Oxone/iron(II) sulfate/graphite oxide as a highly effective system for oxidation of alcohols under ultrasonic irradiation

Article abstract of DOI:10.1016/j.tetlet.2013.11.019

Oxone, in the presence of a catalytic amount of iron(II) sulfate and graphite oxide, oxidizes efficiently alcohols into their corresponding carboxylic acid or ketone compounds at room temperature in short reaction times and in good to quantitative yields under ultrasonic irradiation.

Full text of DOI:10.1016/j.tetlet.2013.11.019

Tetrahedron Letters 55 (2014) 342–345
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Tetrahedron Letters
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Oxone/iron(II) sulfate/graphite oxide as a highly effective system
for oxidation of alcohols under ultrasonic irradiation
Maryam Mirza-Aghayan , Mahdieh Molaee Tavana , Rabah Boukherroub b
a,
⇑
a
a
Chemistry and Chemical Engineering Research Center of Iran (CCERCI), PO BOX 14335-186, Tehran, Iran
Institut de Recherche Interdisciplinaire (IRI, USR 3078), Université Lille 1, Parc de la Haute Borne, 50 Avenue de Halley-BP70478, 59658 Villeneuve d’Ascq, France
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 9 July 2013
Revised 14 October 2013
Accepted 7 November 2013
Available online 15 November 2013
Oxone, in the presence of a catalytic amount of iron(II) sulfate and graphite oxide, oxidizes efficiently
alcohols into their corresponding carboxylic acid or ketone compounds at room temperature in short
reaction times and in good to quantitative yields under ultrasonic irradiation.
Ó 2013 Elsevier Ltd. All rights reserved.
Keywords:
Oxone
Iron(II) sulfate
Graphite oxide
Alcohols
Oxidation
The oxidation of alcohols into their corresponding carbonyl
compounds is an important reaction in synthetic organic chemistry
and several oxidizing agents are available for this transformation.
to high yields.11b–d In another report, various alkynes or alcohols
were hydrated or oxidized in situ to give the corresponding methyl
ketones or aldehydes, respectively, which underwent a subsequent
1
11e
The oxidation can be achieved using a number of organic and tran-
sition metal based reagents.2 Traditional methods use large
amounts of transition metals, involve toxic oxidants such as chro-
Claisen–Schmidt condensation at 80 or 100 °C after 24 h.
The use of ultrasound in chemistry offers a method for chemical
activation, which has broad applications and uses relatively inex-
pensive equipment. Ultrasound can generate cavitation within a li-
quid, which provides a source of energy to enhance a wide range of
3
,4
mate and permanganate or require harsh reaction conditions.
Several other systems using aqueous hydrogen peroxide as the oxi-
dant and metal catalysts under phase-transfer catalytic conditions
1
2
chemical processes. The application of ultrasound in oxidations
5
13
have been reported. Recent efforts have been focused on systems
of alcohols has been reported. Sonocatalysis is observed during
which employ metal compounds only in catalytic amounts to-
gether with a stoichiometric oxidant. Several groups have investi-
the course of the oxidation of primary hydroxyl groups in homoge-
6
13a
neous aqueous medium by the NaOCl/TEMPO system.
Luu et al.
gated Oxone (potassium hydrogen monopersulfate) as an efficient
oxidant of various compounds.7 For example, Oxone has success-
fully been used for the oxidation of alcohols into aldehydes and
ketones,7a and benzaldehyde into benzoic acid. Oxidation of pri-
mary and secondary alcohols into their corresponding oxidized
have reported acceleration of the oxidation of alcohols by potas-
sium permanganate adsorbed on copper(II) sulfate pentahydrate
1
3b
using ultrasound.
Also, Adams et al. have investigated the con-
7b
version of alcohols into carbonyl compounds with a pyridinium
chlorochromate/silica gel reagent system by the use of ultrasound
1
3c
products using 2–6 equiv of Oxone was demonstrated by Parida
technology.
8
et al. Wu et al. found that Lewis acids such as AlCl
3
play a domi-
We previously reported the use of GO, a readily available and
inexpensive material, as a highly efficient reagent for the synthesis
of aldehydes or ketones via the oxidation of various alcohols under
9
nant role in the oxidation of alcohols in the presence of Oxone.
