IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild reaction conditions

Article abstract of DOI:10.1016/j.tetlet.2020.151749

An efficient, practical and facile procedure has been developed for the oxidation of primary and secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature. The reaction affords quantitative yields of the corresponding carbonyl compounds without the formation of over oxidized products. The present synthetic protocol is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. The developed synthetic protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 g scale in higher yields by a simple filtration process.

Full text of DOI:10.1016/j.tetlet.2020.151749

Journal Pre-proofs
IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under
mild reaction conditions
Kamlesh Kumar, Prashant Kumar, Penny Joshi, Diwan S Rawat
PII:
S0040-4039(20)30177-5
DOI:
Reference:
https://doi.org/10.1016/j.tetlet.2020.151749
TETL 151749
To appear in:
Tetrahedron Letters
Received Date:
Revised Date:
Accepted Date:
24 December 2019
13 February 2020
15 February 2020
Please cite this article as: Kumar, K., Kumar, P., Joshi, P., Rawat, D.S., IBX-TfOH mediated oxidation of
alcohols to aldehydes and ketones under mild reaction conditions, Tetrahedron Letters (2020), doi: https://
doi.org/10.1016/j.tetlet.2020.151749
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover
page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version
will undergo additional copyediting, typesetting and review before it is published in its final form, but we are
providing this version to give early visibility of the article. Please note that, during the production process, errors
may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
©
2020 Published by Elsevier Ltd.

Graphical Abstract
IBX-TfOH mediated oxidation of alcohols to
aldehydes and ketones under mild reaction
conditions
Leave this area blank for abstract info.
Kamlesh Kumar, Prashant Kumar, Penny Joshi, Diwan S Rawat*
OH
O
IBX(1.1), TfOH (2-5 mol%)
R1 R2
1,4-Dioxane, rt.
R1 R2

1
Tetrahedron Letters
journal homepage: www.elsevier.com
IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild
reaction conditions
a,b
a
b
a*
Kamlesh Kumar, Prashant Kumar, Penny Joshi, Diwan S Rawat
a
Department of Chemistry, University of Delhi, Delhi-110007, India.
Department of Chemistry, DSB Campus, Kumaun University, Nainital, Nainital-263601, India
b
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
An efficient, practical and facile procedure has been developed for the oxidation of primary and
secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature.
The reaction affords quantitative yields of the corresponding carbonyl compounds without the
formation of over oxidized products. The present synthetic protocol is compatible with a variety
of substrates having arene, heteroarene and alkene functionalities. The developed synthetic
protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 gm
scale in higher yields by a simple filtration process.
Available online
Keywords:
Iodoxybenzoic acid
Triflic acid
Oxidation
2
009 Elsevier Ltd. All rights reserved.
Carbonyls
1
. Introduction
oxidant as it works under mild reaction conditions, and affords
excellent yields of the products. Frigerio and Santagostino
primarily demonstrated the synthetic use of IBX for the selective
transformation of alcohols to carbonyl compounds [18].
However, it has few limitations, such as poor solubility in
common organic solvents, explosive nature at high temperature,
and shock sensitivity [19]. To overcome these limitations,
numerous modified IBXs (mIBXs) [20], IBX on solid support
The conversion of alcohols to aldehydes and ketones is one of
the most important and challenging functional group
transformations in organic synthesis. Carbonyl compounds are
precursors of a wide range of agrochemicals, pharmaceuticals,
fine chemicals, vitamins, and fragrances [1]. Therefore,
development of a catalytic system that is selective for the
oxidation of alcohols to aldehydes, or ketones while avoiding
over-oxidation to carboxylic acids, esters or other by-products is
of scientific interest both in academia and industry [2]. A large
number of synthetic methodologies have been reported for the
oxidation of alcohols, among which transition metal-catalysed
approaches (Pd, Ru, Fe, Cu, Pt, Au, Ir, Rh, etc.) have been
extensively studied [3]. However, several limitations and safety
concerns are associated with these methods, such as the use of
toxic heavy metal salts, or expensive transition metals [4-6].
Besides, the complex reaction workup makes these methods less
useful. The conventional non-catalytic oxidation procedures are
considered superior for the oxidation of alcohols [1,7].
[21], tetrafluoro-IBX (FIBX) [21], 2-iodoxybenzoic acid
organosulfonates (IBX-OTs) [22], and 2-iodoxybenzoic acid
ditriflate (IBX-ditriflate) [23] were reported with improved
solubility in common organic solvents [24]. These mIBXs are
neither explosive at elevated temperatures nor shock sensitive
[25]. Dess and Martin have reported the oxidation of alcohols
using Dess Martin Periodinane (DMP) with excellent yields [26].
DMP was also found to be a mild and chemoselective reagent, as
primary alcohols and amino alcohols can be oxidized to
aldehydes and amino carbonyls respectively, without over-
oxidation, and avoiding the protection of the amino group.
Similarly, 1,2-diols can be converted to α-ketols or α-diketones
without oxidative cleavage. Additionally, β-hydroxy ketones
have been successfully oxidised to 1,3-diketones at elevated
temperatures in ethylacetate [27]. To avoid the structural
modification of IBX, few additives like oxone [28], acetic acid
Chromium or manganese-based species (e.g., MnO
CrO ) [8], hypervalent iodine reagents [9], and activated
2 4
, KMnO ,
3
sulfoxides [10,13], have been successfully utilized for such
conversions. Alcohols can also be oxidised by non-metal-based
catalytic systems such as Swern oxidation [10-12], Moffatt
oxidation [13,14], Corey- Kim oxidation [15] etc. Even though a
plethora of procedures are available at our disposal, yet there is a
necessity for the development of a better methodology that
obviates the use of copious amounts of heavy metal oxidants and
environmentally inauspicious halogenated solvents [16].
[29], trifluoroacetic acid [30], β-cyclodextrin in water/acetone
mixture [31] etc., are used with pleasant efficiency. Several
reports suggest that IBX is a powerful oxidant when used in ionic
liquids [32], or solvents like ethyl acetate/acetone (2:1) [33], 1,2-
DCE [33], acetone or acetonitrile [33], DMSO [34], and DMF
[35] (Fig. 1).
Recently, o-iodoxybenzoic acid (IBX, 1-hydroxy-1,2-
benziodoxol-3(1H)-one 1-oxide) [17] has emerged as a popular
While synthesizing biologically important molecules [36,37],
we required few aldehyde and ketone substrates. However, the

