Metal-Free Synthesis of β-Bromoalkenyl Sulfides via Deoxygenative Bromination/Olefination/Sulfenylation of Ketones with Sulfonyl Hydrazides and Pyridinium Tribromide

Article abstract of DOI:10.1002/cjoc.201800375

A novel metal-free method for synthesis of β-bromoalkenyl sulfides via deoxygenative bromination/olefination/sulfenylation process using commercially available ketones, sulfonyl hydrazides and pyridinium tribromide as starting materials has been developed. In this reaction, pyridinium tribromide plays the role of oxidant and substrate, wherein water and molecular nitrogen are generated as environmentally benign by-products. Preliminary investigation revealed that vinyl bromides were critical intermediate. Importantly, this protocol not only obviates the use of alkynes and traditional sulfenylating agents, but also reveals that ketones can be used as precursors of vinyl bromides.

Full text of DOI:10.1002/cjoc.201800375

Metal-Free Synthesis of β-Bromoalkenyl Sulfides via Deoxygenative
Bromination/Olefination/Sulfenylation of Ketones with Sulfonyl
Hydrazides and Pyridinium Tribromide
a
a
a
a
a
Yishu Bao, Lingyu Zhong, Qiaodan Hou, Qingfa Zhou, * and Fulai Yang *
ABSTRACT A novel metal-free method for synthesis of β-bromoalkenyl sulfides via deoxygenative bromination/olefination/sulfenylation process using
commercially available ketones, sulfonyl hydrazides and pyridinium tribromide as starting materials has been developed. In this reaction, pyridinium
tribromide plays the role of oxidant and substrate, wherein water and molecular nitrogen are generated as environmentally benign by-products.
Preliminary investigation revealed that vinyl bromides were critical intermediate. Importmantly, this protocol not only obviates the use of alkynes and
traditional sulfenylating agents, but also reveals that ketones can be used as precursors of vinyl bromides.
KEYWORDS Ketones, Sulfonyl hydrazides, Deoxygenative, β-Bromoalkenyl sulfides, Pyridinium tribromide
Introduction
Carbon-carbon double bond is ubiquitous structural motif
because of its occurrence in a wide range of natural products,
proposed mechanism, sulfonyl hydrazides reacted with ketones
to afford sulfonylhydrazones which were oxidized by iodine to
afford vinyl iodides, and then vinyl iodides reacted with the in situ
generated sulfenyl iodides afford β-iodoalkenyl sulfides.
Encouraged by this work, we questioned whether bromides could
be used to oxidize sulfonylhydrazones to give β-bromoalkenyl
sulfides without additive and metal catalyst.
[1]
drugs, functional materials and biologically relevant molecules.
Consequently, developing new methodologies for rapid and
efficient construction of functionalized carbon-carbon double
bonds represents one of the major domains in chemical synthesis.
In this context, developing effective methods to access
β-haloalkenyl sulfides represents a striking research topic because
they can be easily decorated into various alkenes and alkynyl
sulfides due to the presence of carbon-halogen bond and
Scheme 1 Methods for β-Bromoalkenyl Sulfides Synthesis.
[
2]
carbon-sulfur bond. Increasing attention has been devoted to
the synthesis of β-haloalkenyl sulfides since the original work of
Modena’s group on the addition of sulfenyl chlorides to
[3]
acetylenes. Later, many similar methods were reported to
synthsize β-haloalkenyl sulfides via the halothiolation of alkynes
[
4]
using different sulfenylating agents, such as sulfenyl halides,
[
5]
[6]
[6a]
[7]
sulfenamides, disulfides, thiols, sodium arenesulfinates,
[
8]
and thiosulfate.
However, methods for the synthesis of
[
4c, 5, 6]
β-bromoalkenyl sulfides are scarce (Scheme 1).
Nevertheless, these strategies have some well-known
disadvantages: (1) many of the sulfenylating agents are unstable
to air and moisture, and prepare difficultly, or possess unpleasant
smelling; (2) many of these reactions involve the use of metal
[
4a, 4b, 5]
[7]
catalysts
or excess additives, which are not consistent
with the concept of green chemistry. To address such issues, it is
highly desirable to develop new strategies for synthesis of
β-bromoalkenyl sulfides using readily accessible substrates
through environmentally-friendly reaction conditions.
Results and Discussion
Sulfonyl hydrazides which are stable, commercially available
[
9]
and low-toxic could serve as ideal sulfenylating agents, and they
have been widely employed to react with ketones to deliver
sulfonylhydrazones which have been one of the most important
synthons for the formation of various olefins since the seminal
However, the much lower reactivity of bromides might render
the development of such a tandem reaction a great challenge.
