(Dichloroiodo)benzene - An Easily Available Reagent for Chloro- and Iodoalkoxylation, Iodohydroxylation, and Iodochlorination of Alkenes

Article abstract of DOI:10.1081/SCC-120027283

A convenient synthesis of vicinal methoxychlorides, methoxyiodides, iodhydrines and iodochloride from alkenes using PhICl₂/CH ₃OH, I₂/ PhICl₂/CH₃OH, I ₂/PhICl₂/CH₃CN/H₂O and I ₂/PhICl₂/CH₂Cl₂ is described.

Full text of DOI:10.1081/SCC-120027283

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(Dichloroiodo)benzene—An Easily Available Reagent
for Chloro‐ and Iodoalkoxylation, Iodohydroxylation,
and Iodochlorination of Alkenes
M. S. Yusubov a b , R. J. Yusubova a , V. D. Filimonov a & Ki‐Whan Chi c
a Department of Organic Chemistry, Tomsk Polytechnic University, Tomsk, 634034, Russia
b Department of Chemistry, Siberian State Medical University, Tomsk, Russia
c Department of Chemistry, University of Ulsan, Ulsan, Republic of Korea
Version of record first published: 16 Aug 2006.
To cite this article: M. S. Yusubov , R. J. Yusubova , V. D. Filimonov & Ki‐Whan Chi (2004): (Dichloroiodo)benzene—An
Easily Available Reagent for Chloro‐ and Iodoalkoxylation, Iodohydroxylation, and Iodochlorination of Alkenes, Synthetic
Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry, 34:3, 443-450
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SYNTHETIC COMMUNICATIONSw
Vol. 34, No. 3, pp. 443–450, 2004
(Dichloroiodo)benzene—An Easily
Available Reagent for Chloro- and
Iodoalkoxylation, Iodohydroxylation,
and Iodochlorination of Alkenes
1
1
M. S. Yusubov,1,2, R. J. Yusubova, V. D. Filimonov,
*
and Ki-Whan Chi3
1Department of Organic Chemistry, Tomsk Polytechnic University,
Tomsk, Russia
2Department of Chemistry, Siberian State Medical University,
Tomsk, Russia
3Department of Chemistry, University of Ulsan, Ulsan
Republic of Korea
ABSTRACT
A convenient synthesis of vicinal methoxychlorides, methoxyiodides,
iodhydrines and iodocloride from alkenes using PhICl2/CH3OH, I2/
PhICl2/CH3OH, I2/PhICl2/CH3CN/H2O and I2/PhICl2/CH2Cl2 is
described.
*
Correspondence: M. S. Yusubov, Department of Organic Chemistry, Tomsk
Polytechnic University, Tomsk 634034, Russia; E-mail: yusubov@mail.ru.
443
DOI: 10.1081/SCC-120027283
0039-7911 (Print); 1532-2432 (Online)
www.dekker.com
Copyright # 2004 by Marcel Dekker, Inc.

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Yusubov et al.
Key Words: (Dichloroiodo)benzene; Alkenes; Methoxychlorides;
Methoxyiodides; Iohydrines.
(Dichloroiodo)benzene is known as a good reagent for chlorination and
oxidation of various organic compounds.[1–3] It is also an effective mediator
of addition reactions to triple and double bonds. Recently the Moriarty group
has found that the combination of PhICl2 and lead(II) thiocyanate provides
stereoselective 1,2-dithiocyanation of alkynes[4] and a-thiocyanation of silyl
enol ethers, silyl ketene acetals and b-dicarbonyl compounds.[5]
We have found, that the PhICl2 in reactions with alkenes in MeOH at
room temperature easily forms products of electrophilic chloromethoxylation,
but in presence of iodine processes of iodomethoxylation, iodohydroxylation,
or iodochlorination take place. In general, synthesis of alkoxychlorides and
alkoxybromides or corresponding halohydrins from alkenes is a well-
established preparative procedure. However, direct synthesis of methoxy-
chlorides, methoxyiodides and iodohydrins from olefins is often difficult to
achieve.
PhICl2 easily reacts with aromatic alkenes (1–3) in MeOH at room
temperature,[6] giving the chloromethoxy derivative (4–6) with 68–90%
preparative yields (Sch. 1, Table 1). This reaction is typical electrophilic anti-
addition process, since the mixture of erythro-/treo-diastereoisomers 5 in a
ratio 64 : 36% is formed from E-stilbene.
Side process is observed only in the case of a-methylstyrene (7), when
besides a product of addition 8, the product of chlorination of methyl groups
(9) is formed (Sch. 2). Compounds 8 and 9 could not be separated by flash
chromatography under a variety of conditions: these compounds were
obtained in a yield of 70% and in a ratio of approximately 75 : 25% as judged
from GC-MS and NMR spectra.
The product 9 is result of the minor contribution of the free-radical
chlorination methyl group of compound 8 (or parent a-methylstyrene 7) under
action of PhICl2 which is known as a reagent of chlorination alkane.[2,3]
Scheme 1.

