Transition metal-mediated oxidations utilizing monomeric iodosyl- and iodylarene species

Article abstract of DOI:10.1016/j.tet.2010.04.046

Several transition metal-mediated oxidations using hypervalent iodine species are reported. A convenient procedure for preparation of iodylarenes via RuCl₃-catalyzed oxidation of iodoarenes has been developed. This procedure allows the generation of highly reactive monomeric iodine(V) species, which are excellent oxidants toward alcohols and hydrocarbons in situ. A broad range of substrates can be oxidized to carbonyl compounds by a tandem catalytic system based on the Ru(III)-catalyzed reoxidation of ArIO to ArIO₂ using Oxone as oxidant. It was shown that electrophilic iodine(III) species, originating from oligomeric iodosylbenzene sulfate (PhIO)₃SO₃, are efficient oxygenating agents in catalytic oxidation of aromatic hydrocarbons in the presence of metalloporphyrin complexes.

Full text of DOI:10.1016/j.tet.2010.04.046

Tetrahedron 66 (2010) 5745e5752
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Transition metal-mediated oxidations utilizing monomeric iodosyl-
and iodylarene species
,
Mekhman S. Yusubov b, Victor N. Nemykin a, Viktor V. Zhdankin a
*
a Department of Chemistry and Biochemistry, University of Minnesota Duluth, Duluth, MN 55812, USA
b Siberian State Medical University and Tomsk Polytechnic University, 2 Moskovsky trakt, 634050 Tomsk, Russia
a r t i c l e i n f o
a b s t r a c t
Article history:
Several transition metal-mediated oxidations using hypervalent iodine species are reported. A conve-
nient procedure for preparation of iodylarenes via RuCl3-catalyzed oxidation of iodoarenes has been
developed. This procedure allows the generation of highly reactive monomeric iodine(V) species, which
are excellent oxidants toward alcohols and hydrocarbons in situ. A broad range of substrates can be
oxidized to carbonyl compounds by a tandem catalytic system based on the Ru(III)-catalyzed reoxidation
of ArIO to ArIO2 using OxoneÒ as oxidant. It was shown that electrophilic iodine(III) species, originating
from oligomeric iodosylbenzene sulfate (PhIO)3SO3, are efficient oxygenating agents in catalytic oxida-
tion of aromatic hydrocarbons in the presence of metalloporphyrin complexes.
Received 1 March 2010
Received in revised form 8 April 2010
Accepted 12 April 2010
Available online 11 May 2010
Keywords:
Hypervalent iodine
Oxidation
Ó 2010 Elsevier Ltd. All rights reserved.
Catalysis
Ruthenium
Porphyrins
1. Introduction
biomimetic oxygenations catalyzed by metalloporphyrins and
other transition metal complexes.9 Primary and secondary alcohols
Hypervalent iodine compounds have found wide application as
versatile and environmentally friendly oxidizing reagents in or-
ganic chemistry.1 It has also been found that transition metals have
a dramatic catalytic effect on some oxidations with hypervalent
iodine reagents. In 1979 Groves and co-workers reported that
iodosylbenzene, (PhIO)n, is the most efficient source of oxygen in
oxygenation of hydrocarbons in the presence of iron(III) porphyrin
complexes,2 and since then iodosylarenes and other hypervalent
iodine reagents have been widely used as stoichiometric oxidants
in the reactions mimicking natural oxidations performed by the
heme-containing cytochrome P-450 class of enzymes.3 Recent ex-
amples of transition metal-catalyzed oxidations employing iodo-
sylbenzene include the hydroxylation of hydrocarbons,4 the
transition metal-mediated epoxidation of alkenes,5 oxidation of
can be selectively oxidized to the corresponding carbonyl com-
pounds by DIB in the presence of transition metal catalysts, such as
RuCl3,10 polymer-micelle incarcerated ruthenium catalysts,11a chi-
ral-Mn(salen)-complexes,11b,c Mn(TPP)CN/Im catalytic system,11d
and (salen)Cr(III) complexes.11e The epoxidation of alkenes, such
as stilbenes, indene, and 1-methylcyclohexene, using DIB in the
presence of chiral binaphthyl ruthenium(III) catalysts (5 mol %) has
also been reported.11f
The mechanisms and applications of Pd-catalyzed reactions of
DIB and other hypervalent iodine reagents in synthetically useful
organic transformations were recently reviewed by Deprez and
Sanford.12a Particularly useful are the Pd-catalyzed oxidation re-
actions, including the oxidative functionalization of CeH bonds and
the 1,2-aminooxygenation of olefinic substrates.12 Representative
examples of these catalytic oxidations are illustrated by the selec-
tive acetoxylation of CeH bonds adjacent to coordinating func-
tional groups,12b and by the Pd(OAc)2-catalyzed intramolecular
alcohols to carbonyl compounds,6,7
d-sultone formation through
Rh-catalyzed CeH insertion,8a and oxidation of organic sulfides to
sulfoxides.8b,c
[Bis(acyloxy)iodo]arenes are also commonly used as stoichio-
metric oxidants in the reactions catalyzed by transition metal salts
and complexes. (Diacetoxyiodo)benzene (DIB) is occasionally
employed instead of iodosylbenzene as the terminal oxidant in
aminoacetoxylation in the reaction of g
-aminoolefins with DIB.12c
The key mechanistic step in these catalytic transformations in-
cludes the DIB promoted oxidation of Pd(II) to the Pd(IV) species, as
proved by the isolation and X-ray structural identification of stable
Pd(IV) complexes prepared by the reaction of PhI(O2CPh)2 with Pd
(II) complexes containing chelating 2-phenylpyridine ligands.12o
Several examples of Pd-catalyzed chlorinations of organic sub-
strates using (dichloroiodo)benzene have also been reported.12p,q
* Corresponding author. Tel.: þ1 218 726 6902; fax: þ1 218 726 7394. E-mail
address: vzhdanki@d.umn.edu (V.V. Zhdankin).
0040-4020/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.04.046

5746
M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
Our interest in the study of transition metal-mediated oxida-
functionalization of organic substrates.14aee The use of (PhIO)3SO3
in metalloporphyrin or phthalocyanine-catalyzed oxygenations is
described in Section 2.2 of this article. The preparation and re-
actions of protonated iodosylbenzene monomer, PhI(OH)BF4,
which can be stabilized by complexation with 18C6 crown ether,
has previously been reported by Ochiai.1r Very recently, we have
developed a mild and convenient procedure for preparation of [bis
(trifluoroacetoxy)iodo]perfluoroalkanes and [bis(trifluoroacetoxy)
iodo]arenes based on the room temperature oxidation of ArI to ArI
(III)-species with OxoneÒ (Scheme 2).14f
tions using hypervalent iodine reagents originated in 2006, when
we had found a simple and efficient procedure for the Ru-catalyzed
oxidation of alcohols to carbonyl compounds using (diacetoxyiodo)
benzene as stoichiometric oxidant.10a This reaction involved an
initial instantaneous RuCl3-catalyzed disproportionation of DIB to
iodobenzene and iodylbenzene with the latter acting as the actual
stoichiometric oxidant toward alcohols. In the present work we
report our further studies on the application of organoiodine(III)
and organoiodine(V) compounds in the transition metal-catalyzed
oxidations of alcohols and aromatic hydrocarbons.