With commercially available acetophenone (1a) and
p-toluenesulfonyl hydrazide (2a) as model substrates, the reaction
was initially investigated (Table 1). First, the reaction was
[
10]
[11]
findings of Bamford–Stevens and Shapiro.
Inspired by this
work, very recently, we developed an unprecedented protocol for
performed in n-hexane in the presence of 0.5 equiv Br , 4.0 equiv
2
o
the synthesis of β-iodoalkenyl sulfides using readily available
KBr at 120 C, unfortunately, β-bromoalkenyl sulfide 3a was
obtained in 34% yield (entry 1), while a similar result was got
without KBr (entry 2). Consequently, a range of other bromides
were evaluated without additive KBr (entries 3-8), among which
pyridinium tribromide was proved to be the optimal choice (entry
8). In addition, the effects of various solvent was also examined,
but no other solvent promoted yield (entries 9-11). Further
[
12]
ketones, sulfonyl hydrazides and iodine as starting materials.
This protocol obviates the need for alkynes and traditional
sulfenylating agents. However, in the view of green chemistry, it
also encounters disadvantages, such as the use of excess KI as
additive and the requirement of 50 mol % iodine which is easy to
sublimate and is environmentally-unfriendly. According to our
a
State Key Laboratory of Natural Medicines, Department of Organic Chemistry,
China Pharmaceutical University, Nanjing, 210009, P. R. China
*E-mail: zhouqingfa@cpu.edu.cn
*E-mail: fly1986@ustc.edu.cn
This article has been accepted for publication and undergone full peer review but has not
been through the copyediting, typesetting, pagination and proofreading process, which
may lead to differences between this version and the Version of Record. Please cite this
article as doi: 10.1002/cjoc.201800375
This article is protected by copyright. All rights reserved.

examination showed that extending the reaction time and
changing the amount of bromide gave no improvements in
efficiency (entries 12-14). To our delight, a satisfactory result was
transformed to corresponding product 4h with lower yields
because of steric hindrance.
obtained when the ratio of 1a, 2a and Py·HBr
3
was adjusted to
Table 2 caption Scope of Ketones 1 for Synthesis of β-Bromoalkenyl
a
2
:4:1, which delivered 3a in 69 % yield (entry 15). However,
Sulfides 3.
decreasing the temperature to 100 °C resulted in only a trace
amount of the expected product (entry 16). Thus, the optimal
reaction conditions were 1 equiv of 1a, 2 equiv of 2a and 0.5
o
equiv of Py·HBr
3
in n-hexane at 120 C.
Table 1 Screening reaction conditions for synthesis of β-bromoalkenyl
a
sulfides
a
Reaction conditions: 1 (0.2 mmol), 2 (0.4 mmol), Py·HBr
3
(0.1 mmol), in
b
n-hexane (1.0 mL), at 120 °C (oil bath), for 3 h. 1h.
Table 3 Scope of Sulfonyl Hydrazides 2 for Synthesis of β- Bromoalkenyl
a
Sulfides 4.
a
Reaction conditions: 1a (0.2 mmol), 2a (0.3 mmol), in solvent (0.5 mL), at
o
b
c
d
1
20 C (oil bath), for 3 h. Yield of isolated product. KBr (4 equiv) 1.0
e f g o
mol / L in methylene chloride. 5h. 2a (0.4 mmol). At 90 C (oil bath).
NBS = N-bromosuccinimide, TBABr
NBP = N-bromophthalimide, Py·HBr
,3-dibromo-5,5-dimethylhydantoin.
3
= tetrabutylammonium tribromide,
= pyridinium tribromide, DBDMH =
3
1
With the optimized reaction conditions in hand, the substrate
a
scope of ketones was explored. As shown in table 2, a range of
aryl methyl ketones reacted smoothly to afford the corresponding
products in moderate to good yields with high E/Z selectivity
Reaction conditions: 1 (0.2 mmol), 2 (0.4 mmol), Py·HBr (0.1 mmol), in
3
n-hexane (1.0 mL), at 120 °C (oil bath), for 3 h.
To obtain insight into a possible reaction mechanism, a series
of control experiments were performed (Scheme 2). 5 and 6, as
the most possible two intermediates, were subjected to the
optimized conditions, however, no desire product 3a was found
when 5 reacted with p-toluenesulfonyl hydrazide (2a), while 6
could afford desire product 3a in 54% yield (eqns (1) and (2)).
Vinyl bromide 7 and vinyl dibromide 8 which were detected to be
two critical intermediates could react with p-toluenesulfonyl
hydrazide (2a) to give final product 3a in 57% and 16% yields,
respectively (eqns (3) and (4)). Sulfonyl hydrazide 2a easily
decomposed upon heating to generate disulfide 9, sulfonothioate
(
3a-3k). Halides including fluoro, chloro, bromo and iodo groups
were successfully introduced into β-bromoalkenyl sulfides (3e-3i).
