Chlorination of Conjugated Nitroalkenes with PhICl 2and so 2Cl 2for the Synthesis of α-Chloronitroalkenes

Article abstract of DOI:10.1055/s-0040-1707396

Chlorination of conjugated nitroalkenes with iodobenzene dichloride or sulfuryl chloride to give target α-chloronitroalkenes in good yields is described. Details of the procedure depend on the donating ability of the nitroalkene substituents. The activity of the described chlorinating agents increases in order 'PhICl ₂/Py' < 'SO ₂Cl ₂' < 'SO ₂Cl ₂/HCl' with the former producing the best yields for highly donating substrates and the latter for non-activated groups. An autocatalytic role of hydrogen chloride and the chemoselectivity of chlorination were also demonstrated.

Full text of DOI:10.1055/s-0040-1707396

SYNTHESIS
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© Georg Thieme Verlag Stuttgart · New York
2020, 52, A–J
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A. A. Fadeeva et al.
Paper
Synthesis
Chlorination of Conjugated Nitroalkenes with PhICl2 and SO2Cl2
for the Synthesis of -Chloronitroalkenes
Anastasia A. Fadeevaa,b
Sema L. Ioffea
Andrey A. Tabolin*a
- 20 examples
R
R
PhICl2 or SO2Cl2
Py or Et3N
- 55–96% yield
- simple reagents
and procedure
- broad scope
0
0
0
0-0
0
0
3-3
2
4
1-8
2
7
9
Cl
NO2
a N. D. Zelinsky Institute of Organic Chemistry,
Russian Academy of Sciences, Leninsky prosp. 47,
Moscow 119991, Russian Federation
atabolin@ioc.ac.ru
NO2
tabolin87@mail.ru
b Higher Chemical College, D. Mendeleev Universi-
ty of Chemical Technology of Russia, Miusskaya
sq. 9, Moscow 125047, Russian Federation
Received: 18.03.2020
Accepted after revision: 28.04.2020
Published online: 14.05.2020
as Michael addition, Diels–Alder cycloaddition, (3+2)-cyc-
loaddition and other ring-forming reactions, including their
asymmetric variants.1 Importantly, the high activating abil-
ity of the nitro group allows for installation of the prerequi-
site functionality into the target molecule using appropri-
ately functionalized substrates. Thus, -halonitroalkenes
are used in the synthesis of halonitroalkyl-substituted
products and (after elimination of HHal and/or HNO2) halo-
vinyl-substituted products and aromatics (Scheme 1).2 In
such a manner, fluorinated 1,2,3-triazoles,3 fluorinated in-
dolizines and their derivatives,4 various fluorovinyl deriva-
tives,5 chlorinated flavone derivatives,6 chloropyrazoles,7
chloroisoxazolidines,8 furane derivatives9 and many other
compounds were prepared.10 However, -halonitroalkenes
are not always readily available substrates. Indeed, electro-
philic substitution in the respective non-halogenated sub-
strates 1 could be considered as the most straightforward
pathway toward halonitroalkenes 2. Nevertheless, this pro-
cedure is widely used only for bromination;11 the synthesis
of other -halonitroalkenes often requires indirect routes.12
For instance, chlorination of nitroalkenes is poorly de-
scribed in the literature, presumably because of the danger-
ous nature of gaseous chlorine.13–15 Particularly, Zhao et al.
reported a few examples of the formation of chloro-
nitroalkenes during attempted chloroformyloxylation of
alkenes using the PhICl2/DMF/H2O system.15 Therefore, the
most popular procedure for the preparation of chloro-
nitroalkenes is the Dauzonne method, starting from aromatic
aldehydes and bromonitromethane (Scheme 2).16 Despite a
broad substrate scope, it has drawbacks such as the use of
large amounts of reagents (e.g., 10-fold excess of
DOI: 10.1055/s-0040-1707396; Art ID: ss-2020-z0149-op
Abstract Chlorination of conjugated nitroalkenes with iodobenzene
dichloride or sulfuryl chloride to give target -chloronitroalkenes in
good yields is described. Details of the procedure depend on the donat-
ing ability of the nitroalkene substituents. The activity of the described
chlorinating agents increases in order ‘PhICl2/Py’ < ‘SO2Cl2’ < ‘SO2Cl2/HCl’
with the former producing the best yields for highly donating substrates
and the latter for non-activated groups. An autocatalytic role of hydro-
gen chloride and the chemoselectivity of chlorination were also demon-
strated.
Key words nitroalkenes, halogenation, chlorination, nitro com-
pounds, chemoselectivity
Conjugated nitroalkenes serve as versatile intermediates
for organic synthesis. The high electrophilicity of these sub-
strates gives rise to diverse chemical transformations such
Ar
F
F
Ar
F
N
N
N
H
Ar
N
N
H
Ar
Ar
R'
Ar'
Cl
Hal
NO2
R
NO2
NO2
O
N
Ar
O
OH
R'
Ar
Cl
R
Ar'
Cl
NO2
Ar
+
Me2NH2 Cl–) and formation of variable amounts of the cor-
O
O
O
N
responding bromo-derivatives as side-products.9a Thus,
considering the importance of organochlorine com-
pounds,17 development of new methods for the synthesis of
-chloronitroalkenes is desirable. We envisioned that
Ar
N
R
Scheme 1 Application of -halogenated nitroalkenes in organic syn-
thesis
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J
Georg Thieme Verlag KG, Rüdigerstraße 14, 70469 Stuttgart, Germany

B
A. A. Fadeeva et al.
Paper
Synthesis
employment of a suitable, readily available equivalent of Cl2
would allow direct chlorination of conjugated nitroalkenes.
Here, we describe our results on the use of PhICl2 and
SO2Cl2 for the preparation of -chloronitroalkenes.
imide and 1,3-dichloro-5,5-dimethylhydantoin (entries 1–
3), incomplete consumption of starting material was ob-
served, indicating insufficient activity of the chlorinating
agent. tert-Butyl hypochlorite and trichloroisocyanuric acid
gave higher conversion, albeit with moderate yields (entries
4–6). Much better results were obtained using iodobenzene
dichloride, which provided good yields of target product 2a.
Further variations showed little dependence on the solvent
(entries 7–9) and pyridine was an appropriate base (entries
7 and 11). Apart from PhICl2, another positive result was
obtained with commercially available reagent, sulfuryl
chloride, which also provided the target chlorinated alkene
2a in >90% yield (entry 16). Here, higher yield was obtained
with triethylamine as base and separation of chlorination
and elimination steps (see Scheme 4 below for further de-
tails). Notably, for both PhICl2 and SO2Cl2, immediate addi-
tion of Et3N and chlorinating reagent to alkene 1 gave inferi-
or results (entries 11 and 13) due to higher sensitivity of
the amine toward oxidation compared to substrate 1a. In
turn, the ability of Et3N to quench SO2Cl2 was useful to pre-
vent side reactions. For instance, quenching with pyridine
resulted in lower yield, which we ascribed to chlorination of
the C=C bond in the target conjugated nitroalkene 2a (entry
Me2NH2+Cl–
(9–10 equiv)
KF (10 mol%)
Ar
Ar
Br
Cl
NO2
+
literature approach
presented approach
O
toluene/xylene
100–140 °C
NO2
(2 equiv.)
PhICl2 or SO2Cl2
(1.1–2 equiv)
base
Ar
Ar
Cl
NO2
CH2Cl2, 0 °C to r.t.