2
Tetrahedron Letters
alcohols, which we considered were awkward to oxidise
Table 1. Optimization of the oxidation condition.
efficiently. Thus, we developed a facile and mild reaction
protocol for the oxidation of alcohols to carbonyl compounds,
using a catalytic amount of TfOH in 1,4-dioxane containing a
stoichiometric amount of IBX at room temperature.
OH IBX (1.1 equiv.), solvent
O
O N
TfOH (5 mol %), rt
O N
2
2
IBX
equiv.)
Yield
Entry
Solvent
Time (min)
(
(%)
32
57
60
98
96
67
70
65
78
O
Previous Work:
Cat. IBX, O
1.
2.
3.
2.5
2.0
2.1
1.1
1.5
2.0
1.7
2.0
1.5
Water
Acetonitrile
Toluene
Dioxane
DCM
630
150
235
15
xone.
R1
Ref. 28
OH
H
Acetonitrile:Water(2:1 v/v),
o
7
0 C, 6 h
4
5
6
7
8
.
.
.
.
.
O
IBX(1.2 equiv.)/
AcOH.(1.2 euiv.)
Acetonitrile, rt, 6 h
20
R1
Ref. 29
DMF
40
DMSO
45

-Cyclodextrin
O
O
Acetone
Ethyl acetate
130
170
H O/Acetone,
2
R1
Ref. 31
Ref. 32
9.
H
H
rt, 12 h
The 1H NMR studies revealed that the oxidation of 4-
nitrobenzyl alcohol using IBX-TfOH in 1,4-dioxane was much
faster than that of IBX alone under identical reaction conditions
OH
IBX,[bmim]Cl
R1
1
R1
(Fig. S1 & S2). The H NMR which was recorded at different
H O, rt, 0.25-8 h
2
time intervals, clearly showed the disappearance of the benzylic
protons signal (at δ 4.69 ppm), and the appearance of a new
signal (at δ 10.06 ppm), confirms the oxidation of alcohol. The
newly developed oxidative system was very efficient and 92%
conversion was observed in 15 min, whereas in the absence of
TfOH, the oxidation was found to be sluggish and only 22.9%
consumption of starting material was observed after 15 minutes.
O
O
IBX(3.0 equiv.),
Solvent, 80 oC
R1
Ref. 33
Ref. 34
H
H
IBX(1.1-5.0 equiv.),
DMSO, rt, upto 48 h
R1
The addition of TfOH to the reaction mixture caused a rapid
1
downfield shift of the benzylic proton signal in H NMR. This
may be due to the protonation of oxygen atom (I=O of IBX) by
TfOH, which makes the iodine centre highly electron-deficient,
and hastens the nucleophilic attack of alcohol, followed by the
loss of water molecule, as suggested by Goddard et al. [38], and
subsequently regeneration of TfOH. Ultimately there is a
formation of IBX-alcohol intermediate, which yields the carbonyl
compound via an intramolecular cleavage mechanism (Fig. 2).
Unfortunately, all our efforts to trap the reactive intermediate
were unsuccessful, due to the high reactivity of present catalytic
system.
O
O
IBX(1.2-2.2 equiv.)
rt, upto 48 h
R1
H
Ref. 35
Current Work:
IBX(1.1 equiv.), Cat.
