Aqueous DMSO mediated conversion of (2-(arylsulfonyl)vinyl)iodonium salts to aldehydes and vinyl chlorides

Article abstract of DOI:10.3390/molecules21081073

Vinyl(aryl)iodonium salts are useful compounds in organic synthesis but they are under-utilized and their chemistry is under-developed. Herein is described the solvolysis of some vinyl(phenyl)iodonium salts, bearing an arylsulfonyl group, in aqueous DMSO

Full text of DOI:10.3390/molecules21081073

molecules
Article
Aqueous DMSO Mediated Conversion of
(2-(Arylsulfonyl)vinyl)iodonium Salts to Aldehydes
and Vinyl Chlorides
Eman Zawia and Wesley J. Moran *
Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK;
eman.zawia@hud.ac.uk
* Correspondence: w.j.moran@hud.ac.uk; Tel.: +44-1484-473741
Academic Editor: Derek J. McPhee
Received: 20 July 2016; Accepted: 6 August 2016; Published: 16 August 2016
Abstract: Vinyl(aryl)iodonium salts are useful compounds in organic synthesis but they are
under-utilized and their chemistry is under-developed. Herein is described the solvolysis of some
vinyl(phenyl)iodonium salts, bearing an arylsulfonyl group, in aqueous DMSO leading to aldehyde
formation. This unusual process is selective and operates under ambient conditions. Furthermore,
the addition of aqueous HCl and DMSO to these vinyl(aryl)iodonium salts allows their facile
conversion to vinyl chlorides.
Keywords: hypervalent iodine; iodonium salt; solvolysis; substitution
1. Introduction
Hypervalent iodine chemistry has received considerable attention in recent years, particularly
in the area of small molecule synthesis [
iodine reagents, their low toxicity and the ability to effect useful, novel synthetic transformations.
Iodonium salts are iodine(III) species (also known as
3-iodanes) with two carbon ligands and
one non-carbon ligand [ ]. These compounds are of increasing importance in synthesis, however,
the majority of reported research in this area deals with the utility of diaryliodonium salts [ ].
1–3]. Reasons for this include the ease-of-use of hypervalent
λ
4
5
Alkenyl(aryl)iodonium salts are also useful reagents in synthesis, but their chemistry is relatively
underdeveloped [6,7].
Alkenyl(aryl)iodonium salts are readily prepared from vinyl metal compounds, including silanes [
stannanes [ ], boronates/boronic acids [10], and zirconiums [11], by metal-iodine(III) exchange and
from alkynyl(aryl)iodonium salts by conjugate addition of nucleophiles under protic conditions [12,13]
Additionally, hypervalent iodine reagents are known to undergo addition reactions to alkynes to
generate alkenyl(aryl)iodonium salts [14 15]. These iodonium salts are reactive compounds due to the
8],
9
.
,
exquisite leaving group ability of the aryliodonium moiety coupled with its highly electron-withdrawing
nature [16]. Reactions with nucleophiles can proceed through either SNV1 pathways [17], i.e., via vinylic
cationic intermediates, or through SN2 mechanisms [18]. In the latter case, SNVσ and SNVπ mechanisms
are possible, leading to inversion or retention of configuration respectively.
One particular reaction of alkenyl(aryl)iodonium salts is solvolysis which has been shown
to occur in protic solvents such as methanol [19]. Typically, primary vinylic substrates require
elevated temperatures for complete conversion and several products are formed. For example,
◦
heating (Z)-2-phenyl-1-propenyl(phenyl)iodonium tetrafluoroborate
1
in methanol at 60 C leads
to the formation of three products in approximately equal yields (Scheme 1). Deuterium labelling
studies suggest that this process proceeds through phenyl-assisted loss of iodobenzene followed by
addition of solvent, 1,2-migration or loss of a proton. Further work demonstrated that the outcome of
this solvolysis process is dependent on the structure of the iodonium salt and the solvent used.
Molecules 2016, 21, 1073; doi:10.3390/molecules21081073
www.mdpi.com/journal/molecules

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Scheme 1. Solvolysis of (Z)-2-phenyl-1-propenyl(phenyl)iodonium tetrafluoroborate
at 60 C.
1 with MeOH
◦
Hinkle and co-workers studied the fragmentation of similar
β,β-disubstituted alkenyl(aryl)
iodonium triflates in methanol solution and observed similar results to the tetrafluoroborate salts [20].
They also observed decomposition of the iodonium triflates upon standing in CDCl3 at room
temperature over several hours. Okuyama and Ochiai reported the acetolysis of (E)-styryl- and
(E)-1-decenyl(phenyl)iodonium tetrafluoroborate at elevated temperature [21].
Another process that alkenyl(aryl)iodonium salts have been shown to undergo is conversion
to vinyl halides upon treatment with tetrabutylammonium halide in dichloromethane [22].
This transformation proceeds with retention of configuration.
During our studies on β-sulfone substituted alkenyl(phenyl)iodonium salts we noticed that
upon standing in wet deuterated DMSO, the water was slowly consumed and the iodonium salt was
converted into a new chemical entity. We decided to investigate this process.
2. Results and Discussion
We initiated our study with the preparation of a range of alkynyl(phenyl)iodonium
trifluoroacetates 2, which were prepared in one step from the terminal acetylenes following Carroll’s
method (Scheme 2) [23]. High yields were obtained in all cases and recrystallization provided
analytically pure samples, apart from 2e which appeared to be somewhat unstable. 2e was taken
forward to the next step immediately before further decomposition could occur.
Scheme 2. Preparation of alkynyl(phenyl)iodonium trifluoroacetates 2.

