Cobalt-catalyzed stereoselective iodosulfonylation and diiodination of alkynes via oxidation of potassium iodide in air

Article abstract of DOI:10.1016/j.tet.2018.02.004

Cobalt-catalyzed iodosulfonylation of alkynes can be achieved using sodium sulfinates in the presence of KI. This procedure produces numerous stereoselective (E)-β-iodoalkenyl sulfones with good yields and suppresses the formation of diiodoalkenes. Furthermore, when this reaction is performed in the absence of sodium sulfinates, the expected (E)-diiodoalkenes are obtained.

Full text of DOI:10.1016/j.tet.2018.02.004

Accepted Manuscript
Cobalt-catalyzed stereoselective iodosulfonylation and diiodination of alkynes via
oxidation of potassium iodide in air
Nobukazu Taniguchi
PII:
S0040-4020(18)30129-7
10.1016/j.tet.2018.02.004
TET 29275
DOI:
Reference:
To appear in: Tetrahedron
Received Date: 5 November 2017
Revised Date: 29 January 2018
Accepted Date: 1 February 2018
Please cite this article as: Taniguchi N, Cobalt-catalyzed stereoselective iodosulfonylation and
diiodination of alkynes via oxidation of potassium iodide in air, Tetrahedron (2018), doi: 10.1016/
j.tet.2018.02.004.
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ACCEPTED MANUSCRIPT
Cobalt-Catalyzed Stereoselective
Leave this area blank for abstract info.
Iodosulfonylation and Diiodination of
Alkynes via Oxidation of Potassium Iodide in
Air
Nobukazu Taniguchi
Department of Chemistry, Fukushima Medical University, Fukushima 960-1295, Japan

1
ACCEPTED MANUSCRIPT
Tetrahedron
journal homepage: www.elsevier.com
Cobalt-Catalyzed Stereoselective Iodosulfonylation and Diiodination of Alkynes
via Oxidation of Potassium Iodide in Air
Nobukazu Taniguchia,
a Department of Chemistry, Fukushima Medical University, Fukushima 960-1295, Japan
ARTICLE INFO
ABSTRACT
Article history:
Received
Cobalt-catalyzed iodosulfonylation of alkynes can be achieved using sodium sulfinates in the
presence of KI. This procedure produces numerous stereoselective (E)- -iodoalkenyl sulfones
β
Received in revised form
Accepted
with good yields and suppresses the formation of diiodoalkenes. Furthermore, when this reaction
is performed in the absence of sodium sulfinates, the expected (E)-diiodoalkenes are obtained.
Available online
2009 Elsevier Ltd. All rights reserved
.
Keywords:
Cobalt catalyst
Iodosulfonylation
Diiodination
Sodium Sulfinate
Potassium Iodide
———
Corresponding author. Tel.: +81-24-5471369; fax: +81-24-5471369; e-mail: taniguti@fmu.ac.jp

2
Tetrahedron
1. Introduction
presence of KI was completed. In this article, it will be described
ACCEPTED MANUSCRIPT
about the developed methodology.
Transition metal-catalyzed synthesis of vinyl sulfones is an
important methodology that is widely used in organic chemistry.1
This is because these compounds are useful as convenient
synthetic intermediates.2 To synthesize vinyl sulfones, numerous
procedures have been developed3, including the Horner-Emmons
reaction4, aldol condensation5, and oxidation of alkenyl sulfides6.
Scheme 1. Cobalt-catalyzed sulfonylation of alkynes or
alkenes
X
ArSO2Na
or
R
R
SO2R3
R
cat.Co, air or O2
By comparison, reactions employing sodium sulfinate are
restricted to the Michael reaction,7 or a transition-catalyzed cross-
coupling with alkenyl halides.8 Furthermore, reports of catalytic
sulfonylation of nonactivated alkynes using sodium sulfinate are
limited.9 The exploration of a simple catalytic procedure is
therefore necessary.
X = O or OH
Lower yield
2. Results and Discussion
Table 1. Investigation of suitable conditionsa
To prepare β-halovinyl sulfones, several procedures are
employed (Figure 1). For example, reactions of sulfonyl
chlorides with alkynes have been widely reported for use in the
preparation of alkenyl sulfones (eq. 1).10 Furthermore, these
reactions can be performed in the presence of a copper or an iron
catalyst. Sulfonyl radicals or cations generated from sulfonyl
chlorides can work as promoting reagents. Although these
reactions are typically used because they are convenient, the
halogen that is introduced is generally limited to chlorine. On the
other hand, stoichiometric reactions using sodium sulfinates have
been also investigated.11 This method usually requires addition of
NXS (X = Cl or Br)10a, CAN-NaI10b or iodine10c (eq. 2) wherein
these reagents result in the oxidation of the sulfonyl anion. In a
similar manner, copper-catalyzed sulfonylation of alkynes has
also been recently reported,9 and the procedure proceeds via the
copper-catalyzed oxidation of the sulfonyl anion (eq. 3).
Therefore, the generation of the sulfonyl radical or cation is the
most important step to perform the sulfonylation of alkynes.
Entry
1
[Co]-L
KX
None
KI
3a (%)g
None
0
2
None
0
3
CoBr2
KI
57
87
85
87
80
12
0
4
CoBr2-bpy
CoBr2- Phen
CoBr2- PhenꢀH2O
KI
5
KI
6
KI
7b
8c
KI
KI
9
CoBr2-PPh3
KI
Figure 1. Sulfonylation of alkynes
10
11d
12e
13f
14
15
16
17
CoBr2-dppb
KI
trace
trace
trace
0
CoBr2- PhenꢀH2O
CoBr2- PhenꢀH2O
CoBr2- PhenꢀH2O
CoCl2- PhenꢀH2O
Co(OAc)2- PhenꢀH2O
CoBr2- PhenꢀH2O
CoBr2-PhenꢀH2O
KI
KI
KI
KI
61
68
0
KI
KBr
KCl
0
aReaction condition: The mixture of 1a (0.3 mmol), 2b (0.33 mmol), KI (0.33
mmol) and CoX2-L (1:1, 5 mol%) was treated in AcOH (0.3 mmol) at 100 ºC.
bat 80 ºC
cat 60 ºC
dDMF (0.3 mmol) was used as a solvent.
eDMSO (0.3 mmol) was used as a solvent.
fPhMe (0.3 mmol) was used as a solvent.
gIsolated yield.