Graphite oxide (GO), prepared by exhaustive oxidation of
graphite, has been explored as a heterogeneous catalyst for various
organic transformations.10,11 Recently, GO was applied for the
oxidation of alcohols and alkenes, and the hydration of various
alkynes into their respective aldehydes and ketones in moderate
1
4
ultrasonic irradiation. Herein, we report on the use of Oxone/iro-
n(II) sulfate/GO as a highly efficient system for the oxidation of
alcohols to the corresponding carboxylic acid or ketone com-
pounds under ultrasonic irradiation in water as the solvent
(
Scheme 1).
Parida et al. reported that the oxidation of 4-nitrobenzyl alco-
hol is very slow using Oxone. Thus we investigated the oxidation of
8
⇑
Corresponding author. Tel.: +98 21 44580720; fax: +98 2144580777.
E-mail address: m.mirzaaghayan@ccerci.ac.ir (M. Mirza-Aghayan).
0
040-4039/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tetlet.2013.11.019

M. Mirza-Aghayan et al. / Tetrahedron Letters 55 (2014) 342–345
343
tion.14 Finally, we studied the influence of GO on the Oxone
oxidation process. We performed this reaction in the presence of
0.1, 0.05 and 0.025 g of GO (Table 1, entries 11–13). The results ob-
tained show that 0.05 g of GO was required for this reaction
affording 4-nitrobenzoic acid in 95% yield via the oxidation of
Oxone/FeSO /GO
4
Alcohol
Acid or ketone
H O, )))
2
Scheme 1. Oxidation of alcohols into carboxylic acid or ketone compounds using
the Oxone/FeSO /GO system under ultrasonic irradiation.
4
4
-nitrobenzyl alcohol with Oxone (1.5 mmol) and iron(II) sulfate
(
5 mol %) (Table 1, entry 12). In comparison to other examined con-
4
-nitrobenzyl alcohol (1 mmol) in the presence of Oxone under dif-
ditions, the results also indicated that the reaction was cleaner in
the presence of GO; purification of the product was easily achieved
through simple crystallization. According to the results in Table 1,
the optimum conditions for the oxidations are as follows: alcohol
(1 mmol) in the presence of Oxone (1.5 mmol)/FeSO Á7H O (5
ferent conditions to check the efficiency of our method. Various
experimental conditions were screened to obtain the maximum
yield of product. The results are summarized in Table 1. The oxida-
tion of 4-nitrobenzyl alcohol (1 mmol) in the presence of 5 mmol
of Oxone at reflux in water/acetonitrile (1/1) as solvent gave the
corresponding 4-nitrobenzoic acid in 72% yield after 24 h. We
examined the effect of different Lewis acid catalysts such as
4
2
mol %)/GO (0.05 g), water, ultrasonic irradiation. Under these con-
ditions, oxidation of 1-phenylethanol gave acetophenone in 59%
yield in the absence of GO, and in 86% in the presence of GO. This
result clearly supports the positive effect of GO on the oxidation
process.
CuSO
4
Á5H
2
O, COCl
2
Á6H
2
O and FeSO
4
Á7H
2
O on the reaction yield.
The results showed that FeSO
4
Á7H O was more efficient in compar-
2
ison with other Lewis acid catalysts (Table 1, entries 2–4). The
oxidation occurs in high yield (78%) in the presence of iron(II)
sulfate as a Lewis acid in a very short reaction time (2 h) (Table 1,
entry 4). In the next step, we investigated the effect of ultrasonic
irradiation on the oxidation reaction in water. Ultrasonic irradia-
tion was performed using an ultrasonic homogenizer (Bandelin
Sonopuls HD 3100) with probe model MS 73 at 100% power. The
results indicate that ultrasonic irradiation accelerates this reaction,
has a beneficial effect on the yield and decreases the reaction time.