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These alkynyl(phenyl)iodonium trifluoroacetates
alkenyl(phenyl)iodonium tetrafluoroborates
2
were converted into a small family of
3
by mixing with aryl sulfinic acids in methanol
(Scheme 3). As expected, only one isomer of product was formed in these reactions. These iodonium
salts are completely stable in CDCl3 unlike those in Hinkle’s study [14]; possibly due to a stabilizing
interaction between the sulfone oxygen and the iodine(III) center. With these compounds in hand,
their reactivity in DMSO was investigated.
Scheme 3. Preparation of alkenyl(phenyl)iodonium tetrafluoroborates 3.
Iodonium salt 3aa was dissolved in anhydrous DMSO and no observable change occurred after
stirring overnight at room temperature (Table 1). However, when water was added to the solution the
iodonium salt was slowly consumed and aldehyde 4aa was formed along with unknown compounds
in ratios that changed with each repetition (entry 2). We varied the solvent but no conversion of 3aa
occurred in all cases (entries 3–6). We avoided the use of alcohol solvents because of the previous
studies highlighted above. Returning to the use of DMSO as solvent, we hypothesized that acidic or
basic conditions could have an effect on this process. In the event, the addition of 2 M NaOH solution
provided clean access to aldehyde 4aa (entry 7). Subsequently, we found that simply shaking the
reaction mixture with added water containing the aldehyde and unknown compounds led to complete
conversion to the aldehyde 4aa (entry 8). Presumably, the unknown compounds are intermediates
en route to 4aa and the increased agitation completes the solvolysis process. Performing the reaction
with added hydrochloric acid led to complete conversion to the vinyl chloride 5aa with retention of
stereochemistry (entry 9).
The scope of this solvolysis reaction was investigated and aldehydes
4 were immediately reduced
to the alcohols to facilitate isolation of analytically pure compounds (Scheme 4). In all cases, yields
6
of 60%–70% were obtained for the two steps. The tetrafluoroborate counterion is not critical to this
process as the triflate analog of 3aa underwent similarly facile hydrolysis. However, (E)-phenyl(styryl)-
and (E)-1-octen-1-yl(phenyl)iodonium tetrafluoroborate, vinyliodonium salts lacking the β-sulfone
moiety, were stable under these conditions and were returned unchanged.

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Table 1. Effect of solvent and additives on reactivity of iodonium salt 3aa.
Entry
Additive
Solvent
Conversion/% a
1
2
3
4
5
6
7
8
9
None
2 equiv. H2O
2 equiv. H2O
2 equiv. H2O
2 equiv. H2O
2 equiv. H2O
2 equiv. 2 M NaOH
2 equiv. H2O b
2 equiv. 2 M HCl
a
DMSO
DMSO
MeCN
MeNO2
EtOAc
Et2O
DMSO
DMSO
DMSO
0
100 (25%–75% 4aa)
0
0
0
0
100 (4aa)
100 (4aa)
100 (5aa)
Determined by 1H-NMR analysis; b With vigorous shaking.
Scheme 4. Conversion of iodonium salts 3 to aldehydes 4 and reduction to alcohols 6.
The conversion of the iodonium salts
3 to vinyl chlorides 5 was investigated next and excellent
yields were obtained in all cases (Scheme 5). Remarkably, this functional group conversion was complete
within 15 min at room temperature. But again, (E)-phenyl(styryl)- and (E)-1-octen-1-yl(phenyl)iodonium
tetrafluoroborate, vinyliodonium salts lacking the β-sulfone moiety, were stable under these conditions
and were returned unchanged. As detailed above, this transformation has already been demonstrated
using alternative conditions but we wished to determine whether DMSO was critical in our case
(as with the aldehyde conversion). In the event, attempting the chlorination with 2 M HCl in a range of
solvents, including dichloromethane, ethyl acetate, nitromethane, diethyl ether and acetonitrile, led to
low conversions (5%–40%) in all cases after stirring overnight.

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Scheme 5. One-pot conversion of iodonium salts 3 to vinyl chlorides 5.
It is clear that DMSO has properties that aid the degradation of vinyliodonium salts and care
should be taken that perfectly anhydrous solvent is used when this phenomenon is not desirable.
In summary, the solvolysis of alkenyl(phenyl)iodonium tetrafluoroborates containing a β-sulfone
moiety occurs readily in aqueous DMSO solution at room temperature leading to selective aldehyde
formation. Furthermore, the addition of aqueous HCl to the DMSO solution allows rapid vinyl chloride
formation. This particular decomposition of vinyliodonium salts is unprecedented and demonstrates
the unique properties of DMSO as a solvent.
3. Materials and Methods
3.1. General Information
All commercially available materials were used as received. 1H-NMR spectra were recorded
at 400 MHz and 13C-NMR spectra at 100 MHz. IR spectra were recorded with neat samples and
signals are labelled as strong (s), medium (m) or weak (w). HRMS were recorded in ESI mode and
only molecular masses are reported. 2a and 2b were prepared according to the method of Carroll
and co-workers and the data matched the literature values [23]. 3aa was prepared following Ochiai’s
protocol [14]. 6aa and 6ab are known compounds [24].
