Fe(NO3)3·9H2O-catalyzed aerobic oxidative deoximation of ketoximes and aldoximes under mild conditions

Article abstract of DOI:10.1139/cjc-2017-0567

A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO₃)₃·9H₂O as the single catalyst and molecular oxygen as the green oxidant. The environmentally benign protocol provides moderate to excellent yield and broad functional groups tolerance and is a valuable synthetic method for practical applications. According the relevant verification experiment, a plausible mechanism has been proposed.

Full text of DOI:10.1139/cjc-2017-0567

Page 1 of 22
Fe(NO3)3•9H2OꢀCatalyzed Aerobic Oxidative Deoximation of
Ketoximes and Aldoximes under Mild Conditions
Yongshu Li,a Nizhou Xu,a,b Guangyao Mei,c Yun Zhao,b Yiyong Zhao,b Jinghui Lyu,b Guofu Zhang,b* and
Chengrong Dingb*
a
b
c
College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014
Zhejiang Hongyan pharmacatical Co. Ltd. Taizhou 317016. People's Republic of China
* Corresponding author. Eꢀmail: gfzhang@zjut.edu.cn.; dingcr@zjut.edu.cn

Page 2 of 22
Abstract
A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and
.
aldoximes has been developed, which utilizes Fe(NO3)3 9H2O as the single catalyst and molecular oxygen as the
green oxidant. The environmentally benign protocol provides moderate to excellent yield and broad functional
groups tolerance, and a valuable synthetic method for practical applications. According the relevant verification
experiment, a plausible mechanism has been proposed.
Key words: Feꢀcatalyst, deoximation, molecular oxygen, aldoximes, ketoximes.

Page 3 of 22
Introduction
As an important class of organic compounds in organic synthesis,1 oximes play an important role in
2
protecting groups and are extensively used for the purification and characterization of carbonyl compounds.3
The oximes can be prepared from noncarbonyl compounds as well as from carbonyl compounds.4 The
regeneration of carbonyl compounds from oximes provides an alternative method for the preparation of
aldehydes and ketones.5 Therefore, various methods, including acidꢀcatalytic hydrolysis, oxidative and reductive
deoximation, have been developed for these processes.6 Among these methods, most of them, though they are
efficient, are not free from drawbacks such as toxic and hazardous oxidants or reductants and large amounts of
strong Lewis and Brönsted acids used in these systems being generally needed to be reduced, oxidized and
neutralized, which usually causes serious environmental pollution. Besides, longer reaction time, low yield of
products, difficulty in isolating the products and formation of overꢀoxidized products are also the problems.
In the past decades, there has been increasing interest in developing methods for transition metals and
transitionꢀmetal complexes catalyzed an oxidation reactions employing oxygen as the terminal oxidant.7
Especially iron element, as an exceedingly abundant metal on the earth,8 has been attracted more attention on
oxidation reactions. Remarkably, noteworthy efforts have been contributed to the biomimetic oxidation mediated
by iron porphyrins to effectively activate O2 in the past years.9 Except for them, difficulties, to directly activate
the O2 by commercially available simple iron salts still exist, and only minority coupled catalytic systems have
been developed, facilitating the aerobic oxidative procedures via a lowꢀenergy pathway by introducing some
suitable electronꢀtransfer mediators.10 Since 2005, Liang’s group has sequentially disclosed several efficient
catalytic systems for aerobic oxidation of alcohols with the combination of FeCl3, NaNO2, and TEMPO or
4ꢀacetamidoꢀTEMPO.11 Subsequently, Zhang and coꢀworkers synthesized a novel bimagnetic imidazolium salt