TfOH(2-5 mol%),
OH
R1
2 1,4-Dioxane, rt. 15 min.
R
R1
R2
Figure 1: IBX mediated oxidation of alcohols
. Results and discussion
To optimize the reaction conditions without modifying the
Figure 2. Plausible mechanism of acid catalysed oxidation of
alcohol with IBX.
2
R1
2
H
H
H
O
R
CF SO OH
H
3
2
O
H
H
HO O+
+O
HO
O
O
structure of o-iodoxybenzoic acid, we screened a few additives,
and we used 4-nitrobenzyl alcohol as a model substrate for the
oxidation reaction. The different additives such triflic acid, p-
toluenesulfonic acid, trifluoroacetic acid, trifluoroacetic
anhydride, and triflic anhydride were employed in catalytic
amounts (1 to 10 mol%). The best results were obtained when 5
mol% TfOH was used with 1.1 equiv. IBX in DCM at room
temperature (Table 1; entry 5). Further, to improve the efficiency
of reaction, we screened various polar protic and aprotic solvents:
water, acetonitrile, toluene, 1,4-dioxane, dimethylformamide,
dimethylsulfoxide, acetone and ethyl acetate (Table 1; entries 1-
I
I
I
R1
R2
O
O
O
O
O
O
OH
H O, CF SO OH
I
2
3
2
O
1
R
2
H
R
O
O
O
O
I
O
R1
R2
4
, 6-9). It was observed that the reaction in 1,4-dioxane
O
containing IBX-TfOH completed in 15 minutes (as indicated by
TLC), and yielded 4-nitrobenzaldehyde in 98% yield (Table 1;
entry 4). Next, progress of reaction was studied by varying the
mol% of TfOH and it was found that 2-5 mol% of TfOH with 1.1
equiv. IBX in 1,4-dioxane is the best condition to oxidized 4-
nitrobenzyl alcohol to 4-nitrobenzaldehyde at room temperature.
IBX-Alcohol
After optimizing the reaction conditions, we established the
versatility of the IBX-TfOH system by oxidizing a wide array of
alcohols. It was noted that primary aliphatic and aromatic
alcohols were oxidized to their corresponding carbonyl
compounds, and no over-oxidized side products were observed.
Indanone-1 was obtained in excellent yield by the oxidation of 1-
Indenol, within 15 minutes (Table 2, entry 1).

3
Table 2. Oxidation of alcohols with IBX-TfOH in 1,4-dioxane
S. No.
1
Substrate
Product
Time (minutes)
Yield (%)
96
Melting
Point (⁰C)
OH
O
15
39-40
55-58
OH
O
2
20
98
OH
NO2
O
3
4
25
17
90
98
39-40
NO2
OH
O
105-106
O N
2
2
O N
O
O
O
O
OH
O
5
6
10
12
92
95
35-36
-
OH
O
O
S
S
N
OH
7
8
9
12
8
89
99
93
-
-
-
N
OH
O
28
OH
O
OH
O
1
1
0
1
15
15
98
97
-
OH
O
223-225
HO
O
1
1
2
3
6
98
87
-
-
OH
OH
O
15
1
1
4
5
9
96
94
-
-
O
Ph
Ph
OH
OH
Ph
Ph
O
20
O
1
6
26
85
-
OH
O
1
7
20
92
129-132
OH
OH
O
O
O
1
1
8
9
5
96
88
123-124
164-166
OH
EtOOC
EtOOC
OH
O
15
N
N
H
H