3.2. General Procedure for Alkynyl(phenyl)iodonium Trifluoroacetate 2 Formation: Preparation of
((4-Ethylphenyl)ethynyl)(phenyl)iodonium 2,2,2-trifluoroacetate 2c
Following Carroll’s procedure [23], trifluoroacetic acid (1.4 mL, 19 mmol, 2 equiv.) was added
drop◦wise to a stirred solution of diacetoxyiodobenzene (3 g, 9.3 mmol, 1 equiv.) in CH2Cl2 (60 mL) at
−
30 C. The mixture was stirred for 30 min, then warmed to room temperature and stirred for a further
hour. 1-Ethyl-4-ethynyl benzene (1.3 mL, 9.3 mmol, 1 equiv.) was added dropwise and the resulting
mixture was stirred in darkness at room temperature for 3.5 h. The solution was concentrated in vacuo
to around 30 mL then diethyl ether (20 mL) and petroleum ether (40 mL) were added which initiated
crystallization of the product. After cooling in a freezer (
dried in vacuo to provide 2c as a white crystalline solid (3.8 g, 93%). Melting point: 81–83 C. IR:
1656 (s), 1417 (m), 1124 (s), 989 (m), 720 (s) cm−1 1H-NMR:
. δ 1.22 (3H, t, J = 7.7 Hz), 2.67 (2H, q,
−
20 ◦C) for 48 h, the solid was filtered and
◦

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J = 7.6 Hz), 7.20 (2H, d, J = 8.1 Hz), 7.39 (2H, d, J = 8.1 Hz), 7.49 (2H, t, J = 7.9 Hz), 7.60 (1H, t, J = 7.5
Hz) 8.15 (2H, d, J = 8.0 Hz). 13C-NMR:
15.5, 29.3, 44.8, 105.0, 115.8 (1C, q, J = 292 Hz), 114.4, 117.3,
δ
117.7, 121.1, 128.6 (2C), 132.2, 132.4 (2C), 133.3 (2C), 133.7 (2C), 148.1, 162.9 (1C, q, J = 38 Hz). HRMS:
m/z calcd. for [M − OCOCF3]+ C18H18I+ 333.0135 found 333.0140.
((4-Butylphenyl)ethynyl)(phenyl)iodonium 2,2,2-trifluoroacetate, 2d: Melting point: 83–85 ◦C. IR: 1665 (s),
1
1417 (m), 1183 (s), 991.2 (m), 721 (s) cm−1. H-NMR:
δ 0.91 (3H, t, J = 7.3 Hz), 1.33 (2H, hex, J = 7.3 Hz),
1.57 (2H, pen, J = 7.7 Hz), 2.63 (2H, t, J = 7.6 Hz), 7.18 (2H, d, J = 7.9 Hz), 7.39 (2H, d, J = 7.9 Hz), 7.50
(2H, t, J = 7.9Hz), 7.60 (1H, t, J = 7.4 Hz), 8.16 (2H, d, J = 8.4 Hz). 13C-NMR:
14.2, 22.6, 33.6, 36.0,
44.9, 105.0, 115.7 (1C, q, J = 291 Hz), 117.7, 121.0, 129.1 (2C), 132.1 (2C), 132.1 (2C), 132.4, 133.1 (2C),
δ
133.6 (2C), 146.8, 162.9 (1C, q, J = 38 Hz). HRMS: m/z calcd. for [M
found 361.01463.
−
OCOCF3]+ C16H14I+ 361.448
([1,10-Biphenyl]-4-ylethynyl)(phenyl)iodonium 2,2,2-trifluoroacetate, 2e: This compound is unstable and
1
complete characterization could not be obtained. H-NMR:
δ (2H, d, J = 6.9 Hz), 7.33–7.61 (5H, m),
7.62–7.89 (5H, m), 8.17 (2H, d, J = 7.7 Hz). HRMS: m/z calcd. for [M
−
OCOCF3]+ C20H14I+ 381.0135
found 381.0132.
3.3. General Procedure for Alkenyl(phenyl)iodonium Tetrafluoroborate 3 Formation: Preparation of
(Z)-Phenyl(2-phenyl-2-tosylvinyl)iodonium Tetrafluoroborate, 3ab
Following Ochiai’s procedure [14], phenyl(phenylethynyl)iodonium trifluoroacetate (0.50 g,
1.2 mmol, 1 equiv.) dissolved in MeOH (5 mL) was added to a solution of 4-methylbenzene sulfinic
◦
acid (0.20 g, 1.3 mmol, 1.1 equiv.) in MeOH (2 mL) at 0 C under a N2 atmosphere. The reaction
mixture was stirred for 45 min then poured into saturated aqueous sodium tetrafluoroborate solution
(5 mL). A white precipitate was formed which was filtered off and washed with CH2Cl2 (2
×
8 mL).
The combined organic layers were washed with water, dried over magnesium sulfate, filtered and
concentrated in vacuo. The residue was a clear, colourless, viscous oil. A 1:1 mixture of diethyl
ether and petroleum ether (5 + 5 mL) was added to the residue, then the mixture was swirled and
the solvent removed by decantation. This was repeated until a white solid was formed. This crude
product was recrystallized from the minimum amount of CH2Cl2 with slow addition of petroleum
ether. (Z)-Phenyl(2-phenyl-2-tosylvinyl)iodonium tetrafluoroborate 3ab was isolated as a white
◦
microcrystalline solid (0.54 g, 83%). Melting point: 125–127 C. IR: 1535 (w), 1294 (m), 1135 (m),
1
1076 (s), 627 (s) cm−1. H-NMR:
δ
2.40 (3H, s), 7.28 (2H, d, J = 7.9 Hz), 7.36 (2H, t, J = 7.6 Hz), 7.40–7.49
22.5,
(3H, m), 7.63–7.73 (4H, m), 7.82 (1H, t, J = 7.6 Hz), 8.33 (1H, s), 8.40 (2H, d, J = 7.9 Hz). 13C-NMR:
δ
116.9, 117.1, 129.7 (2C), 129.9 (2C), 130.5 (2C), 131.7 (2C), 131.8 (2C), 133.1 (2C), 133.7, 134.1 (2C), 137.6,
146.9, 148.1. HRMS: m/z calcd. for [M − BF4]+ C21H18IO2S+ 461.0067 found 461.0079.