2. Results and discussion
2.1. Transition metal-mediated oxidations utilizing iodine(V)
species
Our studies of the RuCl3-catalyzed disproportionation of DIB to
iodobenzene and iodylbenzene10a resulted in the development of
a facile experimental procedure for the preparation of iodylarenes
via RuCl3-catalyzed oxidation of iodoarenes with peracetic acid
(Scheme 1).13
AcOOH/AcOH, RuCl3 (0.08 mol%)
ArI
ArIO
2
40 oC, 16 h
up to 96%
1
2
Ar = Ph, 4-MeC6H4, 2-MeC6H4, 2-i-PrC6H4,
2-OMeC6H4, 2-ClC6H4, 3-ClC6H4, 4-ClC6H4, 4-BrC6H4,
4-FC6H4, 4-CF3C6H4, 3,5-CF3C6H3
Scheme 1. Preparation of iodylarenes via RuCl3-catalyzed oxidation of iodoarenes
with peracetic acid.
Further studies have demonstrated that the use of OxoneÒ as the
oxidant instead of peracetic acid leads to even milder reaction
conditions. In a typical procedure, treatment of iodobenzene with
OxoneÒ in aqueous acetonitrile at room temperature in the pres-
ence of RuCl3 (0.16 mol %) results in the formation of iodylbenzene
(PhIO2)n, which can be isolated from the reaction mixture in a 59%
preparative yield (Scheme 2). We suggest that this reaction starts
with the initial oxidation of iodoarene to the iodine(III) species 3
(protonated PhIO) and 4 (hydrated PhIO) by OxoneÒ at room
temperature.
Figure 1. ESI mass spectrum of PhI/OxoneÒ mixture in aqueous acetonitrile in the
absence of RuCl3.
We assume that in the presence of RuCl3 the initially formed
species 3 and 4 are further converted to iodylbenzene via a Ru-
catalyzed oxidation with OxoneÒ. It is likely that the intermediate
oxoruthenium complexes are responsible for catalytic oxidation of
the initially formed iodine(III) species 3 and 4 to the iodine(V)
species. An experimental evidence toward catalytic oxidation of
PhIO to PhIO2 mediated by the oxoruthenium species has pre-
viously been documented,15a and the generation and identification
of highly reactive ruthenium(V)-oxo species were reported in the
literature.15bed The polymertic, insoluble iodylbenzene, (PhIO2)n,16
is the final, isolated product that slowly precipitates from this re-
action (Scheme 2); however, the exact nature of the initially formed
monomeric iodine(V) species in Scheme 2 remains unknown. Most
likely, these species are represented by some activated form of
monomeric PhIO2 (e.g., protonated, hydrated, or a peroxysulfate
derivatives shown in Fig. 2), which show extremely high oxidative
reactivity toward organic substrates.
OH
OH
I
OH
MeCN-H2O, rt
– K2SO4
Ph I+
2PhI + 2KHSO5
(Oxone®)
+
Ph
–
HSO4
3
4
KHSO5
RuCl3 (0.16 mol%)
(PhIO2)n
Scheme 2. RuCl3-catalyzed oxidation of iodobenzene with OxoneÒ
.
A special experiment shows that PhI reacts with OxoneÒ in-
stantaneously at room temperature in the absence of RuCl3 pro-
ducing a yellow solution. The ESI mass-spectrometry study of this
solution indicates the presence of hypervalent iodine(III) species,
hydroxy(phenyl)iodonium ion 3, and iodosylbenzene, along with
unreacted iodobenzene (Fig. 1). The same iodine(III) electrophilic
species are present in the aqueous solutions of oligomeric iodo-
sylbenzene sulfate (PhIO)3SO3 (see ESI mass spectrum of
(PhIO)3SO3 in Section 2.2), which can be prepared by simple
treatment of commercially available (diacetoxyiodo)benzene with
aqueous hydrogen sulfate and isolated as a thermally stable, yellow
crystalline solid, which can be used as a reagent for oxidative
+
I
O
O
OH
Ph
Ph
I
O
protonated PhIO2
monomeric PhIO2
OH
OH
OH
O
SO2OK
Ph
I
O
Ph
I
O
O
peroxysulfate derivative of PhIO2
hydrated PhIO2
Figure 2. Hypothetical active monomeric iodine(V) species generated from PhI/
OxoneÒ mixture in aqueous acetonitrile in the presence of RuCl3.

M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
5747
In our initial research we have utilized the monomeric PhIO2
species as a highly reactive stoichiometric oxidant toward the ox-
idation of alcohols.10a Further studies of this reaction have led us to
the development of extremely mild and efficient tandem catalytic
system for the oxidation of alcohols and hydrocarbons based on
a Ru(III)-catalyzed reoxidation of ArIO to ArIO2 using OxoneÒ as
a stoichiometric oxidant.17
Table 2
PhI/RuCl3-cocatalyzed oxidation of alcoholsa
PhI (5 mol %), Oxone
OH
O
RuCl3 (0.16 mol %)
Taking into account that the Ru(III)-catalyzed oxidation of alco-
hols usually occurs only at temperatures above 80 ꢀC,18 while
iodylarenes are effective oxidants at room temperature,1f,k we in-
vestigated the oxidation of alcohols using ArI/RuCl3 tandem cata-
lytic system. The reaction was optimized using 1-phenylethanol 5 as
a model substrate (Table 1). As expected, in the absence of PhI and in
the presence of RuCl3 (0.16 mol %), or in the presence of PhI without
RuCl3 the oxidation of substrate 5 at room temperature proceeds
very slowly (Table 1, entries 1 and 2). The combined application of
PhI and RuCl3 results in almost instantaneous oxidation of phenyl-
ethanol 5 to acetophenone 6 with a 100% conversion reached in less
than 20 min (entry 3). The optimized reaction requires at least
1 mol equiv of OxoneÒ (2 equiv of active oxygen); the use of smaller
amounts of OxoneÒ leads to incomplete conversion (entry 4) due to
its noticeable decomposition with loss of oxygen gas under reaction
conditions. Several other iodoarenes tested in this reaction showed
a comparable to PhI high catalytic activity (entries 5e8).
R1 R2
7
R1 R2
8
MeCN/H2O (1:1 v/v), rt
Entry
1
Alcohol 7
OxoneÒ (mol equiv) Time (h) Yield of 8 (%)b
OH
Ph
1.2
1.2
0.3
100
96
OH
2
3
10
Ph
Ph
OH
2.0
7
100
OH
4
5
1.0
1.2
2
92
Table 1
Effect of ArI and RuCl3 on the oxidation of 1-phenylethanol to acetophenone with
OH
OxoneÒa
0.8
100
ArI (5 mol %), Oxone®
RuCl3 (0.16 mol %)
O
OH
Ph
Ph
MeCN/H2O (1:1 v/v), rt
OH
5
6
6
7
1.0
0.5
0.5
100
100
Entry
ArI
OxoneÒ (mol equiv)
Time (h)
Conversion (%)b
12c
0
100
83
100
100
100
99
1
2
3
4
5
6
7
8
None
PhId
PhI
1.5
1.0
1.0
0.67
1.25
1.15
1.25
1.22
0.3
1.0
0.3
1.0
0.3
0.3
0.6
1.0
PhI
1.05
OH
OH
2-IC6H4SO3H
4-IC6H4SO3H
4-IC6H4SO3Na
3-IC6H4CO2H
8
9
1.0
1.0
0.8
0.8
99
a
All reactions were performed at room temperature in MeCN/H2O (1:1 v/v) using
0.1 mmol of 1-phenylethanol, 0.16 mol % of RuCl3, and 5 mol % of ArI unless other-
wise noted.
OH
b
The conversion was determined by GC analysis. According to GC acetophenone
100
6 was the only product resulting from the oxidation of 1-phenylethanol 5 under
these conditions.
c
Also contains 8% of styrene and 80% of unreacted alcohol.
