Preparation and reactivity of polystyrene-supported iodosylbenzene: Convenient recyclable oxidizing reagent and catalyst

Article abstract of DOI:10.1055/s-0030-1260788

A facile preparation of novel polystyrene-supported iodosylbenzene (PS-ISB, loading of IO up to 1.50 mmol/g) from iodopolystyrene is described. This resin has been successfully used for efficient oxidation of a diverse collection of alcohols to aldehydes and ketones in the presence of BF₃OEt ₂. PS-ISB can also be employed as efficient co-catalyst in combination with RuCl₃ in the catalytic oxidation of alcohols and aromatic hydrocarbons, respectively, to corresponding carboxylic acids and ketones using Oxone as the stoichiometric oxidant. Georg Thieme Verlag Stuttgart ? New York.

Full text of DOI:10.1055/s-0030-1260788

LETTER
1613
Preparation and Reactivity of Polystyrene-Supported Iodosylbenzene:
Convenient Recyclable Oxidizing Reagent and Catalyst
ylbenzene g-Min Chen,*a,b Xiao-Mei Zeng, Kyle Middleton, Mekhman S. Yusubov, Viktor V. Zhdankin*
b
b
c
b
P
J
olystyren
i
e-Supp
a
orted
I
odos
n
a
b
c
College of Biological and Chemical Engineering, Jiaxing University, 56 South Yuexiu Rd, Jiaxing 314001, P. R. of China
E-mail: chemcjm@yahoo.com.cn
Department of Chemistry and Biochemistry, University of Minnesota Duluth, 1039 University Dr., Duluth, MN 55812, USA
Fax +1(218)7267394; E-mail: vzhdanki@d.umn.edu
The Siberian State Medical University and The Tomsk Polytechnic University, 634050 Tomsk, Russia
Received 23 March 2011
(
dichloroiodo)benzene (PS-DCIB)6e as chlorination and
Abstract: A facile preparation of novel polystyrene-supported io-
dosylbenzene (PS-ISB, loading of IO up to 1.50 mmol/g) from io-
dopolystyrene is described. This resin has been successfully used
for efficient oxidation of a diverse collection of alcohols to alde-
oxidation reagents, and polystyrene-supported alke-
nyl(phenyl) iodonium salts as synthons of alkenyl cat-
ions. The reduced form of these reagents, iodopolystyrene
6
f
hydes and ketones in the presence of BF ·OEt . PS-ISB can also be (PS-IB), can be conveniently recovered from reaction
3
2
employed as efficient co-catalyst in combination with RuCl in the mixtures and reused for the preparation of the reagent.
3
catalytic oxidation of alcohols and aromatic hydrocarbons, respec-
tively, to corresponding carboxylic acids and ketones using Oxone
Despite significant interest in polymer-supported hyper-
valent iodine reagents and the importance of iodosylar-
enes in organic chemistry, the polystyrene-supported
variant of iodosylbenzene (PS-ISB) has not been reported
in the literature. Our initial attempts to prepare PS-ISB by
a standard approach involving treatment of respective (di-
acetoxyiodo)arene, PS-DIB, with the aqueous solution of
NaOH were unsuccessful. We have found, however, that
as the stoichiometric oxidant.
Key words: polymers, iodine, oxidation, iodosylbenzene, recycla-
ble reagent
In recent years, hypervalent iodine compounds have been
widely used in organic synthesis for various synthetically
useful oxidative transformations with many advantages,
like mild reaction conditions, simple workup, and the en-
PS-DIB (1)6 can be effectively converted into PS-ISB
a,7
8
(
2) under solvent-free conditions (Scheme 1). A similar
1
solvent-free methodology has previously been used for
vironmentally benign nature of the reagents. Iodosylben-
9a
the preparation of [hydroxy(tosyloxy)iodo]benzene and
zene, (PhIO) , is particularly important as an oxygen-
n
9b
oligomeric iodosylbenzene sulfate.
transfer agent that has found widespread application in
catalytic oxygenation reactions after the discovery of its
supreme efficacy as a source of oxygen atoms for oxida-
tions catalyzed by cytochrome P-450 and by discrete tran-
IO
2
,3
PS-ISB (2)
sition-metal complexes.
However, stoichiometric
amount of iodobenzene as a waste product is produced in
these reactions, which leads to low atom economy and
complicated isolation and purification of the products.
Furthermore, the practical use of iodosylbenzene is ham-
pered by its low stability and potentially explosive prop-
erties upon moderate heating and insolubility in most
NaOH
I(OAc)2
or
solvent-free
PS-DIB (1)
OH
I
OH
solvents as a result of its polymeric structure, (PhIO)n.3
,4
hydrated PS-ISB (3)
Polymer-supported hypervalent iodine reagents, however,
overcome these drawbacks and have the similar reactivi-
ties as their monomeric analogues. Several polystyrene-
Scheme 1 Preparation of polystyrene-supported iodosylbenzene
5
In a typical procedure PS-DIB (1) and sodium hydroxide
were ground intensively in a mortar at room temperature
for 10 minutes. The resulting mixture was left to stay at
room temperature for 2 hours, and then water was added
and stirred overnight, then washed subsequently with wa-
ter, acetone, and diethyl ether, and dried in vacuum to ob-
tain a brownish-yellow powder. The loading of IO was
supported hypervalent reagents previously reported by
our group, such as polystyrene-supported (diacetoxy-
6
a
iodo)benzene (PS-DIB),
poly{[4-(hydroxy)(tosyl-
6
b
oxy)iodo]styrene} (PS-HTIB), polystyrene-supported
phenyliodine(III)bis(trifluoroacetate) (PS-PIFA),6c poly-
6
d
styrene-supported iodosylbenzene sulfate (PS-IBS), are
employed as efficient oxidants, polystyrene-supported
–
1
1
.50 mmol g (determined by titration of the iodine liber-
ated from a solution of KI). The IR spectra of the resin
have a typical peak at 760 cm (I=O), which is similar to
SYNLETT 2011, No. 11, pp 1613–1617
Advanced online publication: 15.06.2011
DOI: 10.1055/s-0030-1260788; Art ID: S02411ST
x
x
.x
x
.2
0
1
1
–1
that of (PhIO) . And the disappearance of peaks at 1564
n
–1
and 1288 cm [the characteristic peaks of PS-DIB (1)] in-
©
Georg Thieme Verlag Stuttgart · New York

1
614
J.-M. Chen et al.
LETTER
1
1
dicates that nearly all of I(OAc) groups are converted into iron(III) phthalocyanine(m-oxodimer), anthracene can
2
the IO groups. However, based on the elemental analysis be oxidized only in low yield (8–9%) after long time (72
of PS-ISB (2) samples on oxygen and iodine, the ratio of h, entry 15).
O/I is about 1.85 which is much higher than the calculated
value of 1:1. It is likely that the IO groups in PS-IBS are
partially hydrated as illustrated by structure 3 (Scheme 1).
The final products of all oxidations can be conveniently
separated from byproduct PS-IB (4) by simple filtration
and isolated in good purity after evaporation of solvent.
The oxidative properties of PS-ISB were initially evaluat- The recycled PS-ISB does not show significant loss of ac-
ed in the reaction with various alcohols 5 (Scheme 2).10 tivity in oxidation of 4-nitrobenzyl alcohol to 4-nitrobenz-
The results of oxidations are summarized in Table 1. As aldehyde (Table 1, entry 3).
expected, reactivity of PS-ISB in the BF ·OEt -catalyzed
3
2
oxidation of alcohols is similar to (PhIO) , and the poly-
NaOH
n
I(OAc)2
mer-supported reagent 2 can be used for efficient oxida-
tion of various alcohols 5 to the corresponding carbonyl
compounds 6 under mild conditions. Benzylic alcohols
are oxidized to the corresponding aldehydes with 100%
conversion after 1.5–12 hours except 4-methoxylbenzyl
alcohol (Table 1, entries 1–4). The highly reactive 4-
methoxylbenzyl alcohol under these conditions gave a
dark complex mixture of products (Table 1, entry 5); how-
ever, 4-methoxy-benzaldehyde was obtained smoothly in
the absence of BF ·OEt (Table 1, entry 6). Reactions of
AcOOH,
AcOH
PS-DIB (1)
NaOAc
IO
I
PS-IB (4)
PS-ISB (2)
3
2
all other substrates with PS-ISB in the absence of
BF ·OEt were extremely slow and did not afford any
measurable yield of product even after 12 hours. Primary
aliphatic alcohol, 1-octanol (Table 1, entry 7) was con-
verted into a complex mixture, and secondary alcohols
BF3⋅OEt2
CH2Cl2, r.t.
3
2
O
OH
R1
R2
R1
R2
6
5
(
Table 1, entries 8–13) were selectively oxidized to the re-
or
O
spective ketones in good yields.
The PS-ISB/BF ·OEt system can also be used for the ox-
3
2
idation at phosphorus atom, as illustrated by the conver-
sion of triphenylphosphine into triphenylphosphine oxide
in excellent yield (Table 1, entry 16). Interestingly, the
PS-ISB/BF ·OEt system can oxidize anthracene to an-
O
Scheme 2 Oxidation of organic substrates using PS-ISB (2) as a re-
cyclable reagent
3
2
thraquinone in good yield (Table 1, entry 14), while in the
absence of BF ·OEt , using catalytic amount of binuclear
3
2
Table 1 Oxidation of Organic Substrates Using Polystyrene-Supported Iodosylbenzenea
Entry
Substrate
BF ·OEt (equiv)
Product
Time (h)
12
Conversion (%)b
Yield (%)c
3
2
1
2
3
4
5
6
7
BnOH
1.5d
PhCHO
>95
>95
>95
>99
>99
>99
>99
80e
85
83f
78
–g
4-O NC H CH OH
1.5
1.5
1.5
1.5
none
1.5
4-O NC H CHO
1.5
2
6
4
2
2
6
4
4-O NC H CH OH
4-O NC H CHO
1.5
2
6
4
2
2
6
4
3-O NC H CH OH
3-O NC H CHO
12
2
6
4
2
2
6
4
4-MeOC H CH OH
4-MeOC H CHO
0.25
6
6
4
2
6
4
4-MeOC H CH OH
4-MeOC H CHO
76
–g
6
4
2
6
4
n-C H OH
n-C H CHO
24
8
17
7
15
OH
O
8
9
1.5
1.5
12
12
99
80
Ph
Ph
Ph
Ph
OH
O
>99
88e
Synlett 2011, No. 11, 1613–1617 © Thieme Stuttgart · New York

LETTER
Polystyrene-Supported Iodosylbenzene
1615
a
Table 1 Oxidation of Organic Substrates Using Polystyrene-Supported Iodosylbenzene (continued)
Entry
Substrate
BF ·OEt (equiv)
Product
Time (h)
12
Conversion (%)b
Yield (%)c
85
3
2
OH
OH
O
O
1
1
1
0
1
2
1.5
>99
1.5
1.5
12
12
95
90
66
70e
HO
O
OH
O
1
1
3
4
1.5
3.0
12
3
99
99
85
67
O
O
O
1
5
0h
72
<10
0i
O
O
1
1
6
7
Ph3P
1.5
1.5
Ph P=O
12
48
99
0
92
0i
3
a
b
c
d
e
f
All reactions of organic substrate (0.2 mmol) were performed at r.t. in the presence of BF ·OEt and PS-ISB (1.5 equiv) in dry CH Cl (2 mL).
Based on disappearance of starting substrate measured by GC-MS.
Yields of isolated products.
3
2
2
2
In the absence of BF ·OEt this reaction is extremely slow and does not afford any measurable yield of product even after 12 h.
3
2
Isolated as 2,4-dinitrophenylhydrazone.
Regenerated PS-ISB (2) was used.
g
h
i
Complex mixture was obtained.
5
mol% of binuclear iron(III) phthalocyanine(m-oxodimer)11 catalyst was added.
The starting material was recovered.
Considering active current research activity toward the (acids and ketones) are observed in these reactions in the
development of catalytic systems based on hypervalent absence of RuCl3.
1
j,k,1o–q,1t,w
iodine chemistry,
it would be interesting to test
As expected, a variety of alcohols were smoothly oxidized
these oxidations (Scheme 2) using catalytic amount of PS-
ISB. Recently, we have reported an extremely mild and
efficient tandem catalytic system for the oxidation of al-
cohols and hydrocarbons based on a Ru(III)-catalyzed re-
to afford the respective oxidation products in good yields
13
at room temperature. Similar to the PhI/RuCl /Oxone
3
12
procedure, our protocol afforded carboxylic acids from
primary alcohols (Table 2, entries 1–5) and ketones from
the secondary alcohols (Table 2, entries 6–9). We also in-
vestigated the oxidation of C–H bonds by using the PS-
oxidation of ArIO to ArIO using Oxone as a
2
1
2
stoichiometric oxidant. Since the reactivity of polymer-
supported hypervalent iodine reagents is generally similar
to the monomeric analogues, we expected that PS-ISB (2)
can serve as an active co-catalyst with Ru(III) species in
ISB/RuCl tandem catalytic system. Ethylbenzene shows
3
good reactivity in conversion into acetophenone (Table 2,
entry 10), while propylbenzene is less reactive (Table 2,
entry 11).
the tandem catalytic system PS-ISB/RuCl . The results of
3
the oxidation of some organic substrates using catalytic
Comparing the results of the two protocols (Table 1 and
Table 2) we found that primary alcohols were oxidized to
aldehydes in the PS-ISB/BF ·OEt system, while carbox-
system PS-ISB/RuCl and Oxone as a stoichiometric oxi-
3
dant are summarized in Table 2. A special control experi-
ment has shown that only traces of oxidation products
3
2
ylic acids were obtained in the tandem catalytic system
Synlett 2011, No. 11, 1613–1617 © Thieme Stuttgart · New York

1
616
J.-M. Chen et al.
LETTER
Table 2 Oxidation of Organic Substrates Using Polystyrene-Supported Iodosylbenzenea
O
OH
R2
O
R3
PS-ISB (10 mol%), RuCl3 (0.2 mol%), Oxone
MeCN–H2O, r.t.
R3
or
or
R1
R1
R2
Entry
Substrate
BnOH
PS-catalyst Oxone (equiv) Product
Time (h)
Conversion (%)b
Yield (%)c
1
2
3
4
5
PS-ISB
PS-ISB
PS-ISB
PS-ISB
PS-ISB
3.0
3.0
3.0
3.0
3.0
PhCOOH
PhCOOH
12
24
12
12
24
99
99
99
99
99
95
93d
95
90
60
BnOH
3-O NC H CH OH
3-O NC H COOH
2 6 4
2
6
4
2
4-O NC H CH OH
4-O NC H COOH
2 6 4
2
6
4
2
4-MeOC H CH OH
4-MeOC H COOH
6 4
6
4
2
OH
O
6
7
PS-ISB
PS-ISB
1.5
1.5
1.5
4
99
99
82
Ph
Ph
Ph
Ph
OH
O
84e
OH
OH
O
8
9
PS-ISB
1.5
3.5
99
85e
PS-ISB
PS-ISB
1.5
3.0
6
99
99
70
84
O
O
1
0
15
Ph
O
11
PS-ISB
6.1
24
60
35e,f
Ph
Ph
a
All reactions of organic substrate (0.2 mmol) were performed at r.t. in the presence of RuCl (0.02 equiv), PS-ISB (0.1 equiv), and Oxone in
3
MeCN–H O (1:1, v/v, 2 mL).
2
b
Based on disappearance of starting substrate measured by GC-MS.
Yields of isolated products.
Regenerated PS-ISB (2) was used.
Isolated as 2,4-dinitrophenylhydrazone.
c
d
e
f
Reaction mixture also contains 40% of unreacted propylbenzene.
PS-ISB/RuCl , because the initially formed aldehydes In conclusion, we have prepared a novel polymer-support-
3
were subsequently oxidized by Oxone; secondary alco- ed iodosylbenzene (2), which can find practical applica-
hols were oxidized to ketones in both protocols; aromatic tion as a readily available, stable, and recyclable oxidant
hydrocarbons, like ethylbenzene, can be efficiently oxi- and catalyst. Treating alcohols with PS-ISB in the pres-
dized in the tandem catalytic system (PS-ISB/RuCl ) but ence of BF ·OEt allowed in most cases complete conver-
3
3
2
do not react in the PS-ISB/BF ·OEt system (Table 1, en- sion into aldehydes or ketones, while treating anthracene
3
2
try 17).
led to anthraquinone in good yield, under mild conditions
and with convenient workup. A tandem catalytic system
Finally, we have investigated the use of iodinated polysty-
rene [PS-IB (4)] as a precatalyst to PS-ISB (2) in the tan-
(
PS-ISB/RuCl ) has been developed for the catalytic oxi-
3
dation of alcohols and alkylbenzenes to corresponding
carboxylic acids and ketones using Oxone as stoichiomet-
ric oxidant.
dem system PS-ISB/RuCl . As expected, PS-IB shows
3
much lower catalytic activity compared to PS-ISB, since
a slow initial oxidation of the ArI to the actual ArIO cata-
1
2
lyst is required in this case. In the presence of PS-IB/
RuCl , carboxylic acids from primary alcohols and ke-
3
Acknowledgment
tones from the secondary alcohols were obtained in low
yields, while ethylbenzene and propylbenzene did not re-
act at all.
Jiang-Min Chen thanks the financial Foundation of Jiaxing Univer-
sity for supporting his visit to the University of Minnesota Duluth.
This work was supported by a research grant from the National Sci-
ence Foundation (CHE-1009038). VVZ and MSY are also thankful
Synlett 2011, No. 11, 1613–1617 © Thieme Stuttgart · New York

LETTER
Polystyrene-Supported Iodosylbenzene
1617
to the Government of Russia for support of their cooperative re-
search program on hypervalent iodine chemistry (FCP, GK
(5) Togo, H.; Sakuratani, K. Synlett 2002, 1966.
(6) (a) Chen, J. M.; Huang, X. Synthesis 2004, 2459. (b) Chen,
J. M.; Huang, X. Synthesis 2004, 1577. (c) Chen, J. M.; Wu,
L. L.; Huang, X. Chin. Chem. Lett. 2004, 15, 1387.
0
2.740.11.5211; Zayavka 2010-1.5-000-010-044).
(
2
d) Chen, J.-M.; Zeng, X.-M.; Zhdankin, V. V. Synlett 2010,
771. (e) Chen, J.-M.; Zeng, X.-M.; Middleton, K.;
Zhdankin, V. V. Tetrahedron Lett. 2011, 52, 1952.
f) Chen, J. M.; Huang, X. Synlett 2004, 552.
7) (a) Togo, H.; Nogami, G.; Yokoyama, M. Synlett 1998, 534.
b) Togo, H.; Abe, S.; Nogami, G.; Yokoyama, M. Bull.
References and Notes
(
1) (a) Varvoglis, A. Hypervalent Iodine in Organic Synthesis;
Academic Press: London, 1997. (b) Hypervalent Iodine
Chemistry; Wirth, T., Ed.; Springer: Berlin, 2003.
(
(
(
(
(
c) Koser, G. F. Aldrichimica Acta 2001, 34, 89. (d) Koser,
Chem. Soc. Jpn. 1999, 72, 2351.
8) Preparation of PS-ISB (2)
G. F. Adv. Heterocycl. Chem. 2004, 86, 225. (e) Moriarty,
R. M. J. Org. Chem. 2005, 70, 2893. (f) Zhdankin, V. V.;
Stang, P. J. Chem. Rev. 2008, 108, 5299. (g) Ladziata, U.;
Zhdankin, V. V. ARKIVOC 2006, (ix), 26. (h) Ciufolini, M.
A.; Braun, N. A.; Canesi, S.; Ousmer, M.; Chang, J.; Chai,
D. Synthesis 2007, 3759. (i) Zhdankin, V. V. Science of
Synthesis, Vol. 31a; Thieme: Stuttgart, 2007, Chap. 31.4.1,
7
PS-DIB (1, 1.430 g, 3.0 mmol) and NaOH (0.400 g, 10.0
mmol) were grinded intensively in a mortar at r.t. for 10 min.
The resulting mixture was left to stay at r.t. for 2 h, then H O
2
(15 mL) was added and stirred overnight, the mixture was
filtered, washed with H O (3 × 3 mL), acetone (3 × 3 mL),
2
and Et O (3 × 3 mL) subsequently, and then dried in vacuum
2
1
4
61. (j) Ochiai, M.; Miyamoto, K. Eur. J. Org. Chem. 2008,
229. (k) Dohi, T.; Kita, Y. Chem. Commun. 2009, 2073.
to give a yellow powder (1.05 g). Elem. Anal. (%): O, 8.68;
–
1
I, 37.19. IR (KBr): n = 761 (I=O) cm .
9) (a) Yusubov, M. S.; Wirth, T. Org. Lett. 2005, 7, 519.
(
(
l) Ladziata, U.; Zhdankin, V. V. Synlett 2007, 527.
m) Quideau, S.; Pouysegu, L.; Deffieux, D. Synlett 2008,
(
(b) Koposov, A. Y.; Netzel, B. C.; Yusubov, M. S.;
467. (n) Yusubov, M. S.; Zhdankin, V. V. Mendeleev
Nemykin, V. N.; Nazarenko, A. Y.; Zhdankin, V. V. Eur. J.
Org. Chem. 2007, 4475.
Commun. 2010, 20, 185. (o) Zhdankin, V. V. ARKIVOC
2
2
2
009, (i), 1. (p) Uyanik, M.; Ishihara, K. Chem. Commun.
009, 2086. (q) Ngatimin, M.; Lupton, D. W. Aust. J. Chem.
010, 63, 653. (r) Yusubov, M. S.; Nemykin, V. N.;
(
10) General Procedure for Oxidations Using PS-ISB (2)
To a vigorously stirred suspension of PS-ISB (2, 0.3 mmol)
in CH Cl (2 mL), BF ·OEt (0.040 mL) was added, and the
2
2
3
2
Zhdankin, V. V. Tetrahedron 2010, 66, 5745. (s)Satam,V.;
Harad, A.; Rajule, R.; Pati, H. Tetrahedron 2010, 66, 7659.
resulting mixture was stirred at r.t. for 15 min. To the
mixture, the appropriate alcohol (0.2 mmol) or Ph P (0.2
3
(
(
(
t) Uyanik, M.; Ishihara, K. Aldrichimica Acta 2010, 43, 83.
u) Merritt, E. A.; Olofsson, B. Synthesis 2011, 517.
v) Brand, J. P.; Gonzalez, D. F.; Nicolai, S.; Waser, J.
mmol) or anthracene (0.1 mmol) was added. The resulting
mixture was stirred at r.t. for the indicated time (Table 1). A
portion of the crude reaction mixture (100 mL) was poured
Chem. Commun. 2011, 47, 102. (w) Zhdankin, V. V. J. Org.
Chem. 2011, 76, 1185.
into a flask with Et O (0.5 mL) to precipitate PS-IB, then the
2
mixture was passed through a 2–3 cm of silica gel suspended
in a Pasteur pipette, and the resulting solution was analyzed
by GC-MS to determine the conversion of organic
substrates.
(
2) (a) Groves, J. T.; Nemo, T. E.; Myers, R. S. J. Am. Chem.
Soc. 1979, 101, 1032. (b) Cytochrome P450: Structure,
Mechanism, and Biochemistry; Ortiz de Montellano, P. R.,
Ed.; Kluwer Academic/Plenum Publishers: New York,
(
11) Geraskin, I. M.; Pavlova, O.; Neu, H. M.; Yusubov, M. S.;
2
005. (c) Metalloporphyrins in Catalytic Oxidations;
Sheldon, R. A., Ed.; Marcel Dekker: New York, 1994.
d) Rose, E.; Andrioletti, B.; Zrig, S.; Quelquejeu-Etheve,
Nemykin, V. N.; Zhdankin, V. V. Adv. Synth. Catal. 2009,
351, 733.
(
(
12) Yusubov, M. S.; Zagulyaeva, A. A.; Zhdankin, V. V. Chem.
Eur. J. 2009, 15, 11091.
M. Chem. Soc. Rev. 2005, 34, 573. (e) Simonneaux, G.;
Tagliatesta, P. J. Porphyrins Phthalocyanines 2004, 8,
(
13) Typical Procedure of the PS-ISB/RuCl -Cocatalyzed
3
1166. (f) Bernadou, J.; Meunier, B. Adv. Synth. Catal. 2004,
Oxidation of Alcohols
Oxone (0.92 g, 1.5 mmol) was added to a mixture of 1-
phenylethanol (122 mg, 1 mmol, Table 2, entry 7), PS-ISB
346, 171. (g) Vinhado, F. S.; Martins, P. R.; Iamamoto, Y.
Curr. Top. Catal. 2002, 3, 199. (h) Meunier, B.; Robert, A.;
Pratviel, G.; Bernadou, J. The Porphyrin Handbook, Vol. 4;
Academic Press: San Diego, 2000, 119. (i) Groves, J. T.;
Shalyaev, K.; Lee, J. The Porphyrin Handbook, Vol. 4;
Academic Press: San Diego, 2000, 17. (j) Moro-oka, Y.;
Akita, M. Catal. Today 1998, 41, 327. (k) Noyori, R.
Asymmetric Catalysis in Organic Synthesis; Wiley: New
York, 1994.
(
2, 0.070 g, 0.1 mmol, 10 mol%), and RuCl (10 mL of 0.20
3
M solution in H O, 0.002 mmol, 0.2 mol%) in MeCN (3 mL)
2
and H O (3 mL) in one portions under stirring at r.t. (the
2
reaction was monitored by TLC by the disappearance of 1-
phenylethanol). Then EtOAc (15 mL) and H O (20 mL)
2
were added, and the mixture was stirred for 5 min. The
polymeric catalyst (PS-ISB) was filtered, washed with H O
2
(
(
3) (a) Moriarty, R. M.; Kosmeder, J. W.; Zhdankin, V. V. In
Encyclopedia of Reagents for Organic Synthesis; Paquette,
L. A., Ed.; Wiley: Chichester, 2004. (b) Koposov, A. Y.;
Netzel, B. C.; Yusubov, M. S.; Nemykin, V. N.; Nazarenko,
A. Y.; Zhdankin, V. V. Eur. J. Org. Chem. 2007, 4475.
(
2 × 2 mL) and EtOAc (2 × 2 mL), and collected for next run.
The organic solution was separated, and the aqueous phase
and extracted with EtOAc (2 × 15 mL). The organic
solutions were combined, washed with NaCl (sat. solution,
2
0 mL), and dried over anhyd Na SO . Removal of the
2 4
(
c) Nemykin, V. N.; Koposov, A. Y.; Netzel, B. C.;
Yusubov, M. S.; Zhdankin, V. V. Inorg. Chem. 2009, 48,
908.
solvent under vacuum afforded acetophenone (114 mg,
5%). The oxidation of other alcohols and hydrocarbons
Table 2) was performed by using a similar procedure.
9
(
4
4) An explosion of iodosylbenzene upon drying at elevated
temperature in vacuum has recently been reported:
McQuaid, K. M.; Pettus, T. R. R. Synlett 2004, 2403.
Synlett 2011, No. 11, 1613–1617 © Thieme Stuttgart · New York