(Z)-(2-((2-Fluorophenyl)sulfonyl)-2-phenylvinyl)(phenyl)iodonium tetrafluoroborate, 3ac: Melting point:
1
186–188 ◦C. IR: 1597 (w), 1474 (m), 1317 (m), 1022 (m), 522 (s) cm−1. H-NMR:
δ 7.29–7.38 (4H, m),
7.40–7.46 (2H, t, m), 7.59 (1H, t, J = 9.6 Hz), 7.67 (2H, t, J = 7.8 Hz), 7.74–7.93 (3H, m), 8.40 (2H, d,
J = 7.8 Hz), 8.55 (1H, s). 13C-NMR:
δ
116.9, 118.4, 119.1 (1C, d, J = 20 Hz), 124.4 (1C, d, J = 13 Hz), 127.2,
130.1 (2C), 130.4 (2C), 131.3, 132.1 (1C, d, J = 5.4 Hz), 133.2 (2C), 134.2, 137.7 (2C), 140.5 (1C, d, J = 9.8 Hz),
146.6, 159.1, 161.6. HRMS: m/z calcd. for [M − BF4]+ C20H15FIO2S+ 464.9816 found 464.9826.
(Z)-Phenyl(2-phe◦nyl-2-((4-(trifluoromethyl)phenyl)sulfonyl)vinyl)iodonium tetrafluoroborate, 3ad: Melting
point: 184–186 C. IR: 1317 (s), 1129 (s), 1117 (m), 1059 (s), 641 (s) cm−1 1H-NMR:
. δ 7.29 (2H, d,
J = 7.8 Hz), 7.38 (2H, t, J = 7.6 Hz), 7.46 (1H, t, J = 7.6 Hz), 7.68 (2H, t, J = 7.8 Hz), 7.82 (1H, t, J = 7.4 Hz),
8.1 (4H, S), 8.39 (2H, d, J = 8.6 Hz), 8.50 (1H, s). 13C-NMR: 117.1, 119.2, 124.3 (1C, q, J = 274.2 Hz),
128.3 (1C, d, J = 3.3 Hz), 130.1 (2C), 130.7 (2C), 130.8 (2C), 131.3. 131.9, 133.0 (2C), 134.3 (2C), 136.1
(1C, q, J = 33 Hz), 137.6 (2C), 140.6, 145.8. HRMS: m/z calcd. for [M
found 514.9807.
−
BF4]+ C21H15F3IO2S+ 514.9784

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(Z)-(2-([1,10-Biphenyl]-4-ylsulfonyl)-2-phenylvinyl)(phenyl)iodonium tetrafluoroborate, 3ae: Melting point:
◦
1
162–164 C. IR: 1596 (w), 1484 (m), 1289 (m), 1050 (m), 674 (s) cm−1. H-NMR:
δ 7.33 (2H, d, J = 7.2 Hz),
7.38 (2H, t, J = 7.5 Hz), 7.42–7.58 (4H, m), 7.67 (2H, t, J = 7.9 Hz), 7.77 (2H, d, J = 7.8 Hz), 7.82 (1H,
t, J = 7.5 Hz), 7.88 (2H, d, J = 8.2 Hz), 7.96 (2H, d, J = 8.5 Hz), 8.39 (1H, s), 8.41(2H, d, J = 7.8 Hz).
13C-NMR:
δ 116.9, 117.7, 128.6 (2C), 129.1 (2C), 130.0 (2C), 130.4 (2C), 130.5 (2C), 130.6 (2C), 131.8
(2C), 131.9, 133.1, 134.1(2C), 135.3, 137.6(2C), 138.7, 146.7, 148.1. HRMS: m/z calcd. for [M
−
BF4]+
C26H20IO2S+ 523.0223 found 523.0236.
(Z)-(2-((5-Chlorothiophen-2-yl)sulfonyl)-2-phenylvinyl)(phenyl)iodonium tetrafluoroborate, 3af: Melting
◦
point: 187–189 C. IR: 1399 (w), 1310 (w), 639 (s), 628 (m), 523 (m) cm−1 1H-NMR:
. δ 7.35 (2H,
d, J = 7.6 Hz), 7.39–7.46 (3H, m), 7.51 (1H, t, J = 7.4 Hz), 7.65 (2H, t, J = 7.8 Hz), 7.73–7.83 (2H, m),
8.36 (3H, d, J = 9.4 Hz). 13C-NMR: 116.9, 117.2, 130.2 (2C), 130.9 (2C), 131.6, 131.9, 132.2, 133.2 (2C),
BF4]+ C18H13ClIO2S2 486.9085
+
134.2, 134.6, 137.6 (2C), 139.0, 142.4, 147.3. HRMS: m/z calcd. for [M
found 486.9091.
−
(Z)-Phenyl(2-(phenylsulfonyl)-2-(p-tolyl)vinyl)iodonium, 3ba: Melting point: 125–127 ◦C. IR: 1535 (m),
1
1303 (m), 1136 (m), 1059 (s), 651 (s) cm−1. H-NMR:
δ
2.26 (3H, s), 7.17 (4H, t, J = 6.9 Hz), 7.61–7.72 (4H,
22.07, 116.9, 128.9, 129.6 (2C),
m), 7.77–7.89 (4H, m), 8.29 (1H, S), 8.39 (2H, d, J = 7.8 Hz). 13C-NMR:
δ
130.4 (2C), 130.5 (2C), 131.2 (2C), 133.1(2C), 134.1, 136.8 (3C), 136.9, 137.6, 141.8, 146.7. HRMS: m/z
calcd for [M − BF4]+ C21H18IO2S+ 461.0067 found 461.0082.