Page 4 of 22
[ImimꢀTEMPO][FeCl4], which proved to be effective for oxidation of benzyl alcohols in the presence of
NaNO2.12 The oxidative deoximation, especially using oxygen as the terminal oxidant, is an important
transformation in organic synthesis for both environmental and economic advantages and many excellent
examples have been continuously reported during the past years.13 Currently, our group has developed an
efficient deoximation system using O2 as the green oxidant, FeCl3/TEMPO as the catalysts without any other
additives.14a And two years previously, we also had reported a novel system using NaNO2 as the catalyst, O2 as
the terminal oxidant, and Amberlystꢀ15 as a recyclable initiator for oxidative cleavage of oximes to the
corresponding carbonyl compounds.14b Besides, there are also some examples involving Feꢀcatalyzed aerobic
oxidative deoximation reactions have been reported.15 Notably, all these systematically studies have confirmed
that NaNO2, or TEMPO combines with Fe(Ⅲ) salts is essential for the catalytic oxidation cycle, which
.
encourages us to develop an easier system to proceed deoximation reaction. Herein, a Fe(NO3)3 9H2Oꢀcatalyzed
aerobic oxidative deoximation system without any other extra additives might be established.
Experimental Section
General
Reagents were purchased at commercial quality and used without further purification unless otherwise
stated. All ketone or aldehyde were purchased from Aladdin reagent Co., LTD (Shanghai). Iron nitrate
nonahydrate, iron salts were purchased from Aladdin reagent Co., LTD (Shanghai) too. Yields of the products
referred to isolated yields purified by column chromatography on silica gel (300ꢀ400 mesh) produced by
Qingdao Marine Chemical Factory, Qingdao (China) with hexane and ethyl acetate (for ketoximes, 8:1 and for
aldoximes, 6:1) to give the corresponding carbonyl compounds. NMR spectra were recorded on Bruker

Page 5 of 22
AVANCE III 500MHz instrument with TMS as internal standard. Coupling constants were reported in Hertz
(Hz). Melting points were measured with micro melting point apparatus and were uncorrected.
General Procedure for Preparation of Oximes (1aꢀx)
A mixture of aldehyde or ketone (25.0 mmol), NH2OH·HCl (1.5 eq.), CH3COONa (2.5 eq.), ethyl alcohol
(10.0 mL) and water (30.0 mL) were placed in a 100mL roundꢀbottomed flask equipped with a magnetic stirrer.
Then the mixture was stirred under reflux, the progress was monitored by TLC. After the reaction, the contents
were poured into a beaker (250 ml). After cooling, the precipitate was filtered with suction, thoroughly washed
with water and dried under vacuum, then recrystallization with ethyl alcohol to obtain a pure solid.
General Experimental Procedure for Deoximation to the Corresponding Carbonyl Compounds
.
Oximes (1.0 mmol), Fe(NO3)3 9H2O (0.025 mmol) were introduced into an equipped with a 50 mL Schlenk
flask magnetic stirrer and the flask was purged several times with oxygen (balloon filled). Then the solvent
o
(PhCH3 4.0 mL) was injected into the flask and the reaction mixture was stirred at 37 C for 1.5 hours. After the
reaction was completed (which was monitored by TLC), the products referred to isolated yields purified by
column chromatography on silica gel (300ꢀ400 mesh) with hexane and ethyl acetate (for ketoximes, 8:1 and for
aldoximes, 6:1) to give the corresponding carbonyl compounds.
Acetophenone (2a): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ7.91 – 7.89 (d, J = 8.3 Hz, 2H), 7.53 ꢀ
7.46 (m, 1H), 7.42 ꢀ 7.36 (m, 2H), 2.53 (s, 3H).
4ꢀFluoroacetophenone (2b): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ7.94 – 7.91 (ddd, J = 8.0, 5.4,
1.5 Hz, 2H), 7.11 ꢀ 7.02 (m, 2H), 2.53 (s, 3H).
1
4ꢀChloroacetophenone (2c): liquid. H NMR (500 MHz, Chloroformꢀd) δꢀ7.85 – 7.63 (m, 2H), 7.36 –
7.26 (dt, J = 9.1, 2.0 Hz, 2H), 2.54 (s, 3H).