4
Tetrahedron Letters
OH
O
Br
Br
2
2
0
1
23
45
91
75
204-206
N
H
N
H
OH
O
3
.
N. Kaur, D. Kishore, Catalysis Surveys From Asia 17 (2012) 20-
2.
4
The oxidation of (E)-1,3-diphenylprop-2-en-1-ol (Table 2,
4.
R. A. Sheldon, I.W.C.E. Arends, G. J. Ten Brink, Dijksman, Acc.
Chem. Res. 35 (2002) 774-781.
L. Cheng, J. Wang, M. Wang, Z. Wu, Inorg. Chem. 49 (2010)
entry 2) in 1.1 equiv. IBX and 3 mol% TfOH, afforded (E)-
chalcone in 98% isolated yield in 20 minutes. The o- and p- nitro
benzyl alcohols on oxidation yielded the corresponding
aldehydes in 90% and 98% isolated yields, respectively (Table 2,
entry 3 and 4). Heterocycle-substituted primary and secondary
alcohols were oxidized smoothly, and provided the
corresponding carbonyl compounds in 88-95% yields, without
forming any side product (Table 2; entry 6, 7, 19, 20). The
oxidation of 1-cyclopropylethanol yields cyclopropylmethyl
ketone in 98% yield (Table 2, entry 10) without forming the
rearranged product as reported in previous report [39]. The
oxidation of piperonyl alcohol required 2.5 equiv. of IBX to yield
5
.
9
392-9399.
6
7
.
.
S.S. Stahl, Angew. Chem. Int. Ed. 43 (2004) 3400-3420.
(a) T. Matsumoto, M. Ueno, N. Wang, S. Kobayashi, Chem. Asian
J. 3 (2008) 196-214; (b) C. Parmeggiani, F. Cardona, Green
Chem. 14 (2012) 547-564
8
.
.
F. A. Luzzio, F. S. Guziec, Org. Prep. Proced. Int. 20 (1988) 533-
5
84.
9
1
S. D. Meyer, S. L. Schreiber, J. Org. Chem. 59 (1994) 7549-7552.
0. K. Omura, D. Swern, Tetrahedron 34 (1978) 1651-1660.
11. A. J. Mancuso, D. S. Brownfain, D. Swern, J. Org. Chem. 44
(1979) 4148-4150.
1
2. A. J. Mancuso, S. L. Huang, D. Swern, J. Org. Chem. 43 (1978)
480–2482.
3. K. E. Pfitzner, J. G. Moffatt, J. Am. Chem. Soc. 85 (1963) 3027-
028.
2
7
8% of piperonal but addition of 2 mol% of TfOH increased the
yield of piperonal to 92% in 10 minutes. Adamantan-2-ol (Table
, entry 11) was oxidized to adamantan-2-one by 4 equiv. of IBX
1
3
2
14. J. G. Moffatt, “Sulfoxide-Carbodiimide and Related Oxidations”
in Oxidation vol. 2, R. L. Augustine, D. J. Trecker, Eds. (Dekker,
New York, 1971) pp 1–64.
with 37% yield in 14 hours but when reaction was carried out in
the presence of 5 mol% TfOH and 1.3 equiv. IBX, the isolated
yield of corresponding ketone was 97% in 15 minutes. Trans-
menthol was successfully oxidized to trans-menthone in 75%
yield (Table 2, entry 21) and no racemization was observed as
1
1
1
5. E. J. Corey; C. U. Kim, J. Am. Chem. Soc. 94 (1972) 7586-7587.
6. R. Noyori, M. Aoki, Chem. Commun. (2003) 1977-1986.
7. C. Hartmann, V. Meyer, Chem. Ber. 26 (1893) 1727-1732.
18. (a) M. Frigerio, M. Santogostino, S. Sputore, J. Org. Chem. 64
(1999) 4537-4538; (b) M. Frigerio, M. Santagostino, Tetrahedron
Lett. 35 (1994) 8019-8022
1
evident by H NMR, specific rotation and CD experiments
(
please see SI) [40].
1
2
9. J. B. Plumb, D. J. Harper, Chem. Eng. News 68 (1990) 3.
0. (a) D. B. Dess, J. C. Martin, J. Am. Chem. Soc. 113 (1991) 7277–
Conclusion
7
287; (b) D. Macikenas, E. Skrzypczak-Jankun, J. D.
Protasiewicz, Angew. Chem., Int. Ed. 39 (2000) 2007–2010; (c)
G. Sorg, A. Mengei, G. Jung, J. Rademann, Angew. Chem., Int.
Ed. 40 (2001) 4395–4397; (d) A. P. Thottumkara, T. K. Vinod,
Tetrahedron Lett. 43 (2002) 569–572; (e) V. V. Zhdankin, A. Y.
Koposov, B. C. Netzel, N. V. Yashin, B. P. Rempel, M. J.
Ferguson, R. R. Tykwinski, Angew. Chem. Int. Ed. 42 (2003)
2194–2196; (f) W.-J.Chung, D.-K.Kim, Y.-S. Lee, Tetrahedron
