Novel efficient synthesis of β-fluoro-β-(trifluoromethyl)styrenes

Article abstract of DOI:10.1016/j.jfluchem.2009.12.004

CF₃CFBr₂ was employed in catalytic olefination reactions of aromatic aldehydes. In situ prepared hydrazones of aldehydes were transformed to β-fluoro-β-(trifluoromethyl)styrenes by reaction with CF₃CFBr₂ under CuCl catalysis. Based on this reaction, a novel stereoselective approach towards β-fluoro-β-(trifluoromethyl)styrenes was elaborated. Nucleophilic vinylic substitution of fluorine by secondary amines, thiolates and alkoxides in β-fluoro-β-(trifluoromethyl)styrenes was also tested.

Full text of DOI:10.1016/j.jfluchem.2009.12.004

Journal of Fluorine Chemistry 131 (2010) 384–388
Contents lists available at ScienceDirect
Journal of Fluorine Chemistry
journal homepage: www.elsevier.com/locate/fluor
Novel efficient synthesis of
b-fluoro-b-(trifluoromethyl)styrenes
Aleksey A. Goldberg a, Vasiliy M. Muzalevskiy a, Aleksey V. Shastin b,
Elisabeth S. Balenkova a, Valentine G. Nenajdenko a,
*
a Moscow State University, Department of Chemistry, Leninskie Gory, Moscow 119992, Russia
b Institute of Problems of Chemical Physics, Chernogolovka, Moscow Region 142432, Russia
A R T I C L E I N F O
A B S T R A C T
Article history:
CF3CFBr2 was employed in catalytic olefination reactions of aromatic aldehydes. In situ prepared
Received 8 September 2009
Received in revised form 2 December 2009
Accepted 4 December 2009
Available online 16 December 2009
hydrazones of aldehydes were transformed to
CF3CFBr2 under CuCl catalysis. Based on this reaction, a novel stereoselective approach towards
-(trifluoromethyl)styrenes was elaborated. Nucleophilic vinylic substitution of fluorine by secondary
amines, thiolates and alkoxides in -fluoro- -(trifluoromethyl)styrenes was also tested.
ß 2009 Elsevier B.V. All rights reserved.
b
-fluoro-
b
-(trifluoromethyl)styrenes by reaction with
b
-fluoro-
b
b
b
Keywords:
Aromatic aldehydes
1,1-Dibromotetrafluoroethane
Copper catalysis
Olefination
Fluorinated alkenes
1. Introduction
2. Results and discussion
Fluorinated compounds were intensively investigated in recent
decades [1,2] due to their unique physical and biological properties
caused by the presence of fluorine substituents in the molecules
[3–5]. A lot of researchers focused on the elaboration of new
synthetic pathways to organofluorine compounds, which afforded
an enormous progress in this field [6–8].
2.1. Reactions of CF3CFBr2 with hydrazones of aromatic aldehydes
About a decade ago, a new catalytic olefination reaction (COR)
of aldehydes and ketones was discovered by our research group. It
was found, that unsubstituted hydrazones of carbonyl compounds
can be efficiently transformed into alkenes by treatment with
polyhalogenalkanes in the presence of a base and catalytic amount
of copper salts [16–21]. This reaction has a general character and
became a reliable technique for stereoselective construction of
carbon–carbon double bonds [22]. A range of convenient stereo-
selective methods for the preparation of various fluorinated
alkenes were elaborated using one-pot COR protocol for olefination
of carbonyl compounds by freons. Thus, employing of CF3CCl3,
CF2ClCFCl2, CFCl3, CF2Cl2, CF3CBr3 and CFBr3 afforded a set of novel
It is considered, that freon molecules are involved in ozon layer
destruction, which is a challenging and urgent problem to be
solved nowadays. On the other hand tremendous stocks of freons
were accumulated during last century, which need to be utilized.
Several strategies were developed for processing of freons into
compounds, which are less destructive for the ozon layer. Among
them are the catalytic decomposition or full mineralization [9–11],
partial reduction to less harmful fluorohydrocarbons (FHCs) [12–
13]; and transformation to useful simple fluorinated synthons [14–
15]. The last strategy is very attractive from the economical point
of view, because it combines neutralization of environmentally
dangerous materials with the elaboration of new perspective
synthetic building blocks. Here we would like to present a novel
olefination technique of aromatic aldehydes by freon CF3CFBr2 as a
successful realization of the mentioned strategy.
approaches towards
fluoro- -(chlorodifluoromethyl)styrenes [23],
ostyrenes [24], gem-difluoroalkenes [25], -bromo-
methyl)styrenes [26] and -bromo- -fluorostyrenes [27].
b
-chloro-
b
-(trifluoromethyl)styrenes [23],
-chloro- -fluor-
-(trifluoro-
b-
b
b
b
b
b
b
b
Additionally, unusual COR direction was found, when the reaction
with BrCF2CF2Br was investigated. Saturated fluorinated alkane
derivatives were isolated instead of expected alkene ones [28].
Having such good background results, we decided to involve
CF3CFBr2 into COR-type transformation too. In addition, this freon
was not thoroughly investigated and only few examples of its
reactivity can be found in literature. Addition of CF3CFBr2 to the
alkene double bond afforded corresponding fluorinated alkanes
* Corresponding author. Tel.: +7 495 9328846; fax: +7 495 9328846.
E-mail address: nen@acylium.chem.msu.ru (V.G. Nenajdenko).
0022-1139/$ – see front matter ß 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2009.12.004