No RuCl3 added.
d
OH
10
11
2.4
1.1
4
96c
O2N
CH3(CH2)7OH
A variety of alcohols 7 are smoothly oxidized under optimized
reaction conditions to afford the respective oxidation products 8 in
excellent isolated yields at room temperature (Table 2). Similar to
the high-temperature ArI/OxoneÒ procedure,19 our protocol affords
ketones from the secondary alcohols (entries 1e9) and mainly
carboxylic acids from primary alcohols (entries 10 and 11). Shorter
reaction time, however, allows to oxidize benzyl alcohol pre-
dominantly to benzaldehyde (entry 12). The use of smaller quan-
tities of OxoneÒ and shortening reaction time in the oxidation of
other primary alcohols (cf. entries 10 and 11) also leads to the
predominant formation of aldehydes.
Selective oxidation of activated and unactivated CeH bonds is of
particular interest for organic chemists. The pentavalent iodine
reagent, IBX, has been demonstrated to be a reagent of choice for
the oxidation of benzylic CeH bonds.20 Recently, the oxidation of
benzylic CeH bonds has been performed under catalytic conditions
by the in situ formed IBX using OxoneÒ as a terminal oxidant at
70e80 ꢀC for 8e48 h.21 We investigated the oxidation of CeH
16
100d
12
13
1.25
1.2
1.5
1
80e
82f
Ph
Ph
OH
OH
OH
14
15
1.6
1.4
1
90f
Ph
OH
10
100f
(continued on next page)
N

5748
Table 2 (continued)
M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
The results of the oxidation of several other hydrocarbons under
optimized catalytic conditions are summarized in Table 4. In gen-
eral, moderate to high yields of aromatic ketones are obtained in
these oxidations under very mild reaction conditions (entries 1e8).
Entry
Alcohol 7
OxoneÒ (mol equiv) Time (h) Yield of 8 (%)b
OH
Table 4
16
1.0
4.5
2
93f
PhI/RuCl3-cocatalyzed oxidation of hydrocarbonsa
Entry
Substrate
OxoneÒ (equiv) Time (h) Products
Yield (%)b
80
OH
O
O
87f,g
1
6.1c
26
3
17
18
Ph
Ph
O
a
All reactions were performed at room temperature in MeCN/H2O (1:1 v/v) using
1 mmol of alcohol, 0.16 mol % of RuCl3 and 5 mol % of PhI unless otherwise noted.
b
77
Yields of isolated pure products 8 are shown unless otherwise noted.
4-NO2C6H4CO2H is the only product formed under these conditions.
CH3(CH2)6CO2H is the only isolated product.
Isolated yield of 2,4-dinitrophenylhydrazone of benzaldehyde.
2
2.06
c
d
e
f
O
Yield of product was determined by GC analysis using the initially added PhI as
an internal standard (after reductive treatment of the reaction mixture with
Na2S2O3).
11
g
Also contains 13% of benzoic acid.
bonds using ArI/RuCl3 tandem catalytic system. The reaction was
optimized using ethylbenzene 9 as a model substrate (Table 3). As
expected, in the absence of PhI and in the presence of RuCl3, or in
the presence of PhI and in the absence of RuCl3 the oxidation of
substrate 9 at room temperature does not occur or proceeds very
O
O
3
1.0c
24
18d
Table 3
Effect of ArI and RuCl3 on the oxidation of ethylbenzene 9 with OxoneÒa
ArI (5 mol%), Oxone®
4
5
6
1.2
6
1
1
23
95
69
O
OH
O
RuCl3 (0.16 mol %)
t-Bu
t-Bu
+
Ph
Ph
Ph
MeCN/H2O (1:1 v/v), rt
O
5
6
9
2.0c,e
Entry
ArI
OxoneÒ (mol equiv)
Time (h)
Products (%)b
1
2
3
4
5
6
7
8
None
PhIc
PhI
1.05
1.05
1.05
3.3
24.0
3.3
3.3
3.3
3.3
3.3
3.3
3.3
5 (1%), 6 (8%)
5 (0%), 6 (0%)
O
1.2c
5 (0.5%), 6 (27%)
5 (1%), 6 (31%)
5 (0.5%), 6 (17%)
5 (1%), 6 (30%)
5 (0%), 6 (18%)
5 (0%), 6 (13%)
5 (0%), 6 (21%)
5 (0%), 6 (50%)
5 (0%), 6 (14%)
5 (0%), 6 (80%)
2-IC6H4SO3H
4-IC6H4SO3H
2-IC6H4CO2H
3-IC6H4CO2H
4-IC6H4CF3
4-IC6H4Br
PhI
1.05
1.05
1.05
1.03
1.05
1.05
2.10d
2.10d
4.2f
O
O
O
7
8
8.2c
20
72
9
10
11
12
4.0
4.0
11.5
None
PhIe
4.7c
2.5c
20
8
38d
a
All reactions were performed at room temperature in MeCN/H2O (1:1 v/v) using
0.1 mmol of ethylbenzene 5, 5 mol % of ArI, and 0.16 mol % of RuCl3 unless otherwise
noted.
Product yields were determined by GC analysis; unreacted ethylbenzene 9 was
the only other product present in all entries.
b
9
1.5d
c
OH
No RuCl3 added.
1.05 mol equiv of OxoneÒ added initially and the second portion 1.05 mol equiv
d
a
All reactions were performed at room temperature in MeCN/H2O (1:1 v/v) using
1.0 mmol of a hydrocarbon, 0.16 mol % of RuCl3 and 5 mol % of PhI unless otherwise
noted.
added after 2 h.
e
10 mol % of PhI was used.
0.9 mol equiv of OxoneÒ added initially, the second portion 1.1 mol equiv added
f
b
Yields of isolated products are shown; unreacted hydrocarbons were also
after 2 h, the third portion 1.1 mol equiv added 4 h later, and the final portion
1.1 mol equiv added 3 h later.
present in all entries.
c
OxoneÒ was added in small portions during the indicated time period.
Yield was determined by GC analysis.
10 mol % of PhI was used.
d
e
slowly (Table 3, entries 1, 2, and 11). The combined application of
PhI and RuCl3 results in a 27% conversion of ethylbenzene 9 to
acetophenone 6 (entry 3). The optimized reaction conditions
leading to 80% conversion of substrate 9 to product 6 require the
addition of 4.2 mol equiv of OxoneÒ in small portions over 11 h and
the use of 10 mol % of PhI (entry 12). Out of several other iodoarenes
tested in this reaction, 2-iodosulfonic acid and 2-iodobenzoic acid
showed slightly better catalytic effect than iodobenzene (entries
4e9); however, a noticeable amount of by-product 5 was observed
with these catalysts.
Compared to the high-temperature IBX/OxoneÒ procedure,21 our
protocol is much more selective and generally does not afford
products of CeC bond cleavage and carboxylic acids. The oxidation
of an unactivated CeH bond in adamantane under these conditions
proceeds with a low conversion affording 1-adamantanol in only
1.5% yield (entry 9).
A plausible, simplified mechanism for these catalytic oxidations
is shown in Scheme 3 that includes two catalytic redox cycles. The

M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
5749
RuIII
ArIO2
ArIO
H2O
Oxone®
Ph
(PhIO)3SO3
10
3 PhI(OAc)2 + 2 NaHSO4
– 6 HOAc
– Na2SO4
O
RuV
O
t-Bu
Ph
t-Bu
t-Bu
N
Ph
N
N
Fe
N
N
N
N
Scheme 3. Tandem catalytic system for the oxidation of organic substrates with
OxoneÒ
N
t-Bu
.