NO2
1
2
Scheme 2 Approaches toward -chloronitroalkenes
We started our study with the model reaction of ni-
troalkene 1a. Various commercial or readily available chlo-
rinating agents were tested under different conditions (Ta-
ble 1). A priori electron-withdrawing nitro group should
drastically deactivate a C=C double bond toward electro-
philic substitution. Indeed, for cases of N-chlorosuccin-
Table 1 Screening of the Reaction Conditions for the Synthesis of Nitroalkene 2a
Ar
Ar
conditions
Cl
NO2
2a
NO2
1a
(Ar = 4-MeOC6H4)
Entry
Reagents (equivalents)
Solvent, temperature, time
Recovery of 1a (%)a
Yield 2a (%)a
1
2
NCS (1.2), Py (2)
CH2Cl2, r.t., 3 h
ClCH2CH2Cl, 70 °C, 15 h
CH2Cl2, r.t., 3 h
CH2Cl2, r.t., 4 h
CH2Cl2, r.t., 3 h
CH2Cl2, r.t., 2 d
CH2Cl2, r.t., 3 h
THF, r.t., 3 h
71
34
65
51
0
14
58
11
34
31
66
87
85
82
69
2
NCS (1.2), Py (2)
3
1,3-dichloro-5,5-dimethylhydantoin (1.2), Py (2)
(CONCl)3 (0.4), Py (2)
(CONCl)3 (1.2), Py (2)
t-BuOCl (2), Py (2)
4
5
6
5
7
PhICl2 (1.2), Py (2)
0
8
PhICl2 (1.2), Py (2)
0
9
PhICl2 (1.2), Py (2)
MeCN, r.t., 3 h
CH2Cl2, 0 °C, 3 h
CH2Cl2, r.t., 4 d
CH2Cl2, r.t., 3 d
CH2Cl2, r.t., 3 h
0
10
11
12
13
14
PhICl2 (1.2), Py (2)
17
82
15
63
0
PhICl2 (1.2), Et3N (2)
SO2Cl2 (1.1), Py (2)
82
33
52
SO2Cl2 (1.1), Et3N (2)
SO2Cl2 (1.1),
then Py (2)
CH2Cl2, r.t., 3 h,
then 1.5 h
15
SO2Cl2 (1.1),
then Et3N (1.7)
CH2Cl2, r.t., 3 h,
then 1 h
0
0
96
16
SO2Cl2 (1.1),
then Et3N (1.7)
CH2Cl2, 0 °C, 1 d,
then 1 h
96
a Based on 1H NMR spectroscopic analysis with internal standard (methyl 3,5-dinitrobenzoate).
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
Paper
Synthesis
14). Overall, two procedures (entries 7 and 16) were chosen
for further investigation.
easy purification of target compounds 2 since ionic (e.g.,
triethylammonium salts) and volatile (e.g., SO2) by-prod-
ucts are removed via extractive work-up and evaporation.
The structures of target nitroalkenes 2 were supported by
1H and 13C NMR spectroscopic analysis as well as by HRMS
or elemental analysis data. In all cases, a single isomer at
the C=C double bond was observed, the Z-configuration of
which was assigned by comparison with reported data.16a
To take a deeper look at the chlorination of nitroalkenes
with sulfuryl chloride, we analyzed the content of the reac-
tion mixture (1a+SO2Cl2) prior to the addition of triethyl-
amine. Interestingly, it consisted of two diastereomers of
dichloride 3a (dr = 1.6:1, total yield 75% according to 1H
NMR analysis) and chloronitroalkene 2a (21% yield accord-
ing to 1H NMR analysis) (see Scheme 4). The low diastereo-
selectivity of 3a provided evidence for the intermediacy of
benzylic cation A, rather than chloronium structure B, sta-
bilized by a p-methoxy substituent.19 During the course of
the reaction, A can add a chloride anion from either side of
the plane of the molecule. Moreover, prolonged exposure of
the reaction mixture did not change the 2a/3a ratio. This
also accounted for the formation of cation A, which can suf-
fer elimination of a proton, leading to 2a. In turn, formation
of 2a meant the accumulation of hydrogen chloride in the
reaction mixture. Therefore, we performed qualitative ex-
periments to check whether HCl could influence the chlori-
nation process (Scheme 4, Figure 1). Indeed, addition of 0.1
equivalent of HCl (as 4 M soln in 1,4-dioxane) resulted in
For the determination of substrate scope, a wide variety
of nitroalkenes 1 was selected (Scheme 3). The PhICl2-based
procedure (method A) was found to give good yields of tar-
get products 2 for rather electron-rich substrates, e.g., those
possessing p-methoxy-substituent. In such a way, ni-
troalkenes 2a–f were obtained. However, the sensitivity of
the reaction to the electronic demand of the aromatic ring
was rather high; for example, attempted syntheses of prod-
ucts 2g and 2j resulted in incomplete consumption of start-
ing material. In the absence of donating substituent, such as
in the case of p-halogen-nitrostyrenes 1m–o, the chlorina-
tion with PhICl2 failed; this is consistent with Zhao’s results,
wherein incomplete consumption of starting materials was
also reported in such cases.15 The SO2Cl2-based procedure
(method B) was found to be complementary to the PhICl2-
based approach. Thus, by using SO2Cl2 as a chlorinating
agent, products 2a, 2b, and 2g–k were successfully pre-
pared. In contrast to method A, the use of method B for ex-
cessively electron-rich substrates (e.g., 1c and 1d) resulted
in mixtures of products, presumably because of chlorina-
tion of the aromatic ring. Scalability of the process was
demonstrated with the preparation of gram quantities of
product 2a. Overall, chlorination with methods A and B
gave products 2a–k, including those with a thiophene ring
and pharmaceutically relevant catechol substituents.18 An
additional advantage of the SO2Cl2-procedure is the rather
Method A: PhICl2, Py, CH2Cl2, r.t., 3 h
Method B: SO2Cl2, CH2Cl2, 0 °C to r.t., 1 d, then Et3N
Method C: SO2Cl2, HCl, 1,4-dioxane/CH2Cl2, r.t., 1–2 d
then K2CO3, Et3N
R
R
Cl
NO2
NO2
1a–s
2a–s
OBn
OMe
OMe
OMe
OMe
O
O
CO2Me
O
CO2Et
Br
O
OMe
Cl
O
OMe
Cl
S
Br
Cl
Cl
Cl
Cl
Cl
Cl
Cl
NO2
2b,
NO2
2c,
NO2
2g,
NO2
2h,
NO2
2i,
NO2
2a,
NO2
2d,
NO2
2e,
NO2
2f,
65% (A)
65% (A)
82% (A)
71% (A)
67% (A)
68% (A)
96% (B)
61% (B)
83% (B)
77% (B)
96% (B)
Cl
F
Cl
Br
Me
OMe
OMe
Cl
Cl
O
Br
Cl
Br
Cl
Cl
Cl
Cl
Cl
Cl
Cl
NO2
Cl
NO2
2l,
NO2
2m,
NO2
2n,
NO2
2o,
NO2
2p,
NO2
2q,
NO2
2r,
NO2
2j,
2s,
72% (C)
NO2
2k,
75% (C)
91% (C)
70% (C)
88% (C)
81% (C)
82% (C)
55% (C)
83% (B)
81% (B)
Scheme 3 Synthesis of -chloronitroalkenes 2 via chlorination of nitroalkenes 1
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