-Acetonaphthone was also applied in the reaction with
2
satisfactory yield, however, the regioselectivity was adversely
affected (3l). To further explore scope, alkyl-substituted ketones
were also evaluated. To our delight, aliphatic ketones could also
afford corresponding β-bromoalkenyl (3m, 3n) in moderate yields.
It is worth noting that the reactions of 1m and 1n required a
shorter reaction time to increase the efficiency.
Subsequently, the reaction was further evaluated using a
series of sulfonyl hydrazides (table 3). Various arylsulfonyl
hydrazides with electron-donating and electron-withdrawing
groups reacted with ketones to give the corresponding
β-bromoalkenyl sulfides (4a-4g, 4i) in moderate to good yields.
Moreover, 2,4,6-trimethylbenzenesulfonoh-ydrazide (2h) could
[
6]
1
0 and sulfinic acid 11. Each of them was treated with 1a,
however, no desired product 3a was obtained, which
substantially elucidated the NHNH
2
group in the sulfonyl
hydrazide was required (eqn (5)).
This article is protected by copyright. All rights reserved.

Scheme 2 Control Experiments.
series of coupling reaction. E-3a via a Suzuki–Miyaura coupling
[15]
furnished E-13b in an excellent yield (89%),
while E-13c was
[16]
generated via Sonogashira–Hagihara coupling in yield of 90%.
Furthermore, introducing trimethylsilylacetylene to E-3a could
also take place catalyzed by palladium, providing conjugated
[
17]
enyne E-13d in 80% yield.
Scheme 4 Transformations of E-3a.
[
9, 12, 13]
Based on the above and our previous studies,
a
proposed pathway is delineated (Scheme 3). First, acetophenone
1) easily reacts with sulfonyl hydrazide (2) to give
(
sulfonylhydrazone I, which is oxidized by pyridinium tribromide to
affords intermediate 7. Simultaneously, Sulfonyl hydrazide (2)
reacts with pyridinium tribromide to yield sulfenyl bromide 12. In
(
a) mCPBA (2 equiv), CH
Pd(OAc) (5 mol %), XPhos (10 mol %), K
h. (c) p-MeC CCH (1.2 equiv), Pd(PPh
equiv), CH CN, 70 °C, 3 h. (d) TMSA (1.5 equiv), PdCl
10 mol %), Et N (1.5 equiv), PPh (10 mol %), toluene, 70 °C, 2 h. Tol =
p-tolyl. TMSA trimethylsilylacetylene. XPhos
-dicyclohexylphosphino-2’, 4’, 6’-triisopropylbiphenyl.
2
Cl
2
, 60 °C, 4 h. (b) p-MeC
CO (2 equiv), toluene, 110 °C, 12
(5 mol %), CuI (5 mol %), Et N (2
(PPh (5 mol %), CuI
6 4 2
H B(OH) (2 equiv),
2
2
3
the reaction process, Py.HBr
HOBr, the three of which react to give water and regenerate
Py.HBr to continue the catalytic cycle, so 0.5 equiv. of Py.HBr is
3
is converted into HBr, Py.HBr and
6
H
4
3
)
4
3
3
2
3 2
)
3
3
(
3
3
enough in the transformation. Subsequently, intermediate II,
isomerization of 7, further react with 12 to give the major target
product E-3a and minor product Z-3a, while a part of II via path b
continue to react with bromide afford 8, and then react with 12
=
=
2
[
5]
to furnish E-3a and Z-3a.
Conclusions
In summary, we have developed an unprecedented
metal-free reaction for synthesis of β-bromoalkenyl sulfides via
deoxygenative bromination/olefin-tion/sulfenylation process
using commercially available ketones, sulfonyl hydrazides and
pyridinium tribromide as starting materials. In the presence of 50
mol % pyridinium tribromide, a range of arylsulfonyl hydrazides
smoothly reacted with various ketones to give structurally diverse
β-bromoalkenyl sulfides with high regio- and stereoselectivity.
This novel methodology not only obviates the use of alkynes and
traditional sulfenylating agents, but also reveals that ketones can
be used as precursors of vinyl bromides. Importantly, the versatile
synthetic utilize of β-bromoalkenyl sulfides revealed its great
potential value in organic and medicinal chemistry.
Scheme 3 Plausible Reaction Mechanism.