Transition metal catalysts are known to be oxidants of
sulfonyl anions. 3b-c, 3g, 9,12 In particular, the reactivity of copper
and nickel catalysts has been extensively investigated. The
cobalt-catalyzed oxidation of the sulfonyl anion has not been the
subject of research; however, the oxidation of sulfides has been
performed.13 Via our previous studies, it has been shown that the
cobalt catalyst itself could not promote sulfonylation of alkenes
or alkynes satisfactorily (Scheme 1). To address this issue, the
addition of the iodide ion as an oxidant precursor was attempted.
As a general, iodine radical is able to produce by the oxidation of
KI. This can work as oxidants of sulfonyl anions whereas the
generation of diiodoalkenes is also worried. However in this
investigation, a cobalt-catalyzed sulfonylation of alkynes in the
To determine suitable conditions, numerous combinations of
cobalt catalyst with ligands were initially surveyed (Table 1).
Consideration of Table 1 Entries 1-2, shows that the reaction did
not proceed in the absence of a cobalt catalyst or KI. However,
when CoBr2 (5 mol%) was added, the corresponding β-
iodoalkenyl sulfone 3a was obtained with 57% yield as a single
isomer (Entry 3). Fortunately, the addition of bpy as a ligand
increased the yield to 87% without the formation of diiodoalkene

3
and other isomers (Entry 4).14 The stereochemistry of 3a was (E)-
isomer. Although other amine ligands (Phen or PhenꢀH2O) also
produced excellent results, no reaction using phosphine ligands
proceeded (Entries 5−6, 9−10). The reaction afforded best result
at 100 ºC (Entries 7−8). Other solvents (DMF, DMSO or PhMe)
could not promote the reaction (Entries 11−13). Thus, the
procedure proceeds smoothly under acidic condition.
Furthermore, other cobalt compounds, such as CoCl2 or
Co(OAc)2 were ineffective in promoting the reaction (Entries
14−15). Unfortunately, it was not possible to introduce the
bromide or chloride ion into the procedure via KBr or KCl
(Entries 16−17).
Unfortunately, the procedure using diphenyl acetylene or
ACCEPTED MANUSCRIPT
terminal aliphatic alkynes hardly proceeded with a recovery of
alkynes (Entries 19−20).
The iodosulfonylation of alkynes was achieved through the
use of a cobalt catalyst; however, neither the bromide nor the
chloride ion could be introduced (Table 1). From the above
findings, it seems that the reaction proceeds via the oxidation of
KI as the initial step rather than via sodium sulfinates.
Scheme 2. Oxidation of (E)-β-iodoalkenyl sulfides
Table 2. Preparation of β-iodoalkenyl sulfonesa
KI,
CoBr2-Phen•H2O
(1:1, 5 mol%)
R2
I
R3SO2Na
R1
R2
+
R1
AcOH, air, 100 °C
18 h
SO2R3
2
1
3
3
Entry
R1
R2
R3
3
(%)b
82
1
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
Ph
H
H
H
H
H
H
H
H
H
H
H
H
H
H
Ph
3ba
3bb
3bc
3bd
3be
3bf
3bg
3ab
3ai
2
4-MeC6H4
4-MeOC6H4
4-ClC6H4
4-FC6H4
86
3
74
4
72
5
76
Scheme 3. Deiodination of β-iodoalkenyl sulfone
6
1-Naph
77
7
Me
80
8
4-MeC6H4
4-AcHNC6H4
4-FC6H4
87
9
Ph
38
10
11
12
13
14
15
16
17
18
19
20
Ph
3ae
3cb
3db
3eb
3fb
3gb
3hb
3ib
83
4-MeOC6H4
4-PhC6H4
4-FC6H4
2-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
4-MeC6H4
71
73
79
As a result of the above conclusion, a cobalt-catalyzed
diiodination of alkynes using KI was then investigated in this
study. Typically, the diiodination of unsaturated C−C bonds
employs iodine. However, another method involving a reaction
via oxidation of the iodine ion exists but is not widely reported.16
To perform such a reaction, suitable conditions were initially
investigated (Scheme 4). In some previously reported
experiments, a mixture of phenylacetylene with KI in air at 100
ºC produced the expected (E)-1,2-diiodo-1-phenylethene 4a in
72% yield. However, the reaction did not proceed in the absence
of CoBr2, and the reactivity was slightly lower than
iodosulfonylation.
80
1-Cyclohexenyl
H
59
Ph
Me
Et
71
Ph
80
Ph
CH2OAc
4-MeC6H4
4-MeC6H4
4-MeC6H4
3jb
3kb
3lb
60
Ph
Ph
H
trace
trace
n-Hex
aReaction condition: The mixture of 1 (0.3 mmol), 2 (0.33 mmol), KI (0.33
mmol) and CoBr2-PhenꢀH2O (1:1, 5 mol%) was treated in AcOH (0.3 mmol)
at 100 ºC.
bIsolated yield.
Scheme 4. A cobalt-catalyzed diiodination
CoBr2-Phen•H2O
I
On the basis of developed procedure, the iodosulfonylation of
various alkynes was evaluated (Table 2). When the reaction of
terminal alkynes 1 (0.3 mmol) with sodium sulfinates 2 (0.33
mmol) was performed, the expected β-iodoalkenyl sulfones 3
were obtained in excellent yields (Entries 1−15). Furthermore,
this reaction is not only successful for terminal alkynes but also
for internal alkynes (Entries 16−18). The stereochemistry of these
compounds was determined by comparison with 1H NMR of
authentic samples and previous reported literatures (Scheme 2
and 3).6,15 These results suggested the addition was anti-selective.
(1:1, 5 mol%)
+
Ph
KI
Ph
AcOH, air,
18 h
(2 equiv.)
I
1a
4a
72% (100 °C)
67% (80 °C)
trace (without CoBr2, 100 °C)
As shown in Table 3, the procedure developed in this study
produced the expected (E)-1,2-diiodoalkenes 4 in good yields,

4
Tetrahedron
ACCEPTED MANUSCRIPT
and
proceeded
via
anti-addition
selectively.