A.A. Goldberg et al. / Journal of Fluorine Chemistry 131 (2010) 384–388
385
Scheme 1.
[29–33]. Treatment of CF3CFBr2 with zinc and magnesium
provided an access to 1,2,2-trifluorovinylzinc [34] and 1,2,2-
trifluorovinylmagnesium [35]. Reduction of one [36] or both [37]
C–Br bonds into C–H was also reported. Finally, CF3CFBr2 was also
used for the bromination of enolates [38] and organomagnesium
compounds [39].
Accordingly to our previous experience of olefination by freons,
CF3CFBr2 was expected to be a moderately reactive polyhalogen-
alkane. So we choose a one-pot COR protocol with ethylenediamine
as a base in ethanol solution. We found that CF3CFBr2 reacted
smoothly with prepared in situ hydrazones of aromatic aldehydes 2
Fig. 1. Assignment of configuration of isomeric alkenes 3.
coupling constants between fluorine and the vinylic proton in 1H
NMR spectra of fluoroalkenes 3. The values range from 32.5 to
36.3 Hz for Z-isomers and from 18.2 to 21.6 Hz for E-isomers
(Fig. 1).
We can proudly announce, that the proposed method is a very
good alternative to the previously reported approaches to
fluoro- -(trifluoromethyl)styrenes. Few publications dealt with
synthesis of -fluoro- -(trifluoromethyl)styrenes. Thus, reduction
of 1-phenylpentafluoropropene with LiAlH4 [40], protonation of
fluoro- -trifluoromethyl- -phenylvinylstannanes [41], reaction
of -fluoro- -bromostyrenes with trifluoromethyl anion [42],
b-
b
to form
b
-fluoro-
b
-(trifluoromethyl)styrenes 3 in moderate to
b
b
good yields (Scheme 1, Table 1). According to TLC the only side
products of the reaction were corresponding sym-azines 4, which
were not isolated and their yields were not determined. The
transformation revealed its general character and a wide range of
alkenes 3 both with electron-donating and electron-withdrawing
substituents were prepared using this method.
b-
b
a
b
b
reactions of trifluorovinyllithium [43] and trifluorovinylsilanes
[44] with aromatic aldehydes were used for the preparation of
these alkenes. In contrast to the mentioned approaches, our
method is an extremely simple, straightforward transformation,
which does not need to use absolute solvents, expensive or toxic
reagents. High stereoselectivity and good yields are other
advantages of our method.
The reaction proceeded highly stereoselectively to give
mostly the Z-isomers of styrenes 3. The amount of minor E-
isomers of 3 in a mixture was less than 11% in the case of 3f and
dropped to 3% for 3j. This result is in a good agreement with the
very well known tendency of COR to form the less hindered
stereoisomer [22]. Aryl and trifluoromethyl groups are the most
bulky ones in compounds 3, which make the trans-arrangement
of these groups most favorable. As a result, the Z-isomer of 3
dominates in the reaction mixture. The assignment of the
configuration of isomers was made by NMR spectroscopy. It is
well known, that coupling constants between atoms at double
bond in cis-position are smaller than in trans-position. The
2.2. Reactions of
nucleophiles
b-fluoro-b-(trifluoromethyl)styrenes 3 with
Previously, in a series of publications we investigated nucleo-
philic vinylic substitution of -halogen atom by C-, S- and O-
nucleophiles in -bromo- -fluorostyrenes, -chloro- and
bromo- -(trifluoromethyl)styrenes. We found that such substitu-
tion proceeds easily to give various fluorinated alkenes. Thus, these
b
b
b
b
b-
b
3
configuration of isomers was determined by comparison of JH,F
Table 1
Synthesis of
b-fluoro-b-(trifluoromethyl)styrenes 3.
Styrene 3
Ar
Z/E ratioa
Yield, %
Styrene 3
Ar
Z/E ratioa
Yield, %
a
b
c
d
e
f
4-ClC6H4
93:7
92:8
94:6
93:7
94:6
89:11
52
53
53
61
51
61
g
h
i
2-NO2C6H4
4-(n-BuO)C6H4
4-MeOC6H4
4-MeCO2C6H4
4-CF3C6H4
91:9
94:6
95:5
97:3
95:5
90:10
48
49
47
62
33
66
4-BrC6H4
2,4-diClC6H3
4-MeC6H4
4-EtC6H4
j
k
l
3-NO2C6H4
4-NO2C6H4
a
Determined by 1H and 19F NMR spectroscopy.
Scheme 2. Reactions of
b-fluoro-
b-(trifluoromethyl)styrene 3l and b-chloro-b-(trifluoromethyl)styrene 7 with nucleophiles.