D
A. A. Fadeeva et al.
Paper
Synthesis
significant acceleration of the reaction. At 0 °C (ice-water
bath) nearly full consumption of staring nitroalkene was
achieved within ca. 6 h, whereas in the absence of HCl the
reaction proceeded longer.20 Thus, it can be concluded that
chlorination of 1a is autocatalytic since HCl is released
during the process. We suppose that HCl may form a hydro-
gen bond with an oxygen atom of SO2Cl2, producing a more
electrophilic chlorinating species.21
could compete with the target addition to the side-chain
double bond. For the cases presented in Scheme 3 we ob-
served selective introduction of one chlorine atom to form
the C(Cl)–NO2 moiety. In contrast, this was not the case for
substrates where the activating substituent on the benzene
ring is weaker (or not) conjugated with the C=C–NO2 moi-
ety, but also significantly activate the benzene ring. Thus,
o- and m-methoxy substituted nitroalkenes 1 (Ar = 3-MeOC6H4,
2-MeOC6H4) failed to selectively give target nitroalkenes 2
due to concomitant chlorination of the aromatic ring. How-
ever, in some cases, we achieved the selective formation of
polychlorinated products in reasonable yields. Thus, p-phe-
noxy-substituted substrate 1t gave rise to chlorination of
both C=C–NO2 and the p-position of the benzene ring, ulti-
mately leading to product 2k (Scheme 5). Highly electron-
donating 3,4,5-trimethoxyphenyl substituent also resulted
in aromatic chlorination: for SO2Cl2, product 4 was isolated,
whereas for PhICl2 exhaustive chlorination was observed
with the incorporation of three chlorine atoms in product
5.22
Ar
Ar
Ar
Ar
Ar
Cl
SO2Cl2
CH2Cl2
Cl
NO2
Cl
NO2
2a
Cl
NO2
+
Cl
NO2
NO2
1a
B
A
3a
(dr = 1.6:1)
(Ar = 4-MeOC6H4)
Scheme 4 Chlorination of nitroalkene 1a with SO2Cl2 without Et3N
Cl
O
O
1. SO2Cl2 (3 equiv),
CH2Cl2, r.t., overnight
2. Et3N, 1 h
Cl
NO2
1t
NO2
2k,
65%
Figure 1 Time dependences of yields of reaction components for chlo-
rination of 1a (1 mmol in 2 mL of CH2Cl2) by SO2Cl2 (1.1 mmol) at 0 °C
with and without 0.1 equiv of HCl (Scheme 4, see the Supporting Infor-
mation for full data).
OMe
MeO
Cl
OMe
Cl
1. SO2Cl2 (6 equiv),
CH2Cl2/HCl/1,4-dioxane,
r.t., overnight
2. Et3N, 1 h
OMe
MeO
OMe
The revelation of the critical importance of hydrogen
chloride allowed the chlorination of a wider scope of ni-
troalkenes 1 to be achieved. As was noted above, SO2Cl2 it-
self (method B) successfully chlorinated only electron-rich
substrates. Increase of the acidity of the medium and per-
forming the reaction in the presence of 4 equivalents of HCl
(Scheme 3, Method C) resulted in good yields of chloroni-
troalkenes 2l–r, possessing, for example, p-chloro-, p-bro-
mo-, or o-bromo-phenyl substituents. Moreover, aliphatic
nitroalkene 2s was also prepared in reasonable yield. We
also noted that formation of cations of type A is suppressed
in these cases; no nitroalkenes 2 was observed before treat-
ment with Et3N and the diastereoselectivity of the forma-
tion of dichloride 3n (based on 1H NMR spectroscopic anal-
ysis, dr = 9:1) was high (see the experimental part). These
conditions could account for increased participation of
chloronium cation of type B in the reaction.
NO2
4,
40%
OMe
MeO
Cl
OMe
PhICl2 (5 equiv)
Py (8 equiv)
r.t., overnight
NO2
1u
Cl
Cl
NO2
5,
62%
Scheme 5 Chlorination of nitroalkenes 1t and 1u
In conclusion, we have demonstrated that conjugated
nitroalkenes are chlorinated by either iodobenzene dichlo-
ride or sulfuryl chloride, leading to the corresponding -
chloronitroalkenes in high yields. Appropriate reaction con-
ditions depend on the electronic demands of the substrate.
The most electron-rich substrates required the PhICl2/pyri-
dine system, less electron-rich substrates used the SO2Cl2
Finally, we should note the selectivity of the proposed
method for the chlorination. As was already mentioned, for
aromatic nitroalkenes, electrophilic aromatic substitution
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
Paper
Synthesis
system, and electron neutral substrates required the SO2Cl2/HCl
system. The role of hydrogen chloride in promoting the re-
action with SO2Cl2 was determined.
Chloronitroalkenes 2l–s (Scheme 3, Method C); General Procedure
Nitroalkene 1l–s (1 equiv) was dissolved in CH2Cl2 (2 mL/1 mmol of
nitroalkene), and then SO2Cl2 (2 equiv) and HCl/dioxane (4 M, 4
equiv) were added under argon atmosphere. The mixture was stirred
at r.t. for 1–2 d. After completion of the reaction, K2CO3 (4 equiv) was
added and the mixture was stirred at r.t. for 1 h, then cooled in an ice
bath, and Et3N (3 equiv) was added. After stirring at r.t. for 1 h, the
reaction mixture was extracted with EtOAc/H2O. The aqueous layer
was washed with EtOAc. Combined organic layers were washed with
saturated NaCl solution, dried with anhydrous Na2SO4 and concen-
trated in vacuo to give the crude chloronitroalkene 2.
All reactions were performed in oven-dried (150 °C) glassware. Most
of the chemicals were acquired from commercial sources and used as
received. Petroleum ether (PE) and EtOAc for column chromatography
were distilled. CH2Cl2 was distilled from CaH2 prior to use. Brine refers
to saturated aqueous solution of NaCl. Starting nitroalkenes 1 were
obtained from the corresponding aldehydes and nitromethane using
reported procedures (see the Supporting Information for details).
PhICl2 was prepared upon treatment of PhI in concd aq HCl with
NaClO solution.23 TLC were performed on silica coated on aluminum
with UV254 indicator. Visualization was accomplished with UV light.
Column chromatography was performed on silica (0.04–0.063 mm,
60 Å). NMR spectra were recorded at 300 K with Bruker AM300 and
Fourier 300HD spectrometers at the spectrometer frequencies of 300
MHz (1H NMR) and 75 MHz (13C NMR). Multiplicities are assigned as s
(singlet), d (doublet), t (triplet), q (quadruplet), quint (quintet), m
(multiplet), app (apparent). Assignment of =CHCAr and =CHNO2 for
starting nitroalkenes 1 was made on the basis of 2D NMR analysis for
1i. Assignment of Z-configuration of chloronitroalkenes 2 and 5 was
made on the basis of the chemical shifts for =CHCAr and comparison
to reported data.16a Note: For chloronitroalkenes 2 the signal of
=C(Cl)NO2 is not always clearly visible in regular 13C NMR spectra due
to quadrupole broadening/low intensity, although it can be assigned
(Z)-1-(2-Chloro-2-nitrovinyl)-4-methoxybenzene (2a)
Obtained from nitroalkene 1a (358 mg, 2 mmol) according to Method
A. Reaction time: 3 h. The crude product was subjected to column
chromatography (eluent: 10:1, PE/EtOAc) to give the target ni-
troalkene 2a (348 mg, 82%) as yellow crystals.
Obtained from nitroalkene 1a (895 mg, 5 mmol) according to Method
B. Reaction time: 1 d. The crude product was crystallized from EtOH
to give target nitroalkene 2a (1021 mg, 96%) as yellow crystals.