N
M
N
N
N
t-Bu
O
N
Ph
Ph
t-Bu
reaction starts with the initial oxidation of ArI to ArIO and then to
ArIO2 by the OxoneÒ/Ru(III,V) system as inferred from Schemes 1
and 2. The generated in situ, highly active monomeric ArIO2 spe-
cies (Fig. 2) are responsible for actual oxidation of organic sub-
strates by known mechanisms.20,21 We propose that the
intermediate oxoruthenium complexes are responsible for the
reoxidation of the initially formed ArIO to ArIO2 (Scheme 3). An
experimental evidence toward catalytic oxidation of PhIO to PhIO2
mediated by the oxoruthenium species has previously been doc-
umented,15a and the generation and identification of highly reactive
ruthenium(V)-oxo species was reported in the literature.15bed It is
also possible that the oxidation of organic substrates with ArIO2 in
this system is additionally catalyzed by ruthenium species. Several
examples of transition metal-catalyzed oxidations using ArIO2 as
a stoichiometric oxidant have been reported.7,10,14e
N
N
Fe
N
N
N
N
N
Ph
t-Bu
t-Bu
12, M = Co
13, M = Ru(CO)
11
Scheme 4. Oligomeric iodosylbenzene sulfate 10, Fe(III)-phthalocyanine complex 11,
Co(II)-tetraphenylporphyrin 12, and Ru(II)-tetraphenylporphyrin 13.
iodosylbenzene sulfate 10 was prepared by simple treatment of
commercially available (diacetoxyiodo)benzene with aqueous hy-
drogen sulfate and isolated as a thermally stable, yellow crystalline
solid.14a,b The structure of reagent 10 was previously established by
single crystal X-ray diffraction and confirmed by mass-spectrom-
etry in solution.14a In particular, the ESI mass-spectrometry study of
compound 10 in aqueous solution indicates mainly the presence of
hydroxy(phenyl)iodonium ion 3 along with dimeric and trimeric
protonated iodosylbenzene units (Fig. 3).
2.2. Transition metal-catalyzed oxidations utilizing iodine(III)
species
The m-oxo diiron-phthalocyanine complex 11 was prepared using
Among hypervalent iodine(III) reagents, iodosylbenzene,
(PhIO)n, is particularly important as an efficient oxygen transfer
agent that has found widespread application in various oxygena-
tion reactions.1,22 Since 1979 (PhIO)n has been widely used as
a terminal oxidant in the reactions mimicking natural oxidations
performed by the heme-containing cytochrome P-450 class of en-
zymes.2,3 Despite its usefulness as an oxidant, practical applications
of iodosylbenzene are hampered by its low solubility in nonreactive
media,22 as well as low thermal stability and explosive properties
upon moderate heating.23
direct high-temperature reaction between 4-tert-butylphthalonitrile
and iron(II) acetate as described previously,24aec while Co(II)-tetra-
phenylporphyrin 12 and Ru(II)-carbonyl tetraphenylporphyrin 13
were used from commercial sources. It was shown recently that
porphyrin and phthalocyanine iron (III) m m-nitrido-
-oxo-,24def and
dimers,24g,h which were earlier considered as catalytically inactive
compounds, in many cases have high catalytic activity in different
oxidation reactions. Previously, we have reported the use of com-
plexes 11e13 in catalytic oxidations of alcohols.7
We have investigated catalytic oxidation of anthracene 14 to
anthraquinone 15 using complexes 11e13 as catalysts and oligo-
meric iodosylbenzene sulfate 10 as the oxidant in comparison with
iodosylbenzene as the common oxygenating reagent (Scheme 5).
The use of iodosylbenzene in this reaction in the presence of tran-
sition metal complexes was previously reported in the literature.25
We have investigated relative reactivity of iodosylbenzene and
a readily available, stable oligomeric iodosylbenzene sulfate 10 in
the oxygenation of anthracene to anthraquinone catalyzed by m-oxo
diiron-phthalocyanine complex 11, Co(II)-tetraphenylporphyrin 12
or Ru(II)-tetraphenylporphyrin 13 (Scheme 4).14e The oligomeric
Figure 3. HR-ESI mass spectrum of oligomeric iodosylbenzene sulfate 10 in aqueous acetonitrile (calculated mass shown in parenthesis).

5750
M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
however, the availability and low cost of iron(III) complex 11 as
compared to the ruthenium porphyrin 13 make it a potentially
useful reagent for biomimetic catalytic transformations.
In order to demonstrate the general character of the optimized
reaction conditions, we performed the oxidation of 2-tert-butylan-
thracene 16 using oxidant 10 in the presence of the m-oxo diiron-
O
oxidant (6-7.5 equiv. of O)
catalyst 11-13 (10-15 mol%)
CH2Cl2 or toluene
14
O
15
phthalocyanine complex 11 (Scheme 6). Compared tothe oxidation of
anthracene 14, the reaction of 2-tert-butylanthracene 16 was slower,
probably due to steric hindrance caused by the tert-butyl group, with
a 100% conversion reached only after 20 h at room temperature. The
GC analysis of the reaction mixture indicated the presence of a single
product of oxidation, 2-tert-butylanthraquinone 17, along with
iodobenzene resulting from the reduction of reagent 10. 2-tert-
Butylanthraquinone 17 was isolated from the reaction mixture by
preparative column chromatographyon silica gel as yellow needles in
72% yield and identified by comparison with authentic sample.26
Scheme 5. Catalytic oxidation of anthracene 14 to anthraquinone 15.
The oxidation of anthracene was carried out in dry dichloro-
methane or in toluene using 2.0e2.5 times excess (6.0e7.5 mol e-
quiv of active oxygen per one molecule of anthracene 14) with
0.10e0.15 equiv of the appropriate catalyst (Table 5). After in-
dicated time, the catalyst was removed by flash chromatography
and the obtained solution was analyzed by GCeMS to determine
the conversion of anthracene 14 to anthraquinone 15. According to
the GCeMS and NMR data, anthraquinone 15 and iodobenzene
resulting from the reduction of hypervalent iodine reagents were
the only products formed under these reaction conditions.
Dichloromethane was found to be the best solvent for the oxida-
tions in the presence of metalloporphyrins 12 and 13. Toluene was
oxidant 10 (6.6 equiv of O)
catalyst 11 (0.14 equiv.)
toluene, rt, 20 h
O
t-Bu
t-Bu
used for the reactions catalyzed by m-oxo diiron-phthalocyanine 11
72% isolated yield
due to the instability of complex 11 in dichloromethane solutions.
The results of the oxidations are summarized in Table 5.
O
17
16
Scheme 6. Catalytic oxidation of 2-tert-butylanthracene 16 to 2-tert-butylan-
thraquinone 17 using oligomeric iodosylbenzene sulfate 10 as the oxidant.
Table 5
Metalloporphyrin or phthalocyanine-catalyzed oxidations of anthracene 14 to
anthraquinone 15 using hypervalent iodine(III) reagentsa
3. Conclusions
Entry
Reagent
Catalyst (mol %)
Solvent
Time (h)
Yield of 15 (%)b
In summary, we have reported a series of transition metal-me-
diated oxidations using hypervalent iodine species. Based on the
facile RuCl3-catalyzed disproportionation of (diacetoxyiodo)ben-
zene to iodobenzene and iodylbenzene, we have developed a con-
venient experimental procedure for the preparation of iodylarenes
via RuCl3-catalyzed oxidation of iodoarenes with peracetic acid.