The
in the presence of both sodium sulfinates and KI. Finally, the
stereochemistry of these compounds was determined by
reaction in the presence of I2 was researched (Scheme 9). It is
well known that a reaction of sodium sulfinates with I2 usually
affords sulfonyl iodides. When some conditions were examined,
these produced the corresponding iodoalkenylsulfones in lower
yields without the formation of diiodoalkenes. The result shows
that the iodosulfonylation slightly proceeds via the formation of
sulfonyl iodide.
1
comparison with H NMR of authentic samples prepared by a
reaction of alkynes with I2 or literatures (Scheme 5).16
17
Numerous terminal or internal alkynes were available for
reaction except for 4-octyne (Entry 8). However, the procedure
could not perform dibromination or dichlorination of alkynes
through the use of KBr or KCl (Entries 9−10).
Scheme 6. Reactivity in the absence of oxygen
Table 3. Preparation of diiodoalkenesa
Scheme 7. Reactivity in the presence of TEMPO
Entry
R1
R2
H
4
4 (%)b
72
1
Ph
4a
4b
4c
4d
4e
4f
4g
4h
4i
2
4-MeC6H4
4-FC6H4
Ph
H
70
3
H
70
4
Me
H
72
5
n-Bu
n-Hex
n-Pentyl
n-Pr
62
Scheme 8. Oxosulfonylation of alkyne
Scheme 9. Reaction in the presence of I2
6
H
73
7
Me
n-Pr
H
75
8
traced
9e
10e
Ph
0
Ph
H
4j
0
aReaction condition: The mixture of 1 (0.3 mmol), KI (0.63 mmol), and
CoBr2-PhenꢀH2O (1:1, 5 mol%) was treated in AcOH (0.3 mmol) at 100 ºC.
b Isolated yield.
cDetermined by 1H NMR.
dThe reaction gave complex mixtures including the expected diiodoalkene.
eKBr or KCl (0.63 mmol) was used instead of KI.
Figure 2. A plausible reaction mechanism
17
Scheme 5. Diiodination of alkynes using I2
To clear the whole reaction mechanism, some constituent
reactions were examined. When the iodosulfonylation of
phenylacetylene in the absence of oxygen was tested, the product
yield was found to be merely 17% (Scheme 6). Similarly, a
reaction in the presence of TEMPO or TBC (4-t-butyl catechol)
as a radical scavenger was completely inhibited (Scheme 7).
These results indicate that the procedure requires oxygen and
therefore proceeds via radical intermediates. In addition, the
oxidation of sodium sulfinates by the cobalt catalyst was also
investigated (Scheme 8). When the cobalt-catalyzed
oxosulfonylation of phenylacetylene was performed using a
previously developed Ni-catalyzed method12, the production of
the expected oxosulfone was obtained in 23% yield. The cobalt-
catalyzed oxidation of sodium sulfinates is therefore a very slow
reaction. Hence, it is presumed that the oxidation of KI proceeds
A plausible reaction mechanism is illustrated as shown in
Figure 2.18 This mechanism comprises two reactions that
generate sulfonyl radicals, which are as follows: 1) oxidation by
iodine radicals or I2 that are formed by the cobalt-catalyzed
oxidation of KI and 2) direct oxidation by the cobalt catalyst. Of
these two reactions, the oxidation by iodine radicals proceeds as
the dominant process. Sequentially, after sulfonyl radicals are
oxidized by iodine radicals or Co(II) catalyst, sulfonyl cations or
sulfonyl iodides19 are formed. Finally, (E)-β-iodoalkenyl sulfones

5
are stereoselectively prepared via sulfonyl cations react with
21.4.; Anal. Calcd for C16H15IO2S required C, 48.25; H, 3.80%.
Found: C, 48.36; H, 3.90
ACCEPTED MANUSCRIPT
alkynes, and the Co(II) catalyst is regenerated in the presence of
oxygen. On the other hand, a reaction of sulfonyl radicals of
alkynes also produces (E)-β-iodoalkenyl sulfones via the
formation of the corresponding (Z)-vinyl radical intermediates by
thermodynamic control.20,21 Thus, the procedure proceeds via
both cation and radical process.
4.2.3.(E)-1-Iodo-2-(4-methoxylphenylsulfonyl)-1-(4-
methylphenyl)ethene (3bc)11b
The title compound was obtained as white solid (88.4 mg,
74%). mp 88−90 °C; nmax (CHCl3) 3019, 1594, 1498, 1324, 1261
cm-1; 1H NMR (270 MHz, CDCl3) δ 7.52 (2H, d, J 8.2 Hz, ArH),
7.31 (1H, s, =CHSO2), 7.17–7.07 (4H, m, ArH), 6.85 (2H, d, J
8.2 Hz, ArH), 3.84 (3H, s, OMe), 2.35 (3H, s, Me); 13C NMR
(67.5 MHz, CDCl3) δ 163.6, 141.0, 140.1, 136.9, 131.8, 130.0,
128.5, 127.8, 114.2, 55.6, 21.4.; Anal. Calcd for C16H15IO3S
required C, 46.39; H, 3.65%. Found: C, 45.99; H, 3.68
3. Conclusion
In conclusion, the cobalt-catalyzed iodosulfonylation of alkynes
using sodium sulfinates and KI can produce stereoselective (E)-
β-iodoalkenyl sulfones in good yields. The reaction proceeded
via oxidation of KI in air, and the production of diiodoalkenes is
completely suppressed. Furthermore, this process also resulted in
the preparation of (E)-diiodoalkenes.