Experimental
General Information. Reactions were monitored through thin
layer chromatography (TLC) on 0.30 mm SiliCycle silica gel plates
and visualized under UV light. All known compounds were
1
13
identified by H NMR, C NMR and compared with previously
reported data. NMR spectra of the new products were recorded
using Bruker AC-300 or Bruker AC-500 instruments, calibrated to
1
13
CDCl
3
as the internal reference (7.26 and 77.0 ppm for H and
C
NMR spectra, respectively). Chemical shifts (δ) and coupling
constants (J) were expressed in ppm and Hz, respectively. The
following abbreviations indicated the multiplicities: s, singlet; d,
doublet; t, triplet; q, quartet; m, multiplet. Mass spectra were
taken on a Finnigan TSQ Quantum-MS instrument in the
electrospray ionization (EI), electron spray ionization (ESI) or
atmospheric pressure chemical iosziaa-lion (APCI) mode.
Sulfonyl hydrazides (except 2a) and compounds 5 were
prepared according to literature procedures. The rest of chemical
reagents were obtained from commercial suppliers.
To showcase the utility of this methodology, further
transformation were conducted as shown in Scheme 4. Upon
treatment with m-CPBA, E-3a successfully converted into the
corresponding oxidized products E-13a in a yield of 87%. The
presence of carbon–bromine bond can be subsequently used in a
[18]
[18]
[14]
This article is protected by copyright. All rights reserved.

1
General Procedures for the Synthesis of β-Bromoalkenyl Sulfides
3 or 4). To a solution of sulfonyl hydrazide 2 (0.40 mmol) in
n-hexane (0.5 mL) was added acetophenone 1 (0.20 mmol) and
oil (70%, 44.7 mg); H NMR (300 MHz, CDCl
3
) δ 7.36 (d, J = 5.7 Hz,
(
2H), 7.28 (t, J = 7.8 Hz, 3H), 7.14 (d, J = 7.5 Hz, 3H), 6.84 (s, 1H),
2.39 (s, 3H), 2.34 (s, 3H); C NMR (75 MHz, CDCl ) δ 138.0, 137.7,
3
13
pyridinium tribromide (31.98 mg, 0.10 mmol). The resulting
mixture was stirred at 120 C (oil bath) under air for 3 h, cooled to
room temperature, and purified by silica gel chromatography,
137.5, 131.5, 130.3, 130.0, 129.9, 129.6, 128.1, 127.0, 126.1,
o
+
+
116.3, 21.5, 21.2; HRMS (APCI) m/z calcd. for C16
319.0151, found 319.0158.
H16BrS (M+H)
eluting with petroleum ether to give mainly desired product 3 or
(E)-(2-bromo-2-(4-fluorophenyl)vinyl)(4-methoxyphenyl) sulfane
1
4
.
(E-3e), light yellow oil (52%, 35.3 mg); H NMR (300 MHz, CDCl
3
) δ
[
14]
The synthesis of E-13a. To a solution of E-3a (61.05 mg, 0.20
mmol) in CH Cl (1.0 mL) was added mCPBA (86.29 mg, 0.50
mmol). The resulting mixture was stirred at 60 C for 4 h, cooled
to room temperature, and purified by silica gel chromatography,
eluting with petroleum ether/ethyl acetate (10:1), to give E-13a
7.58–7.53 (m, 2H), 7.35 (d, J = 8.1 Hz, 2H), 7.08 (t, J = 8.4 Hz, 2H),
1
3
2
2
6.88 (d, J = 8.1 Hz, 2H), 6.79 (s, 1H), 3.81 (s, 3H); C NMR (75 MHz,
CDCl ) δ 162.5 (d, J = 248.18 Hz), 159.8, 134.8, 133.7, 133.0, 131.0
(d, J = 8.4 Hz), 128.6, 125.0, 115.2 (d, J = 21.8 Hz), 113.6, 55.4;
o
3
+
+
HRMS (APCI) m/z calcd. for C15
338.9848.
H13BrFOS (M+H) 338.9849, found
(
58.7 mg) in 87% yield.
[15]
The synthesis of E-13b. Under argon atmosphere, to a solution
of E-3a (61.05 mg, 0.20 mmol) in anhydrous toluene (2.0 mL) was
(E)-(2-bromo-2-(4-chlorophenyl)vinyl)(4-methoxyphenyl) sulfane
1
(E-3f), light yellow oil (54%, 38.4 mg); H NMR (300 MHz, CDCl
3
) δ
2
CO
3
1
3
2
o
layers were washed with brine and dried over anhydrous MgSO
4
.
1
Concentration in vacuo followed concentration in vacuo followed
by silica gel chromatography, eluting with petroleum ether, to
give E-13b (56.3 mg) in 89% yield.