Further studies have demonstrated that the use of OxoneÒ as the
oxidant instead of peracetic acid leads to even milder reaction
conditions allowing the generation of the highly reactive mono-
meric iodine(V) species in situ at room temperature. Based on these
observations, we have developed extremely mild and efficient
tandem catalytic system for the oxidation of alcohols and hydro-
carbons based on a Ru(III)-catalyzed reoxidation of ArIO to ArIO2
using OxoneÒ as a stoichiometric oxidant. Due to the mild reaction
conditions our protocol is highly selective and generally does not
afford products of CeC bond cleavage. Finally, we have shown that
the electrophilic iodine(III) species, originating from oligomeric
iodosylbenzene sulfate 10, are efficient oxygenating agents in cat-
alytic oxidation of aromatic hydrocarbons in the presence of met-
alloporphyrin or phthalocyanine complexes. Reagent 10, which can
be conveniently prepared from (diacetoxyiodo)benzene and
NaHSO4 in aqueous solution, can be used as a safe and convenient
alternative to the potentially explosive iodosylbenzene in the bio-
mimetic oxidations mimicking natural oxidations performed by the
heme-containing cytochrome P-450 class of enzymes.
1
2
3
4
5
6
7
8
9
10
10
10
10
(PhIO)n
(PhIO)n
(PhIO)n
(PhIO)n
(PhIO)n
None
PhMe
PhMe
CH2Cl2
CH2Cl2
PhMe
PhMe
CH2Cl2
CH2Cl2
CH2Cl2
24
2
2
1
24
5
2
3
24
0
100
100
100
0
100
26
7
11 (10)
12 (10)
13 (10)
None
11 (10)
12 (15)
13 (15)
13 (15)
100
a
All reactions were performed at room temperature using 2.5 mol equiv of re-
agent 10 or 7.5 mol equiv of (PhIO)n.
b
Yield was determined by GC analysis.
First of all, we have found that the oxidation of anthracene with
hypervalent iodine reagents in the absence of catalysts at room
temperature in toluene or dichloromethane proceeds extremely
slow and does not show any measurable conversion to anthra-
quinone after 24 h (entries 1 and 5). The addition of 0.1 mol equiv
of catalysts 11e13 leads to a significant increase in the reaction rate.
The oligomeric iodosylbenzene sulfate 10 shows high reactivity in
catalytic oxidations at room temperature in the presence of any of
the catalysts 11e13 (10 mol %), while the reaction in the absence of
catalysts at room temperature does not occur (entry 1). The best
catalytic effect is observed in the presence of Ru(II)-porphyrin 13
(entry 4; 100% conversion in 1 h). The reactivity of oxidant 10 in the
presence of catalysts 11 and 12 is slightly lower (entries 2 and 3;
100% conversion in 2 h). Iodosylbenzene is less reactive as the
source of oxygen under identical reaction conditions (entries 6e9)
with a 100% conversion reached after 5 h using catalyst 11 (entry 6)
and only after 24 h when using catalyst 13 (entry 9).
4. Experimental section
4.1. General
The data presented in Table 5 clearly indicate that the oligomeric
iodosylbenzene sulfate 10 is the best oxidant, significantly more
reactive than the commonly used iodosylbenzene. The slower re-
action with iodosylbenzene can partially be explained by its poly-
meric structure, (PhIO)n, requiring initial depolymerization, while
the structure of sulfate 10 consists of smaller oligomeric units of
PhIO (cf. Fig. 3), which have more electrophilic character due to the
ionic nature of this reagent. The ruthenium(II) complex 13 shows
the highest catalytic activity in oxidations with reagent 10;
All reactions were performed under dry nitrogen atmosphere
with flame-dried glassware. All commercial reagents were ACS
reagent grade and used without further purification. Toluene and
dichloromethane were distilled from CaH2 and stored over mo-
lecular sieves. Catalyst 11,24a,b iodosylbenzene sulfate 1014a,b and
iodosylbenzene22 were prepared by known methods. GCeMS
analysis was carried out with a HP 5890A Gas Chromatograph using
a 5970 Series mass selective detector. Mass spectrometric (ESIeMS)

M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
5751
analyses were obtained at the University of Minnesota Minneapolis
4.4. Typical preparative procedure for PhI/RuCl3-cocatalyzed
Mass Spectrometry Facility, using BioTOF II mass spectrometer.
NMR spectra were recorded on Varian INOVA instrument with
500 MHz frequency for 1H NMR and 125 MHz for 13C NMR.
Chemical shifts are reported in parts per million and referenced to
TMS as an internal standard.
oxidation of alcohols (Table 2)
Table 2, entry 2. To a mixture of benzhydrol (184 mg, 1 mmol),
PhI (0.5 mL of standard solution; 0.05 mmol; 5 mol %), and OxoneÒ
(0.737 g, 1.2 mmol) in 3 mL of acetonitrile and 3 mL of water, an
aqueous solution of RuCl3 (10
mL
of standard solution;
4.2. General procedure for the preparation of iodylarenes 2
via RuCl3-catalyzed oxidation of iodoarenes 1 with peracetic
acid (Scheme 1)
0.0016 mmol; 0.16 mol %) was added under stirring at room tem-
perature. The reaction mixture was stirred for 10 h (the reaction
was monitored by TLC by disappearance of benzhydrol). Then
15 mL of ethyl acetate and 20 mL of water were added and the
mixture was stirred for 5 min. The organic solution was separated
and the aqueous phase was extracted with ethyl acetate (2ꢁ15 ml).
Organic phases were combined, washed with NaCl (saturated so-
lution, 20 ml), dried over Na2SO4 (anhydrous). Removal of the sol-
vent under vacuum afforded 175 mg (96%) of benzophenone. The
oxidation of other alcohols (Table 2) was performed using a similar
procedure. All products were identified by comparison with com-
mercially available samples and some volatile carbonyl products
were additionally identified as 2,4-dinitrophenylhydrazones.
The mixture of acetic anhydride (16 mL) and 35% H2O2 (4 mL)
was stirred at 40 ꢀC for 4 h, then the appropriate iodoarene
(5 mmol) was added and the mixture was stirred at 40 ꢀC for ad-
ditional 1 h. Then the solution of RuCl3 in water (10 mL, 0.04 mmol/
mL) was added and the reaction was stirred at the same tempera-
ture for 16 h. Diethyl ether (80 mL) was added to the mixture, the
resulting solid precipitate was collected by filtration, washed with
Et2O, and dried in vacuo to give product 2 as white microcrystalline
solid. Samples for elemental analysis were additionally recrystal-
lized from boiling water.
4.5. Typical preparative procedure for PhI/RuCl3-cocatalyzed
oxidation of aromatic hydrocarbons (Table 4)
4.2.1. Representative data for products 2. 4.2.1.1. 1-Iodyl-2-iso-
propylbenzene. Oxidation of 1-iodo-2-isopropylbenzene (1.23 g,
5.0 mmol) according to the general procedure afforded 0.50 g (36%)
of product, isolated as microcrystalline solid, mp 173e175 ꢀC. 1H
Table 4, entry 1. To a mixture of propylbenzene (120 mg,
1 mmol), PhI (0.5 mL of standard solution; 0.05 mmol; 5 mol %),
NMR (DMSO-d6):
d
7.94 (d, J¼7.5 Hz, 1H), 7.57 (m, 3H), 3.22 (septet,
and RuCl3 (10 mL of standard solution; 0.0016 mmol; 0.16 mol %) in
6.5 Hz, 1H), 1.29 (d, 7.0 Hz, 6H). 13C NMR (DMSO-d6):
d
148.7, 147.0,
3 mL of acetonitrile and 3 mL of water, OxoneÒ (total 3.74 g;
6.1 mmol) was added in five portions during 22 h under stirring at
room temperature. The reaction mixture was stirred for additional
4 h (the reaction was monitored by TLC by disappearance of pro-
pylbenzene). Then 15 mL of ethyl acetate and 20 mL of water were
added and the mixture was stirred for 5 min. The organic solution
was separated, and the aqueous phase was extracted with ethyl
acetate (2ꢁ15 ml). Organic phases were combined, washed with
NaCl (saturated solution, 20 ml), dried over Na2SO4 (anhydrous).