4.2.4.(E)-1-Iodo-2-(4-chlorophenylsulfonyl)-1-(4-
methylphenyl)ethene (3bd)
The title compound was obtained as white solid (90.5 mg,
72%). mp 145−147 °C; nmax (CHCl3) 3020, 1607, 1583, 1475,
1328 cm-1; 1H NMR (270 MHz, CDCl3) δ 7.49 (2H, d, J 8.9 Hz,
ArH), 7.33 (2H, d, J 8.9 Hz, ArH), 7.32 (1H, s, =CHSO2), 7.14–
7.06 (4H, m, ArH), 2.36 (3H, s, Me); 13C NMR (67.5 MHz,
CDCl3) δ 140.4, 140.3, 140.1, 138.7, 136.6, 129.3, 129.2, 128.6,
127.7, 115.8, 21.4.; Anal. Calcd for C15H12ClIO2S required C,
43.03; H, 2.89%. Found: C, 43.43; H, 2.54
4. Experimental Section
4.1 General Procedure
All reactions were carried out in air. NMR spectra were
recorded on a JEOL EX-270 spectrometer (270 MHz for 1H, 67.5
MHz for 13C). Chemical shifts are reported in δ ppm referenced
to an internal tetramethylsilane standard for 1H NMR and
chloroform-d (δ 77.0) for 13C NMR. IR spectra were measured by
Perkin-Elmer Spectrum One FT-IR spectrometer. Melting points
were measured on a BÜCHI Melting Point B-540 apparatus.
Elemental analysis was performed at the Instrumental Analysis
Center for Chemistry, Tohoku University (Japan).
4.2.5.(E)-1-Iodo-2-(4-fluorophenylsulfonyl)-1-(4-
methylphenyl)ethene (3be)
The title compound was obtained as white solid (91.1 mg,
76%). mp 119−121 °C; nmax (CHCl3) 3022, 1669, 1591, 1491,
1326 cm-1; H NMR (270 MHz, CDCl3) δ 7.60–7.55 (2H, m,
1
ArH), 7.34 (1H, s, =CHSO2), 7.14–7.01 (6H, m, ArH), 2.35 (3H,
s, Me); 13C NMR (67.5 MHz, CDCl3) δ 165.5 (d, J(C, F) 255.6
1
3
Hz), 140.6, 140.4, 136.7, 136.2, 130.7 (d, J(C, F) 10.2 Hz), 128.6,
127.7, 116.1 (d, J(C, F) 23.1 Hz, d), 115.5, 21.4.; Anal. Calcd for
C15H12FIO2S required C, 44.79; H, 3.01%. Found: C, 44.83; H,
2.94
2
4.2 Typical procedure for cobalt-catalyzed iodosulfonylation of
alkynes:
Synthesis
of
(E)-1-iodo-2-phenylsulfonyl-1-(4-
methylphenyl)ethene (3ba) (Table 2, entry 1).
4.2.6.(E)-1-Iodo-2-(1-naphtylphenylsulfonyl)-1-(4-
methylphenyl)ethene (3bf)
4.2.1.(E)-1-iodo-2-phenylsulfonyl-1-(4-methylphenyl)ethene
The title compound was obtained as white solid (100.1 mg,
77%). Pale yellow oil; nmax (CHCl3) 3020, 1607, 1593, 1504,
(3ba).
1
1315, 1215 cm-1; H NMR (270 MHz, CDCl3) δ 8.48 (1H, d, J
A mixture of 4-methylphenyl acetylene (34.8 mg, 0.3 mmol),
sodium benzenesulfinate (54.2 mg, 0.33 mmol), KI (54.2 mg,
0.33 mmol), CoBr2 (3.3 mg, 0.015 mmol) and PhenꢀH2O (3.0 mg,
0.015 mmol) in AcOH (0.3 mL) was stirred at 100 °C for 18 h in
air. After the residue was dissolved in Et2O, the solution was
washed with H2O and saturated sodium chloride and dried over
anhydrous magnesium sulfate. Chromatography on silica gel
(20% diethyl ether / hexane) gave (E)-1-iodo-2-phenylsulfonyl-1-
(4-methylphenyl)ethene (3ba) (94.7 mg, 82%): pale yellow oil;
8.6 Hz, , ArH), 7.98 (1H, d, J 8.2 Hz, , ArH), 7.91 (1H, d, J 7.9
Hz, , ArH), 7.84 (1H, dd, J 7.2, 1.0 Hz, ArH), 7.72–7.56 (2H, m,
ArH), 7.50–7.49 (1H, m, ArH), 7.33–7.25 (1H, m, ArH), 6.96
(4H, s, ArH), 2.30 (3H, s, Me); 13C NMR (67.5 MHz, CDCl3) δ
140.6, 140.2, 136.5, 134.9, 134.8, 133.9, 130.2, 128.9, 128.5,
128.4, 127.7, 126.9, 124.3, 124.0, 114.8, 21.4.; Anal. Calcd for
C19H15IO2S required C, 52.55; H, 3.48%. Found: C, 52.67; H,
3.44
nmax (CHCl3) 3039, 1584, 1503, 1446, 1318 cm-1; H NMR (270
1
4.2.7.(E)-1-Iodo-2-methylsulfonyl-1-(4-methylphenyl)ethene
(3bg)
MHz, CDCl3) δ 7.62–7.52 (3H, m, ArH), 7.42–7.36 (2H, m,
ArH), 7.33 (1H, s, =CHSO2), 7.16–7.06 (4H, m, ArH), 2.35 (3H,
s, Me); 13C NMR (67.5 MHz, CDCl3) δ 140.5, 140.3, 140.2,
136.8, 136.6, 133.4, 128.9, 128.6, 127.8, 115.3, 21.4.; Anal.
Calcd for C15H13IO2S required C, 46.89; H, 3.41%. Found: C,
46.63; H, 3.44.