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(Dichloroiodo)benzene
445
Table 1. Synthesis of methoxychlorides, methoxyiodides, iodohydrines
and iodochloride by reaction of alkenes with PhICl2 or I2/PhICl2 in
different medium.
Substrate
Product
Reaction conditionsa
Yield,b %
1
2
4
5
PhICl2/MeOH
PhICl2/MeOH
PhICl2/MeOH
68
90
72
80
94
91
78
78
88
95
93
84
3
6
1
12
13
14
15
16
17
18
19
20
I2/PhICl2/MeOH
I2/PhICl2/MeOH
I2/PhICl2/MeOH
I2/PhICl2/MeOH
I2/PhICl2/MeOH
I2/PhICl2/CH3CN/H2Oc
I2/PhICl2/CH3CN/H2O
I2/PhICl2/CH3CN/H2O
I2/PhICl2/CH2Cl2
3
7
10
11
1
3
7
1
aReaction at r.t. and in during 30 min.
bYield of isolated pure product.
cCH3CN (5 mL)/H2O (1 mL) for 1.0 mmol of alkene.
At the same time, reaction of PhICl2 with alkenes (1, 3, 7, 10, 11) in the
presence of iodine in MeOH has another pathway, easily giving products of
the iodomethoxylation of double bonds with 78–94% yield (Sch. 3).
When cyclohexene (10) in MeOH was reacted with PhICl2 in the presence
of iodine at room temperature, a major product of the reaction is trans-1-iodo-
2-methoxycyclohexane (15) in 78% preparative yield. Therefore the reaction
has a high trans-stereoselectivity and anti-addition character.
It is important to note, that at iodomethoxylation of the alkenes under
action of I2/PhICl2 halogenation of methyl groups does not take place in
difference from chloromethoxylation (see above).
Stilbene (2) was practically inert to action of I2/PhICl2 while it is shown
above, the chloromethoxylation reaction proceeds with a high yield. Probably,
Scheme 2.

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Yusubov et al.
Scheme 3.
phenyliodosodichloride acts as an oxidizer of iodine up to electrophilic iodine
intermediates—ICl or CH3OI. These intermediates possess lower electrophilic
activity, than intermediates, formed in the case of the chloromethoxylation
(for example, Cl2, or CH3OCl). In this connection we can note, that stilbene
(2) was inert also to action of tert-butylhypoiodide, formed from tert-BuOK
and iodine monochloride.[7]
When reaction of I2/PhICl2 with alkenes 1, 3, and 7 was carried out in
CH3CN–H2O mixture instead of methanol, corresponding iodohydrins 17–19
were obtained with 88–95% yields (Sch. 4).
Preparation of iodohydrins from alkenes and the organic derivative of
polyvalent iodine-phenyliodine(III) bistrifluoroacetate is known.[8] But in this
case is necessary to use 0.7–1.0 equivalents of expensive PhI(OCOCF3)2 on
Scheme 4.

