Synthesis of (E)-iodo vinylsulfones via oxidative addition of thiol into alkyne under metal free condition

Article abstract of DOI:10.1016/j.tet.2021.132310

An efficient, transition-metal free and molecular iodine promoted protocol for the construction of (E)-β-iodovinyl sulfone derivatives via oxidative C–S coupling of thiol and alkyne has been demonstrated. Both aryl and alkyl terminal acetylenes were found to be an excellent substrate for the present reaction which provides a wide range of β-iodovinyl sulfone derivatives with very good yield and excellent regio and stereo-selectivities. Diaryldisulfide is also found to be an equally efficient sulfonyl group surrogate under identical reaction conditions.

Full text of DOI:10.1016/j.tet.2021.132310

Tetrahedron 94 (2021) 132310
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Tetrahedron
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Synthesis of (E)-iodo vinylsulfones via oxidative addition of thiol into
alkyne under metal free condition
Surya Kanta Samanta, Rumpa Sarkar, Mrinal K. Bera*
Department of Chemistry, Indian Institute of Engineering Science and Technology (IIEST), Shibpur PO- Botanic Garden, Howrah, 711 103, WB, India
a r t i c l e i n f o
a b s t r a c t
Article history:
An efficient, transition-metal free and molecular iodine promoted protocol for the construction of (E)-b-
iodovinyl sulfone derivatives via oxidative CeS coupling of thiol and alkyne has been demonstrated. Both
aryl and alkyl terminal acetylenes were found to be an excellent substrate for the present reaction which
provides a wide range of b-iodovinyl sulfone derivatives with very good yield and excellent regio and
stereo-selectivities. Diaryldisulfide is also found to be an equally efficient sulfonyl group surrogate under
identical reaction conditions.
Received 12 March 2021
Received in revised form
15 June 2021
Accepted 21 June 2021
Available online 25 June 2021
© 2021 Elsevier Ltd. All rights reserved.
Keywords:
Iodovinyl sulfone
Thiol
Stereoselective oxidative coupling
Metal free
Iodine
1. Introduction
[5a] and Li [5b] to synthesize (E)-
alkyne with complete regio- and stereoselectivity. Copper catalyzed
addition of sulfonyl chloride to acetylene offering -chlorovinyl
sulfone was first reported in 1971 by Amiel [5c]. Recently, Liu et al.
reported another copper(I)halide catalyzed halosulfonylation of
terminal alkyne using sulfonohydrazides as sulfonylating agent to
b-vinylsulfones from terminal
Direct difunctionlization on adjacent C-atom of an alkyne is
considered to be a powerful synthetic tool [1] to introduce two
functional group in a single step to access polyfunctionalized
alkene derivatives. Among various literature known methods [2]
for direct alkyne difunctionalization, halosulfonylation [1b-c] is of
b
b
-halovinyl sulfone derivatives with Z-selectivity [5d]. Apart from
particular interest as it directly furnishes functionally rich
b
-hal-
halosulfonylation of alkyne, various transition metal catalyzed
sulfonylation of olefin offering vinyl sulfone are also well estab-
lished synthetic methods [5e-g]. Despite their synthetic efficiency,
very often, metal catalyzed reactions are being considered as
environmentally unfavorable due to toxic metal byproducts.
Therefore, development of environmentally benign and syntheti-
cally more efficient methods for difunctionalization of alkyne is an
issue of urgent significance. As a consequence, a sizeable number of
metal free halosulfonylation of alkyne have been reported in the
ovinyl sulfone derivatives. Vinyl sulfones and halogenated vinyl
sulfones are the compounds of contemporary interest because of
their prevalence in biologically functional molecules [3] and their
versatility as starting material in organic synthesis [4]. Additionally,
sulfone functionality can play multiple role as an activating agent, a
good leaving group or as an electron withdrawing group which
made this class of compounds more appealing. Due to their above
mentioned importance, synthetic chemists showed their long-
standing interest towards this class of molecules. As a result,
various elegant methods have been developed to access haloge-
nated vinyl sulfone derivatives.
recent literature [6]. In this regard, iodine mediated
b-hal-
osulfonylation of alkyne via CeS coupling is of great importance. In
general, iodine promoted organic transformations constitute a
large area in organic research [7].
A diverse range of important heterocyclic compounds such as
pyridine [7a], indole [7b], pyrrole [7c], furan [7d], thiophene [7e],
thiazole [7f] and many more have been successfully synthesized via
iodine mediated reactions. Similarly, many molecular iodine pro-
A variety of transition metal catalysts have been employed for
direct difunctionalization of alkyne leading to halovinyl sulfone
derivatives [5]. Inexpensive iron catalysts were used by Nakamura
moted difuctionalization reaction of alkyne offering
sulfone derivatives have been reported recently. Wang et al. [6a]
b-halovinyl
* Corresponding author.
E-mail address: mrinalkbera26@gmail.com (M.K. Bera).
https://doi.org/10.1016/j.tet.2021.132310
0040-4020/© 2021 Elsevier Ltd. All rights reserved.