(Z)-(2-(4-Ethylphenyl)-2-(phenylsulfonyl)vinyl)(phenyl)iodonium, 3ca: Melting point: 122–124 ◦C. IR: 1526
1
(m), 1299 (m), 1134 (m), 1060 (s), 620 (s) cm−1. H-NMR:
δ
1.10 (3H, t, J = 7.5 Hz), 2.56 (2H, q, J = 7.8 Hz),
7.20 (4H, s), 7.67 (4H, t, J = 7.6 Hz), 7.85–7.97 (4H, m), 8.31 (1H, S), 8.39 (2H, d, J = 3.8 Hz). 13C-NMR:
16.4, 29.1, 116.9, 117.0, 129.1, 129.3 (2C), 129.5 (2C), 130.5 (2C), 131.2 (2C), 133.1 (2C), 134.1, 136.7,
136.9, 137.6 (2C), 146.7, 147.9. HRMS: m/z calcd. for [M
BF4]+ C22H20IO2S+ 475.0223 found 475.0247.
δ
−
(Z)-(2-(4-Butylphenyl)-2-(phenylsulfonyl)vinyl)(phenyl)iodonium tetrafluoroborate, 3da: Melting point:
1
120–122 ◦C. IR: 1526 (m), 1293 (m), 1130 (s), 1048 (s), 569 (s) cm−1. H-NMR:
δ
0.84 (3H, t, J = 7.5 Hz),
1.21 (2H, hex, J = 7.5 Hz), 1.77 (2H, pen, J = 7.5 Hz), 2.49–2.55 (2H, m), 7.18 (4H, s), 7.66 (4H, q,
J = 7.2 Hz), 7.81 (4H, t, J = 8.6 Hz) 8.31 (1H, S), 8.39 (2H, d, J = 3.9 Hz). 13C-NMR:
δ
14.9, 22.7, 33.9, 35.6,
116.8, 116.9, 129.01, 129.5, 129.8 (2C), 130.4 (2C), 131.1 (2C), 133.03 (2C), 134.1, 136.7 (2C), 136.9, 137.6
(2C), 146.5, 146.7. HRMS: m/z calcd. for [M − BF4]+ C24H24IO2S+ 503.0536 found 503.0549.
◦
(Z)-(2-([1,10-Biphenyl]-4-yl)-2-(phenylsulfonyl)vinyl)(phenyl)iodonium, 3ea: Melting point: 164–166 C.
1
IR: 1501 (w), 1310 (m), 1132 (m), 1073 (m), 533 (s) cm−1. H-NMR:
δ 7.40 (3H, t, J = 8.5 Hz), 7.47 (2H, t,
J = 7.6 Hz), 7.62–7.73 (8H, m), 7.83 (2H, t, J = 7.2 Hz), 7.80 (2H, d, J = 7.8 Hz), 8.41 (3H, t, J = 7.3 Hz).
13C-NMR:
δ
117.0, 117.8, 127.9 (2C), 128.0 (2C), 129.5, 129.6 (2C), 130.3 (2C), 130.7, 131.13 (2C), 131.3
(2C), 131.9, 133.1 (2C), 134.1, 136.8, 137.1, 137.6, 139.7, 143.2, 146.3. HRMS: m/z calcd. for [M
−
BF4]+
C26H20IO2S+ 523.0223 found 523.0207.
3.4. General Procedure for Formation of Alcohols
(Z)-Phenyl(2-phenyl-2-(phenylsulfonyl)vinyl)iodonium tetrafluoroborate, 3aa (50 mg, 0.094 mmol,
1 equiv.) was dissolved in DMSO (0.5 mL) at room temperature. Deionized water (20 L) was added
and the mixture was stirred overnight. Water (2.5 mL) was added to the mixture and the solution was
shaken and then extracted with ethyl acetate (2 5 mL). The organic layer was dried with anhydrous
6: Preparation of 2-phenyl-2-(phenylsulfonyl)ethan-1-ol, 6aa
µ
×
magnesium sulfate, filtered and concentrated under vacuum. The crude product was dissolved in
methanol (2 mL) and LiBH4 (2 mg, 0.094 mmol, 1 equiv.) was added in one portion. The mixture was
stirred overnight and then extracted with diethyl ether (2
The residue was purified by flash chromatography (5:1 petrolem ether/EtOAc) which furnished 6aa as
a colorless oil (0.015 g, 61%). IR: 3521 (w), 2428 (s), 1235 (m), 567 (w) cm−1. H-NMR:
×
5 mL) and washed with water (5 mL).
1
δ
2.77 (OH, dd,
J = 8.7, 4.8 Hz), 4.16 (1H, ddd, J = 13, 8.7, 4.5 Hz), 4.38 (1H, dd, J = 7.9, 4.7 Hz), 4.66 (1H, ddd, J = 12, 7.9,
4.5 Hz), 7.06 (2H, d, J = 7.4 Hz), 7.22–7.30 (3H, m), 7.34 (1H, t, J = 7.4 Hz), 7.59–7.70 (4H, m). 13C-NMR:

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δ
61.5, 73.3, 126.1, 126.2, 129.2 (2C), 129.8 (2C), 129.9 (2C), 130.0 (2C), 130.6, 140.7. HRMS: m/z calcd.
for [M + H]+ C14H15O3S+ 263.0736 found 263.0701.