Removal of the solvent under vacuum afforded 107 mg (80%) of
propiophenone. The oxidation of other hydrocarbons (Table 4) was
performed using a similar procedure. All products were identified
by comparison with commercially available samples and some
carbonyl products were additionally identified as 2,4-
dinitrophenylhydrazones.
132.1, 127.1, 126.9, 122.6, 33.0, 23.7. Anal. Calcd for
C9H11IO2$0.75H2O: C, 37.07; H, 4.32. Found: C, 37.04; H, 3.92.
4.2.1.2. 1-Iodyl-4-trifluoromethylbenzene. Oxidation of 1-iodo-
4-trifluoromethylbenzene (1.36 g, 5.0 mmol) under general condi-
tions afforded 1.26 g (83%) of product, isolated as microcrystalline
solid, mp 213e215 ꢀC (with decomposition). 1H NMR (DMSO-d6):
d
8.17 (d, J¼8.0, 2H), 7.95 (d, J¼8.1 Hz, 2H). 13C NMR (DMSO-d6):
155.4 (d, J¼1.5 Hz), 131.1 (d, J¼31.7 Hz), 127.5, 125.7 (q, J¼3.8 Hz),
d
123.8 (q, J¼271 Hz). Anal. Calcd for C7H4F3IO2$0.25H2O: C, 27.25; H,
1.47. Found: C, 27.00; H, 1.23.
4.2.1.3. 1-Iodyl-3,5-bis(trifluoromethyl)benzene. Oxidation of 1-
iodo-3,5-bis(trifluoromethyl)benzene (1.70 g, 5.0 mmol) under
general conditions afforded 1.69 g (91%) of product, isolated as
microcrystalline solid, mp 206e209 ꢀC (with decomposition). 1H
4.6. ArI/RuCl3-cocatalyzed oxidation of organic substrates
(general procedure for GCeMS experiments)
NMR (DMSO-d6):
d
8.58 (s, 2H), 8.3 (s, 1H). 13C NMR (DMSO-d6):
d
153.8, 130.2 (q, J¼33.2 Hz), 127.5 (d, J¼3.4 Hz), 124.8 (q¼3.6 Hz),
123.0 (q, J¼273.3 Hz). Anal. Calcd for C8H3F6IO2: C, 25.83; H, 0.81.
To a mixture of an organic substrate (0.1 mmol), ArI (50 mL of
Found: C, 25.48; H, 0.83.
0.1 M solution in MeCN; 0.005 mmol; 5 mol %), and OxoneÒ
(0.062e0.277 g, 0.1e0.45 mmol; see Tables) in 0.3 mL of acetoni-
4.3. RuCl3-catalyzed oxidation of iodobenzene to
iodylbenzene using OxoneÒ (Scheme 2)
trile and 0.3 mL of water, an aqueous solution of RuCl3 (1.0 mL of
standard solution; 0.00016 mmol; 0.16 mol %) was added under
stirring at room temperature. The reaction mixture was stirred for
a period of time indicated in the Tables (the reactions were moni-
tored by TLC by disappearance of organic substrate). Then 2 mL of
ethyl acetate and 2 mL of 5%-aqueous solution of sodium thiosul-
fate were added and the mixture was stirred for 5 min. The organic
solution was separated and analyzed using GCeMS. Products were
identified by comparison with commercially available samples.
To a mixture of iodobenzene (0.204 g, 1 mmol) and OxoneÒ
(0.33 g, 0.54 mmol) in 3 mL of aqueous acetonitrile (MeCN/H2O,
1:1) an aqueous solution of RuCl3 (10 mL of standard 0.16 M solu-
tion; 0. 0016 mmol) was added via syringe under stirring at room
temperature. After stirring for 30 min the second portion of OxoneÒ
(0.32 g, 0.52 mmol) was added and then after additional 50 min the
third portion of OxoneÒ (0.11 g, 0.18 mmol) was added. The reaction
mixture was stirred for 2 h 20 min (the reaction was monitored by
TLC by disappearance of PhI), and then the precipitate was filtered,
washed with cold water, and dried to afford 0.14 g (59%) of iodyl-
benzene, mp 229e230 ꢀC (crystallized from hot water; explodes at
4.7. Typical procedure for catalytic oxidation of anthracene
(Scheme 5)
A solution of anthracene 14 (0.10e0.15 mmol) in toluene or
dichloromethane (3e5 mL) was mixed with the appropriate cata-
lyst 11e13 (0.010e0.015 mmol) and the hypervalent iodine oxidant
(6e7.5 equiv of O), with stirring, at room temperature (see Table 5).
mp); IR (KBr): 731, 713 (IO2); 1H NMR (DMSO-d6)
(m, 3H); 13C NMR (DMSO-d6)
150.8 (CeIO2), 131.7, 129.1, 126.6.
Literature data: mp 235 ꢀC (expl.).27
d 7.92 (m, 2H) 7.59
d

5752
M.S. Yusubov et al. / Tetrahedron 66 (2010) 5745e5752
8. (a) Wolckenhauer, S. A.; Devlin, A. S.; Du Bois, J. Org. Lett. 2007, 9, 4363e4366; (b)
Samples of the reaction mixture (50 mL) were collected every
Ferrand, Y.;Daviaud, R.; LeMaux, P.;Simonneaux, G. Tetrahedron: Asymmetry2006,
17, 952e960; (c) Bryliakov, K. P.; Talsi, E. P. Chem.dEur. J. 2007, 13, 8045e8050.
9. (a) Young, K. J. H.; Mironov, O. A.; Periana, R. A. Organometallics 2007, 26,
2137e2140; (b) Li, Z.; Xia, C.-G. J. Mol. Catal. A 2004, 214, 95e101; (c) In, J.-H.;
Park, S.-E.; Song, R.; Nam, W. Inorg. Chim. Acta 2003, 343, 373e376.
10. (a) Yusubov, M. S.; Chi, K.-W.; Park, J. Y.; Karimov, R.; Zhdankin, V. V. Tetrahe-
dron Lett. 2006, 47, 6305e6308; (b) Yusubov, M. S.; Gilmkhanova, M. P.;
Zhdankin, V. V.; Kirschning, A. Synlett 2007, 563e566.
30 min, filtered through 2e3 cm of silica gel suspended in a Pasteur
pipette, washed with a mixture of ethyl acetate and hexane (2:3 v/
v), and analyzed using GCeMS.
4.8. Catalytic oxidation of 2-tert-butylanthracene (Scheme 6)
11. (a) Miyamura, H.; Akiyama, R.; Ishida, T.; Matsubara, R.; Takeuchi, M.; Ko-
bayashi, S. Tetrahedron 2005, 61, 12177e12185; (b) Sun, W.; Wang, H.; Xia, C.; Li,
J.; Zhao, P. Angew. Chem., Int. Ed. 2003, 42, 1042e1044; (c) Li, Z.; Tang, Z. H.; Hu,
X. X.; Xia, C. G. Chem.dEur. J. 2005, 11, 1210e1216; (d) Karimipour, G. R.;
Shadegan, H. A.; Ahmadpour, R. J. Chem. Res. 2007, 252e256; (e) Adam, W.;
Hajra, S.; Herderich, M.; Saha-Moeller, C. R. Org. Lett. 2000, 2, 2773e2776; (f)
Provins, L.; Murahashi, S.-I. ARKIVOC 2007, x, 107e120.