Under ultrasonic irradiation conditions, the reaction time
decreased to 30 min and the yield increased to 97% (Table 1, entry
In a similar fashion, various alcohols were oxidized smoothly using
Oxone (1.5 mmol)/FeSO Á7H O (5 mol %)/GO (0.05 g) in water un-
4
2
der ultrasonic irradiation to give the corresponding carboxylic acid
or ketone compounds. The results are summarized in Table 2. Un-
der these experimental conditions, the reactions of benzyl alcohol,
2-hydroxybenzyl alcohol and 4-nitrobenzyl alcohol gave the corre-
sponding acids in 98%, 92% and 90% yields, respectively, (Table 2,
entries 1–3). Oxidation of substrates containing electron-donating
groups such as 4-methoxybenzyl alcohol resulted in the formation
of the corresponding acid derivative in moderate yield 67% (Table 2,
entry 4). The oxidation of 4-chlorocinnamyl alcohol gave 4-chloro-
cinnamic acid in 94% yield (Table 2, entry 5). We also investigated
the oxidation of heterocyclic alcohols such as thiophene-2-methanol
and 3-pyridine-3-methanol. Oxidation of thiophene-2-methanol
gave only the corresponding aldehyde in 96% yield even after 60
min, while oxidation of 3-pyridine-3-methanol afforded the corre-
sponding nicotinic acid in 94% yield after 30 min (Table 2, entries 6
and 7).
5
). The exact role of ultrasonic irradiation in the oxidation process
is not clear, but it cannot be excluded that ultrasonic irradiation
participates in the oxidation process by generating locally high
temperatures. Thus the optimal conditions were attained by
using ultrasonic irradiation as the source of energy and water as
a green solvent. We next examined the effect of Oxone concentra-
tion (2, 1.5 and 1 mmol) and iron(II) sulfate (40, 20, 10 and 5 mol %)
1
5
(
Table 1, entries 5–10). The results indicate that Oxone (1.5 mmol)
Oxidation of secondary alcohols such as 1-phenylethanol, 1-
phenylpropanol, benzhydrol and 1-indanol yielded acetophenone,
propiophenone, benzophenone and 1-indanone in 86%, 81%, 81%
and 83% yields, respectively, (Table 2, entries 8–11). Similarly, oxi-
dation of an aliphatic alcohol, cyclohexanol, using this method,
afforded cyclohexanone in 95% yield (Table 2, entry 12). It should
be noted that under these experimental conditions, no reaction
occurred with the tertiary alcohol, 2-(4-biphenylyl)-2-propanol
and iron(II) sulfate (5 mol %) are optimum for this reaction (Table 1,
entry 10).
In a previous report, we demonstrated that GO could be applied
as a mild and efficient oxidizing agent for the oxidative aromatiza-
tion of Hantzsch 1,4-dihydropyridine derivatives.16 More recently,
we described the high performance of GO for the synthesis of alde-
hydes or ketones from various alcohols under ultrasonic irradia-
OH
O
Oxidation
O
2
N
O N
2
OH
Table 1
Effect of the Lewis acid, solvent and ultrasonic irradiation on the oxidation of 4-nitrobenzyl alcohol
Entry
Conditions
Time
Yielda,b (%)
1
2
3
4
5
6
7
8
9
Oxone (5 mmol), reflux, H
2
O–MeCN (1:1)
O (40 mol %), reflux, H
O (40 mol %), reflux, H
O (40 mol %), reflux, H
24 h
4 h
4 h
2 h
30 min
30 min
30 min
30 min
30 min
30 min
30 min
30 min
30 min
72
79
43
78
97
59
95
91
89
86
98
96
87
Oxone (2 mmol)/CuSO
4
Á5H
2
2
O–MeCN (1:1)
O–MeCN (1:1)
O–MeCN (1:1)
Oxone (2 mmol)/COCl
Oxone (2 mmol)/FeSO
Oxone (2 mmol)/FeSO
Oxone (1 mmol)/FeSO
2
Á6H
2
2
4
4
4
Á7H
Á7H
Á7H
2
2
2
O (40 mol%), H
O (40 mol%), H
2
O,)))
O,)))
2
2
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
Oxone (1.5 mmol)/FeSO
4
4
4
4
4
4
4
Á7H
Á7H
Á7H
Á7H
Á7H
Á7H
Á7H
2
2
2
2
2
2
2
O (40 mol %), H
O (20 mol %), H
O (10 mol %), H
2
2
2
O,)))
O,)))
O,)))
10
11
12
13
O (5 mol %), H
O (5 mol%)/GO (0.1 g), H
O (5 mol %)/GO (0.05 g), H
O (5 mol%)/GO (0.025 g), H
2
O,)))
2
O,)))
O,)))
O,)))
2
2
a
Reaction conditions: 4-nitrobenzyl alcohol (1 mmol) in 10 ml of solvent.