The title compound was obtained as white solid (77.2 mg,
80%). mp 129−130 °C; nmax (CHCl3) 3020, 1588, 1320, 1218 cm-
1
1; H NMR (270 MHz, CDCl3) δ 7.38 (2H, d, J 8.2 Hz, ArH),
7.27 (1H, s, =CHSO2), 7.20 (2H, d, J 8.2 Hz, ArH), 2.66 (3H, s,
Me), 2.37 (3H, s, Me); 13C NMR (67.5 MHz, CDCl3) δ 140.9,
139.8, 136.5, 128.9, 127.9, 115.5, 42.9, 21.4.; Anal. Calcd for
C10H11IO2S required C, 37.28; H, 3.44%. Found: C, 37.37; H,
3.57
4.2.2.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(4-
methylphenyl)ethene (3bb)11b
The title compound was obtained as white solid (102.6 mg,
86%). mp 107−109 °C; nmax (CHCl3) 3019, 1596, 1503, 1326 cm-
1
1; H NMR (270 MHz, CDCl3) δ 7.50 (2H, d, J 8.2 Hz, ArH),
4.2.8.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-phenylethene
(3ab)9c,10c,11b-c
7.30 (1H, s, =CHSO2), 7.21–7.07 (6H, m, ArH), 2.39 (3H, s, Me),
2.09 (3H, s, Me); 13C NMR (67.5 MHz, CDCl3) δ 144.5, 140.6,
140.1, 137.4, 136.8, 129.6, 128.5, 127.8, 127.7, 114.7, 21.6,

6
Tetrahedron
The title compound was obtained as white solid (78.1 mg,
Calcd for C15H12FIO2S required C, 44.79; H, 3.01%. Found: C,
ACCEPTED MANUSCRIP
T
68%). mp 81−83 °C; nmax (CHCl3) 3020, 1598, 1586, 1325 cm-1;
1H NMR (270 MHz, CDCl3) δ 7.46 (2H, d, J 8.2 Hz, ArH), 7.36
45.06; H, 2.95
4.2.14.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(2-
methylphenyl)ethene (3fb)
(1H, s, =CHSO2), 7.32−7.17 (7H, m, ArH), 2.39 (3H, s, Me); 13
C
NMR (67.5 MHz, CDCl3) δ 144.5, 141.2, 139.6, 137.3, 129.7,
129.6, 127.9, 127.8, 127.7, 114.1, 21.6.; Anal. Calcd for
C15H13IO2S required C, 46.89; H, 3.41%. Found: C, 46.93; H,
3.39
The title compound was obtained as yellow oil (95.3 mg,
80%).; nmax (CHCl3) 3042, 2921, 1594, 1480, 1454, 1326 cm-1;
1H NMR (270 MHz, CDCl3) δ 7.41 (1H, s, =CHSO2), 7.38 (2H, d,
J 6.3 Hz, ArH), 7.25–7.16 (4H, m, ArH), 7.08 (1H, t, J 7.6 Hz,
ArH), 6.94 (1H, d, J 7.6 Hz, ArH), 2.40 (3H, s, Me), 2.03 (3H, s,
Me); 13C NMR (67.5 MHz, CDCl3) δ 144.6, 141.9, 138.7, 137.0,
134.5, 130.3, 129.6, 127.9, 126.7, 125.4, 114.0, 21.6, 19.3.; Anal.
Calcd for C16H15IO2S required C, 48.25; H, 3.80%. Found: C,
47.96; H, 3.67
4.2.9.(E)-1-Iodo-2-(4-N-acetylaminophenylsulfonyl)-1-
phenylethene (3ai)
The title compound was obtained as pale yellow solid (50.7
mg, 38%). mp 57−59 °C; nmax (CHCl3) 3349, 301, 1694, 1590,
1530, 1402, 1323 cm-1; H NMR (270 MHz, CDCl3) δ 7.76 (1H,
1
brs, NH), 7.51−7.44 (4H, m, ArH), 7.38−7.23 (6H, m, ArH and
=CHSO2), 2.17 (3H, s, Me); 13C NMR (67.5 MHz, CDCl3) δ
168.8, 142.8, 140.9, 139.6, 134.4, 129.9, 129.1, 127.9, 127.6,
119.1, 114.6, 24.7.; Anal. Calcd for C16H14INO3S required C,
44.98; H, 3.30%. Found: C, 44.87; H, 3.31
4.2.15.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(1-
cyclohexenyl)ethene (3gb)
The title compound was obtained as white solid (69.1 mg,
59%).; nmax (CHCl3) 3021, 2937, 1596, 1433, 1319 cm-1; 1H
NMR (270 MHz, CDCl3) δ 7.72 (2H, d, J 8.2 Hz, ArH), 7.33 (2H,
d, J 8.2 Hz, ArH), 7.04 (1H, s, =CHSO2), 5.89–5.86 (1H, m,
CH=C), 2.44 (3H, s, Me), 2.00–1.95 (4H, m, CH2), 1.55–1.51
(4H, m, CH2); 13C NMR (67.5 MHz, CDCl3) δ 144.5, 139.2,
138.2, 137.7, 129.9, 129.7, 127.9, 121.0, 27.1, 25.2, 21.6, 21.5,
21.0.; Anal. Calcd for C15H17IO2S required C, 46.40; H, 4.41%.
Found: C, 46.30; H, 4.47
4.2.10.(E)-1-Iodo-2-(4-fluorophenylsulfonyl)-1-phenylethene
(3ae)
The title compound was obtained as white solid (96.4 mg,
83%). mp 86−88 °C; nmax (CHCl3) 3020, 1590, 1490, 1325, 1217
1
cm-1; H NMR (270 MHz, CDCl3) δ 7.56–7.51 (2H, m, ArH),
7.39 (1H, s, =CHSO2), 7.32–7.25 (3H, m, ArH), 7.24–7.17 (2H,
m, ArH), 7.06–6.99 (2H, m, ArH); 13C NMR (67.5 MHz, CDCl3)
δ 165.5 (d, 1J(C, F) 255.6 Hz), 141.2, 139.4, 136.2, 130.7 (d, 3J(C, F)
4.2.16.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-phenylpropene
(3hb)9c,11c
2
10.2 Hz), 129.9, 127.9, 127.6, 116.2 (d, J(C, F) 22.4 Hz), 114.9.;
Anal. Calcd for C14H10FIO2S required C, 43.32; H, 2.60%.