Rf = 0.38 (9:1, PE/EtOAc) (UV); mp 78–81 °C (Lit.16a 74–75 °C (hex-
ane)).
1H NMR (300 MHz, CDCl3):  = 8.38 (s, 1 H, =CH), 7.89 (d, J = 8.9 Hz,
2 H, CHAr), 7.03 (d, J = 8.9 Hz, 2 H, CHAr), 3.91 (s, 3 H, OMe).
NMR matches previously reported data.16a
1
on the basis of H-13C HMBC. High-resolution mass spectra were ac-
(Z)-1-(Benzyloxy)-4-(2-chloro-2-nitrovinyl)benzene (2b)
quired with a Bruker micrOTOF spectrometer using electrospray ion-
ization (ESI). Elemental analyses were performed in the Analytical
laboratory of N. D. Zelinsky Institute. Low-resolution mass spectra
were acquired at Chromatec-Crystal instrument using electron im-
pact (EI) ionization (200 °C, ionization energy – 70 eV). Intensities
relative to the most intensive peak are reported in parentheses. Melt-
ing points were determined with a Kofler melting point apparatus
and are uncorrected.
Obtained from nitroalkene 1b (255 mg, 1 mmol) according to Method
A with PhICl2 (2 equiv). Reaction time: 3 h. The crude product was
crystallized from EtOAc to give the target nitroalkene 2b (188 mg,
65%) as yellow crystals.
Obtained from nitroalkene 1b (255 mg, 1 mmol) according to Method
B. Reaction time: 1 d. The crude product was crystallized from EtOH
to give the target nitroalkene 2b (221 mg, 77%) as yellow crystals.
Rf = 0.43 (9:1, PE/EtOAc) (UV); mp 160–161 °C (EtOAc).
1H NMR (300 MHz, CDCl3, COSY):  = 8.38 (s, 1 H, =CH), 7.89 (d,
J = 8.6 Hz, 2 H, CHAr), 7.51–7.33 (m, 5 H, CHPh), 7.10 (d, J = 8.8 Hz, 2 H,
CHAr), 5.18 (s, 2 H, CH2Ph).
13C NMR (75 MHz, CDCl3, DEPT, HMBC, HSQC):  = 161.8 (CArO), 136.0
(CPh), 135.4 (CNO2), 133.6 (CHAr), 131.6 (=CH), 128.8 (CHPh), 128.4
(CHPh), 127.5 (CHPh), 122.3 (CAr), 115.5 (CHAr), 70.3 (CH2Ph).
Chloronitroalkenes 2a–g (Scheme 3, Method A); General Proce-
dure
Nitroalkene 1a–g (1 equiv) and pyridine (2 equiv) were dissolved in
CH2Cl2 (2 mL/1 mmol of nitroalkene), and then PhICl2 (1.2 equiv) was
added. The mixture was stirred at r.t. for 3 h (unless otherwise stated)
and extracted with EtOAc/H2O. The aqueous layer was washed with
EtOAc. Combined organic layers were washed with saturated NaCl
solution, dried with anhydrous Na2SO4 and concentrated in vacuo to
give the crude chloronitroalkene 2.
MS (EI, 70 eV): m/z (%) = 291 (1) [M + 2]+, 289 (3) [M]+, 91 (100)
[C7H7]+.
Anal. Calcd. for C15H12ClNO3: C, 62.19; H, 4.18; N, 4.83. Found: C,
62.18; H, 4.05; N, 4.81.
Chloronitroalkenes 2a, 2b, 2h–k (Scheme 3, Method B); General
Procedure
(Z)-4-(2-Chloro-2-nitrovinyl)-1,2-dimethoxybenzene (2c)
Nitroalkene 1a, 1b, 1h–k (1 equiv) was dissolved in CH2Cl2 (2 mL/1 mmol
of nitroalkene), the solution was cooled in an ice bath under argon at-
mosphere, and then SO2Cl2 (1.1 equiv) was added. The mixture was
stirred at 0 °C for 1 d (unless otherwise stated). After completion of
the reaction, Et3N (1.7 equiv) was added and the mixture was stirred
at r.t. for 1 h, and then extracted with EtOAc/H2O. The aqueous layer
was washed with EtOAc. Combined organic layers were washed with
saturated NaCl solution, dried with anhydrous Na2SO4 and concen-
trated in vacuo to give the crude chloronitroalkene 2.
Obtained from nitroalkene 1c (209 mg, 2 mmol) according to Method
A. Reaction time: 3 h. The crude product was subjected to column
chromatography (eluent: 10:1, PE/EtOAc) to give the target ni-
troalkene 2c (314 mg, 65%) as orange crystals.
Rf = 0.22 (9:1, PE/EtOAc) (UV); mp 108–110 °C (EtOH) (Lit.24 113–
114 °C (heptane)).
1H NMR (300 MHz, CDCl3):  = 8.37 (s, 1 H, =CH), 7.48–7.51 (m, 2 H,
CHAr(3 and 5)), 6.99 (d, J = 9.1 Hz, 1 H, CHAr(6)), 3.98 (s, 3 H, OMe),
3.96 (s, 3 H, OMe).
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13C NMR (75 MHz, CDCl3, HSQC, HMBC):  = 152.6 (CAr(1)O), 149.2
(CAr(2)O), 135.3 (CNO2), 131.9 (=CH), 126.8 (CHAr(3 or 5)), 122.3
(CAr(4)), 113.0 (CHAr(3 or 5)), 111.2 (CHAr(6)), 56.1 (OMe), 56.0 (OMe).
Anal. Calcd for C6H3BrClNO2S: C, 26.84; H, 1.13; N, 5.22. Found: C,
26.69; H, 1.09; N, 5.09.
NMR matches previously reported data.24
(Z)-5-(2-Chloro-2-nitrovinyl)benzo[d][1,3]dioxole (2g)
Obtained from nitroalkene 1g (386 mg, 2 mmol) according to Method
B. Reaction time: 3 d. The crude product was crystallized from EtOH
to give the target nitroalkene 2g (436 mg, 96%) as a yellow powder.
(Z)-4-(2-Chloro-2-nitrovinyl)-2-(cyclopentyloxy)-1-methoxyben-
zene (2d)
Obtained from nitroalkene 2d (132 mg, 0.5 mmol) according to
Method A. Reaction time: 3 h. The crude product was subjected to
column chromatography (eluent: 15:1, PE/EtOAc) to give the target
nitroalkene 2d (106 mg, 71%) as yellow crystals.
Rf = 0.48 (5:1, PE/EtOAc) (UV); mp 98–100 °C.
1H NMR (300 MHz, CDCl3):  = 8.32 (s, 1 H, =CH), 7.54 (d, J = 1.8 Hz,
1 H, CHAr), 7.33 (dd, J = 8.2, 1.8 Hz, 1 H, CHAr), 6.93 (d, J = 8.2 Hz, 1 H,
CHAr), 6.10 (s, 2 H, CH2).
Rf = 0.28 (9:1, PE/EtOAc) (UV); mp 85–87 °C (EtOH).
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 151.1 (CArO), 148.5 (CArO),
135.5 (CNO2), 131.7 (=CH), 128.9 (CHAr), 123.6 (CAr), 109.5 (CHAr),
108.9 (CHAr), 102.2 (CH2).
MS (EI, 70 eV): m/z (%) = 229 (27) [M + 2]+, 227 (95) [M]+, 182 (15) [M
+ 2 – HNO2]+, 181 (20) [M – NO2]+, 180 (43) [M – HNO2]+, 146 (100) [M
– NO2Cl]+.