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
temperature to 100 ꢀC without altering any other reaction condi-
tions (Table 1, Entry 3). To our delight, the desired product 3a was
obtained with 74% yield and with no detectable amount of disulfide
4a. We also examined the feasibility of other oxidant such as TBHP,
DTBP, K2S2O8 and Oxone (Table 1, Entry 4e7). TBHP and DTBP were
able to furnish desired product 3a though with slightly inferior
yield whereas oxone failed to initiate the reaction. On the other
hand, disulfide 4a was formed exclusively when K2S2O8 was used as
oxidant (Table 1, Entry 6). Therefore, H2O2 was proved to be the best
oxidant among all the oxidant examined in this reaction. To
improve the yield, we planned to increase the amount of iodine up
to 100 mol% using H2O2 as oxidant. The best result was obtained
when the reaction was carried out with 100 mol% of iodine and
H2O2 as oxidant in DMSO at 100 ꢀC (Table 1, Entry 8). Under this
optimized condition, formation of disulfide 4a was completely
suppressed. We also investigated the effect of oxygen by perform-
ing the reaction under oxygen (Table 1, Entry 9) atmosphere and we
isolated the desired product 3a with marginally inferior yield
compared to the best result. Different iodine sources including NIS,
IBX, KI and TBAI were systematically examined (Table 1, Entry
10e13). NIS and IBX were able to produce the desired product
though with much inferior yield while both KI and TBAI failed to
Scheme 1. Cascade iodination and sulfonylation into alkyne.
produce any trace of b-iodovinyl sulfone derivative. Among all the
solvents investigated, DMSO was found to be the best one for the
current reaction. Other solvents like acetonitrile, DMF and THF
(Table 1, Entry 14e16) were also examined under standard reaction
condition but in none of the cases the yield was found to be
satisfactory.
Having the optimized reaction condition in hand, we focused
our attention to explore the scope and limitation of our newly
developed synthetic method. First, we investigated the substrate
scope of the reaction with various alkynes and the results are
summarized in Table 2. Terminal aryl acetylenes with different alkyl
substitution (H, Me, Et, nBu) at para-position were treated with
diclosed an efficient approach to access (E)-b-iodovinyl sulfones via
direct difunctionalization of alkynes with sulfinic acid and iodine
(Scheme 1). Liu and coworkers accomplished the same trans-
formation using sodium sulfinate as sulfonating agent and molec-
ular iodine in aqueous medium (Scheme 1) [6b]. Again, sulfonyl
hydrazide was used as sulfonating reagent in presence of iodine by
Gong et al. [6d] to synthesize the title compound in aqueous me-
dium (Scheme 1). In a different instance, TosMIC was explored as
potential sulfonylating agent in association with molecular iodine
as catalyst by Yallapragada group (Scheme 1) [6e]. Jiang and co-
workers [6f] demonstrated a NBS or NIS promoted sulfonylation of
terminal alkyne using sodium sulfinate to access bromo or iodo-
vinyl sulfone derivative with high regio- and stereoselectivity
(Scheme 1). Even DMSO-H2O system in presence of iodine is suc-
cessfully used as sulfonylating agent furnishing halovinyl sulfone
from alkyne [6g]. Though a number of synthetic methods are
thiophenol 2a under optimized reaction condition and desired b-
iodovinyl sulfone derivatives were isolated with excellent yield
(Table 2, Entry 3a-3e) and complete regio and stereoselectivity. It is
worth mentioning that in all the cases the product was found to be
(E)-selective. Terminal acetylene with polyaryl appendage such as
4-ethynylbiphenyl and 1-ethynylnaphthalene were successfully
employed as substrate to afford the title compound with excellent
yield and complete selectivity (Table 2, Entry 3f-3g). We antici-
pated that aliphatic acetylenes could also be equally potential
candidates for our current investigation. Towards this end, we
examined the potential of 1-pentyne, 1-hexyne and cyclo-
propylacetylene as substrate under the optimized reaction condi-
tion. It was gratifying that in each case, the desired product
iodovinyl sulfone was obtained though with moderate yield
(Table 2, Entry 3h-3j).
available to get
more efficient, metal free process to access various
b
-halovinyl sulfone derivatives, development of
-halovinyl
b
sulfones from commercially cheap materials is still highly desirable.
Owing to our continuing interest in developing molecular iodine
mediated organic transformations [8], herein, we report a iodine
promoted
b
-halovinyl sulfonylation of terminal alkyne using thiol
-iodo-
as sulfonyl precurssor and H2O2 as oxidant to access (E)-
b
vinyl sulfone derivatives with good to excellent yield and complete
selectivity.
Internal alkyne such as diphenylacetylene was tested as sub-
strate under optimized reaction condition but all our efforts were
proved to be futile and no trace of desired product 3k was identified
(Table 2, Entry 3k).
At this juncture, it was important to confirm the stereochemical
orientation of the iodovinyl sulfone derivatives. Therefore, com-
pound 3b was crystallized from dichloromethane and ethyl acetate
(20:80) solvent system at room temperature to get a pale yellow
crystal suitable for X-ray analysis. Structure determination of 3b
confirmed unambiguously the stereochemistry across the olefinic
double bond.