[
16]
The synthesis of E-13c. Under argon atmosphere, to a solution
of E-3a (70.45 mg, 0.20 mmol) in anhydrous CH CN (1.0 mL) was
added 4-methylphenylacetylene (27.88 mg, 0.24 mmol), Et
+
3
2
OS
3
3
N
(
(
40.48 mg, 0.40 mmol), CuI (1.90 mg, 0.01 mmol) and Pd(PPh
)
4
o
11.56 mg, 0.01 mmol). The reaction mixture was heated at 70 C
3
) δ
for 3 h, cooled to room temperature. The product was extracted
with ethyl acetate (10 mL) three times. The combined organic
layers were washed with brine and dried over anhydrous MgSO .
4
7.73 (d, J = 8.1 Hz, 2H), 7.36–7.30 (m, 4H), 6.87 (d, J = 8.4 Hz, 2H),
1
3
6.81 (s, 1H), 3.81 (s, 3H); C NMR (75 MHz, CDCl
3
) δ 159.8, 137.3,
137.0, 133.1, 130.7, 129.5, 114.9, 114.9, 113.3, 94.8, 55.5; HRMS
+
+
Concentration in vacuo followed concentration in vacuo followed
by silica gel chromatography, eluting with petroleum ether, to
give E-13c (61.3 mg) in 90% yield.
(APCI) m/z calcd. for C15
446.8913.
H13BrIOS (M+H) 446.8910, found
(E)-(2-bromo-2-(3-bromophenyl)vinyl)(p-tolyl)sulfane (E-3i), light
[
17]
1
The synthesis of E-13d. To a solution of E-3a (70.45 mg, 0.20
yellow oil (61%, 48.8 mg); H NMR (300 MHz, CDCl
3
) δ 7.72 (s, 1H),
7.52–7.44 (m, 2H), 7.36 (d, J = 7.8 Hz, 2H), 7.20–7.23 (m, 1H), 6.88
1
3
(d, J = 8.4 Hz, 2H), 6.84 (s, 1H), 3.81 (s, 3H); C NMR (75 MHz,
CDCl ) δ 159.9, 139.4, 133.2, 132.0, 131.9, 130.2, 129.7, 127.6,
124.8, 122.2, 114.9, 112.3, 55.5; HRMS (APCI) m/z calcd. for
3
+
+
C
15
H13Br
2
OS (M+H) 398.9048, found 398.9041.
(E)-(2-bromo-2-(4-methoxyphenyl)vinyl)(p-tolyl)sulfane
(E-3j),
1
light yellow oil (61%, 40.9 mg); H NMR (300 MHz, CDCl
3
) δ 7.51 (d,
J = 8.7 Hz, 2H), 7.28 (d, J = 8.1 Hz, 2H), 7.13 (d, J = 8.1 Hz, 2H), 6.91
13
(d, J = 8.4 Hz, 2H), 6.78 (s, 1H), 3.83 (s, 3H), 2.33 (s, 3H); C NMR
(125 MHz, CDCl ) δ 159.9, 137.5, 131.6, 130.6, 130.2, 130.0, 125.7,
116.7, 113.8, 113.5, 55.3, 21.0; HRMS (EI) m/z calcd. for
15BrOS (M) 334.0027, found 334.0037.
H), 7.42–7.27 (m, 5H), 7.14 (d, J = 7.8 Hz, 2H), 6.86 (s, 1H), 2.34 (s, (E)-5-(1-bromo-2-(p-tolylthio)vinyl)benzo[d][1,3]dioxole (E-3k),
3
16
C H
1
3
) δ 7.30–
7.26 (m, 2H), 7.14 (d, J = 7.8 Hz, 2H), 7.07–7.04 (m, 2H), 6.86–6.77
1
3
(m, 1H), 6.77 (s, 1H), 6.00 (s, 2H), 2.34 (s, 3H); C NMR (75 MHz,
CDCl ) δ 148.1, 147.4, 137.7, 131.4, 131.4, 130.3, 130.0, 126.6,
123.4, 115.7, 109.5, 107.8, 101.5, 21.1; HRMS (APCI) m/z calcd.
3
+
+
2
for C16H14BrO S (M+H) 348.9892, found 348.9894.
(E)-(2-bromo-2-(naphthalen-2-yl)vinyl)(p-tolyl)sulfane
(E-3l),
) δ 8.00 (s,
1
light yellow oil (64%, 45.5 mg); H NMR (300 MHz, CDCl
3
1
3
25.4, 115.7, 20.3, 20.0; HRMS (EI) m/z calcd. for C16
18.0078, found 318.0075.