A solution of 2-tert-butylanthracene 16 (16 mg, 0.068 mmol) in
toluene (2.5 mL) was mixed with Fe(III)-phthalocyanine complex
11 (15 mg, 0.0094 mmol) and reagent 10 (110 mg, 0.15 mmol) and
was stirred 24 h at room temperature. The solvent was removed
and the residue was separated by column chromatography on silica
gel (ethyl acetate/hexane, 1:20) to give 13 mg (72%) of 2-tert-
butylanthraquinone 17 as yellow needles, mp 101e102.5 ꢀC (lit.26
mp: 103e104 ꢀC).
12. (a) Deprez, N. R.; Sanford, M. S. Inorg. Chem. 2007, 46, 1924e1935; (b) Dick, A.
R.; Hull, K. L.; Sanford, M. S. J. Am. Chem. Soc. 2004, 126, 2300e2301; (c)
Alexanian, E. J.; Lee, C.; Sorensen, E. J. J. Am. Chem. Soc. 2005, 127, 7690e7691;
(d) Desai, L. V.; Hull, K. L.; Sanford, M. S. J. Am. Chem. Soc. 2004, 126,
9542e9543; (e) Kalyani, D.; Sanford, M. S. Org. Lett. 2005, 7, 4149e4152; (f)
Kalyani, D.; Dick, A. R.; Anani, W. Q.; Sanford, M. S. Org. Lett. 2006, 8,
2523e2526; (g) Wang, D.-H.; Hao, X.-S.; Wu, D.-F.; Yu, J.-Q. Org. Lett. 2006, 8,
3387e3390; (h) Welbes, L. L.; Lyons, T. W.; Cychosz, K. A.; Sanford, M. S. J. Am.
Chem. Soc. 2007, 129, 5836e5837; (i) Desai, L. V.; Sanford, M. S. Angew. Chem.,
Int. Ed. 2007, 46, 5737e5740; (j) Liu, G.; Stahl, S. S. J. Am. Chem. Soc. 2006, 128,
7179e7181; (k) Streuff, J.; Hoevelmann, C. H.; Nieger, M.; Muniz, K. J. Am. Chem.
Soc. 2005, 127, 14586e14587; (l) Muniz, K.; Hoevelmann, C. H.; Streuff, J. J. Am.
Chem. Soc. 2008, 130, 763e773; (m) Giri, R.; Chen, X.; Yu, J.-Q. Angew. Chem., Int.
Ed. 2005, 44, 2112e2115; (n) Daugulis, O.; Zaitsev, V. G. Angew. Chem., Int. Ed.
2005, 44, 4046e4048; (o) Dick, A. R.; Kampf, J. W.; Sanford, M. S. J. Am. Chem.
Soc. 2005, 127, 12790e12791; (p) Kalyani, D.; Sanford, M. S. J. Am. Chem. Soc.
2008, 130, 2150e2151; (q) Kalyani, D.; Dick, A. R.; Anani, W. Q.; Sanford, M. S.
Tetrahedron 2006, 62, 11483e11498.
Acknowledgements
This work was supported by research grants from the National
Science Foundation (CHE-1009038) (VVZ) and Petroleum Research
Fund, administered by the American Chemical Society (VNN).
Supplementary data
Supplementary data associated with this article can be found in
the online version at doi:10.1016/j.tet.2010.04.046.
13. Koposov, A. Y.; Karimov, R. R.; Pronin, A. A.; Skrupskaya, T.; Yusubov, M. S.;
Zhdankin, V. V. J. Org. Chem. 2006, 71, 9912e9914.
14. (a) Koposov, A. Y.; Netzel, B. C.; Yusubov, M. S.; Nemykin, V. N.; Nazarenko, A. Y.;
Zhdankin, V. V. Eur. J. Org. Chem. 2007, 4475e4478; (b) Nemykin, V. N.; Ko-
posov, A. Y.; Netzel, B. C.; Yusubov, M. S.; Zhdankin, V. V. Inorg. Chem. 2009, 48,
4908e4917; (c) Yusubov, M. S.; Yusubova, R. Y.; Funk, T. V.; Chi, K.-W.;
Zhdankin, V. V. Synthesis 2009, 2505e2508; (d) Neu, H. M.; Yusubov, M. S.;
Zhdankin, V. V.; Nemykin, V. N. Adv. Synth. Catal. 2009, 351, 3168e3174; (e)
Geraskin, I. M.; Pavlova, O.; Neu, H. M.; Yusubov, M. S.; Nemykin, V. N.;
Zhdankin, V. V. Adv. Synth. Catal. 2009, 351, 733e737; (f) Zagulyaeva, A. A.;
Yusubov, M. S.; Zhdankin, V. V. J. Org. Chem. 2010, 75, 2119e2122.
15. (a) Bressan, M.; Morvillo, A. Inorg. Chem. 1989, 28, 950e953; (b) Khan, M. M. T.;
Rao, A. P.; Mehta, S. H. J. Mol. Catal. 1993, 78, 263e271; (c) Khan, M. M. T.; Rao,
A. P.; Chatterjee, D.; Kumar, S. S. J. Mol. Catal. 1992, 73, 17e21; (d) Wong, K. Y.;
Che, C. M.; Anson, F. C. Inorg. Chem. 1987, 26, 737e741.
16. For X-ray crystal structure of (PhIO2)n and the related structural discussion see:
(a) Alcock, N. W.; Sawyer, J. F. J. Chem. Soc., Dalton Trans. 1980, 115e120; (b)
Macikenas, D.; Skrzypczak-Jankun, E.; Protasiewicz, J. D. Angew. Chem., Int. Ed.
2000, 39, 2007e2010.
17. Yusubov, M. S.; Zagulyaeva, A. A.; Zhdankin, V. V. Chem.dEur. J. 2009, 15,
11091e11094.
18. (a) Barak, G.; Dakka, J.; Sasson, Y. J. Org. Chem. 1988, 53, 3553e3555; (b) Marko,
I. E.; Giles, P. R.; Tsukazaki, M.; Chelle-Regnaut, I.; Urch, C. J.; Brown, S. M. J. Am.
Chem. Soc. 1997, 119, 12661e12662.
19. Uyanik, M.; Akakura, M.; Ishihara, K. J. Am. Chem. Soc. 2009, 131, 251e262.
20. (a) Nicolaou, K. C.; Montagnon, T.; Baran, P. S.; Zhong, Y. L. J. Am. Chem. Soc.
2002, 124, 2245e2258; (b) Moorthy, J. N.; Singhal, N.; Senapati, K. Tetrahedron
Lett. 2006, 47, 1757e1761.
21. Ojha, L. R.; Kudugunti, S.; Maddukuri, P. P.; Kommareddy, A.; Gunna, M. R.;
Dokuparthi, P.; Gottam, H. B.; Botha, K. K.; Parapati, D. R.; Vinod, T. K. Synlett
2009, 117e121.
22. Moriarty, R. M.; Kosmeder, J. W.; Zhdankin, V. V. ‘Iodosylbenzene’ in Encyclo-
pedia of Reagents for Organic Synthesis; Wiley: Chichester, UK, 2001.
23. A violent explosion of iodosylbenzene upon drying at elevated temperature in
vacuum has been reported: McQuaid, K. M.; Pettus, T. R. R. Synlett 2004,
2403e2405.
24. (a) Lukyanets, E. A.; Nemykin, V. N. J. Porph. Phthalocyanines 2010, 14, 1e40; (b)
Nemykin, V. N.; Chernii, V. Y.; Volkov, S. V.; Bundina, N. I.; Kaliya, O. L.; Li, V. D.;
Lukyanets, E. A. J. Porphyr. Phthalocyanines 1999, 3, 87e98; (c) Lukyanets, E. A.;
Nemykin, V. N. ARKIVOC 2010, i, 136e208; (d) Zalomaeva, O. V.; Kholdeeva, O.
A.; Sorokin, A. B. C.R. Chim. 2007, 10, 598e603; (e) Kholdeeva, O. A.; Zalomaeva,
O. V.; Sorokin, A. B.; Ivanchikova, I. D.; Della Pina, C.; Rossi, M. Catal. Today 2007,
121, 58e64; (f) Sorokin, A. B.; Mangematin, S.; Pergrale, C. J. Mol. Catal. A: Chem.
2002, 182e183, 267e281; (g) Kudrik, E. V.; Sorokin, A. B. Chem.dEur. J. 2008, 14,
7123e7126; (h) Sorokin, A. B.; Kudrik, E. V.; Bouchu, D. Chem. Commun. 2008,
2562e2564.
25. (a) Merlau, M. L.; Cho, S.-H.; Sun, S.-S.; Nguyen, S. T.; Hupp, J. T. Inorg. Chem.
2005, 44, 5523e5529; (b) Safari, N.; Naghavi, S. S.-a.-d.; Khavasi, H. R. Appl.
Catal., A 2005, 285, 59e64.
26. (a) Effenberger, F.; Buckel, F.; Maier, A. H.; Schmider, J. Synthesis 2000,
1427e1430; (b) Peters, A. T.; Rowe, F. M. J. Chem. Soc. 1945, 181e182.
27. Kennedy, R. J.; Stock, A. M. J. Org. Chem. 1960, 25, 1901e1906.
References and notes
1. (a) Varvoglis, A. Hypervalent Iodine in Organic Synthesis; Academic: London, 1997;
(b) Hypervalent Iodine Chemistry; Wirth, T., Ed.; Springer: Berlin, 2003; (c) Koser, G.
F. Adv. Heterocycl. Chem. 2004, 86, 225e292; (d) Ladziata, U.; Zhdankin, V. V. Synlett
2007, 527e537; (e) Wirth, T. Angew. Chem., Int. Ed. 2005, 44, 3656e3665; (f) Lad-
ziata, U.; Zhdankin, V. V. ARKIVOC 2006, ix, 26e58; (g) Zhdankin, V. V.; Stang, P. J.
Chem. Rev. 2008, 108, 5299e5358; (h) Zhdankin, V. V. ARKIVOC 2009, i, 1e62; (i)
Richardson, R. D.; Wirth, T. Angew. Chem., Int. Ed. 2006, 45, 4402e4404; (j)
Zhdankin, V. V., Chapter 31.4.1. Science of Synthesis; Georg Thieme: Stuttgart, 2007;
Vol. 31a; 161e234; (k) Tohma, H.; Kita, Y. Adv. Synth. Catal. 2004, 346, 111e124; (l)
Kita, Y.; Fujioka, H. Pure Appl. Chem. 2007, 79, 701e713; (m) Uyanik, M.; Ishihara, K.
Chem. Commun. 2009, 2086e2099; (n) Dohi, T.; Kita, Y. Chem. Commun. 2009,
2073e2085; (o) Ochiai, M.; Miyamoto, K. Eur. J. Org. Chem. 2008, 4229e4239; (p)
Zhdankin, V. V. Curr. Org. Synth. 2005, 2, 121e145; (q) Moriarty, R. M. J. Org. Chem.
2005, 70, 2893e2903; (r) Ochiai, M. Coord. Chem. Rev. 2006, 250, 2771e2781.
2. Groves, J. T.; Nemo, T. E.; Myers, R. S. J. Am. Chem. Soc. 1979, 101, 1032e1033.
3. Representatives books and reviews: (a) Cytochrome P450: Structure, Mechanism,
and Biochemistry; Ortiz de Montellano, P. R., Ed.; Kluwer Academic/Plenum: New
York, NY, 2005; (b) Metalloporphyrins in Catalytic Oxidations; Sheldon, R. A., Ed.;
M. Dekker: New York, NY, 1994; (c) Meunier, B. Chem. Rev. 1992, 92, 1411e1456;
(d) Rose, E.; Andrioletti, B.; Zrig, S.; Quelquejeu-Etheve, M. Chem. Soc. Rev. 2005,
34, 573e583; (e) Simonneaux, G.; Tagliatesta, P. J Porphyr. Phthalocyanines 2004,
8, 1166e1171; (f) Bernadou, J.; Meunier, B. Adv. Synth. Catal. 2004, 346, 171e184;
(g)Vinhado, F. S.; Martins, P. R.;Iamamoto, Y. Curr. Top. Catal. 2002, 3,199e213; (h)
Meunier, B.; Robert, A.; Pratviel, G.; Bernadou, J. Porphyrin Handbook 2000, 4,
119e187; (i) Groves, J. T.; Shalyaev, K.; Lee, J. Porphyrin Handbook 2000, 4, 17e40;
(j) Ji, L.; Peng, X.; Huang, J. Prog. Nat. Sci. 2002, 12, 321e330; (k) Groves, J. T. J.
Porphyr. Phthalocyanines 2000, 4, 350e352; (l) Kimura, M.; Shirai, H. Porphyrin
Handbook 2003, 19, 151e177; (m) Moro-oka, Y. Catal. Today 1998, 45, 3e12; (n)
Moro-oka, Y.; Akita, M. Catal. Today 1998, 41, 327e338; (o) Noyori, R. Asymmetric
Catalysis in Organic Synthesis; Wiley: New York, NY, 1994.
4. (a) Kang, M.-J.; Song, W. J.; Han, A.-R.; Choi, Y. S.; Jang, H. G.; Nam, W. J. Org.
Chem. 2007, 72, 6301e6304; (b) de Visser, S. P.; Oh, K.; Han, A.-R.; Nam, W.
Inorg. Chem. 2007, 46, 4632e4641; (c) Silva, G. d. F.; Carvalho da Silva, D.;
Guimaraes, A. S.; do Nascimento, E.; Reboucas, J. S.; Peres de Araujo, M.; Dai de
Carvalho, M. E. M.; Idemori, Y. M. J. Mol. Cat. A 2007, 266, 274e283; (d) Song, W.
J.; Seo, M. S.; DeBeer George, S.; Ohta, T.; Song, R.; Kang, M.-J.; Tosha, T.; Ki-
tagawa, T.; Solomon, E. I.; Nam, W. J. Am. Chem. Soc. 2007, 129, 1268e1277; (e)
Lindsay Smith, J. R.; Iamamoto, Y.; Vinhado, F. S. J. Mol. Cat. A 2006, 252, 23e30.
5. (a) Murakami, Y.; Konishi, K. J. Am. Chem. Soc. 2007, 129, 14401e14407; (b)
Santos, M. M. C.; Silva, A. M. S.; Cavaleiro, J. A. S.; Levai, A.; Ptonay, T. Eur. J. Org.
Chem. 2007, 2877e2887; (c) Babakhania, R.; Bahadoran, F.; Safari, N. J. Porphyr.
Phthalocyanines 2007, 11, 95e99; (d) Pouralimardan, O.; Chamayou, A.-C.; Jan-
iak, C.; Hosseini-Monfared, H. Inorg. Chim. Acta 2007, 360, 1599e1608; (e) Lee,
S.; MacMillan, D. W. C. Tetrahedron 2006, 62, 11413e11424.
6. (a) Yang, Z. W.; Kang, Q. X.; Quan, F.; Lei, Z. Q. J. Mol. Cat. A 2007, 261, 190e195;
(b) Vatele, J.-M. Synlett 2006, 2055e2058.
7. Geraskin, I. M.; Luedtke, M. W.; Neu, H. M.; Nemykin, V. N.; Zhdankin, V. V.
Tetrahedron Lett. 2008, 49, 7410e7412.