1H NMR (300 MHz, CDCl3):  = 8.35 (s, 1 H, =CH), 7.52 (d, J = 2.1 Hz,
1 H, CHAr(3)), 7.44 (dd, J = 8.5, 2.1 Hz, 1 H, CHAr(5)), 6.96 (d, J = 8.5 Hz,
1 H, CHAr(6)), 4.78–4.85 (m, 1 H, CHO), 3.93 (s, 3 H, OMe), 2.10–1.77
(m, 6 H, 3 × CH2), 1.75–1.56 (m, 2 H, CH2).
13C NMR (75 MHz, CDCl3, DEPT, HSQC, HMBC):  = 153.6 (CAr(1)O),
147.8 (CAr(2)O), 135.1 (CNO2), 132.1 (=CH), 126.7 (CHAr(5)), 122.1
(CAr(4)), 116.2 (CHAr(3)), 111.6 (CHAr(6)), 80.8 (CHO), 56.1 (Me), 32.8
(CH2), 24.2 (CH2).
Anal. Calcd for C9H6ClNO4: C, 47.50; H, 2.66; N, 6.15. Found: C, 47.43;
H, 2.77; N, 6.24.
MS (EI, 70 eV): m/z (%) = 299 (7) [M + 2]+, 297 (31) [M]+, 231 (36) [M +
Methyl (Z)-4-(4-(2-Chloro-2-nitrovinyl)phenoxy)butanoate (2h)
2 – C5H10]+, 229 (100) [M – C5H10]+.
Obtained from nitroalkene 1h (133 mg, 0.5 mmol) according to
Method B. Reaction time: 3 h. The crude product was subjected to col-
umn chromatography (eluent: 8:1, PE/EtOAc) to give the target ni-
troalkene 2h (91 mg, 61%) as yellow crystals.
HRMS (ESI): m/z [M + H]+ calcd for C14H17ClNO4: 298.0841; found:
298.0848.
(Z)-1-Bromo-2-(2-chloro-2-nitrovinyl)-4,5-dimethoxybenzene
(2e)
Rf = 0.30 (3:1, PE/EtOAc) (UV); mp 81–84 °C.
1H NMR (300 MHz, CDCl3):  = 8.37 (s, 1 H, =CH), 7.87 (d, J = 8.8 Hz,
2 H, CHAr), 7.01 (d, J = 8.8 Hz, 2 H, CHAr), 4.12 (t, J = 6.1 Hz, 2 H, CH2O),
3.72 (s, 3 H, OMe), 2.57 (t, J = 7.2 Hz, 2 H, CH2CO2Me), 2.17 (app quint,
J = 6.6 Hz, 2 H, CH2CH2CH2).
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 173.4 (C=O), 161.9 (CArO),
135.3 (CNO2), 133.5 (CHAr), 131.6 (=CH), 122.1 (CAr), 115.1 (CHAr), 67.0
(CH2O), 51.7 (OMe), 30.3 (CH2CO2Me), 24.4 (CH2CH2CH2).
Obtained from nitroalkene 1e (288 mg, 1 mmol) according to Method
A with PhICl2 (2 equiv). Reaction time: 3 h. The crude product was
subjected to column chromatography (eluent: 5:1, PE/EtOAc) to give
the target nitroalkene 2e (216 mg, 67%) as orange crystals.
Rf = 0.48 (3:1, PE/EtOAc) (UV); mp 142–144 °C (EtOH).
1H NMR (300 MHz, CDCl3):  = 7.64 (s, 1 H, =CH), 7.28 (s, 1 H, CHAr),
7.18 (s, 1 H, CHAr), 3.96 (s, 3 H, Me), 3.94 (s, 3 H, Me).
MS (EI, 70 eV): m/z (%) = 301 (1) [M + 2]+, 299 (2) [M]+, 101 (100).
13C NMR (75 MHz, CDCl3, HSQC):  = 152.3 (CArO), 148.3 (CArO), 137.5
(CNO2), 130.7 (=CH), 121.8 (CAr), 119.6 (CAr), 115.9 (CHAr), 112.3
(CHAr), 56.4 (OMe), 56.2 (OMe).
Anal. Calcd for C13H14ClNO5: C, 52.10; H, 4.71; N, 4.67. Found: C,
52.27; H, 4.57; N, 4.72.
MS (EI, 70 eV): m/z (%) = 325 (10) [M + 4]+, 323 (44) [M + 2]+, 321 (28)
[M]+, 276 (15) [M + 2 – HNO2]+, 274 (11) [M – HNO2]+, 242 (85) [M+ –
Br or M+ + 2 – NO2Cl], 240 (16) [M – NO2Cl]+, 212 (100), 197 (70), 196
(34).
Ethyl (Z)-2-(4-(2-Chloro-2-nitrovinyl)phenoxy)-2-methylpropa-
noate (2i)
Obtained from nitroalkene 1i (452 mg, 1.62 mmol) according to
Method B. Reaction time: 1 d. The crude product was subjected to col-
umn chromatography (eluent: 30:1, PE/EtOAc) to give the target ni-
troalkene 2i (420 mg, 83%) as a yellow oil.
Anal. Calcd for C10H9BrClNO4: C, 37.24; H, 2.81; N, 4.34. Found: C,
37.15; H, 2.90; N, 4.19.
Rf = 0.33 (9:1, PE/EtOAc) (UV).
(Z)-2-Bromo-5-(2-chloro-2-nitrovinyl)thiophene (2f)
1H NMR (300 MHz, CDCl3):  = 8.35 (s, 1 H, =CH), 7.82 (d, J = 8.9 Hz,
2 H, CHAr), 6.91 (d, J = 8.8 Hz, 2 H, CHAr), 4.26 (q, J = 7.1 Hz, 2 H, CH2),
1.69 (s, 6 H, Me), 1.25 (t, J = 7.1 Hz, 3 H, CH3CH2).
13C NMR (75 MHz, CDCl3, DEPT):  = 173.5 (C=O), 159.0 (CArO), 135.7
(CNO2), 133.1 (CHAr), 131.4 (=CH), 122.7 (CAr), 118.2 (CHAr), 79.6 (CO),
61.7 (CH2), 25.4 (Me), 14.0 (CH3CH2).
MS (EI, 70 eV): m/z (%) = 315 (14) [M + 2]+, 313 (36) [M]+, 242 (16) [M + 2
– CO2Et]+, 240 (41) [M – CO2Et]+, 201 (39) [M + 2 – CH3C(=CH2)CO2Et]+,
199 (100) [M – CH3C(=CH2)CO2Et]+, 152 (100).
Obtained from nitroalkene 1f (117 mg, 0.5 mmol) according to Meth-
od A. Reaction time: 1 d. The crude product was subjected to column
chromatography (eluent: 4:1, PE/toluene) to give the target ni-
troalkene 2f (91 mg, 68%) as yellow crystals.
Rf = 0.47 (1:1, PE/toluene) (UV); mp 140–143 °C (EtOH).
1H NMR (300 MHz, CDCl3):  = 8.51 (s, 1 H, =CH), 7.41 (d, J = 4.0 Hz,
1 H, CH(4)), 7.23 (d, J = 4.1 Hz, 1 H, CH(3)).
13C NMR (75 MHz, CDCl3, HMBC):  = 137.2 (CH(4)), 135.0 and 134.9
(C(5) and CNO2), 131.2 (CH(3)), 125.6 (=CH), 123.3 (C(2)Br).
Anal. Calcd for C14H16ClNO5: C, 53.60; H, 5.14; N, 4.46. Found: C,
53.68; H, 5.31; N, 4.45.