Page 6 of 22
o
1
4ꢀBromoacetophenone (2d): mp 50ꢀ51 C. H NMR (500 MHz, Chloroformꢀd) δ7.81 – 7.79 (m, 2H),
7.60 – 7.57 (m, 2H), 2.57 (s, 3H).
3ꢀChloroacetophenone (2e): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ7.85 (d, J = 1.7 Hz, 1H), 7.78
– 7.76 (m, 1H), 7.48 ꢀ 7.45 (dt, J = 7.9, 2.0 Hz, 1H), 7.37 ꢀ 7.33 (td, J = 7.8, 1.3 Hz, 1H), 2.54 (s, 3H).
2,4ꢀDichloroacetophenone (2f): mp 33ꢀ34 oC. 1H NMR (500 MHz, Chloroformꢀd) δ7.54 (d, J = 8.3 Hz,
1H), 7.44 (d, J = 2.0 Hz, 1H), 7.31 (dd, J = 8.3, 2.0 Hz, 1H), 2.64 (s, 3H).
4ꢀmethoxyacetophenone (2g): mp 38ꢀ39 oC. 1H NMR (500 MHz, Chloroformꢀd) δ7.95 – 7.92 (m, 2H),
6.98 ꢀ 6.87 (m, 2H), 3.86 (s, 3H), 2.55 (s, 3H).
2ꢀHydroxyacetophenone (2h): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ12.26 (s, 1H), 7.68 (dd, J =
8.0, 1.4 Hz, 1H), 7.44 – 7.41 (m, 1H), 6.93 (d, J = 8.4 Hz, 1H), 6.87 – 6.84 (t, J = 7.6 Hz, 1H), 2.57 (d, J = 0.9
Hz, 3H).
o
1
3,4ꢀDimethoxyacetophenone (2i): mp 48ꢀ52 C. H NMR (500 MHz, Chloroformꢀd) δ7.52 – 7.50 (m,
1H), 7.46 (s, 1H), 6.85 ꢀ 6.80 (m, 1H), 3.88 (d, J = 5.8 Hz, 6H), 2.50 (s, 3H).
4ꢀMethylacetophenone (2j): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ7.85 ꢀ 7.80 (m, 2H), 7.22 (d, J
= 7.9 Hz, 2H), 2.54 (s, 3H), 2.38 (s, 3H).
4ꢀPhenylacetophenone (2k): mp 121ꢀ124 oC. 1H NMR (500 MHz, Chloroformꢀd) δ8.07 ꢀ 8.04 (m, 2H),
7.72 ꢀ 7.69 (m, 2H), 7.66 ꢀ 7.63 (m, 2H), 7.49 (td, J = 6.9, 1.6 Hz, 2H), 7.44 – 7.41 (m, 1H), 2.66 (s, 3H).
1
Propiophenone (2l): liquid. H NMR (500 MHz, Chloroformꢀd) δ7.97 ꢀ 7.92 (m, 2H), 7.55 7.48 (m,
1H), 7.42 (t, J = 7.7 Hz, 2H), 2.97 (q, J = 7.2 Hz, 2H), 1.20 (t, J = 7.2 Hz, 3H).
1
4ꢀMethylpropiophenone (2m): liquid. H NMR (500 MHz, Chloroformꢀd) δ7.84 (d, J = 8.2 Hz, 2H),
7.21 (d, J = 8.5 Hz, 2H), 2.96 – 2.91 (q, J = 7.3 Hz, 2H), 2.37 (s, 3H), 1.21 – 1.18 (s, 3H).

Page 7 of 22
1ꢀTetralone (2n): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ7.98 (dd, J = 7.8, 1.1 Hz, 1H), 7.41 (td, J
= 7.5, 1.4 Hz, 1H), 7.24 (t, J = 7.6 Hz, 1H), 7.19 (d, J = 7.6 Hz, 1H), 2.90 (t, J = 6.1 Hz, 2H), 2.61 ꢀ 2.57 (m, 2H),
2.07 (dt, J = 12.7, 6.4 Hz, 2H).
o
1
Benzophenone (2o): mp 47ꢀ49 C. H NMR (500 MHz, Chloroformꢀd) δ7.83 (dt, J = 8.4, 1.5 Hz, 4H),
7.63 – 7.59 (m, 2H), 7.52 ꢀ 7.48 (m, 4H).
4ꢀMethylbenzophenone (2p) : mp 53ꢀ57 oC. 1H NMR (500 MHz, Chloroformꢀd) δ7.80 (dt, J = 8.4, 1.5
Hz, 2H), 7.76 ꢀ 7.72 (m, 2H), 7.62 ꢀ 7.56 (m, 1H), 7.52 ꢀ 7.46 (m, 2H), 7.30 (d, J = 7.9 Hz, 2H), 2.46 (s, 3H).
Benzaldehyde (2q): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ10.00 (s, 1H), 7.86 (dt, J = 8.3, 1.5 Hz,
2H), 7.63 ꢀ 7.58 (m, 1H), 7.50 (t, J = 7.6 Hz, 2H).
4ꢀMethylbenzaldehyde (2r): liquid. 1H NMR (500 MHz, Chloroformꢀd) δ9.97 (s, 1H), 7.78 (d, J = 8.1
Hz, 2H), 7.34 (d, J = 8.0 Hz, 2H), 2.45 (s, 3H).
1
3,4ꢀDimethylbenzaldehyde (2s): liquid. H NMR (500 MHz, Chloroformꢀd) δ9.91 (s, 1H), 7.63 ꢀ 7.57
(m, 2H), 7.26 (d, J = 7.7 Hz, 1H), 2.31 (d, J = 4.0 Hz, 6H).
o
1
4ꢀChlorobenzaldehyde (2t): mp 48 C. H NMR (500 MHz, Chloroformꢀd) δ9.98 (s, 1H), 7.83 ꢀ 7.80
(m, 2H), 7.52 ꢀ 7.49 (m, 2H).
o
1
4ꢀBromobenzaldehyde (2u): mp 55ꢀ58 C. H NMR (500 MHz, Chloroformꢀd) δ9.97 (s, 1H), 7.76 ꢀ
7.73 (m, 2H), 7.69 ꢀ 7.66 (m, 2H).
1ꢀNaphthaldehyde (2v): mp 1ꢀ2 oC. 1H NMR (500 MHz, Chloroformꢀd) δ10.34 (s, 1H), 9.26 (d, J = 8.6
Hz, 1H), 8.01 (d, J = 8.2 Hz, 1H), 7.90 ꢀ 7.85 (m, 2H), 7.68 – 7.65 (m, 1H), 7.58 ꢀ 7.52 (m, 2H).
1
2ꢀAcethylthiopene (2w): liquid. H NMR (500 MHz, Chloroformꢀd) δ7.62 – 7.61 (m, 1H), 7.59 ꢀ 7.53
(m, 1H), 7.04 (dd, J = 4.9, 3.7 Hz, 1H), 2.47 (s, 3H).