2. Results and discussion
For our initial investigation of vicinal difunctionalization of
alkyne we choose ethynylbenzene 1a and thiophenol 2a as our
model compounds. Accordingly, phenylacetylene 1a (1.0 equiv) and
thiophenol 2a (1.5 equiv) were allowed to react in presence of
iodine (0.5 equiv) and aqueous H2O2 (2.0 equiv) in DMSO as solvent
at room temperature. To our disappointment, the desired b-iodo-
vinyl sulfone 3a was not detected, rather, the isolated product was
found to be the disulfide 4a as exclusive product (Table 1, Entry 1).
Next, the reaction was carried out at 60 ꢀC keeping the other re-
action parameters unchanged (Table 1, Entry 2). This time, the
desired product 3a was detected with moderate yield but the for-
mation of disulfide 4a was not fully suppressed. Being encouraged
by this preliminary result, we further increased the reaction
Substrate scope was further extended with various thiophenol
derivatives under standard reaction condition. Differently
substituted
thiophenol
including
p-thiocresol,
4-
methoxythiophenol and 4-chlorothiophenol reacted with phenyl-
acetylene 1a under optimum reaction condition to afford
2

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
Table 1
Preliminary screening of oxidative addition of thiol into alkynea.
Entry
Iodine source (equiv)
Oxidant
Solvent
Temprature (0C)
Productb ratio(3a/4a)
1
2
3
4
5
6
7
8
I2 (0.5)
I2 (0.5)
I2 (0.5)
I2 (0.5)
I2 (0.5)
I2 (0.5)
I2 (0.5)
I2 (1.0)
I2 (1.0)
NIS (1.0)
IBX
KI
TBAI
I2 (1.0)
I2 (1.0)
I2 (1.0)
aq. H2O2
aq. H2O2
aq. H2O2
TBHP
DTBP
K2S2O8
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
CH3CN
DMF
RT
60
0/84
54/28
74/0
68/0
72/0
0/64
0/0
92/0
88/0
62/0
36/0
ND
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Oxone
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
aq. H2O2
9c
10
11
12
13
14
15
16
ND
43/0
25/0
52/0
THF
a
Reaction condition: 1a (1.0 equiv), 2a (1.5 equiv), I2 (100 mol%), DMSO (2.0 mL), reflux at 100 ꢀC (8e10 h).
Isolated yield.
Reaction was carried out at oxygen atmosphere.
b
c
Table 2
Substrate scope of the protocol with alkynea,b
.
3

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
Table 3
Substrate scope of the protocol with thiola,b
.
corresponding iodovinyl sulfone 5a-5c with comparable yields
(Table 3, Entry 5a-5c) and complete selectivity. Polyaromatic thiol
such as 1-naphthalene thiol was proved to be an excellent substrate
for our newly developed method to furnish corresponding iodo-
vinyl sulfone 5d (Table 3, Entry 5d).
Heterocyclic thiol such as 2-Pyridine thiol was also found to be a
potential candidate to react smoothly with phenylacetylene 1a
producing corresponding sulfone derivatives 5e with very good
yield (Table 3, Entry 5e). The potential of various aliphatic thiols as
substrate was systematically investigated under standard reaction
condition. 1-Butanethiol and 2-propanethiol were subjected to
react with phenylacetylene 1a to afford respective iodo sulfone
derivatives 5f and 5g with satisfactory yield (Table 3, Entry 5f-5g).
Dodecane thiol and aliphatic thiol with aromatic appendage such as
benzyl mercaptan was failed to react with phenylacetylene under
standard reaction condition for some unknown reason (Table 3,
Entry 5h-5i).
We anticipated that disulfides might be useful as sulfonylating
agent under our optimized reaction condition. To check this pos-
sibility, diphenyldisulfide and p-tolyldisulfide were allowed to react
with different terminal alkynes under standard condition. All the
attempts were gratifyingly successful and, the desired products
were obtained with excellent yield and selectivity (Scheme 2).
Since most of the disulfides are solid, it is easy to handle and, the
use of disulfide as sulfonylating agent certainly broadens the scope
of the new reaction.
At this point, we were curious to examine whether our current
method is useful for gram scale preparation. Therefore, the reaction
between our model compounds phenyl acetylene 1a and thio-
phenol 2a was executed in gram scale quantities under standard
reaction condition and the reaction was gratifyingly successful in
terms of both yield and selectivity (Scheme 3).
Alkenes are known to react with different sulfonylating agents
to produce vinyl sulfones under various reaction conditions [1b-
c,9]. We were interested to examine whether our newly
3.92
Scheme 3. Gram scale preparation of iodo-vinyl sulfone.
Scheme 2. Scope of the protocol with disulfides.