Lett. 44 (2003) 9251–9254; (g) U. Ladziata, A. Y. Koposov, K. Y.
Lo, J. Willging, V. N. Nemykin, V. V. Zhdankin, Angew. Chem.
Int. Ed. 44 (2005) 7127–7131; (h) B. V. Meprathu, M. W. Justik,
J. D. Protasiewicz, Tetrahedron Lett. 46 (2005) 5187–5190; (i) A.
Y. Koposov, D. N. Litvinov, V. V. Zhdankin, M. J. Ferguson, R.
McDonald, R. R. Tykwinski, Eur. J. Org. Chem. (2006) 4791–
In conclusion, we have developed an efficient IBX-TfOH
mediated method for the oxidation of a wide range of
functionalized alcohols to carbonyl compounds in 1,4-dioxane at
room temperature. Notably, the present method is readily
accessible, has a broad substrate scope and good functional group
tolerance under mild reaction conditions.
Acknowledgments
DSR thanks Council of Scientific and Industrial Research, India (File
Number: 02(0318)/17/EMR-II) for financial support. We thank
USIC-CIF, University of Delhi for assisting to acquire analytical
data.
4
795; (j) R. D. Richardson, J. M. Zayed, S. Altermann, D. Smith,
T. Wirth, Angew. Chem. Int. Ed. 46 (2007) 6529–6532; (k) L.-Q.
Cui, Z.-L. Dong, K. Liu, C. Zhang, Org. Lett. 13 (2011) 6488–
6491; (l) J. N. Moorthy, K. Senapati, K. N. Parida, S. Jhulki, K.
Sooraj, N. N. Nair, J. Org. Chem. 76 (2011) 9593–9601; (m) S.
Seth, S. Jhulki, J. N. Moorthy, Eur. J. Org. Chem., 2013, 2445–
References and notes
2
7
452; (n) J. N. Moorthy, K.Senapati, K. N.Parida. J. Org. Chem.
5 (2010) 8416–8421.
1
.
.
(a) T. Mallat, A. Baiker, Chem. Rev. 104 (2004) 3037–3058;
b) M. S. Sigman, D. R. Jensen, Acc. Chem. Res. 39 (2006) 221-
2
1. (a) M. M¨ulbaier, A. Giannis, Angew. Chem., Int. Ed. 40 (2001)
393–4394; (b) A. Ozanne, L. Pouyse´gu, D. Depernet, B.
(
4
2
8
29; (c) M. J. Schultz, M. S. Sigman, Tetrahedron 62 (2006)
227-8241; (d) T. Daisuke, T. Masayuki, M. Katsuhiko, H. Togo,
Francüois, S. Quideau. Org. Lett. 5 (2003) 2903-2906.
2. M. S. Yusubov, D. Y. Svitich, A. Yoshimura, V. N. Nemykin, V.
V. Zhdankin. Chem. Commun. 49 (2013) 11269-11271.
3. M. S. Yusubov, N. S. Soldatova, P. S. Postnikov, R. R. Valiev, A.
Yoshimura, T. Wirth, V. N. Nemykin, V. V. Zhdankin. Chem.
Commun. 55 (2019) 7760-7763.
4. R. D. Richardson, J. M. Zayed, S. Altermann, D. Smith, T. Wirth,
Angew. Chem. Int. Ed. 46 (2007) 6529-6532.
5. J. N. Moorthy, K. Senapati, K. N. Parida, S. Jhulki, K. Sooraj, N.
N. Nair, J. Org. Chem. 76 (2011) 9593-9601.
2
2
Tetrahedron 68 (2012) 6849-6855.
(a) G. J. T. Brink, I. W. C. E. Arends, R. A. Sheldon, Science, 287
2
(2000) 1636-1639; (b) L. Tebben, A. Studer, Angew. Chem. Int.
Ed. 50 (2011) 5034-5068; (c) D. I. Enache, J. K. Edwards, P.
Landon, B. Solsona-Espriu, A. F. Carley, A. A. Herzing, M.
Watanabe, C. J. Kiely, D. W. Knight, G. J. Hutchings, Science,
2
2
3
11 (2006) 362-365; (d) H. Li, F. Qin, Z. Yang, X. Cui, J. Wang,
L. Zhang, J. Am. Chem. Soc., 139 (2017) 3513-3521; (e) M.
Rafiee, K. C. Miles, S. S. Stahl, J. Am. Chem. Soc. 137 (2015)
2
2
6. D. B. Dess, J. C. Martin, J. Org. Chem. 48 (1983) 4155-4156.
7. S. L. Bartlett, C. M. Beaudry, J. Org. Chem. 76 (2011)
1
4
4751-14757. (f) A. Badalyan, S. S. Stahl, Nature 535 (2016) 406-
10; (g) I. Enache, J. K. Edwards, P. Landon, B. Solsona-Espriu,
9
852−9855.
8. A. P. Thottumkara, M. S. Bowsher, T. K. Vinod, Org. Lett. 7
2005) 2933-2936.
9. C.-K. Lin, T.-J. Lu, Tetrahedron, 60 (2010) 9688-9693.
A. F. Carley, A. A. Herzing, M. Watanabe, C. J. Kiely, D. W.
Knight, G. J. Hutchings, Science 311 (2006) 362-365; (h) J. M.
Hoover, S. S. Stahl, J. Am. Chem. Soc. 133 (2011) 16901-16910.
2
2
(