MS (EI, 70 eV): m/z (%) = 271 (9) [M + 4]+, 269 (30) [M + 2]+, 267 (22)
[M]+, 222 (19) [M + 2 – HNO2]+, 220 (12) [M – HNO2]+, 188 (29) [M + 2
– NO2Cl]+, 186 (17) [M – NO2Cl]+, 142 (100).
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
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Synthesis
(Z)-2-Bromo-4-(2-chloro-2-nitrovinyl)-1-methoxybenzene (2j)
Rf = 0.44 (9:1, PE/EtOAc) (UV); mp 66–68 °C (EtOH) (Lit.24 76–77 °C
(hexane)).
Obtained from nitroalkene 1j (453 mg, 1.76 mmol) according to
Method B. Reaction was performed at r.t. Reaction time: 1 d. The
crude product was crystallized from EtOH to give the target ni-
troalkene 2j (428 mg, 83%) as a yellow powder.
1H NMR (300 MHz, CDCl3):  = 8.38 (s, 1 H, =CH), 7.91 (dd, J = 8.7,
5.3 Hz, 2 H, CHAr), 7.22 (t, J = 8.7 Hz, 2 H, CHAr).
13C NMR (75 MHz, CDCl3, HMBC):  = 164.5 (d, JCF = 255.6 Hz, CF),
1
3
Rf = 0.42 (5:1, PE/EtOAc) (UV); mp 102–103 °C.
137.3 (CNO2), 133.5 (d, JCF = 8.9 Hz, CHAr), 130.4 (=CH), 125.9 (d,
4JCF = 3.5 Hz, CAr), 116.5 (d, 2JCF = 22.0 Hz, CHAr).
1H NMR (300 MHz, CDCl3):  = 8.30 (s, 1 H, =CH), 8.14 (d, J = 2.3 Hz,
1 H, CHAr), 7.84 (dd, J = 8.6, 2.3 Hz, 1 H, CHAr), 7.02 (d, J = 8.6 Hz, 1 H,
CHAr), 4.00 (s, 3 H, OMe).
NMR matches previously reported data.24
13C NMR (75 MHz, CDCl3, DEPT):  = 158.7 (CArO), 136.3 (CNO2), 135.9
(CHAr), 132.6 (CHAr), 130.1 (=CH), 123.3 (CAr), 112.6 (CArBr), 111.9
(CHAr), 56.6 (OMe).
MS (EI, 70 eV): m/z (%) = 295 (21) [M + 4]+, 293 (74) [M + 2]+, 291 (62)
[M]+, 248 (26), 247 (31), 246 (100), 245 (25) and 244 (71) [(M+ + 4 or
M++2 or M+) – (HNO2 or NO2)], 212 (61) [M + 2 – NO2Cl]+, 210 (59) [M
+ 2 – NO2Cl]+.
(Z)-1-Chloro-4-(2-chloro-2-nitrovinyl)benzene (2n)
Obtained from nitroalkene 1n (184 mg, 1 mmol) according to Method
C. Reaction time: 1 d. The crude product was crystallized from EtOH
to give the target nitroalkene 2n (152 mg, 70%) as pale-yellow crys-
tals.
Rf = 0.49 (9:1, PE/EtOAc) (UV); mp 98–100 °C (Lit.16a 107–108 °C (hep-
tane)).
1H NMR (300 MHz, CDCl3):  = 8.35 (s, 1 H, =CH), 7.82 (d, J = 8.4 Hz,
2 H, CHAr), 7.50 (d, J = 8.4 Hz, 2 H, CHAr).
Anal. Calcd for C9H7BrClNO3: C, 36.96; H, 2.41; N, 4.79. Found: C,
36.98; H, 2.39; N, 4.80.
13C NMR (75 MHz, CDCl3, HMBC):  = 138.2 (CArCl), 137.9 (CNO2),
132.3 (CHAr), 130.3 (=CH), 129.5 (CHAr), 128.1 (CAr).
(Z)-1-Chloro-4-(4-(2-chloro-2-nitrovinyl)phenoxy)benzene (2k)
Obtained from nitroalkene 1k (551 mg, 2 mmol) according to Method
B. Reaction was performed at r.t. Reaction time: 1 d. The crude prod-
uct was crystallized from EtOH to give the target nitroalkene 2k (500
mg, 81%) as a yellow powder.
NMR matches previously reported data.16a
(Z)-1-Bromo-4-(2-chloro-2-nitrovinyl)benzene (2o)
Obtained from nitroalkene 1o (228 mg, 1 mmol) according to Method
C. Reaction time: 2 d. The crude product was crystallized from EtOH
to give the target nitroalkene 2o (232 mg, 88%) as pale-yellow crys-
tals.
Obtained from nitroalkene 1t (120 mg, 0.5 mmol) according to Meth-
od B with SO2Cl2 (3 equiv) and then Et3N (5 equiv). Reaction was per-
formed at r.t. Reaction time: 1 d. The crude product was subjected to
column chromatography (eluent: 25:1, PE/EtOAc) to give the target
nitroalkene 2k (100 mg, 65%) as a yellow powder.
Rf = 0.58 (9:1, PE/EtOAc) (UV); mp 116–119 °C (Lit.15 58–60 °C).
1H NMR (300 MHz, CDCl3):  = 8.33 (s, 1 H, =CH), 7.74 (d, J = 8.3 Hz,
2 H, CHAr), 7.66 (d, J = 8.3 Hz, 2 H, CHAr).
Rf = 0.51 (9:1, PE/EtOAc) (UV); mp 88–90 °C.
1H NMR (300 MHz, CDCl3):  = 8.37 (s, 1 H, =CH), 7.88 (d, J = 8.5 Hz,
2 H, CHAr), 7.39 (d, J = 8.3 Hz, 2 H, CHAr), 7.04–7.09 (m, 4 H, CHAr).
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 160.6 (CArO), 153.9 (CArO),
136.4 (CNO2), 133.4 (CHAr), 131.0 (=CH), 130.2 (CHAr), 130.0 (CAr),
124.3 (CAr), 121.5 (CHAr), 118.0 (CHAr).
Anal. Calcd for C8H5BrClNO2: C, 36.61; H, 1.92; N, 5.34. Found: C,
36.67; H, 1.80; N, 5.24.
NMR matches previously reported data.15
(Z)-1-(2-Chloro-2-nitrovinyl)-4-methylbenzene (2p)
MS (EI, 70 eV): m/z (%) = 311 (68) [M + 2]+, 309 (100) [M]+, 265 (27)
[M + 2 – NO2]+, 264 (53) [M+ + 2 – HNO2], 263 (33) [M – NO2]+, 262
(66) [M – HNO2]+, 230 (34) [M + 2 – NO2Cl]+, 228 (87) [M – NO2Cl]+,
165 (66).
Obtained from nitroalkene 1p (163 mg, 1 mmol) according to Method
C. Reaction time: 1 d. The crude product was subjected to column
chromatography (eluent: 15:1, PE/EtOAc) to give the target ni-
troalkene 2p (160 mg, 81%) as pale-yellow crystals.
Anal. Calcd for C14H9Cl2NO3: C, 54.22; H, 2.93; N, 4.52. Found: C,
54.13; H, 2.80; N, 4.37.
Rf = 0.48 (9:1, PE/EtOAc) (UV); mp 68–70 °C (EtOH) (Lit.14 82–83 °C).