1
2-Phenyl-2-tosylethan-1-ol, 6ab: IR: 3521 (w), 2428 (s), 1235 (m), 567 (w) cm−1. H-NMR:
δ
2.40 (3H, s),
2.99 (OH, br), 4.08 (1H, ddd, J = 13, 7.8, 4.9 Hz), 4.33 (1H, dd, J = 8.2, 4.5 Hz), 4.61 (1H, t, J = 10 Hz),
7.03 (2H, d, J = 7.9 Hz ), 7.19 (2H, d, J = 7.4 Hz), 7.21–7.27 (2H, m), 7.38 (2H, d, J = 8.2 Hz). 13C-NMR:
δ
21.9, 61.7, 73.0, 128.9 (2C), 129.3 (2C), 129.4 (2C), 129.7 (2C), 129.9 (2C), 131.3, 134.0, 145.4. HRMS:
m/z calcd. for [M + H]+ C15H17O3S+ 277.0893 found 277.0876.
2-Phenyl-2-((4-(trifluoromethyl)phenyl)sulfonyl)ethan-1-ol, 6af: IR: 2359 (w), 1319 (s), 1172 (s), 712 (m)
1
cm−1. H-NMR:
δ 2.79 (OH, br), 4.16 (1H, d, J = 12 Hz), 4.38 (1H, dd, J = 7.9, 4.7 Hz), 4.66 (1H, dd,
J = 12, 7.9 Hz), 7.06 (2H, d, J = 7.5 Hz ), 7.27 (2H, t, J = 7.4 Hz), 7.34 (1H, t, J = 7.4 Hz), 7.61–7.70 (4H, m).
13C-NMR:
δ61.4, 73.3, 123.4 (1C, q, J = 271.4 Hz), 126.2 (1C, d, J = 3.4 Hz), 129.2 (2C), 129.8 (2C), 129.9
(2C), 130.0 (2C), 130.6, 135.7, 136.0, 140.8. HRMS: m/z calcd. for [M + NH4]+ C15H17F3NO3S+ 348.0876
found 348.0877.
2-([1,10-Biphenyl]-4-ylsulfonyl)-2-phenylethan-1-ol, 6ag: IR: 3565 (w), 2359 (s), 2250 (m), 650 (w) cm−1
1H-NMR:
2.92–3.00 (OH, m), 4.07–4.19 (1H, m), 4.39 (1H, dd, J = 8.3, 4.5 Hz), 4.61–4.71 (1H, m), 7.08
.
δ
(1H, d, J = 7.5 Hz), 7.26 (4H, t, J = 7.2 Hz), 7.33 (1H, t, J = 7.2 Hz), 7.38–7.52 (3H, m), 7.53–7.65 (5H, m).
13C-NMR: δ 61.7, 73.2, 127.6 (2C), 127.7 (2C), 129.0 (2C), 129.1, 129.4 (2C), 129.6, 129.9 (2C), 130.0 (2C),
131.2, 135.5, 139.2, 147.2. HRMS: m/z calcd. for [M + H]+ C20H22O3S+ 356.1315 found 356.1322.
−1
2-(4-Ethylphenyl)-2-(phenylsulfonyl)ethan-1-ol, 6ca: IR: 2561 (s), 1345 (m), 1227 (m), 1162 (s), 767 (m) cm
1H-NMR:
.
δ
1.19 (3H, t, J = 7.7 Hz), 2.61 (2H, q, J = 7.7 Hz), 2.91 (OH, dd, J = 9.0, 4.7 Hz), 4.09 (1H, ddd,
J = 13, 9, 5 Hz), 4.33 (1H, dd, J = 8.2, 4.3 Hz), 4.59 (1H, ddd, J = 12, 8.0, 4.0 Hz), 6.94 (2H, d, J = 8.1 Hz),
7.07 (2H, d, J = 7.8 Hz), 7.41 (2H, t, J = 7.8 Hz), 7.53 (2H, d, J = 7.6 Hz), 7.59 (1H, t, J = 7.4 Hz). 13C-NMR:
δ
15.8, 28.9, 61.7, 72.9, 128.2, 128.5 (2C), 129.1 (2C), 129.4 (2C), 129.8 (2C), 134.3 (2C), 137.1, 145.9. HRMS:
m/z calcd. for [M + NH4]+ C16H22NO3S+ 308.1315 found 308.1318.
2-(4-Butylphenyl)-2-(phenylsulfonyl)ethan-1-ol, 6da: IR: 2341 (s), 1446 (m), 1304 (m), 1142 (s), 687.6 (m)
1
cm−1. H-NMR:
δ 0.91 (3H, t, J = 7.3 Hz), 1.24–1.35 (2H, m), 1.54 (2H, pent, J = 7.4 Hz), 2.56 (2H, t,
J = 7.6 Hz), 2.99 (OH, br), 4.09 (1H, dd, J = 8.1, 4.4 Hz), 4.33 (1H, dd, J = 7.9, 4.6 Hz), 4.59 (1H, dd, J = 12,
8.1 Hz), 6.92 (2H, d, J = 7.9 Hz), 7.04 (2H, d, J = 7.4 Hz), 7.39 (2H, t, J = 7.8 Hz), 7.51 (2H, d, J = 3.8 Hz),
7.60 (1H, t, J = 7.4 Hz). 13C-NMR:
δ 14.2, 22.5, 33.7, 35.6, 61.6, 72.8 128.1, 129.0 (3C), 128.9, 129.4, 130.4,
129.7, 134.2, 137.1, 144.5. HRMS: m/z calcd. for [M + NH4]+ C18H26NO3S+ 336.1628 found 336.1630.
2-([1, 10-Biphenyl]-4-yl)-2-(phenylsulfonyl)ethan-1-ol, 6ea: IR: 3568 (w), 2358 (s), 2248 (m), 647 (w) cm−1
.