4

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
iodosulfonylation process, we have conducted
a couple of
controlled experiments as depicted in Scheme 6. Radical trapping
experiment was carried out to know whether any radical inter-
mediate was involved in the reaction pathway. When TEMPO, a well
known radical scavenger was employed under optimum reaction
condition (Scheme 6, Eqn. a), trace amount of desired product was
detected indicating the involvement of radical intermediate in the
reaction. Again, when thiophenol 2a was reacted with our optimal
reaction condition in absence of alkyne, benzenesulfonothioate 14
was recovered as a major product along with disulfides which is
confirmed by both HRMS and NMR spectroscopy (Scheme 6, eqn.
b). This experiment proves the formation of thiosulfonate as a
crucial intermediate for the generation of sulfonyl radial. Next, we
carried out the reaction in the absence of hydrogen peroxide
keeping other reaction parameter unaltered (Scheme 6, eqn. c). This
time, we did not get any trace of desired product 3a rather we
ended up with disulfide 4a as the sole product. This indicates that
peroxide is playing a crucial role to generate a sulfonyl radical
during the reaction.
Scheme 4. Scope of the protocol with Alkene.
Scheme 5. Synthetic application of iodovinyl sulfone.
On the basis of the findings of control experiments and litera-
ture precedence [12,13] a plausible reaction mechanism of CeS
cross coupling between thiol and alkyne has been proposed in
Scheme 7. The reaction pathway is presumed to involve an initial
oxidative coupling of thiol 2a into disulfide 4a under I2/DMSO
catalytic oxidant system [12a]. Upon further oxidation with
peroxide, disulfide 4a produced S-phenyl benzenethiosulfonate 14
[13] which on subsequent thermal decomposition generates sul-
fonyl radical A [12c,14]. This in situ generated sulfonyl radical A may
add to alkyne in two different pathways. In path-a, sulfonyl radial A
may directly add to alkyne to produced intermediate B which on
iodination generates product 3a. Again in path-b, sulfonyl radical A
may recombine with iodine to produce phenyl sulfonyl iodide C
which then add to alkyne followed by iodination liberates E-iodo
vinyl sulfone 3a (Scheme 7).
discovered condition is compatible with alkenes to deliver vinyl-
sulfone derivatives. Therefore, the reaction was carried out be-
tween styrene 7 and thiophenol 2a employing our optimized
reaction condition. The expected (E)-vinylsulfone 8 was obtained
with moderate yield along with the formation of b-iodosulfone 9,
Scheme 4. Probably, incomplete elimination of HI leads to the
isolation of 9 as a minor product.
It is needless to mention that Iodovinyl sulfones are invaluable
starting material for numerous organic transformation. Iodovinyl
motif is an obvious functionality for transition metal catalyzed CeC
cross coupling reactions such as Sonogashira [10] and Suzuki [11]
reactions. To demonstrate the synthetic utility, iodovinyl sulfone 3a
was treated with phenylacetylene 1a under typical Sonogashira
condition to furnish (E)-enyne 10 with very good yield (Scheme 5).
Again, 3a was allowed to react with phenylboronic acid in presence
of base and Pd-catalyst to afford Suzuki product 11 with satisfactory
3. Conclusion
In summary, we have developed an efficient, molecular iodine
promoted and transition metal free method for the synthesis of (E)-
iodo vinyl sulfones from commercially available, inexpensive
starting material via oxidative CeS coupling. A wide range of
iodovinyl sulfone derivatives can be readily prepared from milli-
gram to multi-gram scale with excellent yield and complete regio
and stereoselectivity. The operational simplicity and environmen-
tally benign nature make the protocol more attractive. Further
study and application of iodovinyl sulfones are currently underway
in our laboratory.
yield. Alkynyl sulfone can readily be accessed from (E)-b-iodovinyl
sulfone under basic condition [6b]. Therefore, treatment of 3a with
K2CO3 in methanol under heating condition smoothly furnished
alkenylsulfone 12 with good yield (Scheme 5). In addition, NaOAc
promoted C (sp2)-I hydroxylation of 3a could efficiently offer
tosylacetophenone 13 (Scheme 5) [4d].
a-
In order to understand the mechanistic pathway of the
4. Experimental section
General procedure for the synthesis of (E)-(1-iodo-2-(phenyl-
sulfonyl)vinyl)benzene (3a) and derivatives:
To a 10 mL round bottom flask was charged with thiophenol 2a
Scheme 6. Control experiments.
Scheme 7. Postulated reaction pathway.
5

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
(0.15 mL, 1.5 mmol), DMSO (2 mL) and iodine (127 mg, 0.5 mmol)
and aqueous H2O2 (0.06 mL, 2 mmol) and the mixture was stirred
for half an hour at room temperature. After that phenyl acetylene
1a (0.11 mL, 1.0 mmol) was added and the resulting reaction
mixture was heated to 100 ꢀC for 6e8 h under nitrogen atmo-
sphere. After completion of the reaction as indicated by TLC, reac-
tion flask was cooled for a while. After that 10% aqueous Na2S2O3
solution (30 mL) was added to the flask, the whole reaction mixture
was extracted with ethyl acetate (3 ꢁ 60 mL). The combined
organic layer was washed with brine solution and dried over
anhydrous Na2SO4 and concentrated under reduced pressure. The
crude product was purified on via column chromatography
(100e200 mesh silica gel) with petroleum ether and ethyl acetate
(20% of solution) as eluent to yield the desired product 3a as pale
yellow solid (340 mg, yield 92%). Also other derivatives of iodo-
sulfone 3b-3m were synthesized by the above procedure in smooth
yield.