Found: C, 43.23; H, 2.76
The title compound was obtained as white solid (85.1 mg,
71%). mp 133−135 °C.; nmax (CHCl3) 3020, 1616, 1593, 1443,
1
1320 cm-1; H NMR (270 MHz, CDCl3) δ 7.39 (2H, d, J 8.2 Hz,
4.2.11.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(4-
ArH), 7.26–7.08 (7H, m, ArH), 2.50 (3H, s, Me), 2.38 (3H, s,
Me); 13C NMR (67.5 MHz, CDCl3) δ 144.1, 143.9, 142.9, 137.3,
129.5, 128.6, 127.7, 127.6, 127.5, 115.7, 27.0, 21.6.; Anal. Calcd
for C16H15IO2S required C, 48.25; H, 3.80%. Found: C, 48.44; H,
3.85
methoxyphenyl)ethene (3cb)11c
The title compound was obtained as white solid (87.5 mg,
71%). mp 114−115 °C; nmax (CHCl3) 3020, 1670, 1599, 1323,
1265 cm-1; 1H NMR (270 MHz, CDCl3) δ 7.50 (2H, d, J 8.2 Hz,
ArH), 7.29 (1H, s, =CHSO2), 7.26–7.19 (4H, m, ArH), 6.80 (2H,
d, J 8.2 Hz, ArH), 3.82 (3H, s, OMe), 2.39 (3H, s, Me); 13C NMR
(67.5 MHz, CDCl3) δ 160.8, 144.5, 140.2, 137.5, 131.8, 129.9,
129.6, 127.8, 114.9, 113.2, 55.4, 21.6.; Anal. Calcd for
C16H15IO3S required C, 46.39; H, 3.65%. Found: C, 46.11; H,
3.68
4.2.17.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-phenylbutene
(3ib)
The title compound was obtained as white solid (96.1 mg,
80%). mp 114−115 °C.; nmax (CHCl3) 3020, 1596, 1443, 1312
cm-1; 1H NMR (270 MHz, CDCl3) δ 7.27 (2H, d, J 8.2 Hz, ArH),
7.17–7.12 (3H, m, ArH), 7.07 (2H, d, J 8.2 Hz, ArH), 7.09–6.99
(2H, m, ArH), 2.95 (2H, q, J 7.7 Hz, CH2), 2.35 (3H, s, Me), 1.31
(3H, t, J 7.7 Hz, CH2Me); 13C NMR (67.5 MHz, CDCl3) δ 149.7,
143.7, 142.7, 137.7, 129.3, 128.4, 127.7, 127.6, 127.5, 114.8,
33.4, 21.5, 12.7.; Anal. Calcd for C17H17IO2S required C, 49.52;
H, 4.16%. Found: C, 49.59; H, 4.10
4.2.12.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(4-
phenylphenyl)ethene (3db)
The title compound was obtained as pale yellow solid (101.2
mg, 73%). mp 154−156 °C; nmax (CHCl3) 3020, 1597, 1485, 1323
cm-1; 1H NMR (270 MHz, CDCl3) δ 7.58 (2H, d, J 7.6 Hz, ArH),
7.50–7.38 (8H, m, ArH and =CHSO2), 7.31 (2H, d, J 8.5 Hz,
ArH), 7.17 (2H, d, J 7.6 Hz, ArH), 2.37 (3H, s, Me); 13C NMR
(67.5 MHz, CDCl3) δ 144.5, 142.6, 141.3, 139.9, 138.4, 137.2,
129.6, 128.9, 128.3, 127.9, 127.8, 127.1, 126.5, 113.9, 21.6.;
Anal. Calcd for C21H17IO2S required C, 54.79; H, 3.72%. Found:
C, 54.7; H, 3.71
4.2.18.(E)-3-Acetoxy-1-iodo-2-(4-methylphenylsulfonyl)-1-
phenylpropene (3jb)
The title compound was obtained as white solid (82.1 mg,
60%). mp 165−166 °C; nmax (CHCl3) 3020, 1743, 1596, 1443,
1
1320 cm-1; H NMR (270 MHz, CDCl3) δ 7.32–7.21 (5H, m,
ArH), 7.13–7.05 (4H, m, ArH), 5.30 (2H, s, CH2OAc), 2.38 (3H,
s, Me), 2.11 (3H, s, COMe); 13C NMR (67.5 MHz, CDCl3) δ
170.2, 144.3, 143.6, 142.1, 137.2, 129.3, 129.2, 127.9, 127.6,
127.3, 123.5, 68.9, 21.6, 20.6.; Anal. Calcd for C18H17IO4S
required C, 47.38; H, 3.76%. Found: C, 49.98; H, 3.74
4.2.13.(E)-1-Iodo-2-(4-methylphenylsulfonyl)-1-(4-
fluorophenyl)ethene (3eb)11c
The title compound was obtained as white solid (95.0 mg,
79%). mp 92−94 °C; nmax (CHCl3) 3020, 1597, 1501, 1325 cm-1;
1H NMR (270 MHz, CDCl3) δ 7.49 (2H, d, J 8.2 Hz, ArH), 7.35
(1H, s, =CHSO2), 7.28–7.23 (4H, m, ArH), 7.01–6.95 (2H, m,
ArH), 2.40 (3H, s, Me); 13C NMR (67.5 MHz, CDCl3) δ 143.7 (d,
4.3 Typical procedure for cobalt-catalyzed iodosulfonylation of
alkynes: Synthesis of (E)-1,2-diiodo-1-phenylethene (4a) (Table 3,
entry 1).
4.3.1. (E)-1,2-diiodo-1-phenylethene (4a)16a,b
3
1J(C, F) 214.2 Hz), 137.2, 135.6, 129.9, 130.0 (d, J(C, F) 9.4 Hz),
129.7, 127.8, 127.6, 115.0 (d, 2J(C, F) 21.7 Hz), 112.5, 21.6.; Anal.

7
A mixture of 4-methylphenyl acetylene (34.8 mg, 0.3 mmol),
92.9, 50.8, 40.4, 30.5, 27.9, 22.5, 14.0.; Anal. Calcd for C8H14I2
required C, 26.40; H, 3.88%. Found: C, 26.78; H, 3.85
ACCEPTED MANUSCRIPT
KI (104.6 mg, 0.63 mmol), CoBr2 (3.3 mg, 0.015 mmol) and
PhenꢀH2O (3.0 mg, 0.015 mmol) in AcOH (0.3 mL) was stirred at
100 °C for 18 h in air. After the residue was dissolved in Et2O,
the solution was washed with H2O and saturated sodium chloride
and dried over anhydrous magnesium sulfate. Chromatography
on silica gel (20% diethyl ether / hexane) gave (E)-1,2-diiodo-1-
phenylethene (4a) (76.5 mg, 72%)16a: white solid; mp 75−76 °C;
Supplementary data
Supplementary data related to this article can be found at
http:// xxxxxxxx.
