Efficient oxidation of alcohols with KBrO3 in the presence of silica chloride and wet SiO2

Article abstract of DOI:10.1080/713744572

Alcohols were oxidized to their corresponding carbonyl compounds with KBrO₃ in the presence of silica chloride and wet SiO₂, in solution and under solvent free conditions.

Full text of DOI:10.1080/713744572

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Phosphorus, Sulfur, and Silicon and the Related
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Efficient Oxidation of Alcohols with KBrO 3 in the
Presence of Silica Chloride and Wet SiO 2
Farhad Shirini a , Mohammad Ali Zolfigol b & Mahroo Khaleghi a
a Guilan University , Rasht, Iran
b Bu-Ali Sina University , Hamadan, Iran
Published online: 27 Oct 2010.
To cite this article: Farhad Shirini , Mohammad Ali Zolfigol & Mahroo Khaleghi (2003) Efficient Oxidation of Alcohols with
KBrO 3 in the Presence of Silica Chloride and Wet SiO 2, Phosphorus, Sulfur, and Silicon and the Related Elements, 178:10,
2107-2110, DOI: 10.1080/713744572
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Phosphorus, Sulfur, and Silicon, 178:2107–2110, 2003
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Copyright Taylor & Francis Inc.
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500390221555
EFFICIENT OXIDATION OF ALCOHOLS WITH
KBrO3 IN THE PRESENCE OF SILICA CHLORIDE
AND WET SiO2
Farhad Shirini,a Mohammad Ali Zolfigol,b
and Mahroo Khaleghia
Guilan University, Rasht, Irana and Bu-Ali Sina University,
Hamadan, Iranb
(Received February 13, 2003; accepted March 25, 2003)
Alcohols were oxidized to their corresponding carbonyl compounds with
KBrO3 in the presence of silica chloride and wet SiO2, in solution and
under solvent free conditions.
Keywords: Oxidation of alcohols; silica chloride; solution; solvent free
conditions
The total syntheses of complex molecules demand new methods in
different areas of organic chemistry. Therefore, the development of
reagents is always rewarding to synthetic organic chemists.
Oxidation is one of the most important classes of reactions in syn-
thetic organic chemistry and the development of new oxidizing agents
and the modification of known reagents have been studied actively in
recent years.3,4
The most powerful oxidation state of bromine is (+55). Bromates
have been used for oxidation of a variety of inorganic compounds under
aqueous conditions. However, a literature search shows that bromates
have not found many applications as oxidizing agents in the field of
organic synthesis. To the best of our knowledge only a few reports are
available that deal with oxidation of organic compounds with bromate
ion in either strong acidic or basic solution using sodium or potassium
bromates.6–8
In connection with our ongoing research program directed toward the
development of new oxidizing agents,9–12 herein we report an efficient
The authors acknowledge the financial support of this work by the Guilan University
Research Council.
Address correspondence to Farhad Shirini, Department of Chemistry, Faculty of Sci-
ence, Guilan University, Rasht, Iran. E-mail: shirini@guilan.ac.ir
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F. Shirini et al.
method for the oxidation of alcohols in solution and under solvent free
conditions with KBrO3 in the presence of silica chloride and wet SiO2
(Scheme 1, Table I). Yields and reaction times are given in Table I.
Overoxidation of the products using this method was not observed.
SCHEME 1
As shown in Table I, there are appreciable differences between the
results obtained in solution and those in solvent free conditions. Thus,
by omiting the solvent, in addition to the ease of the work-up procedure,
the reaction time was reduced and the need for sovent is avoided. This
method is not suitable for the oxidation of allylic alcohols (Table I, entry
14).
It should be noted that oxidation did not proceed using KBrO3 or
silica chloride or wet SiO2 alone even after prolonged heating.
In conclusion the ready availability and low cost of the reagents,
the simple and clean work-up and the high product yields make this
method a useful addition to the present methodologies for the oxidation
of alcohols.
EXPERIMENTAL
Oxidation of 2-Bromobenzyl Alcohol Under Solvent-Free
Conditions. A Typical Procedure
To a mixture of silica chloride (0.3 g), wet SiO2 [(SiO2/H2O: 50% w/w),
0.2 g] and KBrO3 (0.167 g, 1 mmol), was added 2-bromobenzyl alco-
hol (0.187 g, 1 mmol). The resultant mixture was heated in an oil bath
(80◦C) for 6 min. The progress of the reaction was monitored by TLC.
The reaction mixture was triturated with CH2Cl2 (10 mL) and then fil-
tered. Anhydrous MgSO4 was added to the filterate which was filtered
after 10 min. Evaporation of the solvent followed by column chromatog-
raphy on silica gel gave 2-bromobenzaldehyde in 95% yield.
Oxidation of 1-Phenylpropan-2-ol in n-Hexane. A Typical
Procedure
In a round-bottomed flask (10 mL) equipped with a condenser
and a magnetic stirrer a mixture of silica chloride (0.3 g), wet

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SiO2[SiO2/H2O:50% w/w), 0.2 g], KBrO3 (0.167 g, 1 mmol) and 1-
phenylpropan-2-ol (0.136 g, 1 mmol) in hexane (5 ml) was prepared
and refluxed for 70 min. The progress of the reaction was monitored
by TLC. The reaction mixture was filtered and the residue was washed
with CH2Cl2(15 mL). Anhydrous MgSO4 was added to the filterate and
filtered after 10 min. Evaporation of the solvent followed by column
chromatography on silica gel gave phenylpropan-2-one in 90% yield.
REFERENCES
[1] H. Firouzabadi, N. Iranpoor, B. Karimi, and H. Hazarkhani, Synlett, 263 (2000).
[2] M. A. Zolfigol, F. Shirini, and A. Ghorbani, Chogamarani Synth. Commun., 32, 1809
(2002).
[3] H. O. House, Modern Synthetic Reactions (W. A. Benjamin, Inc., New York, 1972),
2nd ed.
[4] B. M. Trost, Comprehensive Organic Synthesis (Oxidation) (Pergamon, New York,
1991), vol. 7.
[5] Z. E. Jolles, Bromine and Its Compounds (Benn, London, 1966).
[6] S. Kajigashi, T. Nakagawa, N. Nagasaki, and H. Yamasaki, Bull. Chem. Soc. Jpn.,
59, 747 (1986).
[7] T. Veeraiah and M. Periasamy, Synth. Commun., 19, 2151 (1989).
[8] S. Narayana and V. S. Srinivasan, J. Chem. Soc. Perkin Trans. II, 1557 (1986).
[9] F. Shirini, H. Tajik, and F. Jalili, Synth. Commun., 31, 2885 (2001).
[10] F. Shirini, H. Tajik, A. Aliakbar, and A. Akbar, Synth. Commun., 31, 767 (2001).
[11] F. Shirini, M. A. Zolfigol, and M. R. Azadbar, Russ. J. Org. Chem., 37, 1673 (2001).
[12] F. Shirini, M. A. Zolfigol, and A. Pourhabib, J. Chem Res. (S), 476 (2001).