(125 MHz, CDCl3)
d
(ppm): 142.6, 138.1, 134.9, 132.3, 132.0, 129.1,
127.4, 127.2, 126.7, 125.5, 125.2, 124.2, 123.9, 123.8, 118.9, 111.3.
HRMS ESI (m/z): Calculated for C18H13IO2S [MþH]þ: 420.9759,
found: 420.9763.
(E)-((2-iodopent-1-en-1-yl)sulfonyl)benzene
(3h):
Oil
(174 mg, 52%). 1H NMR (400 MHz, CDCl3)
d
(ppm) ¼ 7.93 (d,
J ¼ 7.7 Hz, 2H), 7.70e7.67 (m,1H), 7.59 (t, J ¼ 7.5 Hz, 2H), 7.06 (s,1H),
3.04 (t, J ¼ 7.7 Hz, 2H), 1.65e1.56 (m, 2H), 0.99e0.95 (m, 3H). 13C
NMR (100 MHz, CDCl3)
d(ppm) ¼ 140.9, 138.8, 133.8, 129.5, 127.5,
16.0, 41.5, 23.3, 12.8. HRMS ESI (m/z): Calculated for C11H13IO2S
[MþH]þ: 336.9759, found: 336.9763.
(E)-((2-iodohex-1-en-1-yl)sulfonyl)benzene (3i): Oil (162 mg,
46%). 1H NMR (400 MHz, CDCl3)
d
(ppm) ¼ 7.85e7.83 (m, 2H),
7.61e7.57 (m, 1H), 7.52e7.48 (m, 2H), 6.94 (s, 1H), 2.97 (t, J ¼ 7.6 Hz,
2H), 1.47e1.41 (m, 2H), 1.33e1.27 (m, 2H), 0.93e0.85 (m, 3H). 13C
NMR (100 MHz, CDCl3)
d(ppm) ¼ 141.0, 138.6, 133.7, 129.5, 127.4,
126.2, 39.9, 32.0, 21.7, 13.8. HRMS ESI (m/z): Calculated for
(E)-(1-iodo-2-(phenylsulfonyl)vinyl)benzene (3a): White
C
12H15IO2S [MþH]þ: 350.9916, found: 350.9920.
solid (340 mg, yield 92%), mp 68e69 ꢀC.1H NMR (400 MHz, CDCl3)
(E)-((2-cyclopropyl-2-iodovinyl)sulfonyl)benzene (3j): Brown
d
(ppm): 7.56e7.49 (m, 3H), 7.36 (t, J ¼ 8.6 Hz, 3H), 7.29e7.22 (m,
Semi solid (198 mg,60%). 1H NMR (400 MHz, CDCl3)
d (ppm): 7.92 (t,
3H), 7.19 (t, J ¼ 6.7 Hz,2H). 13C NMR (100 MHz, CDCl3)
d
(ppm): 141.1,
J ¼ 7.6 Hz, 2H), 7.67e7.63 (m,1H), 7.56 (t, J ¼ 7.9 Hz, 2H), 7.06 (s,1H),
140.2, 139.6, 133.5, 129.9, 129.1, 128.0, 127.8, 127.7, 114.8. HRMS ESI
(m/z): Calculated for C14H11IO2S [Mþ Na]þ: 392.9422, found:
392.9427.
2.47e2.41 (m, 1H), 0.94e0.83 (m, 4H). 13C NMR (100 MHz, CDCl3)
d
(ppm): 141.3, 138.0, 137.2, 134.2, 129.5, 129.2, 127.4, 17.6, 17.4, 12.2.
HRMS ESI (m/z): Calculated for C11H11IO2S [MþH]þ: 334.9603,
(E)-1-(1-iodo-2-(phenylsulfonyl)vinyl)-4-
found: 334.9612.
methylbenzene(3b): White solid (323 mg, 84%), mp 113e115 ꢀC. 1H
(E)-1-((2-iodo-2-phenylvinyl)sulfonyl)-4-methylbenzene
(5a): White solid (345 mg, 90%), mp 80e82 ꢀC. 1H NMR (500 MHz,
NMR (400 MHz, CDCl3)
J ¼ 7.4 Hz, 1H), 7.31 (t, J ¼ 7.5 Hz, 2H), 7.07e6.99 (m, 4H), 2.26 (s,
3H). 13C NMR (100 MHz, CDCl3)
(ppm): 140.5, 140.3, 136.8, 133.5,
d
(ppm): 7.52 (d, J ¼ 7.7 Hz, 2H), 7.46 (t,
CDCl3)
J ¼ 7.0 Hz, 3H), 7.21 (d, J ¼ 7.1 Hz, 2H), 7.16 (d, J ¼ 7.3 Hz, 2H), 2.34
(s,3H). 13C NMR (125 MHz, CDCl3)
(ppm): 144.6, 141.3, 139.7, 137.3,
d
(ppm) ¼ 7.44 (d, J ¼ 7.6 Hz, 2H), 7.35 (s,1H), 7.27 (t,
d
129.0, 128.7, 128.6, 127.8, 115.4, 21.5. HRMS ESI (m/z): Calculated for
d
C
15H13IO2S [M þ Na]þ: 406.9579, found: 406.9584.