5
3
3
3
0. J. N. Moorthy, N. Singhal, K. Senapati, Org. Biomol. Chem. 5
2007) 767–771.
1. K. Surendra, N. S. Krishnaveni, M. A. Reddy, Y. V. D. Nageswar,
K. R. Rao, J. Org. Chem. 68 (2003) 2058-2059.
2. (a) G. Karthikeyan, P. T. Perumal, Synlett, (2003) 2249-2251; (b)
Z. Liu, Z. C. Chen, Q. G. Zheng, Org. Lett. 5 (2003) 3321-3323;
37. N. Kumar, S. I. Khan, H. Atheaya, R. Mamgain, D. S. Rawat,
Eur. J. Med. Chem. 46 (2011) 2816-2827.
(
38. J. T. Su, W. A. Goddard, J. Am. Chem. Soc., 127 (2005) 14146-
14147.
39. S. Sarell, J. Yovell, M. Sarel-Imber, Angew. Chem. Int. Ed. 7
(1987) 577-578.
(
c) J. S. Yadav, B. V. S. Reddy, A. K. Basak, A. V. Narsaiah,
40. (a) R. P. Bell, B. G. Cox, J. Chem. Soc. B, (1970) 194-196 (b) H. C.
Geiger, J. S. Donohoe, J. Chem. Educ. 89 (2012) 1572-1574. (c)
K. Yoshikai, T. Hayama, K. Nishimura, Ken-ichi Yamada, K.
Tomioka J. Org. Chem. 70 (2005) 681-683.
Tetrahedron, 60 (2004) 2131-2135.
3
3
3. J. D. More, N. S. Finney, Org. Lett. 17 (2002) 3001-3003.
4. M. Frigerio, M. Santagostino, S. Sputore, G. Palmisano, J. Org.
Chem. 60 (1995) 7272-7276.
3
3
5. M. A. Lapitskaya, L. L. Vasiljeva, K. K. Pivnitsky, Mendeleev
Commun. 18 (2008) 309–311.
6. K. Arya, U. C. Rajesh, D. S. Rawat, Green Chem. 14 (2012) 3344-
3
351.

6
Tetrahedron
Declaration of Interest Statement
Authors declare no conflict of interest.

7
Highlights:

IBX-TfOH mediated oxidation of primary and
secondary alcohols to carbonyls is reported.
The catalytic system is compatible with a
variety of substrates having arene, heteroarene
and alkene functionalities.


The developed synthetic protocol can be used
for the oxidation of alcohols at 1 gm scale.