Page 8 of 22
2ꢀAcethylfuran (2x): mp 29ꢀ30 oC. 1H NMR (500 MHz, Chloroformꢀd) δ7.42 (d, J = 1.5 Hz, 1H), 7.00
(d, J = 3.6 Hz, 1H), 6.36 – 6.34 (dd, J = 3.5, 1.7 Hz, 1H), 2.27 (s, 3H).
Results and discussion
At outset of this study, we embarked on condition optimization with acetophenone oxime 1a as model
substrate, and the detailed results were summarized in Table 1. Surprisingly, the initial result shows that the
desired product 2a was formed in 83% yield when the reaction was carried out with 10 mol% Fe(NO3)3·9H2O, 1
o
atm O2 as the oxidizing agent at 37 C for 1.5 h (Table 1, entry 1). In following studies, other Fe catalysts such
as Fe(OAc)3, FeCl3, FeBr3 and Fe(OTf)3 were also tried (Table 1, entries 2ꢀ5). Unfortunately, these catalysts
ꢀ
showed any catalytic activity in this reaction, which indicates the essential of both Fe(III) and NO3 for this
catalytic oxidative deoximation reaction. Aimed at further improve the reactivity, the amounts of
Fe(NO3)3·9H2O were further screened (Table 1, entries 6ꢀ10). It was found that with 2.5 mol% Fe(NO3)3·9H2O,
the desired product 2a was formed in 93% yield. When PhCl, Hexane, DCE, CH3CN, or CCl4 was used to
replace toluene as the reaction medium, the yield of 2a would be decreased (Table 1, entries 11ꢀ15 vs entry 8).
Meanwhile, other solvents, like tertꢀamy alcohol, ethyl acetate (AcOEt) and cyclohexane were less effective for
this transformation (for details see Table S1 in Supporting Information). Furthermore, the factors of
temperature (Table 1, entries 16 and 17) and the reaction time (Table 1, entries 18 and 19) all had significant
influences to this reaction (for details see Table S1 in Supporting Information). Meanwhile, we found that the
reaction could not progress under N2 (Table 1, entry 20) and also ineffective under an air which gained low yield
(Table 1, entry 21), which means that oxygen plays an essential role in this proceed. Finally, it was noteworthy
to emphasize that when the reaction was carried out with 4Å MS, the yield of desired product 2a was obviously
decreased (Table 1, entry 22).