129.8, 129.7, 127.9, 127.8, 127.7, 114.2, 21.6. HRMS ESI (m/z): Calcu-
lated for C15H13IO2S [MþH]þ: 384.9759, found: 384.9764.
(E)-1-((2-iodo-2-phenylvinyl)sulfonyl)-4-methoxybenzene
(5b): White solid (352 mg, 88%), mp 112e114 ꢀC. 1H NMR (500 MHz,
(E)-1-ethyl-4-(1-iodo-2-(phenylsulfonyl)vinyl)benzene(3c):
Gummy solid (270 mg, 68%). 1H NMR (400 MHz, CDCl3)
d(ppm):
7.61e7.54 (m, 3H), 7.41e7.37 (m, 3H), 7.17 (d, J ¼ 8.3 Hz, 2H), 7.11 (d,
J ¼ 8.3 Hz, 2H), 2.69e2.64 (m, 2H), 1.27 (t, J ¼ 7.6 Hz, 3H). 13C NMR
DMSO‑d6)
d (ppm): 7.52e7.49 (m, 2H), 7.39 (s, 1H), 7.33e7.29 (m,
(100 MHz, CDCl3)
d(ppm): 146.5, 140.7, 140.2, 136.9, 133.4, 128.9,
3H), 7.25 (t, J ¼ 5 Hz, 2H), 6.87e6.85 (m, 2H), 3.86 (s, 3H). 13C NMR
127.9, 127.8, 127.4, 115.4,28.7, 15.3. HRMS ESI (m/z): Calculated for
(125 MHz, DMSO‑d6) d (ppm): 163.6, 141.6, 139.7, 131.7, 130.1, 129.7,
C
16H15IO2S [M þ H]þ: 398.9916, found: 398.9918.
127.9, 127.7, 114.2, 113.6, 55.7. HRMS ESI (m/z): Calculated for
(E)-1-(1-iodo-2-(phenylsulfonyl)vinyl)-3,5-dimethylbenzene
C
15H13IO3S [MþNa]þ: 422.9528, found: 422.9538.
(3d): Light brown solid (302 mg, 76%), mp 108e110 ꢀC. 1H NMR
(E)-1-chloro-4-((2-iodo-2-phenylvinyl)sulfonyl)benzene
(400 MHz, CDCl3)
d
(ppm): 7.58e7.54 (m, 3H), 7.42e7.37 (m, 3H),
(5c): White solid (380 mg, 94%), mp 104e106 ꢀC. 1H NMR
6.93 (s, 1H), 6.76 (s, 2H), 2.26 (d, J ¼ 1.9 Hz, 6H). 13C NMR (100 MHz,
(400 MHz, CDCl3)
d
(ppm): 7.45 (d, J ¼ 8.3 Hz, 2H), 7.38 (s, 1H),
CDCl3)
d
(ppm): 140.9, 140.3, 139.4, 137.6, 133.2, 131.5, 128.8, 127.9,
7.32e7.24 (m, 5H), 7.17 (t, J ¼ 6.8 Hz, 2H). 13C NMR (100 MHz, CDCl3)
125.1, 115.5, 21.2. HRMS ESI (m/z): Calculated for C16H15IO2S
d (ppm): 141.0, 140.2, 139.5, 138.7, 130.0, 129.4, 129.3, 128.0, 127.7,
[MþH]þ: 398.9916, found: 398.9920.
115.3. HRMS ESI (m/z): Calculated for C22H16O2S [MþH]þ:
(E)-1-butyl-4-(1-iodo-2-(phenylsulfonyl)vinyl)benzene (3e):
345.0949, found: 345.0956.
Brown semi solid (298 mg, 70%). 1H NMR (400 MHz, CDCl3)
d(ppm):
(E)-1-((2-iodo-2-phenylvinyl)sulfonyl)naphthalene
White solid (316 mg, 75%), mp 78e80 ꢀC. 1H NMR (400 MHz,
DMSO‑d6)
(ppm): 7.98 (s, 1H), 7.82 (d, J ¼ 8.4 Hz, 2H), 7.73 (d,
J ¼ 8.1 Hz, 1H), 7.62e7.51 (m, 3H), 7.45 (s, 1H), 7.20e7.15 (m, 5H),
6.73e6.71 (m, 1H). 13C NMR (100 MHz, DMSO‑d6)
(ppm): 141.3,
(5d):
7.56e7.49 (m, 3H), 7.35 (t, J ¼ 8.7 Hz, 3H), 7.13 (t, J ¼ 6.4 Hz, 2H), 7.06
(d, J ¼ 8 Hz, 2H), 2.59 (t, J ¼ 7.6 Hz, 2H), 1.63e1.56 (m, 2H),1.42e1.32
d
(m,2H), 0.95 (t, J ¼ 7.3 Hz, 3H). 13C NMR (125 MHz, CDCl3)
d(ppm):
145.3, 140.8, 140.3,136.9, 135.3,129.0, 128.0,128.0, 127.9, 115.7, 35.6,
33.4, 22.4, 14.1.
d
139.5,136.8,135.1,131.9,130.0,129.9,129.4,129.3,127.9,127.7,127.6,
112.4, 114.9. HRMS ESI (m/z): Calculated for C18H13IO2S [MþNa]þ:
442.9579, found: 442.9584.