H
15BrS (M)
1
3
(
E)-(2-bromo-2-(o-tolyl)vinyl)(p-tolyl)sulfane (E-3c), light yellow
1
oil (69%, 44.1 mg); H NMR (300 MHz, CDCl
3
) δ 7.26–7.23 (m, 6H),
1
3
7
.12 (d, J = 7.2 Hz, 2H), 6.86 (s, 1H), 2.39 (s, 3H), 2.33 (s, 3H);
C
3
NMR (75 MHz, CDCl ) δ 137.6, 137.4, 136.2, 131.0, 130.5, 130.0,
1
29.4, 129.1, 128.3, 126.2, 115.8, 21.1, 19.4; HRMS (APCI) m/z
+
+
1
calcd. for C16
H16BrS (M+H) 319.0151, found 319.0150.
(
E)-(2-bromo-2-(m-tolyl)vinyl)(p-tolyl)sulfane (E-3d), light yellow
7.09 (d, J = 8.1 Hz, 2H), 2.96–2.88 (m, 2H), 2.42–2.32 (m, 2H), 2.32
This article is protected by copyright. All rights reserved.

(
1
0
7
(m, 2H), 2.32 (s, 3H), 1.68–1.58 (m, 1H), 1.52 (s, 1H), 1.14 (t, J =
7
C
(
colorless oil (45%, 33.1 mg); H NMR (300 MHz, CDCl
=
(m, 1H), 2.47–2.37 (m, 1H), 2.31 (s, 3H), 2.12–2.02 (m, 1H), 1.78–
1
1
2
C
(
oil (62%, 36.1 mg); H NMR (300 MHz, CDCl
2
1
HRMS (EI) m/z calcd. for C14
(
yellow oil (64%, 39.6 mg); H NMR (300 MHz, CDCl
7
140.5, 139.4, 138.8, 137.0, 136.9, 133.0, 130.0, 129.9, 129.8,
129.0, 128.3, 127.7, 127.1, 124.0, 21.1, 21.1; HRMS (APCI) m/z
calcd. for C22H21S (M+H) 317.1358, found 317.1356.
1
3
+
+
(d, J = 8.18 Hz), 130.0 (d, J = 3.53 Hz,), 129.1, 129.0, 128.2, 126.6,
1
C
17.0,116.4 (d, J = 21.98 Hz); HRMS (APCI) m/z calcd. for
(E)-(2-phenyl-4-(p-tolyl)but-1-en-3-yn-1-yl)(p-tolyl)sulfane
(E-13c), colorless oil (90%, 61.3 mg); H NMR (300 MHz, CDCl
+
+
1
14
H11BrFS (M+H) 308.9743, found 308.9738.
3
)
(
7.71 (d, J = 7.8 Hz, 2H), 7.39 (m, 7H), 7.14 (m, 4H), 7.01 (s, 1H),
2.35 (d, J = 3.3 Hz, 6H); C NMR (75 MHz, CDCl ) δ 138.1, 137.9,
3
1
13
yellow oil (60%, 39.1 mg); H NMR (300 MHz, CDCl
7
CDCl
1
3
136.8, 135.0, 131.3, 130.8, 130.0, 129.0, 128.4, 128.3, 128.2,
127.8, 120.3, 120.2, 89.7, 88.8, 21.4, 21.1; HRMS (APCI) m/z calcd.
+
+
for C24
H
21S (M+H) 341.1358, found 341.1364.
(E)-trimethyl(3-phenyl-4-(p-tolylthio)but-3-en-1-yn-1-yl) silane
1
(
(E-13d), colorless oil (80%, 51.6 mg); H NMR (300 Hz, CDCl
3
) δ
yellow oil (56%, 41.5 mg); H NMR (300 MHz, CDCl
7.71–7.66 (m, 2H), 7.48–7.36 (m, 5H), 7.20 (d, J = 8.1 Hz, 2H), 7.03
1
3
7
3
) δ 138.0,
136.9, 131.0, 130.0, 128.4, 128.3, 128.1, 127.8, 125.3, 119.7,
1
+
1
C
105.7, 93.0, 21.1, 0.0; HRMS (APCI) m/z calcd. for C20
(M+H) 323.1284, found 323.1286.
H23SSi
+
(
E)-(2-bromo-2-phenylvinyl)(4-iodophenyl)sulfane (E-4e), light
1
yellow oil (61%, 50.9 mg); H NMR (300 MHz, CDCl
3
) δ 7.63 (d, J =
Supporting Information
The supporting information for this article is available on the
WWW under https://doi.org/10.1002/cjoc.2018xxxxx.