Page 9 of 22
Table 1. Optimization of reaction conditions.a
Entry
Solvent
[Fe]
Amt of [Fe]
(mol %)
Yieldb
(%)
1
Toluene
Fe(NO3)3·9H2O
10
83
2
3
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
PhCl
Fe(OAc)3
10
10
ꢀ
ꢀ
FeCl3
4
FeBr3
10
ꢀ
5
Fe(OTf)3
10
ꢀ
6
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
1.0
2.0
2.5
3.0
20
70
89
93
88
80
69
75
82
77
52
45
61
80
93
<10
23
54
7
8
9
10
11
12
13
14
15
16c
17d
18e
19f
20g
21h
22i
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Hexane
DCE
CH3CN
CCl4
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
a Conditions: acetophenone oxime (1.0 mmol), [Fe] (2.5 mol%), 4 mL solvent, under 1 atm O2, 1.5 h, in a 50 mL
Schlenk flask. b Isolated yield. c 25 oC. d 50 oC. e 0.5 h. f 5 h. g Under N2. h Under air. i Additive 4Å MS.
Having obtained the optimal reaction conditions, we further explored the generality of this transformation
with respect to the ketoximes and aldoximes derivatives (Scheme 1). It was delightful to observe that all
substrates tested could afford the desired products in moderate to excellent yields under the standard reaction
conditions. Regardless of whether oximes were in electronicꢀdonating or electronicꢀwithdrawing groups on the
benzene ring were well accommodated. For instance, the ketoximes bearing electronicꢀwithdrawing haloarenes
(F, Cl, Br) on the aromatic ring were all easily converted to the corresponding products with 87ꢀ91% yields
(Scheme 1, 2bꢀ2f), and the others possessing electronꢀdonating groups also gained the wonderful yields

Page 10 of 22
(Scheme 1, 2gꢀ2k). Notably, the steric hindered oximes could underwent the deoximative transformation
smoothly, giving ideal yields of the desired products (Scheme 1, 2lꢀ2n). To our delight, the desired products of
heteroaromatic ketoxime were also obtained in good yields (Scheme 1, 2w, 2x). Surprisingly, aldoximes
derivatives were oxidized to corresponding carbonyl compounds in excellent isolated yields when the
temperature was raised to 60 oC (Scheme 1, 2qꢀ2v).
Scheme 1. Scope of ketoꢀ and aldoximes.a,b
1a:93%
1f:91%
1b:87%
1g:94%
1l:95%
1c:91%
1h:94%
1m:89%
c 1r:84%
1w:81%
1d:89%
1i:84%
1e:88%
1j:95%
1o:94%
c 1t:85%
1k:91%
1p:92%
c 1u:92%
1n:93%
c 1s:97%
1x:85%
c 1q:80%
c 1v:91%
a
.
Conditions: oxime (1.0 mmol), Fe(NO3)3 9H2O (2.5 mol%), 4 mL toluene, under 1 atm O2, 1.5 h, in a 50 mL Schlenk
flask. b Isolated yield. c 60 oC.

Page 11 of 22
In further research, the gramꢀscale application of this methodology was also studied and acetophenone
oxime 1a was taken as a representative substrate. When the amount of the substrate was increased from 1 mmol
.
(0.135 g) to 50 mmol (6.750 g) and the amount of Fe(NO3)3 9H2O were not changed, to our delight, the desired
product was isolated in 75%ꢀ93% yields (Table 2).
Table 2. Gramꢀscale test for deoximation of acetophenone oxime.a
Entry
Substrate
Amt of
Toluene
Time
(h)
Yield b
(%)
.
Fe(NO3)3 9H2O
(mmol)
(ml)
(mol %)
2.5
1
2
3
4
1
2
4
4
5
1.5
3
93
86
81
75
10
20
50
2.5
2.5
8
2.5
12
a
Conditions: acetophenone oxime, Fe(NO3)3 9H2O, PhCH3, under 1 atm O2. b Isolated yield
.
.
To gain insight into the mechanism, we conducted the rate control experiments for deoximation of
acetophenone oxime (Scheme 2). It is obviously that the oxidative deoximation proceeded sluggishly during the
ꢀ
ꢀ
first 60 minutes, mainly because of the slow process of NO3 to NO2 . But the rest of the deoximative
transformation proceeded very fast, indicating that NO was released from the cleavage of the reactant oxime for
accelerating the catalytic process. Since the released NO could be easily oxidized to NO2 by molecular oxygen
ꢀ
ꢀ
and reacted with water to provide NO3 , we did some detection of the NO3 concentration in aqueous phase by
ꢀ
Ionic Chromatography. To our delight, a great quantity of NO3 was detected after the reaction, which in some
degree confirmed our hypothesis of the generation of NO.
Scheme 2. Experiments on the rate of deoximation.