1H-NMR:
δ
4.1–4.2 (1H, m), 4.40 (1H, dd, J = 8.1, 4.5 Hz), 4.65 (1H, dd, J = 12, 8.1 Hz), 7.11 (2H, d,
J = 7.7 Hz), 7.37 (1H, t, J = 7.3 Hz), 7.40–7.51 (6H, m), 7.52–7.64 (5H, m). 13C-NMR:
δ
61.6, 72.8, 127.4
(2C), 127.6 (2C), 128.2, 129.2 (2C), 129.3 (2C), 129.4 (2C), 130.1 (2C), 130.4, 134.4, 137.2, 140.4, 142.4.
HRMS: m/z calcd. for [M + Na]+ C20H18NaO3S+ 361.0869 found 361.0869.
3.5. General Procedure for Formation of Vinyl Chlorides 5: Preparation of
(Z)-(2-Chloro-1-(phenylsulfonyl)vinyl)benzene, 5aa
(Z)-Phenyl(2-phenyl-2-(phenylsulfonyl)vinyl)iodonium tetrafluoroborate 3aa (0.050 g,
0.094 mmol) was dissolved in DMSO (0.5 mL) at room temperature. HCl (2 N, 50
added and the mixture was stirred for 15 min. Brine (5 mL) was added to the mixture and the solution
was shaken. This was extracted with ethyl acetate (2 10 mL) and washed with water (5 mL).
µL) was
×
The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated under
vacuum. The residue was purified by flash chromatography (20:1 petrolem ether/EtOAc) which
furnished 5aa as a colorless oil (0.026 g, 80%). IR: 1586 (w), 1444 (m), 1320 (m), 1147 (s), 628 (s) cm−1
.
1H-NMR:
t, J =7.8 Hz), 7.62 (1H, t, J = 7.4 Hz), 7.83 (2H, d, J = 7.6 Hz). 13C-NMR:
δ
6.73 (1H, s), 7.26 (2H, d, J = 7.3 Hz), 7.34 (2H, t, J = 7.2 Hz), 7.41 (1H, t, J = 7.2 Hz), 7.49 (2H,
128.7 (2C), 128.8 (2C), 129.2,
δ

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129.4 (2C), 130.0, 130.5, 133.2 (2C), 134.2, 140.5, 145.6. HRMS: m/z calcd. for [M + H]+ C14H11ClO2S+
279.0232 found 279.0241.
(Z)-1-((2-Chloro-1-phenylvinyl)sulfonyl)-4-methylbenzene, 5ab: IR: 1578 (m), 1443 (m), 1146 (s), 1083 (m),
754 (s) cm−1 1H-NMR:
. δ 2.42 (3H, s), 6.69 (1H, s), 7.26 (4H, d, J = 16 Hz), 7.33 (2H, t, J = 7.4 Hz),
7.35 (1H, t, J = 7.4 Hz), 7.70 (2H, d, J = 7.7 Hz). 13C-NMR:
δ 22.7, 128.7 (2C), 128.8, 128.9 (2C), 129.9
(3C), 130.5, 133.3 (2C), 137.5, 145.2, 145.7. HRMS: m/z calcd. for [M + H]+ C15H14ClO2S+ 293.0398
found 293.0390.
(Z)-1-((2-Chloro-1-phenylvinyl)sulfonyl)-2-fluorobenzene, 5ac: IR: 1599 (w), 1264 (m), 1146 (m), 1076 (s),
1
770 (m) cm−1. H-NMR:
δ
6.82 (1H, s), 7.16 (1H, t, J = 9.0 Hz), 7.29 (1H, t, J = 7.6 Hz), 7.32–7.43 (5H,
117.2 (1C, d, J = 20 Hz), 124.7 (1C, d,
m), 7.56–7.65 (1H, m), 7.99 (1H, dd, J = 7.5, 1.6 Hz). 13C-NMR:
δ
J = 3.8 Hz), 128.8 (3C), 129.4 (1C, d, J = 1.2 Hz), 130.1 (2C), 130.4 (1C, d, J = 1.2 Hz), 131.3, 132.5, 136
(1C, d, J = 8.5 Hz), 145.9, 160.0 (1C, d, J = 256 Hz). HRMS: m/z calcd. for [M + NH4]+ C14H14ClFNO2S+
314.0412 found 314.0410.
(Z)-1-((2-Chloro-1-phenylvinyl)sulfonyl)-4-(trifluoromethyl)benzene, 5ad: IR: 1591 (m), 1320 (s), 1125 (s),
1
1085 (s), 714 (m) cm−1. H-NMR:
δ 6.80 (1H, s), 7.27 (2H, d, J = 8.5 Hz), 7.33–7.47 (3H, m), 7.76 (2H, d,
J = 7.9 Hz), 7.96 (2H, d, J = 7.97 Hz). 13C-NMR:
δ 123.5 (1C, q, J = 274 Hz), 126.4, 128.9 (2C), 129.1 (2C),
130.3 (2C), 130.5 (2C), 132.6, 135.8 (1C, q, J = 33 Hz), 143.9, 144.9. HRMS: m/z calcd. for [M + NH4]+
C15H14ClF3NO2S+ 364.0380 found 364.0375.
(Z)-4-((2-Chloro-1-phenylvinyl)sulfonyl)-1,10-biphenyl, 5ae: IR: 1592 (w), 1329 (m), 1148 (m), 1085 (w),
581 (m) cm−1
.