1
nmax (CHCl3) 3067, 3018, 1484, 1442 cm-1; H NMR (270 MHz,
CDCl3) δ 7.37–7.33 (5H, m, ArH), 7.26 (1H, s, =CHI); 13C NMR
(67.5 MHz, CDCl3) δ 143.1, 128.9, 128.5, 128.4, 96.1, 80.8.;
Anal. Calcd for C8H6I2 required C, 27.00; H, 1.70%. Found: C,
27.02; H, 1.76.
References and Notes
1. Selected reviews: (a) Fang, Y.; Luo, Z.; Xu, X. RSC advances
2016, 6, 59661‒59676. (b) Baird, C. P.; Rayner, C. M. J. Chem.
Soc. Perkin Trans. 1 1998, 1973‒2003. (c) Payner, C. M.
Contemporary Organic Synthesis 1995, 2, 499‒533. (d)
Comprehensive Organic Functional Group Transformations;
Kartritzky, A., Meth-Cohn, O., Rees, C. W. Eds.; Pergamon Press
Ltd.: Cambrige UK, 1995, Vol. 2.
4.3.2. (E)-1,2-Diiodo-1-(4-methylphenyl)ethene (4b)16a
The title compound was obtained as colorless oil (78.1 mg, 70%);
1
nmax (CHCl3) 2925, 2856, 1464, 1374, 1055 cm-1; H NMR (270
MHz, CDCl3) δ 7.27 (2H, d, J 8.2 Hz, ArH), 7.21 (1H, s, =CHI),
7.16 (2H, d, J 8.2 Hz, ArH), 2.35 (3H, s, Me); 13C NMR (67.5
MHz, CDCl3) δ 140.1, 139.0, 129.1, 128.4, 96.6, 80.2, 21.4.;
Anal. Calcd for C9H8I2 required C, 29.22; H, 2.18%. Found: C,
29.32; H, 2.18
2. Selected reviews: (a) Perlmutter, P.; Conjugate Addition Reactions
in Organic Synthesis; Baldwin, J. L., Magnus, F. P. D. Eds.;
Pergamon Press: Oxford, 1992. (b) Organosulfur Chemistry; Page,
P. Eds.; Academic Press: San Diego, 1995.
3. Selected articles: (a) Back, T. G.; Collins, S.; Low, K.-W.
Tetrahedron Lett. 1984, 25, 1689‒1692. (b) Rokade, B. V.;
Prabhu, K. R. J. Org. Chem. 2014, 79, 8110‒8117. (c) Jiang, Q.;
Xu, B.; Zhao, A.; Zhoo, Y.-R.; Li, Y.-Y.; He, N.; Guo, C.-C. J.
Org. Chem. 2014, 79, 7372‒7379. (d) Xiao, F.; Chen, H.; Xie, H;
Chen, S.; Yang, L.; Deng, G.-J. Org. Lett. 2014, 16, 50‒53. (e)
Truce, E. W.; Goralski, C. T. J. Org. Chem. 1971, 36, 2536‒2538.
(f) Sinnreich, J.; Asscher, M. J. Chem. Soc. Perkin Trans. 1 1972,
1543‒1545. (g) Mochizuki, T.; Hayakawa, S.; Narasaka, K. Bull.
Chem. Soc. Jpn. 1996, 69, 2317‒2325. (h) Wang, D.; Zhang, R.;
Li, S.; Yan, Z.; Guo, S. Synlett 2016, 27, 2003‒2008.
4. Posner, G. H.; Brunelle, D. J. J. Org. Chem. 1972, 37, 3547−3549.
5. Hoogenboom, B. E.; El-Faghi, M. S.; Fink, S. C.; Ihring, P. J.;
Langsjoen, A. N.; Linn, C. J.; Maehling, K. L. J. Org. Chem.
1975, 40, 880‒883.
4.3.3. (E)-1,2-Diiodo-1-(4-fluorophenyl)ethene (4c)
The title compound was obtained as colorless oil (78.8 mg,
70%); nmax (CHCl3) 3064, 1601, 1499, 1232, 1157 cm-1; 1H NMR
(270 MHz, CDCl3) δ 7.38–7.33 (2H, m, ArH), 7.33 (1H, s,
=CHI), 7.08–7.02 (2H, m, ArH); 13C NMR (67.5 MHz, CDCl3) δ
162.9 (d, 1J(C, F) 248.8 Hz), 139.1 (d, 4J(C, F) 3.4 Hz), 130.6 (d, 3J(C,
2
8.8 Hz), 115.5 (d, J(C, F) 21.7 Hz), 94.8, 81.5.; Anal. Calcd for
F)
C8H5I2 required C, 25.70; H, 1.35%. Found: C, 25.56; H, 1.43
4.3.4. (E)-1,2-Diiodo-1-phenylpropene (4d)16a
The title compound was obtained as colorless oil (80.2 mg,
72%).; nmax (CHCl3) 3019, 1488, 1441 cm-1; 1H NMR (270 MHz,
CDCl3) δ 7.35–7.20 (5H, m, ArH), 2.80 (3H, s, Me); 13C NMR
(67.5 MHz, CDCl3) δ 148.1, 128.4, 128.3, 128.2, 96.3, 95.4,
40.2.; Anal. Calcd for C9H8I2 required C, 29.22; H, 2.18%.
Found: C, 29.52; H, 2.10
6. Bäckvall, J. –E.; Ericsson, A. J. Org. Chem. 1994, 59, 5850−5851.
7. (a) Ochiai, M.; Kitagawa, Y.; Toyonari, M.; Uemura, K.; Oshima,
K.; Shiro, M. J. Org. Chem. 1997, 62, 8001−8008. (b) Benarti, L.;
Montevecchi, P. C.; Spagnolo, P. J. Chem. Soc. Perkin Trans. 1
1995, 1035‒1038.
8. (a) Beletskaya, I. P.; Ananikov, V. P.; Chem. Rev., 2011, 111,
1596–1636. (b) Cacchi, S.; Fabrizi, G.; Goggiamani, A.; Parisi, L.