Page 12 of 22
On the basis of these observations and our related reports in the literature,14ꢀ16 a plausible mechanism is
.
proposed, as outlined in Figure 1. Initially, trace of Fe(NO3)3 9H2O was decomposed into Fe2O3 and nitrogen
dioxide (NO2),16b which was to stand for a single electron.14b Then the high active species NO2 reacts with C=N
double bonds of the oxime to produce an intermediate A. This intermediate A can subsequently through a proton
transfer process to form species B, which is then attacked by NO2 to give an active material C. Subsequent
hydrolysis of C generates the carbonyl compound 2 as well as HNO2, HNO3 and NH2OH. The HNO2 is unstable
and release NO, meanwhile the oxidative HNO3 and reductive NH2OH can also interact to generate NO. They
can both be reoxidized to NO2 by oxygen and continue the catalytic cycle.
.
Figure 1. Plausible mechanism for aerobic oxidative deoximation catalyzed by Fe(NO3)3 9H2O.
O
R1
R2
2
2H2O
NO2
HNO2+HNO3+NH2OH
NO
O
1/2 O2
N
O
2NO+2H2O
1/2 O2
O
NH
R2
.
NO2
Fe(NO3)3 9H2O
R1
C
1/2 O2
Fe2O3+H2O
NO2
O
O
N
O
OH
N
N
O
O
NOH
NH
R2
R1
R2
R1
R2
R1
1
A
B
Conclusion
.
In conclusion, we disclosed an efficient and simple Fe(NO3)3 9H2Oꢀcatalyzed aerobic oxidative
deoximation of ketoximes and aldoximes under mild condition in the presence of inexpensive and green oxygen

Page 13 of 22
molecule, and a plausible aerobic oxidative deoximation mechanism has been proposed. In addition, the
environmentally benign protocol shows moderate to excellent yields and broad functional groups tolerance.
Acknowledgment
We acknowledge financial support from the National Natural Science Foundation of China (no. 20702051),
the Natural Science Foundation of Zhejiang Province (LY13B020017) and the Key Innovation Team of Science
and Technology in Zhejiang Province (no. 2010R50018).
Supporting Information
Supplementary information are available with the article through the journal Web site.
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Page 17 of 22
Table 1. Optimization of reaction conditions.a
Amt of [Fe]
(mol %)
Yieldb
(%)
Entry
Solvent
[Fe]
1
Toluene
Fe(NO3)3·9H2O
10
83
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16c
17d
18e
19f
20g
21h
22i
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
PhCl
Hexane
DCE
CH3CN
CCl4
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Fe(OAc)3
FeCl3
FeBr3
Fe(OTf)3
10
10
10
-
-
-
10
-
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
Fe(NO3)3·9H2O
1.0
2.0
2.5
3.0
20
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
70
89
93
88
80
69
75
82
77
52
45
61
80
93
<10
23
54
a Conditions: acetophenone oxime (1.0 mmol), [Fe] (2.5 mol%), 4 mL solvent, under 1 atm O2, 1.5 h, in a 50
mL Schlenk flask. b Isolated yield. c 25 oC. d 50 oC. e 0.5 h. f 5 h. g Under N2. h Under air. i Additive 4Å MS.

Page 18 of 22
Table 2. Gram-scale test for deoximation of acetophenone oxime.a
Entry
Substrate
Amt of
Fe(NO3)3 9H2O
Toluene
Time
Yield b
.
(mol %)
(mmol)
(ml)
(h)
1.5
3
8
12
(%)
93
86
81
75
1
2
3
4
1
2.5
2.5
2.5
2
4
4
5
10
20
50
2.5
Conditions: acetophenone oxime, Fe(NO3)3 9H2O, PhCH3, under 1 atm O2. b Isolated yield
.
a
.

Page 19 of 22
Scheme 1. Scope of keto- and aldoximes.a,b
1a:93%
1f:91%
1b:87%
1g:94%
1l:95%
1c:91%
1h:94%
1m:89%
c 1r:84%
1w:81%
1d:89%
1i:84%
1e:88%
1j:95%
1o:94%
c 1t:85%
1k:91%
1p:92%
c 1u:92%
1n:93%
c 1s:97%
1x:85%
c 1q:80%
c 1v:91%
a
.
Conditions: oxime (1.0 mmol), Fe(NO3)3 9H2O (2.5 mol%), 4 mL toluene, under 1 atm O2, 1.5 h, in a 50 mL
Schlenk flask. b Isolated yield. c 60 oC.

Page 20 of 22
Scheme 2. Experiments on the rate of deoximation.

Page 21 of 22
Figure 1.
147x87mm (96 x 96 DPI)

Page 22 of 22