1H-NMR:
δ
6.75 (1H, s), 7.30 (2H, d, J = 3.7 Hz), 7.36 (2H, t, J = 7.6 Hz), 7.42 (2H,
t, J = 7.8 Hz), 7.48 (2H, t, J = 7.6 Hz), 7.60 (2H, d, J = 7.6 Hz), 7.70 (2H, d, J = 8.3 Hz), 7.88 (2H, d,
J = 8.3 Hz). 13C-NMR:
δ 127.7 (2C), 127.9 (2C), 128.8 (2C), 129.1, 129.2 (2C), 129.4, 129.5 (2C), 130.0,
130.6 (2C), 133.2, 138.9, 139.4, 145.6, 147.1. HRMS: m/z calcd. for [M + H]+ C20H19ClNO2S+ 372.0820
found 372.0816.
(Z)-2-Chloro-5-((2-chloro-1-phenylvinyl)sulfonyl)thiophene, 5af: IR: 1402 (m), 1332 (s), 1146 (s), 990 (m),
605 (s) cm−1 1H-NMR:
. δ 6.78 (1H, s), 6.93 (1H, d, J = 3.9 Hz), 7.29 (2H, d, J = 7.9 Hz), 7.38 (2H, t,
J = 7.7 Hz) 7.40–7.46 (2H, m). 13C-NMR:
δ 127.4, 128.8 (2C), 129.8, 130.2, 130.5 (2C), 132.6, 134.6, 138.9,
140.5, 145.2. HRMS: m/z calcd. for [M + NH4]+ C12H12Cl2NO2S2 335.9681 found 335.9684.
(Z)-1-(2-Chloro-1-(phenylsulfonyl)vinyl)-4-methylbenzene, 5ba: IR: 1578 (m), 1443 (m), 1146 (s), 1083 (m),
754 (s) cm−1 1H-NMR:
. δ 2.36 (3H, s), 6.70 (1H, s), 7.15 (4H, s), 7.49 (2H, t, J = 7.5 Hz), 7.61(1H, t,
J = 7.5 Hz), 7.83 (2H, d, J = 7.5 Hz). 13C-NMR:
δ 21.7, 128.6 (2C), 128.9, 129.3 (2C), 129.5 (2C), 130.3,
130.4 (2C), 134.1, 140.2, 140.6, 145.5. HRMS: m/z calcd. for [M + NH4]+ C15H17ClNO2S+ 310.0663
found 310.0663.
(Z)-1-(2-Chloro-1-(phenylsulfonyl)vinyl)-4-ethylbenzene, 5ca: IR: 2359 (s), 1709 (m), 1332 (m), 1149 (s),
1
1084 (m), 722 (m) cm−1. H-NMR:
δ
1.23 (3H, t, J = 7.7 Hz), 2.65 (2H, q, J = 7.6 Hz), 6.70 (1H, s), 7.18
15.6, 28.9,
(4H, s), 7.49 (2H, t, J = 7.7 Hz), 7.61(1H, t, J = 7.6 Hz), 7.83 (2H, d, J = 7.7 Hz). 13C-NMR:
δ
128.3 (2C), 128.6 (2C), 128.9, 129.2 (2C), 130.4, 130.5 (2C), 134.1, 140.6, 145.6, 146.4. HRMS: m/z calcd.
for [M + NH4]+ C16H19ClNO2S+ 324.0820 found 324.0822.
(Z)-1-(2-Chloro-1-(phenylsulfonyl)vinyl)-4-propylbenzene, 5da: IR: 2359 (s), 1709 (m), 1332 (m), 1149 (s),
1
1084 (m), 722 (m) cm−1. H-NMR:
δ 0.93 (3H, t, J = 7.3 Hz), 1.34 (2H, hex, J = 7.3 Hz), 1.59 (2H, q,
J = 7.6 Hz), 2.61 (2H, t, J = 7.9 Hz), 6.70 (1H, s), 7.10–7.20 (4H, m), 7.48 (2H, t, J = 7.6 Hz), 7.60 (1H,
t, J = 7.4 Hz), 7.83 (2H, d, J = 8.1 Hz). 13C-NMR:
δ 15.6, 28.9, 128.3 (2C), 128.6 (2C), 128.9, 129.2 (2C),
130.4, 130.5 (2C), 134.1, 140.6, 145.6, 146.4. HRMS: m/z calcd. for [M + H]+ C18H20ClO2S 335.0867
found 335.0866.

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(Z)-4-(2-Chloro-1-(phenylsulfonyl)vinyl)-1,10-biphenyl, 5ea: IR: 1481 (w), 1318 (m), 1180 (m), 1004 (w),
1
648 (s) cm−1. H-NMR:
δ 6.78 (1H, s), 7.32–7.41 (3H, m), 7.42–7.54 (4H, m), 7.55–7.67 (5H, m), 7.88
(2H, d, J = 7.6 Hz). 13C-NMR:
δ 127.4 (2C), 127.5 (2C), 128.2, 128.6 (2C), 129.3 (2C), 129.3 (2C), 129.4,
130.9 (2C), 132.0, 134.2, 140.3, 140.5, 142.9, 145.3. HRMS: m/z calcd. for [M + NH4]+ C20H19ClNO2S+
372.0820 found 372.0821.
Acknowledgments: This work was supported by a graduate studentship (E.Z.) from the State of Libya.
Author Contributions: E.Z. and W.J.M. conceived and designed the experiments; E.Z. performed the experiments;
E.Z. and W.J.M. analyzed the data; W.J.M. wrote the paper.
Conflicts of Interest: The authors declare no conflict of interest. The founding sponsors had no role in the design
of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the
decision to publish the results.
Abbreviations
The following abbreviations are used in this manuscript:
DMSO
NMR
TFA
M
dimethyl sulfoxide
nuclear magnetic resonance
trifluoroacetic acid
molar
rt
room temperature
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Sample Availability: Not available.
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2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access
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