6829.
be attributed to the much stronger electron-withdrawing ability of
nitro group than chlorine and bromine. In addition, steric effects
clearly influence the reaction, which can be seen from a comparison
of the results for 4-chlorobenzyl alcohol and 2-chlorobenzyl alcohol
[10] S. Chakravorty, B. K. Das, Polyhedron 2010, 29, 2006.
[
11] a) M. M. Najafpour, M. Holynska, M. Amini, S. H. Kazemi, T. Lis,
M. Bagherzadeh, Polyhedron 2010, 29, 2837; b) L. Han, P. Xing,
B. Jiang, Org. Lett. 2014, 16, 3428.
(Table 2, entries 3 and 7). Because the vicinal steric effect is greater
than the contrapuntal one, 4-chlorobenzyl alcohol shows higher
reactivity than 2-chlorobenzyl alcohol. Furfurol and α-methylbenzyl
alcohol also present high reactivity and afford excellent yields.
Aliphatic alcohols show low reactivity in this reaction. Moderate
yield is obtained when cyclohexanol is used as substrate and
extremely low yield is obtained when laurinol is used.
In comparison with other catalysts employed for the oxidation of
alcohols, the as-prepared Mn@MNP catalyst is more efficient (Table 3).
Reaction time and yield are the essential factors in view of efficiency.
As is evident from Table 3, the reported catalysts require a longer
reaction time, or benzaldehyde is obtained in low yield.
[
12] a) M. Herbert, F. Montilla, A. Galindo, Polyhedron 2010, 29, 3287; b)
M. N. Missaghi, J. M. Galloway, H. H. Kung, Appl. Catal. A 2011, 391, 297.
13] a) B. Machura, J. Palion, J. Mroziński, B. Kalińska, M. Amini,
M. M. Najafpour, R. Kruszynski, Polyhedron 2013, 53, 132; b)
M. Sutradhar, L. M. D. R. S. Martins, M. F. C. G. D. Silva,
E. C. B. A. Alegria, C. M. Liu, A. J. L. Pombeiro, Dalton Trans. 2014, 43,
3966; c) H. Kargar, Transition Met. Chem. 2014, 39, 811; d) M. Z. Rong,
J. Wang, Y. P. Shen, J. Y. Han, Catal. Commun. 2012, 20, 51.
14] A. R. Massah, R. J. Kalbasi, S. Kaviyani, RSC Adv. 2013, 3, 12816.
15] S. B. Salunke, N. S. Babu, C. T. Chen, Adv. Synth. Catal. 2011, 353, 1234.
16] O. Shin, K. Shinji, J. Am. Chem. Soc. 2010, 132, 4608.
[
[
[
[
[
17] H. Q. Yang, X. J. Han, Z. C. Ma, R. Q. Wang, J. Liu, X. F. Ji, Green Chem.
2010, 12, 441.
Appl. Organometal. Chem. 2016, 30, 215–220
Copyright © 2016 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc