Reaction of iodoarenes with potassium peroxodisulfate/trifluoroacetic acid in the presence of aromatics. Direct preparation of diaryliodonium triflates from iodoarenes

Article abstract of DOI:10.1016/j.tet.2006.04.073

Diaryliodonium triflates have been directly prepared by reaction of some iodoarenes with aromatic substrates in good yields by using K₂S₂O₈/CF₃COOH/CH₂Cl₂. Treatment of a variety of iodoare

Full text of DOI:10.1016/j.tet.2006.04.073

Tetrahedron 62 (2006) 6955–6960
Reaction of iodoarenes with potassium peroxodisulfate/
trifluoroacetic acid in the presence of aromatics. Direct
preparation of diaryliodonium triflates from iodoarenes
*
Md. Delwar Hossain and Tsugio Kitamura
Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University,
Honjo-machi, Saga 840-8502, Japan
Received 1 April 2006; accepted 24 April 2006
Available online 12 May 2006
Abstract—Diaryliodonium triflates have been directly prepared by reaction of some iodoarenes with aromatic substrates in good yields by
using K S O /CF COOH/CH Cl . Treatment of a variety of iodoarenes with iodobenzene under the same conditions resulted in ligand trans-
2 2 8 3 2 2
fer, and (4-iodophenyl)(phenyl)iodonium triflate was obtained. This procedure avoids the use of high temperature and severe reaction
conditions.
Ó 2006 Elsevier Ltd. All rights reserved.
1. Introduction
the dark, without refrigeration. Many methods have been de-
scribed for the preparation of diaryliodonium salts, but very
6
The recent demand for highly efficient and environmentally
benign syntheses of fine chemicals and pharmaceuticals has
encouraged the development of mild, safe, and highly chemo-
selective oxidizers. Hypervalent iodine reagents have been
widely used as green oxidants in organic synthesis due to their
low toxicity, readyavailability, easy handling, high efficiency,
stability to air and moisture, and as an economical alternative
to heavy metal reagents such as lead(IV), thallium(III), and
mercury(II). Recently, extensive studies on hypervalent
iodine compounds such as (diacetoxyiodo)arenes, [bis(tri-
fluoroacetoxy)iodo]arenes, [hydroxy(tosyloxy)iodo]arenes,
diaryliodonium salts, etc., have been carried out and their
few of these involve the synthesis of diaryliodonium triflate
salts. The methods used so far are generally as follows:
(a) One-pot preparation of diaryliodonium triflates through
the in situ preparation of a reactive hypervalent
iodine(III) reagent from iodosylbenzene and triflic acid
7
and its reaction with aromatic substrates.
(b) A convenient synthesis of diaryliodonium triflates via
the reaction of (diacetoxy)iodobenzene, triflic acid
with aromatic substrates.
8
(c) A direct synthesis of diaryliodonium triflates by the
reaction of iodosyl triflate with the trimethylsilyl
derivatives of aromatic compounds.
1
,2
9
use for organic synthesis has been reported. Especially,
symmetric and unsymmetrical diaryliodonium salts represent
an important class of aromatic iodine(III) derivatives. They
are used in organic synthesis mostly as arylating reagents
(d) Synthesis of unsymmetrical diaryliodonium triflates by
the treatment of b-(trifyloxy)vinyl iodonium triflates
with aryl lithium reagents.
1
0
2
for a large variety of organic and inorganic nucleophiles
and, have been applied to the photochemical polymerization
(e) A generalized synthesis of unsymmetrical functional-
ized diaryliodonium triflates through the direct reaction
of bis(acetoxy)iodoarenes with arenes in a triflic acid or
3
4
process and to chemical amplification in imaging systems.
In addition, some of the diaryliodonium salts have also shown
1
1
trifluoroacetic acid medium.
5
biological activity. Diaryliodonium salts are generally solid
compounds, mostly stable towards heat, oxygen, and humid-
ity; they are mildly light-sensitive and should be stored in
Activated aromatic compounds reacted completely with the
reagent [PhIO/TfOH] within an hour; weakly deactivated
aromatics needed prolonged reaction time to produce rea-
7
sonable yields of the diaryliodonium triflates. Strongly
deactivated aromatics such as nitrobenzene and benzonitrile
did not give the corresponding diaryliodonium triflates.
However, the reagent [PhIO/TfOH] also gives (para-phenyl-
ene)bis(aryliodonium)ditriflates as byproducts. Interaction
Keywords: Diaryliodonium triflates; Iodoarenes; Potassium peroxodisul-
fate; Trifluoroacetic acid.
*
Corresponding author. Tel.: +81 952 28 88550; fax: +81 952 28 8548;
e-mail: kitamura@cc.saga-u.ac.jp
0
040–4020/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2006.04.073

6956
M. D. Hossain, T. Kitamura / Tetrahedron 62 (2006) 6955–6960
a
of most aromatic substrates with [PhI(OAc) /TfOH] em-
2
Table 1. Preparation of diaryliodonium triflates from iodoarenes
ployed in the present work gave high yields in the 0.5–1 h
reaction at room temperature. It is noteworthy that halo-
Entry
Iodoarene
PhI
Arene
Yield (%)
8
1
2
3
4
5
6
7
8
9
10
PhH
PhH
PhH
PhH
PhH
PhH
78
72
71
73
67
70
69
72
68
72
70
58
67
genated benzenes require prolonged reaction time (24 h).
However, this reagent also was not effective for strongly
deactivated aromatics such as nitrobenzene and benzonitrile.
The generality of the O]IOTf/ArSiMe /CH Cl procedure
4-BrC
4-ClC
4-FC H I
6
H
H
6 4
4
I
I
6
4
b
4-NO
2
C
6
H
4
I
3
2
2
3 6 4
3-CF C H I
PhI
is indicated by the preparation of various aromatic iodonium
triflate salts bearing methyl, halogen, and other substituents
in the aromatic ring. However, the reaction has limited
t
BuPh
BuPh
t
4-BrC
4-ClC
4-FC H I
6
H
4
I
I
9
t
6
H
4
BuPh
BuPh
t
applicability in case of easily oxidizable aromatic substrates
such as hydroxy, methoxy, and amino derivatives. The reac-
tion of b-(trifyloxy)vinyl iodonium triflates with aryl lithium
reagents affords unsymmetrical diaryliodonium triflates in
good yields, which include synthetically difficult ortho-
6
4
t
1
1
1
1
2
3
4-NO
3-NO
3-CF
2
C
6
H
H
H
4
4
I
I
I
BuPh
BuPh
BuPh
t
2
C
6
t
3
C
6
4
a
The reaction of an iodoarene (1 mmol) was carried out in ArH (3 mmol),
CF COOH (9 mL), and CH Cl (2 mL) in the presence of K S O
1
0
and meta-substituted aryliodonium triflates. Reaction of
equiv of triflic acid or trifluoroacetic acid with bis(acet-
3
2
2
2 2 8
ꢁ
(
treated at room temperature for 8 h.
Benzene (3 mmol) was added after 20 h reaction and the reaction was
continued for another 8 h.
4 mmol) at 36–38 C for 20 h. After workup, the NaOTf solution was
2
oxy)iodoarenes gave an intermediate complex, [ArI(OAc)2/
b
CF SO H] or [ArI(OAc) /CF CO H]. These activated
2
3
3
2
3
complexes were not isolated but were treated in situ with
ꢁ
11
substituted benzene at low temperature (ꢀ30 to 0 C).
addition the oxidation reactions did not proceed. When
K S O was replaced for sodium peroxodisulfate,
2
2 8
Considering the useful properties of salts and other deriva-
Na S O , the starting material was recovered. Deactivated
2 2 8
1
2
tives of triflic acid, the development of a simple and an
efficient procedure for the preparation of diaryliodonium
triflates is a desirable goal. We have previously reported
aromatic iodides employed in the present work gave good
yields together with the complete absence of effluent or
byproduct problems. The essence of our novel method is
described in Scheme 1. It is noteworthy that weakly deacti-
vated aromatic substrates such as chlorobenzene and bromo-
benzene and an activated aromatic compound such as
toluene resulted in low yields (20–25%) due to their lower
reactivity. This method was not applicable for iodoarenes
with strong electron-donating groups and for aromatic sub-
strates with strong electron-donating groups. For example,
iodoanisoles, iodonaphthalene, anisoles, naphthalene, etc.,
were quickly oxidized in the reaction mixtures, but the reac-
tion resulted in decomposition and the formation of tarry
products.
1
3
an easy preparation of [bis(trifluoroacetoxy)iodo]arenes
and ArI(OCOCF ) , from the respective iodoarenes in
CF COOH, using commercial potassium peroxodisulfate,
3
2
3
ꢁ
K S O , as the oxidant at 36–38 C for 20 h. After recrystal-
2
2 8
lization, we obtained the purified products in 36–87% yields.
Iodoarenes bearing strong electron-withdrawing groups at
the meta and para positions gave ArI(OCOCF ) in good
3
2
yields. ArI(OCOCF ) is a relatively reactive reagent and
3
2
can undergo arylation to give diaryliodonium salts. There-
fore, it was expected that the reaction of iodoarenes with
K S O /CF COOH in the presence of appropriate arenes
2
2
8
3
would give diaryliodonium salts. This preliminary work
opened a new way to develop the title method. Herein we
wish to report a direct and an effective method for the prep-
aration of diaryliodonium triflates from iodoarenes, which
1
4
can be used as a strong acid generator.
2
. Results and discussion
A simple, easy, and an efficient method for the direct
preparation of diaryliodonium triflates, Ar I OTf from
Scheme 1.
+
ꢀ
2
iodoarenes was examined. At first, diaryliodonium trifluoro-
acetoxylates Ar I (OCOCF ) were prepared by the reaction
ofiodoarenes, CF COOH, and commercialpotassium peroxo-
3
In the reaction of iodoarenes with aromatic substrates, the aro-
matic substrate was replaced by iodobenzene. Surprisingly,
the reaction of 1-chloro-4-iodobenzene, 1-fluoro-4-iodo-
benzene, and 1-iodo-4-nitrobenzene gave (4-iodophenyl)-
(phenyl)iodonium triflate, the same product as from the
reaction of iodobenzene. As we reported the formation of
[bis(trifluoroacetoxy)iodoarenes in the reaction of iodo-
+
ꢀ
2
3
disulfate, K S O , as the oxidant with aromatic substrates at
2
2 8
ꢁ
6–38 C. K S O is used as a strong oxidizing agent in many
2 2 8
3
applications. It has the particular advantage of being almost
non-hygroscopic, has particularly good storage stability,
and is easy and safe to handle. CH Cl was added for
1
3
arenes with K S O /TFA, it was considered that [bis(tri-
2 2 8
2
2
dissolving iodoarenes completely. Next, interaction of
Ar I (OCOCF ) with sodium triflate, NaOTf, solution pro-
vided the corresponding diaryliodonium triflates at room tem-
perature in fairly good yields. The results are given in Table 1.
fluoroacetoxy)iodo]arenes were formed in situ and then
underwent ligand transfer reactions with iodobenzene to
form [bis(trifluoroacetoxy)iodo]benzene. This [bis(trifluoro-
acetoxy)iodo]benzene reacted with excess iodobenzene
to give (4-iodophenyl)(phenyl)iodonium trifluoroacetate,
which was treated with the NaOTf solution to yield (4-iodo-
phenyl)(phenyl)iodonium triflate (Scheme 2). Preliminarily,
+
ꢀ
2
3
The presence of K S O (in stoichiometric quantities) in the
2
2 8
reaction mixture was indispensable because without its

M. D. Hossain, T. Kitamura / Tetrahedron 62 (2006) 6955–6960
6957
Scheme 2.
Table 2. Formation of (4-iodophenyl)(phenyl)iodonium triflate from iodo-
arenes
4. Experimental
a
4
.1. General
Entry
Iodoarene
PhI
Time (h)
Yield (%)
1
2
3
4
28
20
20
28
80
71
73
68
Melting points were determined with a Yanaco micro-melt-
ing point apparatus and are uncorrected. H NMR and
C NMR spectra were recorded on a JEOL JNM-AL300
4-ClC
4-FC
4-NO
6
H
4
I
1
6
H
4
I
1
3
2
C
6
H
4
I
a
spectrometer and the chemical shifts were expressed in parts
per million downfield from tetramethylsilane. Elemental
analysis was conducted by the Service Center of the
Elemental Analysis of Organic Compounds, Faculty of
Science, Kyushu University.
The reaction of an iodoarene (1 mmol) was carried out in CF
3
COOH
(4 mmol) at 36–
8 C for 20 h. PhI (3 mmol) was added after 20 h and the reaction was
(
3
2 2 2 2 8
9 mL) and CH Cl (2 mL) in the presence of K S O
ꢁ
continued for another 8 h. After workup, the NaOTf solution was treated
at room temperature for 8 h.
4.2. Optimized procedure for preparing diaryliodonium
triflates from iodoarenes
we conducted the reaction of 1-[bis(trifluoroacetoxy)iodo]-
4-chlorobenzene with iodobenzene in TFA in order to con-
firm the ligand transfer reaction. We observed the formation
A solution of an appropriate iodoarene (1 mmol) in a mixture
of an arene (3 mmol), CF COOH (9 mL) and CH Cl
2
of [bis(trifluoroacetoxy)iodo]benzene in the reaction at 36–
ꢁ
3
2
38 C for 12 h. Similar-type ligand transfer reactions were
observed in the reaction of hydroxy(tosyloxyiodo)benzene
ꢁ
(
2 mL) was heated with stirring to 36–38 C. Next, potas-
sium peroxodisulfate (4 mmol) was added portionwise dur-
ing 10 min and the stirring was continued until TLC analysis
indicated completion of reaction. Reaction time needed
1
5
with iodoarenes. The results are given in Table 2. The
purity of the purified products, diaryliodonium triflates,
Ar I OTf was checked by melting points, H NMR and
+
ꢀ
1
2
20 h. After completion of the reaction, water (10 mL) was
1
3
C NMR spectra, and elemental analysis.
added. The precipitates were collected by filtration under
reduced pressure, washed with CH Cl (10 mL), and dis-
2
2
carded. The crude product was obtained by extraction of
the filtrate with dichloromethane (3ꢂ10 mL) followed by
drying (anhydrous Na SO ), filtration, and removal of the
3. Conclusion
2
4
We have found a new (or considerably) improved method for
the direct preparation of diaryliodonium triflates, which is
easy and cheap. The new method gives diaryliodonium tri-
flates in good yields by the reaction of iodoarenes with
K S O , CF COOH, CH Cl , and aromatic substrates at
solvent by evaporation under reduced pressure. The crude
product was treated with a NaOTf (10 mL) solution at
room temperature for 8 h. The NaOTf solution was prepared
by mixing with NaHCO (1.0 g), H O (10 mL) and TfOH
3
2
(1.5 mL). The precipitates were collected by filtration under
reduced pressure, washed with H O (10 mL), and dried in
2
2
8
ꢁ
3
2
2
3
6–38 C. In the case of an aromatic substrate, iodobenzene,
2
ligand transfer reaction occurred with iodoarenes. Because
of its simplicity and convenience we are sure that the present
method will continue to attract significant research activity.
vacuo. Another crop was obtained by extraction of the fil-
trate with dichloromethane (3ꢂ10 mL) followed by drying
(anhydrous Na SO ), filtration, and removal of the solvent
2
4

6958
M. D. Hossain, T. Kitamura / Tetrahedron 62 (2006) 6955–6960
by evaporation under reduced pressure. The combined crude
product was washed with hexane (10 mL), Et O (10 mL),
8.09 (d, J¼8 Hz, 2H, ArH), 7.66 (t, J¼7 Hz, 1H, ArH),
13
7.58–7.49 (m, 4H, ArH), 1.30 (s, 9H, Me); C NMR
(75 MHz, CD OD) d 157.77, 136.34, 136.25, 133.53,
2
and dried in vacuo. Further purification was conducted by
repeating crystallization from CH Cl /hexane.
3
133.09, 130.48, 121.75 (q, J ¼315.9 Hz, SO CF ),
2
2
CF
2
3
1
15.97, 112.39, 36.08, 31.30.
4
1
.2.1. Diphenyliodonium triflate. 0.336 g (78%); mp 176–
ꢁ
14
ꢁ
1
77 C (lit.
mp 178–180 C); H NMR (300 MHz,
4
flate. 0.416 g (72%); mp 199–200 C; H NMR (300 MHz,
.2.8. (4-Bromophenyl)(4-tert-butylphenyl)iodonium tri-
ꢁ
1
CD OD) d 8.17 (d, J¼8 Hz, 4H, ArH), 7.69 (t, J¼8 Hz,
3
1
3
2
H, ArH), 7.50 (t, J¼8 Hz, 4H, ArH); C NMR (75 MHz,
3 CF
CD OD) d 8.11 (d, J¼9 Hz, 2H, ArH), 8.07 (d, J¼9 Hz,
3
CD OD) d 136.42, 133.62, 133.15, 121.80 (q, J ¼
2H, ArH), 7.65 (d, J¼9 Hz, 2H, ArH), 7.58 (d, J¼9 Hz,
1
3
3
17.7 Hz, SO CF ), 115.89.
2 3
2H, ArH), 1.31 (s, 9H, Me); C NMR (75 MHz, CD OD)
3
d 157.97, 137.99, 136.30, 136.15, 130.57, 128.45, 121.78
4
.2.2. (4-Bromophenyl)(phenyl)iodonium triflate. 0.365 g
ꢁ
(
q, J ¼316.5 Hz, SO CF ), 114.18, 112.64, 36.10, 31.30.
CF
2
3
8
ꢁ
1
(
72%); mp 131–132 C (lit. mp 129–136 C); H NMR
Found: C, 36.15; H, 3.02%. Calcd for C H O IBrF S: C,
17 17 3 3
(
300 MHz, CD OD) d 8.20 (d, J¼8 Hz, 2H, ArH), 8.09 (d,
3
36.12; H, 3.01%.
J¼8 Hz, 2H, ArH), 7.65–7.71 (m, 3H, ArH), 7.53 (t,
1
3
J¼8 Hz, 2H, ArH);
C NMR (75 MHz, CD OD)
3
4
flate. 0.372 g (68%); mp 178–179 C; H NMR (300 MHz,
.2.9. (4-tert-Butylphenyl)(4-chlorophenyl)iodonium tri-
ꢁ
d 138.08, 136.48, 136.19, 133.76, 133.21, 128.53, 121.77
(
1
q, J ¼317.7 Hz, SO CF ), 116.17, 114.13.
CF
2
3
CD OD) d 8.13 (d, J¼9 Hz, 2H, ArH), 8.08 (d, J¼9 Hz,
3
2
2
H, ArH), 7.58 (d, J¼9 Hz, 2H, ArH), 7.53 (d, J¼9 Hz,
4
.2.3. (4-Chlorophenyl)(phenyl)iodonium triflate. 0.331 g
ꢁ
13
H, ArH), 1.31 (s, 9H, Me); C NMR (75 MHz, CD OD)
3
7
ꢁ
1
(
71%); mp 108–110 C (lit. mp 110–111 C); H NMR
d 157.89, 140.15, 137.96, 136.30, 133.11, 130.53, 121.76
q, J ¼316.4 Hz, SO CF ), 113.36, 112.69, 36.06, 31.29.
(
300 MHz, CDCl ) d 8.03 (d, J¼8 Hz, 2H, ArH), 7.98 (d,
3
(
Found: C, 39.22; H, 3.26%. Calcd for C H O IClF S: C,
CF
2
3
J¼8 Hz, 2H, ArH), 7.50 (t, J¼8 Hz, 1H, ArH), 7.40 (t,
1
7
17
3
3
1
3
J¼8 Hz, 2H, ArH), 7.34 (d, J¼8 Hz, 2H, ArH); C NMR
3
9.20; H, 3.27%.
(
75 MHz, CDCl ) d 139.27, 136.73, 135.38, 132.43,
3
1
1
32.13, 132.07, 120.04 (q, J ¼317.7 Hz, SO CF ),
CF
2
3
4
flate. 0.371 g (72%); mp 137–138 C; H NMR (300 MHz,
.2.10. (4-tert-Butylphenyl)(4-fluorophenyl)iodonium tri-
ꢁ
14.12, 110.86.
1
CD OD) d 8.23 (dd, J¼5, 8 Hz, 2H, ArH), 8.10 (d,
1
6
3
4
0
.2.4. (4-Fluorophenyl)(phenyl)iodonium triflate.
ꢁ
J¼8 Hz, 2H, ArH), 7.58 (d, J¼8 Hz, 2H, ArH), 7.29 (t,
1
.329 g (73%); mp 133–134 C; H NMR (300 MHz,
1
3
J¼8 Hz, 2H, ArH), 1.31 (s, 9H, Me); C NMR (75 MHz,
CD OD) d 166.33 (d, J ¼252.2 Hz, CF), 157.90, 139.25
CD OD) d 8.25–8.16 (m, 4H, ArH), 7.69 (t, J¼8 Hz, 1H,
3
3
CF
ArH), 7.53 (t, J¼8 Hz, 2H, ArH), 7.29 (t, J¼8 Hz, 2H,
(
d, J ¼9.3 Hz, CCCF), 136.18, 130.53, 121.79 (q,
1
3
CF
ArH);
C NMR (75 MHz, CD OD) d 166.42 (d,
3
J ¼315.8 Hz, SO CF ), 120.46 (d, J ¼22.9 Hz, CCF),
CF 2 3 CF
J ¼252.2 Hz, CF), 139.32 (d, J ¼8.7 Hz, CCCF),
CF
CF
112.88, 109.81, 36.11, 31.31. Found: C, 40.50; H, 3.34%.
Calcd for C H O IF S: C, 40.48; H, 3.37%.
1
36.36, 133.73, 133.21, 121.80 (q, J ¼315.8 Hz,
CF
1
7
17
3
4
SO CF ), 120.54 (d, J ¼23.5 Hz, CCF), 116.39, 109.76.
2 3 CF
4
flate. 0.375 g (70%); mp 151–152 C; H NMR (300 MHz,
.2.11. (4-tert-Butylphenyl)(4-nitrophenyl)iodonium tri-
ꢁ
4
(
.2.5. (4-Nitrophenyl)(phenyl)iodonium triflate. 0.316 g
1
ꢁ
67%); mp 189–190 C; H NMR (300 MHz, CD OD)
3
1
CD OD) d 8.42 (d, J¼9.0 Hz, 2H, ArH), 8.30 (d,
3
d 8.43 (d, J¼9 Hz, 2H, ArH), 8.30 (d, J¼9 Hz, 2H, ArH),
J¼9.0 Hz, 2H, ArH), 8.17 (d, J¼9.0 Hz, 2H, ArH), 7.61
8
.27 (d, J¼8 Hz, 2H, ArH), 7.73 (t, J¼8 Hz, 1H, ArH),
3
1
3
1
3
(d, J¼9.0 Hz, 2H, ArH), 1.31 (s, 9H, Me); C NMR
3
7
d 151.47, 137.67, 136.86, 134.07, 133.42, 127.45, 121.77
.57 (t, J¼8 Hz, 2H, ArH); C NMR (75 MHz, CD OD)
(75 MHz, CD OD) d 158.32, 151.42, 137.56, 136.66,
1
1
30.76, 127.43, 121.76 (q, J ¼316.42 Hz, SO CF ),
CF
2
3
(
3
q, J ¼316.5 Hz, SO CF ), 121.56, 116.18. Found: C,
CF
2
3
21.65, 112.65, 36.16, 31.29.
2.91; H, 1.90; N, 2.98%. Calcd for C H O NIF S: C,
13 9 5 3
3
2.85; H, 1.89; N, 2.95%.
4
flate. 0.335 g (58%); mp 159–160 C; H NMR (300 MHz,
.2.12. (4-tert-Butylphenyl)(3-nitrophenyl)iodonium tri-
ꢁ
1
4
flate. 0.351 g (70%); mp 107–108 C; H NMR (300 MHz,
.2.6. (3-Trifluoromethylphenyl)(phenyl)iodonium tri-
ꢁ
1
CD OD) d 9.08 (t, J¼2 Hz, 1H, ArH), 8.53 (d, J¼8 Hz,
3
1
H, ArH), 8.49 (dd, J¼2, 8 Hz, 1H, ArH), 8.18 (d,
CD OD) d 8.59 (s, 1H, ArH), 8.45 (d, J¼8 Hz, 1H, ArH),
3
J¼8 Hz, 2H, ArH), 7.78 (t, J¼8 Hz, 1H, ArH), 7.61 (d,
8
.25 (d, J¼8 Hz, 2H, ArH), 7.99 (d, J¼8 Hz, 1H, ArH),
1
3
1
3
J¼8 Hz, 2H, ArH), 1.31 (s, 9H, Me); C NMR (75 MHz,
7
NMR (75 MHz, CD OD) d 140.10, 136.68, 134.46 (q,
.72 (t, J¼8 Hz, 2H, ArH), 7.56 (t, J¼8 Hz, 2H, ArH);
C
CD OD) d 158.37, 150.40, 141.83, 136.58, 133.95,
3
3
1
SO CF ), 115.63, 112.86, 36.19, 31.30. Found: C, 38.53;
31.02, 130.76, 128.09, 121.78 (q, J ¼316.5 Hz,
J ¼33.4 Hz, CCF ), 133.94, 133.80, 133.30, 133.08 (q,
CF
CF
3
J ¼3.7 Hz, CCCF ), 130.29 (q, J ¼3.7 Hz, CCCF ),
2 3
CF
3
CF
3
H, 3.26; N, 2.64%. Calcd for C H O F NIS: C, 38.43;
17 17 5 3
H, 3.20; N, 2.64%.
1
3
1
24.13 (q, J ¼270.2 Hz, CCF ), 121.77 (q, J ¼
CF
3
CF
16.5 Hz, SO CF ), 116.31, 116.05. Found: C, 33.77; H,
2
3
.77%. Calcd for C H O IF S: C, 33.74; H, 1.81%.
3
1
4
9
6
4
iodonium triflate. 0.375 g (67%); mp 162–163 C; H NMR
.2.13. (4-tert-Butylphenyl)(3-trifluoromethylphenyl)-
ꢁ
1
4
.2.7. (4-tert-Butylphenyl)(phenyl)iodonium triflate.
ꢁ
ꢁ
8
1
0
.344 g (69%); mp 162–163 C (lit. mp 163–165 C); H
(300 MHz, CD OD) d 8.57 (s, 1H, ArH), 8.42 (d, J¼8 Hz,
3
NMR (300 MHz, CD OD) d 8.17 (d, J¼8 Hz, 2H, ArH),
1H, ArH), 8.15 (d, J¼8 Hz, 2H, ArH), 7.99 (d, J¼8 Hz, 1H,
3

M. D. Hossain, T. Kitamura / Tetrahedron 62 (2006) 6955–6960
6959
ArH), 7.73 (t, J¼8 Hz, 1H, ArH), 7.60 (d, J¼8 Hz, 2H, ArH),
(ee) Wirth, T. Angew. Chem., Int. Ed. 2001, 40, 2812–2814;
(ff) Chaudhari, S. S. Synlett 2000, 278; (gg) Ochiai, M. Rev.
Heteroat. Chem. 1989, 2, 92–111; (hh) Moriarty, R. M.; Vaid,
R. K.; Koser, G. F. Synlett 1990, 365–383; (ii) Moriarty,
R. M.; Vaid, R. K. Synthesis 1990, 431–447; (jj) Stang, P. J.
Angew. Chem., Int. Ed. Engl. 1992, 31, 274–285; (kk)
Prakash, O.; Sainai, N.; Sharma, P. K. Synlett 1994, 221–227;
(ll) Umemoto, T. Chem. Rev. 1996, 96, 1757–1777; (mm)
Kita, Y.; Takada, T.; Toma, H. Pure Appl. Chem. 1996, 68,
627–630; (nn) Zhdankin, V. V. Rev. Heteroat. Chem. 1997,
17, 133–151; (oo) Togo, H.; Katohgi, M. Synlett 2001, 565–
581.
13
1
1
1
.32 (s, 9H, Me); C NMR (75 MHz, CD OD) d 158.26,
3
39.99, 136.46, 134.47 (q, J ¼33.4 Hz, CCF ), 133.81,
CF
3
33.01 (q, J ¼4.4 Hz, CCCF ), 130.69, 130.29 (q,
CF
3
J ¼3.1 Hz, CCCF ), 124.19 (q, J ¼270.2 Hz, CCF ),
CF
3
CF
3
1
21.79 (q, J ¼316.5 Hz, SO CF ), 116.12, 112.77,
CF
2
3
36.18, 31.30. Found: C, 39.03; H, 3.07%. Calcd for
C H O IF S: C, 39.00; H, 3.07%.
18
17
3
6
4
.2.14. (4-Iodophenyl)(phenyl)iodonium triflate. 0.476 g
ꢁ
7
ꢁ
1
(
(
7
80%); mp 138–140 C (lit. mp 144–148 C); H NMR
300 MHz, CD OD) d 8.17 (d, J¼8 Hz, 2H, ArH), 7.91–
3
.85 (m, 4H, ArH), 7.69 (t, J¼8 Hz, 1H, ArH), 7.53 (t,
2. (a) Chen, D.-J.; Chen, Z.-C. Synlett 2000, 1175–1177; (b)
Wang, L.; Chen, Z.-C. Synth. Commun. 2000, 30, 3607–
3612; (c) Radhakrishnan, U.; Stang, P. J. Org. Lett. 2001, 3,
859–860; (d) Crivello, J. V.; Bulut, U. J. Polym. Sci., Part A:
Polym. Chem. 2005, 88, 290–296; (e) Zhang, B.-X.; Nuka,
T.; Fujiwara, Y.; Yamaji, T.; Hou, Z.; Kitamura, T.
Heterocycles 2004, 64, 199–206; (f) Zhou, T.; Chen, Z.-C.
Synth. Commun. 2002, 32, 887–891; (g) Wang, L.; Chen,
Z.-C. J. Chem. Res., Synop. 2000, 372–373; (h) Zhou, T.;
Chen, Z.-C. Synth. Commun. 2002, 32, 903–907; (i)
Makioka, Y.; Fujiwara, Y.; Kitamura, T. J. Organomet. Chem.
2002, 611, 509–513; (j) Wang, F.-Y.; Chen, Z.-C.; Zheng,
Q.-G. J. Chem. Res., Synop. 2003, 810–811; (k) Davydov,
D. V.; Beletskaya, I. P.; Leninsky, G. Tetrahedron Lett. 2002,
43, 6217–6219; (l) Kang, S.-K.; Yamaguchi, T.; Ho, P.-S.;
Kim, W.-Y.; Ryu, H.-C. J. Chem. Soc., Perkin Trans. 1 1998,
841–842; (m) Hou, R.-S.; Wang, H.-M.; Lin, Y.-C.; Chen,
L.-C. J. Chin. Chem. Soc. 2005, 52, 1029–1032; (n) Zhou, T.;
Chen, Z.-C. Heteroat. Chem. 2002, 13, 617–619; (o) Wang,
L.; Chen, Z.-C.; Zheng, Q.-G. Chin. J. Chem. 2002, 20,
1457–1459; (p) Zhou, T.; Chen, Z.-C. J. Chem. Res., Synop.
2001, 235–237.
3. (a) Crivello, J. V. Adv. Polym. Sci. 1984, 62, 1–48; (b) Pappas,
S. P. Prog. Org. Coat. 1985, 13, 35–64; (c) Yagci, Y.;
Schnabel, W. Makromol. Chem., Macromol. Symp. 1988, 13/
14, 161–174; (d) Wilson, C. G.; Bowden, M. J. CHEMTECH
1989, 19, 182–189.
4. Ito, H.; Ueda, M. J. Photopolym. Sci. Technol. 1989, 2, 1–10.
5. Koser, G. F. The Chemistry of Functional Groups, Supplement
D; Patai, S., Rappoport, Z., Eds.; Wiley: New York, NY, 1983,
Chapter 25.
6. (a) Zefirov, N. S.; Kasumov, T. M.; Koz’min, A. S.; Sorokin,
V. D.; Stang, P. J.; Zhadankin, V. V. Synthesis 1993, 1209–
1210; (b) Beringer, F. M.; Dresler, M.; Gindler, E. M.;
Lumpkin, C. C. J. Am. Chem. Soc. 1953, 75, 2705–2708; (c)
Beringer, F. M.; Falk, R. A.; Karniol, M.; Lillien, I.; Masullo,
G.; Mausner, M.; Sommer, E. J. Am. Chem. Soc. 1959, 81,
342–351; (d) Beringer, F. M.; Chang, L. L. J. Org. Chem.
1972, 37, 1516–1519; (e) Tyrra, W.; Butler, H.; Naumann, D.
J. Fluorine Chem. 1993, 60, 79–83; (f) Beringer, F. M.;
Dehn, J. W.; Winicov, M. J. Am. Chem. Soc. 1960, 82, 2948–
2952; (g) Schmeisser, M.; Dahmen, K.; Sartori, P. Chem. Ber.
1970, 103, 307–311; (h) Stang, P. J.; Tykwinski, R.;
Zhdankin, V. V. J. Heterocycl. Chem. 1992, 29, 815–818; (i)
Beringer, F. M.; Lillien, I. J. Am. Chem. Soc. 1960, 82, 725–
731; (j) Kasumov, T. M.; Brel, V. K.; Kozmin, A. S.; Zefirov,
N. S. Synthesis 1995, 775–776.
1
3
J¼8 Hz, 2H, ArH);
C NMR (75 MHz, CD OD)
3
d 142.23, 137.75, 136.45, 133.73, 133.20, 121.73 (q,
J ¼316.4 Hz, SO CF ), 116.04, 115.12, 100.59.
CF
2
3
References and notes
1
. Reviews on organohypervalent iodine compounds and their
applications in organic synthesis: (a) Varvoglis, A. Chem. Soc.
Rev. 1981, 10, 377–407; (b) Merkushev, E. B. Usp. Khim.
1
987, 56, 1444–1479; Chem. Abstr. 1988, 108, 204265; (c)
Kirschning, A. J. Prakt. Chem./Chem.-Ztg. 1998, 340, 184–
86; (d) Pohnert, G. J. Prakt. Chem. 2000, 342, 731–734; (e)
1
Tohma, H. Yakugaku Zasshi 2000, 120, 620–629; Chem.
Abstr. 2000, 133, 222460; (f) Arisawa, M.; Toma, H.; Kita, Y.
Yakugaku Zasshi 2000, 120, 1061–1073; Chem. Abstr. 2001,
1
34, 29586; (g) Varvoglis, A. The Organic Chemistry of
Polycoordinated Iodine; VCH: Weinheim, 1992; (h) Stang,
P. J.; Zhdankin, V. V. Chem. Rev. 1996, 96, 1123–1178; (i)
Varvoglis, A. Hypervalent Iodine in Organic Synthesis;
Academic: San Diego, CA, 1997; (j) Kitamura, T.; Fujiwara,
Y. Org. Prep. Proced. Int. 1997, 29, 409–458; (k) Varvoglis,
A. Tetrahedron 1997, 53, 1179–1255; (l) Muraki, T.; Togo,
H.; Yokoyama, M. Rev. Heteroat. Chem. 1997, 17, 213–243;
(
m) Togo, H.; Hoshina, Y.; Nogami, G.; Yokoyama, M. Yuki
Gosei Kagaku Kyokaishi 1997, 55, 90–98; Chem. Abstr.
997, 126, 156952; (n) Moriarty, R. M.; Prakash, O. Adv.
1
Heterocycl. Chem. 1998, 69, 1–87; (o) Kirschning, A. Eur. J.
Org. Chem. 1998, 11, 2267–2274; (p) Zhdankin, V. V.; Stang,
P. J. Tetrahedron 1998, 54, 10927–10966; (q) Varvoglis, A.;
Spyroudis, S. Synlett 1998, 221–232; (r) Ochiai, M. Kikan
Kagaku Sosetsu 1998, 34, 181–193; Chem. Abstr. 1998, 129,
2
16196; (s) Ochiai, M. Farumashia 1999, 35, 140–144;
Chem. Abstr. 1999, 130, 153211; (t) Kita, Y.; Egi, M.;
Takada, T.; Thoma, H. Synthesis 1999, 885–897; (u) Wirth,
T.; Hirt, V. H. Synthesis 1999, 1271–1287; (v) Chemistry of
Hypervalent Compounds; Akiba, K., Ed.; VCH: New York,
NY, 1999; pp 359–387; (w) Grushin, V. V. Chem. Soc. Rev.
2
000, 29, 315–324; (x) Ochiai, M.; Kitagawa, Y. Yuki Gosei
Kagaku Kyokaishi 2000, 58, 1048–1056; Chem. Abstr. 2000,
33, 362660; (y) Mamaeva, E. A.; Bakibaev, A. A. Izv.
Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2000, 43, 53–
4; Chem. Abstr. 2000, 133, 266754; (z) Zhdankin, V. V.;
1
6
Stang, P. J. Chem. Rev. 2002, 102, 2523–2584; (aa) Thoma,
H.; Kita, Y. Adv. Synth. Catal. 2004, 346, 111–124; (bb)
Thoma, H.; Kita, Y. Yuki Gosei Kagaku Kyokaishi 2004, 62,
7. Kitamura, T.; Matsuyuki, J.; Nagata, K.; Furuki, R.; Taniguchi,
H. Synthesis 1992, 945–946.
8. Kitamura, T.; Matsuyuki, J.; Taniguchi, H. Synthesis 1994,
147–148.
1
16–127; (cc) Hypervalent Iodine Chemistry; Wirth, T., Ed.;
Top. Curr. Chem.; Springer: Berlin, Heidelberg, 2003; Vol.
24; (dd) Togo, H.; Sakuratani, K. Synlett 2002, 1966–1975;
2

6960
M. D. Hossain, T. Kitamura / Tetrahedron 62 (2006) 6955–6960
9
. Stang, P. J.; Zhdankin, V. V.; Tykwinski, R.; Zefirov, N. S.
Tetrahedron Lett. 1991, 32, 7497–7498.
0. Kitamura, T.; Kotani, M.; Fujiwara, Y. Tetrahedron Lett. 1996,
7, 3721–3722.
Acta 1983, 16, 15–22; (c) Howells, R. D.; Mc Cown, J. D.
Chem. Rev. 1977, 77, 69–92; (d) Stang, P. J.; Hanack, M.;
Subramanian, L. R. Synthesis 1982, 85–126.
13. Hossain, M. D.; Kitamura, T. Bull. Chem. Soc. Jpn. 2006, 79,
142–144.
14. Dektar, J. L.; Hacker, N. P. J. Org. Chem. 1990, 55, 639–647.
15. Koser, G. F.; Wettach, R. H. J. Org. Chem. 1980, 45, 1542–
1543.
1
1
1
3
1. Shah, A.; Pike, V. W.; Widdowson, D. A. J. Chem. Soc., Perkin
Trans. 1 1997, 2463–2465.
2. For reviews see: (a) Huang, W.-Y.; Chen, Q.-Y. The Chemistry
of Sulfonic Acids, Esters and Their Derivatives; Patai, S.,
Rappoport, Z., Eds.; Wiley-Interscience: Chichester, UK,
16. Shah, A.; Pike, V. W.; Widdowson, D. A. J. Chem. Soc., Perkin
Trans. 1 1998, 2043–2046.
1991, Chapter 21; (b) Stang, P. J.; White, M. R. Aldrichimica