Isolated yield.
b

3
44
M. Mirza-Aghayan et al. / Tetrahedron Letters 55 (2014) 342–345
Table 2
Oxidation of various alcohols using Oxone/FeSO
4
Á7H
2
O (5 mol %)/GO (0.05 g)
Entry
Substrate
Product17,18
Benzoic acid
2-Hydroxybenzoic acid
4-Nitrobenzoic acid
4-Methoxybenzoic acid
4-Chlorocinnamic acid
Thiophene-2-carbaldehyde
Nicotinic acid
Acetophenone
Propiophenone
Benzophenone
1-Indanone
Time (min)
Yielda (%)
1
2
3
4
5
6
7
8
9
Benzyl alcohol
30
30
30
60
45
60
30
20
30
30
30
30
30
98
92
90
67
94
96
94
86
81
81
83
95
—
2-Hydroxybenzyl alcohol
4-Nitrobenzyl alcohol
4-Methoxybenzyl alcohol
4-Chlorocinnamyl alcohol
Thiophene-2-methanol
3-Pyridinylmethanol
1-Phenylethanol
1-Phenylpropanol
Benzhydrol
1-Indanol
Cyclohexanol
1
1
1
1
0
1
2
3
Cyclohexanone
No reaction
2-(4-Biphenylyl)-2-propanol
a
Isolated product.
(
Table 2, entry 13). Only the starting compound was recovered,
even after 180 min and the dehydration product was not observed.
A comparison of the present system (Oxone/FeSO O/GO)
ketones, respectively, under these conditions. This protocol is
advantageous as the oxidation takes place under mild conditions,
in short reaction times and in good to high yields with a very sim-
ple work-up procedure. Further investigations using GO for other
chemical transformations (synthesis of pyridine and xanthene
derivatives) are currently in progress.
4
Á7H
2
with our previous results using GO system14 for the oxidation of
secondary alcohols clearly indicates that the present system is
more active and gives better yields. Indeed, the oxidation of
cyclohexanol, benzhydrol and thiophene-2-methanol using GO
afforded cyclohexanone, benzophenone and thiophene-2-carbal-
dehyde in 98%, 35% and 10% yields after 120, 60 and 90 min,
respectively, as compared to 95%, 81% and 96% yields obtained
after 30, 30, and 60 min, respectively, using Oxone/FeSO
GO.
References and notes
1
4
1.
Hudlicky, M. Oxidation in Organic Chemistry; American Chemical Society:
4 2
Á7H O/
Washington, DC, 1990. pp 114–163.
2. Tojo, G.; Fernandez, M. In Oxidation of Alcohols to Aldehydes and Ketones; Tojo,
G., Ed.; Springer Science & Business Media: New York, 2006.
The mechanism of oxidation using the Oxone/FeSO
4
Á7H O/GO
2
3.
Mijs, W. J.; de Jonge, C. R. H. Organic Synthesis by Oxidation with Metal
Compounds; Plenum: New York, 1986.
system under ultrasonic irradiation is not clear. Different condi-
tions were tested to clarify the role of ultrasonic irradiation. We
first investigated the influence of ultrasound on the GO properties.
It is well known that ultrasound irradiation of graphite oxide al-
lows its exfoliation to graphene oxide. Graphite oxide (0.05 g)
was irradiated in water by ultrasound for 3 h and then 4-nitroben-
4. Enache, D. I.; Edwards, J. K.; Landon, P.; Solsona-Espriu, B.; Carley, A. F.;
Herzing, A. A.; Watanabe, M.; Kiely, C. J.; Knight, D. W.; Hutchings, G. J. Science
2006, 311, 362.
5
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.
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(a) Barak, G.; Dakka, J.; Sasson, Y. J. Org. Chem. 1988, 53, 3553; (b) Schrader, S.;
Dehmlow, E. V. Org. Prep. Proced. Int. 2000, 32, 123; (c) Hulce, M.; Marks, D. W. J.
Chem. Educ. 2001, 78, 66.
(a) Zondervan, C.; Hage, R.; Feringa, B. L. Chem. Commun. 1997, 419; (b)
Coleman, K. S.; Lorber, C. Y.; Osborn, J. A. Eur. J. Inorg. Chem. 1998, 1, 1673; (c)
Moody, C. J.; Palmer, F. N. Tetrahedron Lett. 2002, 43, 139; (d) Dijksman, A.;
Marino-Gonzales, A.; Payeras, A. M. I.; Arends, I. W. C. E.; Sheldon, R. A. J. Am.
Chem. Soc. 2001, 123, 6826.
zyl alcohol (1 mmol)/Oxone (1.5 mmol)/FeSO
4 2
Á7H O (5 mol %) was
added. The obtained results indicated that the oxidation was very
slow even at reflux of water. We concluded that the transformation
of graphite oxide to graphene oxide under ultrasonic irradiation is
not important for this reaction. In the next test, we investigated the
influence of microwave irradiation on the reaction of 4-nitrobenzyl
7.
(a) Koo, B. S.; Lee, K. L.; Lee, K. J. Synth. Commun. 2002, 32, 2115; (b) Webb, K. S.;
Ruszkay, S. J. Tetrahedron 1998, 54, 401; (c) Brik, M. E. Tetrahedron Lett. 1995,
36, 5519; (d) Trost, B. M.; Curran, D. P. Tetrahedron Lett. 1981, 22, 1287; (e)
Evans, T. L.; Grade, M. M. Synth. Commun. 1986, 16, 1207; (f) Trost, B. M.;
Braslau, R. J. Org. Chem. 1988, 53, 532; (g) De Poorter, B.; Ricci, M.; Meunier, B.
Tetrahedron Lett. 1985, 26, 4459; (h) Bolm, C.; Magnus, A. S.; Hilderbrand, J. P.
Org. Lett. 2000, 2, 1173; (i) Zolfigol, M. A.; Bagherzadeh, M.; Chehardoli, G.;
Malakpour, S. E. Synth. Commun. 2001, 31, 1149.
alcohol (1 mmol)/Oxone (1.5 mmol)/FeSO
ite oxide (0.05 g) in water. After 3 min of microwave irradiation,
-nitrobenzoic acid was obtained only in 37% yield. We concluded
4
2
Á7H O (5 mol %)/graph-
4
that a high temperature can assist in the oxidation process, but it is
not enough for this reaction.
8
9
.
.
Parida, K. N.; Jhulki, S.; Mandal, S.; Moorthy, J. N. Tetrahedron 2012, 68, 9763.
Wu, S.; Ma, H.; Lei, Z. Tetrahedron 2010, 66, 8641.
From these results, we believe that under ultrasonic irradiation
potassium persulfate in the presence of Fe(II) can produce sulfate
ion radicals, Fe(III) and hydroxyl radicals, which are responsible
for the oxidation reaction (Scheme 2). Indeed, sonolysis of organic
compounds is mainly ascribed to the sonochemical generation of
radicals and thermal decomposition in the cavitation microbub-
10. Spiro, M. Catal. Today 1990, 7, 167.
1
1. (a) Vijay Kumar, A.; Rama Rao, K. Tetrahedron Lett. 2011, 52, 5188; (b) Dreyer,
D. R.; Jia, H.-P.; Bielawski, C. W. Angew. Chem., Int. Ed. 2010, 49, 6813; (c)
Dreyer, D. R.; Bielawski, C. W. Chem. Sci. 2011, 2, 1233; (d) Jia, H.-P.; Dreyer, D.