HRMS ESI (m/z): Calculated for C18H19IO2S [MþH]þ: 427.0229,
found: 427.0234.
(E)-4-(1-iodo-2-(phenylsulfonyl)vinyl)-1,1′-biphenyl
Gummy solid (290 mg, 65%), 1H NMR (400 MHz, CDCl3)
(3f):
(ppm):
(E)-2-((2-iodo-2-phenylvinyl)sulfonyl)pyridine (5e): White
d
solid (223 mg, 60%), brown oil. 1H NMR (400 MHz, CDCl3)
d
(ppm):
8.67 (d, J ¼ 4.3 Hz, 1H), 7.68 (t, J ¼ 7.7 Hz, 1H), 7.56 (t, J ¼ 9.7 Hz, 1H),
7.43e7.20 (m, 6H). 13C NMR (100 MHz, CDCl3)
(ppm): 157.6, 150.3,
7.59 (t, J ¼ 8.4 Hz, 4H), 7.53 (t, J ¼ 7.5 Hz, 1H), 7.48 (t, J ¼ 8.3 Hz, 4H),
7.41e7.35 (m, 4H), 7.29 (d, J ¼ 8.2 Hz, 2H). 13C NMR (125 MHz,
d
CDCl3)
d
(ppm): 142.7, 141.3, 140.2, 139.9, 138.4, 133.5, 129.0, 128.9,
139.7, 138.6, 137.9, 129.9, 127.9, 127.7, 127.3, 122.5, 116.1. HRMS ESI
128.4, 128.0, 127.9, 127.1, 126.6, 114.4. HRMS ESI (m/z): Calculated
(m/z): Calculated for
371.9548.
C
13H10INO2S [MþH]þ: 371.9555, found:
for C20H15IO2S [MþH]þ: 446.9916, found: 446.9921.
(E)-1-(1-iodo-2-(phenylsulfonyl)vinyl)naphthalene
Brown liquid (345 mg, 82%). 1H NMR (400 MHz, CDCl3)
(3g):
(ppm):
(E)-(2-(butylsulfonyl)-1-iodovinyl)benzene (5f): Yellowish
d
Green oil (280 mg, 80%), mp 86e88 ꢀC. 1H NMR (400 MHz, CDCl3)
7.78e7.72 (m,2H), 7.65 (s, 2H), 7.49e7.47 (m,1H), 7.39e7.32 (m, 4H),
d
(ppm): 7.45e7.42 (m, 2H), 7.37e7.34 (m, 3H), 7.21 (s, 1H),
7.27e7.25 (m, 2H), 7.18e7.14 (m, 1H), 7.01e6.97 (m, 2H). 13C NMR
2.69e2.65 (m, 2H), 1.70e1.62 (m, 2H), 1.36e1.26 (m, 2H). 0.85 (t,
6

S.K. Samanta, R. Sarkar and M.K. Bera
Tetrahedron 94 (2021) 132310
J ¼ 7.6 Hz, 3H). 13C NMR (100 MHz, CDCl3)
d
(ppm): 139.6, 138.9,
Acknowledgments
130.3, 128.7, 128.2, 127.9, 115.2, 54.5, 24.0, 21.5, 13.5. HRMS ESI (m/
z): Calculated for C12H15IO2S [MþH]þ: 350.9916, found: 350.9925.
Financial support from DST-SERB New Delhi, India (Grant No:
SB/S1/OC-15/2014) and CSIR-New Delhi, India (Grant No. 02(0270)/
16/EMR-II) is most gratefully acknowledged. One of the authors,
SKS and RS gratefully thanks CSIR New Delhi for financial support
in form of CSIR-JRF. Authors would like to sincerely thank the So-
phisticated Analytical Instruments Facility (SAIF), IIEST Shibpur for
single-crystal X-ray analysis. We extend our special thanks to Dr.
Deepak Chopra, IISER Bhopal for helping us in solving crystal
structure.
(E)-(1-iodo-2-(isopropylsulfonyl)vinyl)benzene
(5g):
Yellowish Green oil (275 mg, 82%), mp 136e138 ꢀC. 1H NMR
(400 MHz, CDCl3) (ppm): 7.44e7.39 (m, 3H), 7.33e7.31 (m, 2H),
7.16 (s, 1H), 2.82e2.75 (m, 1H), 1.25 (d, J ¼ 6.8 Hz, 6H).
13C NMR (100 MHz, CDCl3)
(ppm): 136.4, 130.1, 128.7, 128.5,
d
d
128.0, 127.8, 116.1, 54.5, 15.1. HRMS ESI (m/z): Calculated for
C
11H13IO2S [MþH]þ: 336.9759, found: 336.9764.