.8 Hz, 2H), 7.52 (d, J = 7.5 Hz, 2H), 7.42–7.33 (m, 3H), 7.09 (d, J =
1
3
.5 Hz, 2H), 6.83 (s, 1H); C NMR (75 MHz, CDCl
3
) δ 143.0, 138.2,
31.6, 131.1, 129.2, 129.0, 128.2, 124.8, 119.0, 92.4; HRMS (APCI)
+
+
(
E)-(2-bromo-2-phenylvinyl)(4-(tert-butyl)phenyl)sulfane (E-4f), Acknowledgement
1
light yellow oil (54%, 37.5 mg); H NMR (300 MHz, CDCl
J = 7.8 Hz, 2H), 7.39–7.31 (m, 7H), 6.88 (s, 1H), 1.31 (s, 9H);
NMR (75 MHz, CDCl ) δ 150.9, 137.6, 131.4, 130.1, 129.0, 128.9,
1
C
3
) δ 7.57 (d,
13
The acknowledgements come at the end of an article after the
conclusions and before the notes and references This work was
financially supported by the National Natural Science Foundation
of China (21502182, 21102179 and 21572271), Qing Lan Project
of Jiangsu Province, National Found for Fostering Talents of Basic
Science (J1030830), the Fundamental Research Funds for the
Central Universities (3010050077) and Postgraduate Scientific
Research Innovation Projects of Jiangsu Province (KYCX17_0664).
C
3
28.1, 127.1, 126.3, 116.2, 34.6, 31.2; HRMS (APCI) m/z calcd. for
+ +
18
H20BrS (M+H) 347.0464, found 347.0465.
E)-(2-bromo-2-phenylvinyl)(4-methoxyphenyl)sulfane
(
(E-4g),
) δ 7.57 (d,
1
light yellow oil (41%, 26.3 mg); H NMR (300 MHz, CDCl
3
J = 7.5 Hz, 2H), 7.42–7.33 (m, 5H), 6.87 (d, J = 8.4 Hz, 2H), 6.81 (s,
1
1
3
H), 3.80 (s, 3H); C NMR (125 MHz, CDCl
3
) δ 159.8, 137.6, 134.8,
1
33.0, 129.0, 128.9, 128.4, 128.2, 125.4, 114.9, 55.4; HRMS (APCI)
+
+
m/z calcd. for C15
H14BrOS (M+H) 320.9943, found 320.9946.
References
(
E)-(2-bromo-2-(4-methoxyphenyl)vinyl)(mesityl)sulfane (E-4h),
1
[1] For reviews, see: a) Modern Carbonyl Olefination (Ed.: Takeda, T.),
Wiley-VCH, Weinheim (Germany), 2004. (b) Preparation of Alkenes:
A Practical Approach (Ed.: Williams, J. M. J.), Oxford University Press,
Oxford (UK), 1996.
light yellow oil (40%, 29.1 mg); H NMR (300 MHz, CDCl
3
) δ 7.57 (d,
J = 8.4 Hz, 2H), 6.92–6.91 (m, 4H), 6.32 (s, 1H), 3.85 (s, 3H), 2.42 (s,
1
3
6
1
H), 2.27 (s, 3H); C NMR (75 MHz, CDCl
30.4, 130.4, 129.2, 128.1, 127.4, 114.3, 113.5, 55.3, 21.9, 21.0;
19BrOS (M) 362.0340, found
3
) δ 163.3, 142.3, 139.0,
[
2] (a) Modha, S. G.; Mehta, V. P.; Van der Eycken, E. V. Chem. Soc. Rev.
013, 42, 5042−5055. (b) Chen, J.; Tang, Z.; Qiu, R.; He, Y.; Wang, X.;
HRMS (EI) m/z calcd. for C18
62.0321.
E)-(2-bromo-2-(4-methoxyphenyl)vinyl)(naphthalen-1-yl)
H
2
3
(
Li, N.; Yi, H.; Au, C.-T.; Yin, S.-F.; Xu, X. Org. Lett. 2015, 17, 2162. (c)
Zhao, W.; Yang, C.; Cheng, Z.; Zhang, Z.; Green Chem. 2016, 18, 995.
3] Caló, V.; Scorrano, G.; Modena, G. J. Org. Chem. 1969, 34, 2020.
1
sulfane (E-4i), light yellow oil (65%, 48.3 mg); H NMR (300 MHz,
CDCl ) δ 7.82–7.75 (m, 4H), 7.56–7.40 (m, 5H), 6.95–6.88 (m, 3H),
3
.83 (s, 3H); C NMR (75 MHz, CDCl ) δ 160.0, 133.7, 132.5, 132.3,
[
3
1
3
[4] (a) Iwasaki, M.; Fujii, T.; Yamamoto, A.; Nakajima, K.; Nishihara, Y.