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(Dichloroiodo)benzene
447
Scheme 5.
0.6 equivalent of the alkene (8). In our case it is required only 0.52 equivalents
of the more accessible PhICl2 on 1.0 equivalent of the alkene.
In the absence of oxygen-containing nucleophiles under action of I2/
PhICl2 in CH2Cl2 on styrene (1) iodochlorination reaction takes place and
1-chloro-2-iodophenylethane (20) is formed in good yield (84%) (Sch. 5).
Earlier similar iodochlorination was observed with use of KICl2, but this
reagent has shown lower regioselectivity and formed .15% of the regio-
isomer of compound (20).[9]
In the case of reaction of a-methylstyrene (7) with I2/PhICl2 in
CH2Cl2 iodochlorination proceeds also easily, but prepared product was not
isolated preparatively, since it decomposes at insignificant heating or action
of a daylight, especially during attempts of separating by the flash
chromatography.
Finally, our results demonstrate that (dichloroiodo)benzene is accessible,
general, and effective reagent for chloro- and iodomethoxylation, iodohy-
droxylation or iodochlorination of alkenes. Especially it would be noteworthy
that these processes does not require any special condition (inert atmosphere,
anhydrous solvents and reagents), and proceeds at room temperature within
30 min in good yields.
EXPERIMENTAL
Elemental analysis was carried out on an E.A. 1106 Carlo Erba CHNS-O
instrument. Mass spectra were recorded using a Finnigan MAT-8200 mass
spectrometer. 1H and 13C NMR spectra recorded on a Bruker AC-200 (200.13
and 50.32 MHz), AM-300 (300.13 and 75.47 MHz), AM-400 (400.13 and
100.61 MHz), DRX-500 (500.13 and 125.76 MHz) spectrometer.
Typical procedure. 2-Iodo-1-methoxy-1-phenylethane (12). To a
mixture of (dichloroiodo)benzene (289 mg, 1.05 mmol) and iodine (280 mg,
1.1 mmol) in MeOH (8.0 mL) was added at room temperature styrene (1)
(208 mg, 2.0 mmol) in MeOH (2 mL). The resulting solution was stirred at

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Yusubov et al.
room temperature for 10 min. The reaction mixture was poured into 1%
aq Na2S2O3 (20 mL) and extracted with diethyl ether (2 ꢀ 50 mL). The
combined organic extracts were washed with water (50 mL) and brine
(30 mL), and dried with Na2SO4. The organic solvents were evaporated in
vacuo and the residual products were purified by flash chromatography
(hexane, after hexane/benzene) with silica gel to give the product 12 (420 mg
1
in 80% yield as an oil (lit. [10], oil). H NMR (400 MHz, CCl4-(CD3)2CO-
3 : 1, TMS, d, ppm, J, Hz): 3.21 (s, 3H, OCH3), 3.23 (m, 2H, CH2), 4.21 (dd,
1H, J ¼ 5.0, 8.0), 7.26–7.34 (m, 5Harom.). 13C NMR (100 MHz, ppm, CCl4-
(CD3)2CO–3 : 1, d, ppm): 10.10 (CH2I), 56.94 (OCH3), 83.55 (CH-OCH3),
126.51, 128.23, 128.53, 139.98 (Carom). HRMS (m/z): Calcd. for C9H11IO:
261.98564. Found: 261.98537. MS (EI, 70 eV): 262 (,1), 135 (14), 121 (100),
104 (10), 103 (9), 91 (10), 77 (13) amu.
1
1-Methoxy-1,1-diphenyl-2-iodoethane (13). m.p. 85–868C. H NMR
(500 MHz, CCl4-CDCl3–3 : 1, CHS, d, ppm): 3.12 (s, 3H, OCH3), 4.08 (s, 2H,
CH2), 7.21 (t, 2Harom) 7.27(t, 4Harom.), 7.34 (d, 4Harom). 13C NMR (125 MHz,
CCl4-CDCl3–3 : 1, d): 15.34 (CH2-I), 50.02 (OCH3), 80.51 (CHOCH3),
127.13, 127.26, 127.98, 142.92 (Carom). Calcd. for C15H15IO: C 53.27%,
H 4.47%, I 37.53%. Found: C 53.72%, H 4.34%, I 37.47%. HRMS (m/z):
Calcd. for C15H15IO: 338.01694. Found: 338.01713.
1-Iodo-2-methoxy-2-phenylpropane (14). oil. 1H NMR (500 MHz,
CCl4-CDCl3–3 : 1, CHS, d, ppm, J, Hz): 1.69 (s, 3H, CH3), 3.11 (s, 3H,
OCH3), 3.37 (d, 1Ha, J ¼ 10.0), 3.46 (d, 1Hb, J ¼ 10.0), 7.25 (t, 1Harom
)
7.32(t, 2Harom.), 7.37 (d, 2Harom). 13C NMR (125 MHz, CCl4-CDCl3–3 : 1, d,
ppm): 19.25 (CH2-I), 23.85 (CH3), 51.14 (OCH3), 76.87 (C-OCH3), 126.27,
127.69, 128.44, 141.50 (Carom). Calcd. for C10H13IO: C 43.50%, H 4.75%,
I 43.96%. Found: C 43.48%, H 4.67%, I 45.83%. HRMS (m/z): Calcd. for
C10H13IO: 276.00129. Found: 276.00142. MS (EI, 70 eV): 276 (,1), 261
(,1), 149 (14), 148 (49), 135 (75), 118 (74), 105 (57), 91 (63), 77 (58).
trans-1-Iodo-2-methoxycyclohexane (15). oil. 1H NMR (200 MHz,
CCl4-CDCl3–3 : 1, TMS, d, ppm, J, Hz): 3.16 (ddd, 1H, J ¼ 8.2, 8.2, 4.0),
3.31 (s, OCH3), 3.99 (ddd, 1H, J ¼ 9.8, 8.1, 4.2). 13C NMR (50 MHz, CCl4-
CDCl3–3 : 1, TMS, d, ppm): 23.10, 26.44, 29.58, 34.19 (CH-I), 36.81, 56.56
(OCH3), 83.32 (CH-OCH3). Calcd. for C7H13IO: C 35.02%; H 5.46%;
I 52.86%. Found: C 35.24%; H 5.36%; I 52.46%.
r-2-iodo-t-1-methoxy-1-methylcyclohexane
(16). oil.
1H NMR
(200 MHz, CCl4-CDCl3–3 : 1, TMS, d, ppm, J, Hz): 1.27 (s, CH3), 3.15 (s,
OCH3), 4.29 (dd, 1H, J ¼ 8.2, 4.0). 13C NMR (50 MHz, CCl4-CDCl3–3 : 1,
TMS, d, ppm): 22.10 (CH3), 23.38, 25.56, 32.48, 35.29 (CH2-I), 41.42, 48.60
(OCH3), 75.30 (CH-OCH3). HRMS (m/z): Calcd. for C8H15IO: 254.01694.
Found: 254.01840. MS (EI, 70 eV, I.(%)): 254 (,1), 127 (31), 97 (34), 95
(37), 85 (54), 71 (63), 57 (100), 43 (85).

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(Dichloroiodo)benzene
449
1
2-Iodo-1-phenylethanol (17). oil. H NMR (200 MHz, CCl4-CDCl3–
3 : 1, TMS, d, ppm, J, Hz): 3.31 (s, 1H, OH), 3.37 (m, 2H, H-2), 4.73 (dd, 1H,
J ¼ 4.1, 8.2), 7.30 (s, 5Harom). 13C NMR (50 MHz, CCl4-CDCl3–3 : 1, TMS,
d, ppm): 14.62 (CH2-I), 73.73 (CH-OH), 125.63, 127.97, 128.33, 141.18
(Carom).
2-Iodo-1,1-diphenylethanol (18). oil. 1H NMR (300 MHz, (-(CD3)2CO,
CHS, d, ppm, J, Hz): 1.70 (s, 3H, CH3), 2.96 (s, 1H, OH), 3.63 (d, 1Ha,
J ¼ 12.5), 3.67 (d, 1Hb, J ¼ 12.5), 7.33 (m, 1Harom) 7.54 (m, 2Hrom.), 7.56 (d,
2Harom). 13C NMR (75 MHz, -(CD3)2CO, d, ppm): 23.86 (CH2-I), 29.40
(CH3), 72.79 (C-OH), 126.00, 127.69, 128.79, 146.20 (Carom). Calcd. for
C9H11IO: C 41.24%, H 4.23%. Found: C 41.48%, H 4.16%.
1
1-Iodo-2-phenylpropan-2-ol (19). oil. H NMR (300 MHz, (-(CD3)2-
CO, CHS, d, ppm): 4.18 (s, 2H, CH2-OH), 5.47 (s, 1H, OH), 7.33 (m, 2Harom
)
7.39 (m, 4Harom.), 7.54 (d, 4Harom). 13C NMR (75 MHz, -(CD3)2CO, d, ppm):
21.90 (CH2-I), 114.67 (C-OH), 127.10, 127.86, 128.72, 128.87, 128.97,
129.18, 146.05 (Carom). Calcd. for C14H13IO: C 51.87%, H 4.04%. Found: C
51.34%, H 4.26%.
1-Chloro-2-iodo-1-phenylethane (20). 44–458C (lit.[11] 42–438C).
1H NMR (200 MHz, CCl4-CDCl3–3 : 1, TMS, d, ppm, J, Hz): 3.80 (m 2H,
H-2), 5.11 (dd, 1H, H-1, J ¼ 6.0, 9.2), 7.42 (s, 5Harom). 13C NMR (50 MHz,
CCl4-CDCl3–3 : 1, TMS, d, ppm): 9.80 (CH2-I), 61.39 (CH-Cl), 127.05,
128.52, 128.85, 138.96 (Carom).
ACKNOWLEDGMENT
We thank Russian Foundation for Fundamental Researches (grant N 00-
03-32812a) and Ministry of Education (grant N E02-5.0-176) for the financial
support of this work.
REFERENCES
1. Skulski, L. Organic iodine (I, III and V) chemistry. 10 Years of develop-
ments at the Medical University Warsaw, Poland. Molecules 2000, 5,
1331–1371.
2. Varvoglis, A. Hypervalent Iodine in Organic Synthesis; Academic Press:
London, 1997; 223.
3. Stang, P.J.; Zhdankin, V.V. Recent development in the chemistry of
polyvalent iodine compounds. Chem. Rev. 2002, 102 (7), 2523–2584.
4. Prakash, O.; Sharma, V.; Batra, H.; Moriarty, R.M. (Dichloroiodo)ben-
zene and lead (II) thiocyanate as an efficient reagent combination for

ORDER
REPRINTS
450
Yusubov et al.
stereoselective 1,2-dithiocyanation of alkynes. Tetrahedron Lett. 2001,
44 (2), 553–555.
5. Prakash, O.; Kaur, H.; Batra, H.; Rani, N.; Singh, S.P.; Moriarty, R.M.
a-Thiocyanation of carbonyl and b-dicarbonyl compounds using
(dichloroiodo)benzene—lead (II) thiocyanate. J. Org. Chem. 2001,
66 (6), 2019–2023.
6. Yusubov, M.S.; Yusubova, R.J.; Filimonov, V.D.; Chi, Ki-Whan.
(Dichloroiodo)benzene convenient reagent of chloro- and iodomethoxy-
lation of double and triple bond. Zh. Org. Chem. 2002, 38 (6), 944–945.
7. Glover, S.A.; Goosen, A. Synthesis of b-iodo-t-butyl and methyl ethers
from the reaction of alkenes with t-butyl and methyl hypoiodites.
Tetrahedron Lett. 1980, 21, 2005–2008.
8. De Corso, A.R.; Panunzi, B.; Tingoli, M. Iodohydroxylation of alkenes
promoted by molecular and hypervalen (III) iodine. Tetrahedron Lett.
2001, 42, 7245–7247.
9. Zefirov, N.S.; Sereda, G.A.; Sosonuk, S.E.; Zyk, N.V.; Likhomanova, T.I.
Versatile iodination of olefins by potassium dichloroiodate (I). Synthesis
1995, 11, 1359–1361.
10. Cambie, R.C.; Noall, W.I.; Potter, G.J.; Rutledge, P.S.; Woodgate, P.D.
Reactions of alkenes with electrophilic iodine in tetramethylene
sulphone-chloroform. J.S.C. Perkin Trans. I. 1977, 2, 226–230.
11. Sket, B.; Zupet, P.; Zupan, M. Regio- and stereospecific iodochlorination
of alkenes and alkynes with polyfstyrene-[4-vinylpyridnium dichloroio-
date (I)]g. Tetrahedron 1990, 46 (7), 2503–2510.
Received in Poland May 7, 2003

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