(E)-(2-(phenylsulfonyl)vinyl)benzene (8): Yellowish Green oil
(159 mg, 65%), mp 70e72 ꢀC.1H NMR (400 MHz, CDCl3)
d (ppm):
7.87e7.85 (m, 2H), 7.60 (d, J ¼ 15.4 Hz, 1H), 7.51 (t, J ¼ 6.1 Hz, 2H),
Appendix A. Supplementary data
7.47e7.43 (m, 2H), 7.40e7.37 (m, 2H), 7.31 (d, J ¼ 5.2 Hz, 3H), 6.78
(d, J ¼ 15.4 Hz, 1H). 13C NMR (100 MHz, CDCl3)
d (ppm): 41.5, 140.7,
Supplementary data related to this article can be found at
https://doi.org/10.1016/j.tet.2021.132310.
133.4, 132.3, 131.2, 129.4, 129.1, 128.6, 127.7, 127.3. HRMS ESI (m/z):
Calculated for C14H12O2S [MþNa]þ: 267.0456, found: 267.0458.
(1-iodo-2-(phenylsulfonyl)ethyl)benzene (9): Gummy solid
References
(104 mg, 28%). 1H NMR (500 MHz, CDCl3)
d
(ppm): 7.46 (t, J ¼ 7.3 Hz,
2H), 7.38 (d, J ¼ 4.3 Hz, 4H), 7.37e7.32 (m, 3H), 7.28 (t, J ¼ 5.2 Hz,
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13C NMR (125 MHz, CDCl3)
d (ppm): 142.2, 135.0, 130.2, 129.2,
128.7, 128.6, 128.0, 126.8, 12-5.9, 125.8, 71.7, 44.0. HRMS ESI (m/z):
Calculated for C14H13IO2S [MþH]þ: 372.9759, found: 372.9762.
(E)-(4-(phenylsulfonyl)but-3-en-1-yne-1,3-diyl)dibenzene
(10)1: Yellowish Green oil (241 mg, 70%). 1H NMR (4-00 MHz,
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CDCl3) d (ppm): 7.82e7.80 (m,2H), 7.57e7.51 (m, 4H), 7.44e7.42 (m,
2H), 7.37e7.32 (m, 5H), 7.04 (t, J ¼ 7.1 Hz, 1H), 6.52 (s, 1H). 13C NMR
(100 MHz, CDCl3)
d (ppm): 153.4, 143.5, 135.1, 132.7, 131.7, 131.6,
129.9, 129.7, 129.1, 128.6, 128.4, 127.9, 127.7, 121.7, 99.5, 85.1. HRMS
ESI (m/z): Calculated for C22H16O2S [MþH]þ: 345.0949, found:
345.0951.
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d
(ppm): 8.07 (d, J ¼ 6.5 Hz, 1H), 7.77 (s, 1H), 7.59 (d,
J ¼ 9.0 Hz, 1H), 7.46 (t, J ¼ 1.5 Hz, 1H), 7.16e7.13 (m, 1H), 6.90 (d,
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d (ppm): 155.3, 141.5, 139.1, 135.5, 132.9, 130.4,
129.8, 129.0, 128.8, 128.7, 128.7, 128.3 HRMS ESI (m/z): Calculated
for C20H16O2S [MþH]þ: 321.0949, found: 321.0952.
((phenylethynyl)sulfonyl)benzene (12)1: Gummy liquid
(157 mg, 65%). 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.98 (d,
J ¼ 8.3 Hz, 2H), 7.55e7.51 (m, 2H), 7.49e7.47 (m, 1H), 7.42e7.37 (m,
5H). 13C NMR (100 MHz, CDCl3)
(ppm): 145.4, 138.9, 132.7, 131.5,
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130.0, 128.7, 127.5, 118.0, 92.9, 85.6. HRMS ESI (m/z): Calculated for
C
14H10O2S [MþH]þ: 243.0480, found: 243.0486.
1-phenyl-2-(phenylsulfonyl)ethanone (13)2: White solid,
(218 mg, 84%), mp 100e102 ꢀC. 1H NMR (400 MHz, CDCl3)
d (ppm):
7.91e7.87 (m, 4H), 7.65e7.56 (m, 2H), 7.51 (t, J ¼ 8.0 Hz, 2H), 7.44 (t,
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d (ppm):
188.0, 138.8, 135.7, 134.3, 134.2, 129.3, 129.2, 128.8, 128.5, 63.3.
HRMS ESI (m/z): Calculated for C14H12O3S [MþH]þ: 261.0585,
found: 261.0595.
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S-phenyl benzenesulfonothioate (14): Yellowish liquid
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d (ppm): 7.48e7.43 (m,
3H), 7.38e7.34 (m,1H), 7.24e7.20 (m, 4H), 7.30 (t, J ¼ 7.9 Hz, 2H). 13C
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128.9, 127.8, 127.5. HRMS ESI (m/z): Calculated for C12H10O2S2
[MþH]þ: 251.0200, found: 251.0190.
Declaration of competing interest
g) P. Zhou, Y. Pan, H. Tan, W. Liu, J. Org. Chem. 84 (2019) 15662e15668;
h) T. Sawangphon, P. Katrun, K. Chaisiwamongkhol, M. Pohmakotr,
V. Reutrakul, T. Jaipetch, D. Soorukram, C. Kuhakarn, Synth. Commun. 43
(2013) 1692e1707.
The authors declare that they have no known competing
financial interests or personal relationships that could have
appeared to influence the work reported in this paper.
7

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8