3
This article is protected by copyright. All rights reserved.

Chem.-Asian J. 2014, 9, 58. (b) Iwasaki, M.; Fujii, T.; Nakajima, K.;
2017, 19, 4552.
Nishihara, Y. Angew. Chem. Int. Ed. 2014, 53, 13880. (c) Benati, L.; [15] Martin, R.; Buchward, S. L. Acc. Chem. Res. 2008, 41, 1461.
Montevecchi, P. C. Tetrahedron 1993, 49, 5365.
5] Zyk, N. V.; Beloglazkina, E. K.; Belova, M. A.; Zefirov, N. S. Russ. Chem.
Bull. 2000, 49, 1846.
6] (a) Taniguchi, N. Tetrahedron 2009, 65, 2782. (b) Taniguchi, N.
Synlett 2008, 849.
[16] Kawaguchi, S.; Gonda, Y.; Masuno, H. Tetrahedron Lett. 2014, 55,
[
[
6779.
[17] Giri, S. S.; Lin, L.-H.; Jadhav, P. D.; Liu, R.-S. Adv. Synth. Catal. 2017,
359, 590.
[18] Liu, C.; Ding, L.; Guo, G.; Liu, W.; Yang, F.-L. Org. Biomol. Chem. 2016,
14, 2824.
[
[
7] Lin, Y.-M.; Lu, G.-P.; Cai, C.; Yi, W.-B. Org. Lett. 2015, 17, 3310.
8] (a) Li, Y.; Xie, W.; Jiang, X. Chem. Eur. J. 2015, 21, 16059. (b) Xiao, X.; [19] Zou, L.-H.; Priebbenow, D. L.; Wang, L.; Mottweiler, J.; Bolm, C.; Adv.
Feng, M.; Jiang, X. Chem. Commun. 2015, 51, 4208. Synth. Catal. 2013, 355, 2558.
9] (a) Yang, F.-L.; Tian, S.-K. Angew. Chem. Int. Ed. 2013, 52, 4929. (b) [20] Xiang, J.; Yuan, R.; Wang, R.; Yi, N.; Lu, L.; Zou, H.; He, W. J. Org.
Yang, F.-L.; Wang, F.-X.; Wang, T.-T.; Wang, Y.-J.; Tian, S.-K. Chem. Chem. 2014, 79, 11378.
Commun. 2014, 50, 2111. (c) Yang, F.-L.; Gui, Y.; Yu, B.-K.; Jin, Y.-X.; [21] Gao, Y.; Wu, W.; Huang, Y.; Huang, K.; Jiang, H. Org. Chem. Front.
[
Tian, S.-K. Adv. Synth. Catal. 2016, 358, 3368. (d) Wang, F.-X.; Tian,
S.-K.; J. Org. Chem. 2015, 80, 12697. (e) Yang, F.-L.; Gui, Y.; Yu, B.-K.;
Jin, Y.-X.; Tian, S.-K.; Adv. Synth. Catal. 2016, 358, 3368.
2014, 1, 361.
(
The following will be filled in by the editorial staff)
Manuscript received: XXXX, 2017
Revised manuscript received: XXXX, 2017
Accepted manuscript online: XXXX, 2017
Version of record online: XXXX, 2017
[
[
[
[
10] Bamford, W. R.; Stevens, T. S.; J. Chem. Soc. 1952, 4735.
11] Shapiro, R. H.; Heath, M. J.; J. Am. Chem. Soc. 1967, 89, 5734.
12] Bao, Y.; Yang, X.; Zhou, Q.; Yang, F. Org. Lett. 2018, 20, 1966.
13] Sar, D.; Bag, R.; Bhattacharjee, D.; Deka, R. C.; Punniyamurthy, T. J.
Org. Chem. 2015, 80, 6776.
[
14] Kawashima, H.; Yanagi, T.; Wu, C.-C.; Nogi, K.; Yorimitsu. H. Org. Lett.
This article is protected by copyright. All rights reserved.

Entry for the Table of Contents
Page No.
Metal-Free Synthesis of β-Bromoalkenyl
Sulfides
via
Deoxygenative
Bromination/Olefination/Sulfenylation of
Ketones with Sulfonyl Hydrazides and
Pyridinium Tribromide
A
novel metal-free method for synthesis of β-bromoalkenyl sulfides via deoxygenative
bromination/olefination/sulfenylation process using commercially available ketones, sulfonyl
hydrazides and pyridinium tribromide as starting materials has been developed.
a
a
a
Yishu Bao, Lingyu Zhong, Qiaodan Hou,
a
a
Ruihua Shi, Qingfa Zhou, * and Fulai Yang
a
*
This article is protected by copyright. All rights reserved.