M.; Bernini, R. J. Org. Chem. 2004, 69, 5608−5614. (c) Battace,
A.; Zair, T.; Doucet, H.; Santelli, M. Synthesis 2006, 3495−3505.
(d) Bian, M.; Xu, F.; Ma, C. Synthesis 2007, 2951−2956.
9. (a) Taniguchi, N. Synlett 2011, 1308‒1312. (b) Taniguchi, N.
Synlett 2012, 1245‒1249. (c) Taniguchi, N. Tetrahedron 2014, 70,
1984‒1990.
10. Cu-catalyzed reactions: (a) Amiel, Y. J. Org. Chem. 1971, 36,
3691‒3692. (b) Amiel, Y. J. Org. Chem. 1971, 36, 3697-3702. (c)
Truce, W. E.; Wolf, G. C. J. Org. Chem. 1971, 36, 1727‒1732.
Fe-catalyzed reactions: (d) Xiaoming, Z.; Laurean, I.; Nakamura,
E. Org. Lett. 2012, 14, 954-956. (e) Li, X.; Shi, X.; Fang, M.; Xu,
X. J. Org. Chem. 2013, 78, 9499‒9504. (f) Iwasaki, M.; Fujii, T.;
Nakajima, K.; Nishihara, Y. Angew. Chem. Int. Ed. 2014, 53,
13880‒13884.
11. (a) Gao, Y.; Wu, W.; Huang, Y.; Huang, K.; Jiang, H. Org. Chem.
Front. 2014, 1, 361‒364. (b) Nair, V.; Augustine, A.; Suja, T. D.;
Synthesis 2002, 2259‒2265. (c) Sun, Y.; Abdukader, A.; Lu, D.;
Zhang, H.; Liu, C. Green Chem. 2017, 19, 1255‒1258.
12. Taniguchi, N. J. Org. Chem. 2015, 80, 7797‒7802.
13. Numata, N.; Watanabe, Y.; Oae, S. Tetrahedron Lett. 1978, 4933‒
4936.
4.3.4. (E)-1,2-Diiodo-1-hexene (4e)
The title compound was obtained as colorless oil (62.5 mg,
62%).; nmax (neat) 3069, 2955, 2869, 1463, 1378, 1204, 1108 cm-
1; 1H NMR (270 MHz, CDCl3) δ 6.80 (1H, s, =CHI), 2.51 (2H, t,
J 7.4 Hz, =CICH2), 1.58–1.44 (2H, m, CH2), 1.41–1.30 (2H, m,
CH2), 0.95 (3H, t, J 7.1 Hz, CH2Me); 13C NMR (67.5 MHz,
CDCl3) δ 104.4, 78.9, 44.4, 30.3, 21.4, 14.0.; Anal. Calcd for
C6H10I2 required C, 21.45; H, 3.00%. Found: C, 21.38; H, 3.02
4.3.5. (E)-1,2-Diiodo-1-octene (4f)
The title compound was obtained as colorless oil (79.7 mg,
1
73%).; nmax (neat) 3070, 2926, 2855, 1464, 1214, 1114 cm-1; H
NMR (270 MHz, CDCl3) δ 6.80 (1H, s, =CHI), 2.50 (2H, t, J 7.2
Hz, =CICH2), 1.56–1.49 (2H, m, CH2), 1.37–1.31 (6H, m, CH2),
0.90 (3H, t, J 6.8 Hz, CH2Me); 13C NMR (67.5 MHz, CDCl3) δ
104.5, 78.9, 44.7, 31.6, 28.1, 27.8, 22.5, 14.1.; Anal. Calcd for
C8H14I2 required C, 26.40; H, 3.88%. Found: C, 26.63; H, 3.77
14. The procedure could not produce alkenyl sulfones or alkenyl
iodides. (a) Meesin, J.; Katrum, P.; Pareseecharone, C.;
Pohmakotr, M.; Reutrakul, V.; Soorukram, D.; Kuhakan, C. J.
Org. Chem. 2016, 61, 2744‒2752.
15. These (E)-iodoalkenyl sulfones and (Z)-alkenyl sulfones were
prepared according to reported paper. (a) Taniguchi, N.
Tetrahedron 2009, 65, 2782‒2790. (b) Zask, A. Helguist, P. J.
Org. Chem. 1978, 43, 1619‒1620.
4.3.6. (E)-2,3-Diiodo-2-octene (4g)
The title compound was obtained as colorless oil (81.8 mg,
1
75%).; nmax (neat) 3062, 2917, 1607, 1500, 1150 cm-1; H NMR
(270 MHz, CDCl3) δ 2.66 (2H, t, J 7.6 Hz, =CICH2), 2.61 (3H, s,
=CIMe), 1.58–1.52 (2H, m, CH2), 1.37–1.30 (4H, m, CH2), 0.92
(3H, t, J 6.9 Hz, CH2Me); 13C NMR (67.5 MHz, CDCl3) δ 130.1,
16. (a) Jiang, Q.; Wang, J.-Y.; Guo, C.-C. Synthesis 2015, 47, 2081‒
2087. (b) Li, J.-H.; Xie, Y.-X.: Yin, D.-L.; Jiang, H.-F. Chin. J.
Org. Chem. 2003, 21, 714‒716.

8
Tetrahedron
17. Hollins, R. A.; Campos, M. P. A. J. Org. Chem. 1979, 44, 3931‒
20. (a) Truce, E. W.; Goralski, C. T. J. Org. Chem. 1971, 36, 2536‒
ACCEPTED MANUSCRIPT
3934.
2538. (b) Amiel, Y. J. Org. Chem. 1974, 39, 3867-3870.
21. (a) Kopchik, R. M.; Kampmeier, J. A. J. Am. Chem. Soc. 1966, 88,
5219-5222. (b) Kampemeier, J. A.; Chen, G. J. Am. Chem. Soc.
1965, 87, 2608-2613.
18. Kochi, J. K.; Organometallic Mechanisms And Catalysis;
Academic Press: San Diego, 1978.
19. (a) Caddick, S.; Hamza, D.; Wadman, S. N. Tetrahedron Lett.
1999, 40, 7285‒7288. (b) Edwards, G. L.; Muldoon, C. A.;
Sinclar, D. J. Tetrahedron 1996, 52, 7779‒7788.