R.; Bielawski, C. W. Tetrahedron 2011, 67, 4431; (e) Jia, H.-P.; Dreyer, D. R.;
Bielawski, C. W. Adv. Synth. Catal. 2011, 353, 528; (f) Dreyer, D. R.; Jia, H.-P.;
Todd, A. D.; Geng, J.; Bielawski, C. W. Org. Biomol. Chem. 2011, 9, 7292; (g)
Dreyer, D. R.; Jarvis, K. A.; Ferreira, P. J.; Bielawski, C. W. Polym. Chem. 2012, 3,
757; (h) Dreyer, D. R.; Jarvis, K. A.; Ferreira, P. J.; Bielawski, C. W.
Macromolecules 2011, 44, 7659.
1
9
bles. GO most likely participates in the oxidation process through
the generation of sulfate and hydroxyl radicals or as an oxidant
1
4
12. (a) Mason, T. J. Chem. Soc. Rev. 1997, 26, 443; (b) Cravotto, G.; Cintas, P. Chem.
Soc. Rev. 2006, 35, 180; (c) Singh, V.; Preet Kaur, K.; Khurana, A.; Kad, G. L.
Resonance 1998, 3, 56; (d) Entezari, M. H.; Kruus, P. Ultrason. Sonochem. 1994, 1,
S75.
itself.
In conclusion, we have investigated the oxidation of aromatic,
heterocyclic and aliphatic alcohol derivatives using Oxone/iro-
n(II)/graphite oxide under ultrasonic irradiation. Primary and sec-
ondary alcohols were converted into the corresponding acids and
1
3. (a) Brochette-Lemoine, S.; Trombotto, S.; Joannard, D.; Descotes, G.; Bouchu, A.;
Queneau, Y. Ultrason. Sonochem. 2000, 7, 157; (b) Luu, T. X. T.; Christensen, P.;
Duus, F.; Le, T. N. Synth. Commun. 2008, 38, 2011; (c) Adams, L. L.; Luzzio, F. A. J.
Org. Chem. 1989, 54, 5387.
14. Mirza-Aghayan, M.; Kashef-Azar, E.; Boukherroub, R. Tetrahedron Lett. 2012, 53,
4
962.
)))
SO - + Fe(III) + OH
.
.
KHSO5 + Fe(II)
15. Suslick, K. S.; Dokytcz, S. J.; Flint, E. B. Ultrasonics 1990, 28, 280.
6. Mirza-Aghayan, M.; Boukherroub, R.; Nemati, M.; Rahimifard, M. Tetrahedron
4
1
Lett. 2012, 53, 2473.
Scheme 2. A plausible reaction mechanism.

M. Mirza-Aghayan et al. / Tetrahedron Letters 55 (2014) 342–345
345
1
7. Ultrasonic irradiation was performed in an ultrasonic homogenizer (Bandelin
Sonopuls HD 3100) with probe model MS 73 at 100% power. The GO utilized in
this work was synthesized using graphite according to a modified Hummers
method. The prepared GO was characterized using powder XRD, UV/vis
and extracted with EtOAc. The organic layer was dried over Na
2
SO
4
, filtered
and evaporated under reduced pressure. Purification was achieved by
recrystallization from EtOAc/n-hexane or by column chromatography using
n-hexane/EtOAc: 9:1 as eluent (for entries 2, 4 and 11). The spectroscopic data
14
18
spectroscopy and FT-IR spectroscopy to establish its authenticity. Typical
procedure for the oxidation of alcohols: To a solution of alcohol (0.1 mmol) in
of the obtained acids were compared with authentic samples.
18. The Aldrich Library of 13C and 1H FT NMR Spectra; Pouchert, C. J., Behnke, J., Eds.,
1st ed., 1993; Vol. 1–3,.
19. Wu, T. N.; Shi, M.-C. Sustain. Environ. Res. 2010, 20, 245.
1
(
0 ml of solvent were added Oxone (1.5 mmol), FeSO
0.05 g). The resulting mixture was irradiated with an ultrasonic probe for the
time indicated in Table 2. The mixture was filtered through a sintered funnel
4
Á7H
2
O (5 mol %) and GO