1H NMR (300 MHz, CDCl3):  = 8.38 (s, 1 H, =CH), 7.79 (d, J = 8.1 Hz,
2 H, CHAr), 7.33 (d, J = 8.1 Hz, 2 H, CHAr), 2.45 (s, 3 H, Me).
(Z)-(2-Chloro-2-nitrovinyl)benzene (2l)
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 143.0 (CMe), 136.7
(CNO2), 131.8 (=CH), 131.4 (CHAr), 129.9 (CHAr), 126.9 (CAr), 21.7 (Me).
NMR matches previously reported data.14
Obtained from nitroalkene 1l (149 mg, 1 mmol) according to Method
C. Reaction time: 1 d. The crude product was subjected to column
chromatography (eluent: 15:1, PE/EtOAc) to give the target ni-
troalkene 2l (138 mg, 75%) as yellow crystals.
Rf = 0.49 (9:1, PE/EtOAc) (UV); mp 35–37 °C (EtOH) (Lit.15 43–45 °C).
1H NMR (300 MHz, CDCl3):  = 8.40 (s, 1 H, =CH), 7.86–7.90 (m, 2 H,
CHAr), 7.46–7.57 (m, 3 H, CHAr).
NMR matches previously reported data.15
(Z)-1-Bromo-2-(2-chloro-2-nitrovinyl)benzene (2q)
Obtained from nitroalkene 1q (228 mg, 1 mmol) according to Method
C. Reaction time: 1 d. The crude product was subjected to column
chromatography (eluent: 15:1, PE/EtOAc) to give the target ni-
troalkene 2q (215 mg, 82%) as pale-yellow crystals.
(Z)-1-(2-Chloro-2-nitrovinyl)-4-fluorobenzene (2m)
Rf = 0.50 (9:1, PE/EtOAc) (UV); mp 38–40 °C (EtOH) (Lit.9a 50–51 °C).
1H NMR (300 MHz, CDCl3, COSY):  = 8.64 (s, 1 H, =CH), 7.93 (dd,
J = 7.8, 1.4 Hz, 1 H, CHAr), 7.73 (dd, J = 8.0, 1.0 Hz, 1 H, CHAr), 7.46 (dt,
J = 7.8, 3.9 Hz, 1 H, CHAr), 7.37 (dt, J = 7.7, 1.6 Hz, 1 H, CHAr).
Obtained from nitroalkene 1m (167 mg, 1 mmol) according to Meth-
od C. Reaction time: 2 d. The crude product was subjected to column
chromatography (eluent: 15:1, PE/EtOAc) to give the target ni-
troalkene 2m (183 mg (91%) as pale-yellow crystals.
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
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Synthesis
13C NMR (75 MHz, CDCl3, HSQC, HMBC):  = 139.6 (CNO2), 133.4
(CHAr), 132.3 (CHAr), 130.7 (=CH), 130.5 (CHAr), 130.4 (CAr), 127.6
(CHAr), 126.1 (CArBr).
1H NMR (300 MHz, CDCl3):  = 7.39 (d, J = 8.7 Hz, 1 H, CHAr), 6.93 (d,
J = 8.7 Hz, 1 H, CHAr), 6.09 (d, J = 6.7 Hz, 1 H, CHClNO2), 5.54 (d,
J = 6.7 Hz, 1 H, CHClAr), 3.84 (s, 3 H, OMe).
Anal. Calcd for C8H5BrClNO2: C, 36.61; H, 1.92; N, 5.34. Found: C,
36.82; H, 1.68; N, 5.15.
13C NMR (75 MHz, CDCl3, HSQC, HMBC):  = 160.9 (CArO), 129.3 (CHAr),
125.6 (CAr), 114.5 (CHAr), 94.7 (CHClNO2), 62.5 (CHClAr), 55.4 (OMe).
NMR matches previously reported data.9a
1-Chloro-4-(1,2-dichloro-2-nitroethyl)benzene (3n)
Nitroalkene 1n was subjected to method C, but the reaction was
(Z)-2-Chloro-4-(2-chloro-2-nitrovinyl)-1-methoxybenzene (2r)
worked up without quenching with K2CO3 and Et3N.
Obtained from nitroalkene 1r (87 mg, 0.4 mmol) according to Method
C. Reaction time: 1 d. The crude product was crystallized from EtOH
to give the target nitroalkene 2r (54 mg, 55%) as brownish crystals.
Dichloride (3n) was characterized as the crude reaction mixture.
dr = 9:1. Configuration of diastereomers was not determined. At-
tempts to purify 3n by column chromatography led to partial elimina-
tion of HCl, resulting in chloronitroalkene 2n.
Rf = 0.33 (9:1, PE/EtOAc) (UV); mp 89–91 °C.
1H NMR (300 MHz, CDCl3):  = 8.31 (s, 1 H, =CH), 7.99 (d, J = 2.2 Hz,
1 H, CHAr), 7.78 (dd, J = 8.7, 2.3 Hz, 1 H, CHAr), 7.05 (d, J = 8.7 Hz, 1 H,
CHAr), 4.01 (s, 3 H, OMe).
13C NMR (75 MHz, CDCl3, HSQC, HMBC):  = 157.8 (CArO), 136.4
(CNO2), 132.7 (CHAr), 132.0 (CHAr), 130.2 (=CH), 123.5 and 122.8 (CArCl
and CAr), 112.1 (CHAr), 56.4 (OMe).
Major Diastereomer
1H NMR (300 MHz, CDCl3):  = 7.38–7.46 (m, 4 H, CHAr), 6.05 (d,
J = 9.5 Hz, 1 H, CHClNO2), 5.39 (d, J = 9.6 Hz, 1 H, CHClAr).
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 136.4 (CAr), 131.9 (CAr),
129.7 (CHAr), 129.5 (CHAr), 91.9 (CHClNO2), 60.2 (CHClAr).
MS (EI, 70 eV): m/z (%) = 249 (42) [M + 2]+, 247 (77) [M]+, 202 (36) [M
+ 2 – HNO2]+, 200 (56) [M–HNO2]+, 168 (30) [M + 2 – NO2Cl]+, 166
(100) [M – NO2Cl]+.
Minor Diastereomer
1H NMR (300 MHz, CDCl3):  = 7.38–7.46 (m, 4 H, CHAr), 6.08 (d,
J = 6.2 Hz, 1 H, CHClNO2), 5.60 (d, J = 6.2 Hz, 1 H, CHClAr).
HRMS (ESI): m/z [M + Na]+ calcd for C9H7Cl2NO3Na: 269.9695; found:
269.9696.
(E)-1,3-Dichloro-4,5,6-trimethoxy-2-(2-nitrovinyl)benzene (4)
Obtained from nitroalkene 1u (120 mg, 0.5 mmol) according to
Method C with SO2Cl2 (6 equiv) and HCl/dioxane (4 equiv). Reaction
time: 1 d. The crude product was subjected to column chromatogra-
phy (eluent: 15:1, PE/EtOAc) to give the target nitroalkene 4 (61 mg,
40%) as yellow crystals.
(Z)-(4-Chloro-4-nitrobut-3-enyl)benzene (2s)
Obtained from nitroalkene 1s (177 mg, 1 mmol) according to Method
C. Reaction time: 1 d. The crude product was subjected to column
chromatography (eluent: 15:1, PE/EtOAc) to give the target nitro-
alkene 2s (153 mg, 72%) as a yellow oil.
Rf = 0.34 (5:1, PE/EtOAc) (UV); mp 78–83 °C (EtOH).
Rf = 0.44 (9:1, PE/EtOAc) (UV).
1H NMR (300 MHz, CDCl3):  = 8.26 (d, J = 13.9 Hz, 1 H, =CHCAr), 7.86
(d, J = 13.9 Hz, 1 H, =CHNO2), 4.03 (s, 3 H, Me), 3.93 (s, 6 H, Me).
13C NMR (75 MHz, CDCl3):  = 149.9 (CArO), 149.7 (CArO), 142.4 (=CHCAr),
1H NMR (300 MHz, CDCl3, COSY):  = 7.49 (t, J = 7.5 Hz, 1 H, =CH),
7.21–7.38 (m, 5 H, Ph), 2.90 (t, J = 7.5 Hz, 2 H, CH2Ph), 2.75 (q,
J = 7.5 Hz, 2 H, CH2CH=).
13C NMR (75 MHz, CDCl3, DEPT, HMBC):  = 140.4 (CNO2), 139.5 (CPh),
134.9 (=CH), 128.8 (CHPh), 128.3 (CHPh), 126.7 (CHPh), 33.4 (CH2Ph),
30.7 (CH2CH=).
132.3 (=CHNO2), 125.6 (CAr), 123.0 (CAr), 61.5 (OMe), 61.3 (OMe).
MS (EI, 70 eV): m/z (%) = 309 (65) [M + 2]+, 307 (100) [M]+, 274 (32)
[M + 2 – Cl]+, 272 (82) [M – Cl]+, 262 (26) [M + 2 – HNO2]+, 260 (36) [M
– HNO2]+.
HRMS (ESI): m/z [M + H]+ calcd for C11H12Cl2NO5: 308.0087; found:
308.0080.
MS (EI, 70 eV): m/z (%) = 196 (8) [M + 2 – OH]+, 194 (24) [M – OH]+,
129 (19), 91 (100) [C7H7]+.
HRMS (ESI): m/z [M + Na]+ calcd for C10H10ClNO2: 234.0292; found:
234.0281.
(Z)-1,3-Dichloro-2-(2-chloro-2-nitrovinyl)-4,5,6-trimethoxyben-
zene (5)
1-(1,2-Dichloro-2-nitroethyl)-4-methoxybenzene (3a)
Obtained from nitroalkene 1u (120 mg, 0.5 mmol) according to
Method A with Py (8 equiv) and PhICl2 (5 equiv). Reaction time: 1 d.
The crude product was subjected to column chromatography (eluent:
20:1, PE/EtOAc) to give the target nitroalkene 5 (105 mg, 62%) as pale-
yellow crystals.
Nitroalkene 1a was subjected to Method B, but the reaction was
worked up without quenching with Et3N.
Dichloride (3a) was characterized as a crude reaction mixture. Ratio
3a/2a = 3.6:1. dr (3a) = 1.6:1. Configuration of diastereomers was not
determined. Attempts to purify 3a by column chromatography led to
partial elimination of HCl, resulting in chloronitroalkene 2a. ESI-
HRMS also detected only 2a.
Rf = 0.50 (5:1, PE/EtOAc) (UV); mp 69–70 °C (PE).
1H NMR (300 MHz, CDCl3):  = 8.16 (s, 1 H, =CH), 4.01 (s, 3 H, Me),
3.94 (s, 6 H, Me).
Major Diastereomer
13C NMR (75 MHz, CDCl3, HMBC):  = 149.6 (CArO), 149.0 (CArO), 143.2
(CNO2), 128.0 (=CH), 124.4 (CAr), 123.0 (CAr), 61.5 (OMe), 61.4 (OMe).
MS (EI, 70 eV): m/z (%) = 345 (26) [M + 4]+, 343 (84) [M + 2]+, 341 (89)
[M]+, 308 (70) [M + 2 – Cl]+, 306 (100) [M – Cl]+, 278 (52), 261 (58),
245 (76), 228 (63).
1H NMR (300 MHz, CDCl3):  = 7.37 (d, J = 8.7 Hz, 1 H, CHAr), 6.96 (d,
J = 8.7 Hz, 1 H, CHAr), 6.07 (d, J = 9.6 Hz, 1 H, CHClNO2), 5.37 (d,
J = 9.6 Hz, 1 H, CHClAr), 3.86 (s, 3 H, OMe).
13C NMR (75 MHz, CDCl3, HSQC, HMBC):  = 160.9 (CArO), 129.7 (CHAr),
125.2 (CAr), 114.6 (CHAr), 92.2 (CHClNO2), 60.9 (CHClAr), 55.4 (OMe).
Anal. Calcd for C11H10Cl3NO5: C, 38.57; H, 2.94; N, 4.09. Found: C,
38.63; H, 2.88; N, 4.06.
Minor Diastereomer
© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
Paper
Synthesis
(8) Jasinski, R.; Mikulska, M.; Koifman, O.; Baranski, A. Chem. Het-
erocycl. Compd. 2013, 49, 1188; In Russian: Khim. Geterotsikl.
Soedin. 2013, 1275.
Funding Information
This work was supported by the Russian Science Foundation (grant
19-73-00146).
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(9) (a) Raut, V. S.; Marion, J.; Vanthuyne, N.; Roussel, C.;
Constantieux, T.; Bressy, X.; Bonne, D.; Rodriguez, J. J. Am. Chem.
Soc. 2017, 139, 2140. (b) Bao, X.; Rodriguez, J.; Bonne, D. Chem.
Sci. 2020, 11, 403. (c) Becerra, D.; Raimondi, W.; Dauzonne, D.;
Constantieux, T.; Bonne, D.; Rodriguez, J. Synthesis 2017, 49,
195. (d) Raimondi, W.; Dauzonne, D.; Constantieux, T.; Bonne,
D.; Rodriguez, J. Eur. J. Org. Chem. 2012, 6119. (e) Dauzonne, D.;
Royer, R. Synthesis 1988, 339.
Acknowledgment
The authors thank Dr. N. G. Kolotyrkina and Dr. A. O. Chizhov (N. D.
Zelinsky Institute of Organic Chemistry) for recording HRMS.
(10) (a) Huang, K.; Ma, Q.; Shen, X.; Gong, L.; Meggers, E. Asian J. Org.
Chem. 2016, 5, 1198. (b) Dauzonne, D.; Josien, H.; Demerseman,
P. Synthesis 1992, 309.
(11) (a) Ganesh, M.; Namboothiri, I. N. N. Tetrahedron 2007, 63,
11973. (b) Yu, S.-W.; Zhao, S.-H.; Chen, H.; Xu, X.-Y.; Yuan, W.-
C.; Zhang, X.-M. ChemistrySelect 2018, 3, 4827. (c) Romashov, L.
V.; Khomutova, Y. A.; Danilenko, V. M.; Ioffe, S. L.; Lesiv, A. V.
Synthesis 2010, 407.
Supporting Information
Supporting information for this article is available online at
https://doi.org/10.1055/s-0040-1707396.
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© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J

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A. A. Fadeeva et al.
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Synthesis
(22) (a) Treatment of substrate 1t with PhICl2 (1.2 equiv) according
to Method A resulted in a mixture of 1t and 2k in ca. 1:1 ratio
(1H NMR and GC-MS). Method B (1.2 equiv of SO2Cl2) gave
monochloro- and dichloro-product (2k) in 2:1 ratio.
(b) Treatment of substrate 1u with PhICl2 (1.2 equiv) according
to Method A resulted in predominant monochlorination of the
aromatic ring. 2.4 equiv (overnight reaction) gave products 4
and 5 in ca. 1:1 ratio.
(23) Zhao, X.-F.; Zhang, C. Synthesis 2007, 551.
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© 2020. Thieme. All rights reserved. Synthesis 2020, 52, A–J