386
A.A. Goldberg et al. / Journal of Fluorine Chemistry 131 (2010) 384–388
reactions resulted in a number of novel convenient approaches to
-fluoro- and -trifluoromethylacrylonitriles [45], -fluoro-
arylvinyl sulfones [46], trifluoromethyl(vinylsulfides) [47], alkoxy-
-(trifluoromethyl)styrenes [48], -trifluoromethyl- -aryl enam-
ines and vinylogous guanidium salts [49].
A very interesting fundamental question is: which halogen is
more easily substituted in the case of vinylic nucleophilic
substitution, fluorine or chlorine? We decided to examine
4.1.1. 1-Chloro-4-(2,3,3,3-tetrafluoroprop-1-enyl)benzene (3a)
Obtained as a 93:7 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.7; IR (nujol) 1590, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
a
a
a
b-
b
a
b
(400 MHz, CDCCl3)
J = 8.6 Hz, 2H, Ar), 7.52 (d, J = 8.6 Hz, 2H, Ar); 19F NMR (377 MHz,
CDCl3)
À131.12 (dq, J = 35.1 Hz, J = 10.9 Hz, F), À72.13 (d,
J = 10.9 Hz, CF3); 13C NMR (100 MHz, CDCl3)
110.34, 118.80
d 6.35 (d, J = 35.1 Hz, 55CH–, 1H), 7.40 (d,
d
d
(qd, JCF = 271.5 Hz, JCF = 41.0 Hz, CF3), 128.09 (d, JCF = 3.7 Hz),
128.67, 129.08, 130.85 (d, JCF = 7.3 Hz), 135.68, 145.33 (dq,
JCF = 267.9 Hz, JCF = 38.8 Hz, CF); E-isomer: 1H NMR (400 MHz,
nucleophilic vinylic substitution in
styrenes 3. It was found that styrenes 3 are less reactive than
chloro and -bromo- -(trifluoromethyl)styrenes. Thus, the reac-
b-fluoro-b-(trifluoromethyl)-
b
-
b
b
CDCl3)
d 6.80 (d, J = 20.5 Hz, 1H,55CH–), 7.22 (d, J = 8.5 Hz, 1H, Ar),
tion of styrene 3l with pyrrolidine and 4-methylphenylthiolate
gave enamine 5 and vinylsulfide 6 in lower yields, comparing with
chlorostyrene 7 [47,49]. In addition, the formation of a mixture of
diastereomers of enamine 5 was observed, although chlorostyrene
7 gave only the Z-isomer of 5. In contrast to chlorostyrene 7 [48],
the reaction of 3l with tert-BuOK did not afforded any isolatable
products at all. We assume, that lower reactivity of 3l comparing
with the corresponding chlorostyrene 7 is explained by different
mobility of fluorine and chlorine atoms. Therefore, fluorine is
harder to substitute, which results in lower yields of substitution
products (Scheme 2).
7.37(1H, d, J = 8.5 Hz, Ar); 19F NMR (377 MHz, CDCl3)
d
À123.55
(dq, J = 20.5 Hz, J = 9.2 Hz, F), À66.77 (d, J = 9.2 Hz, CF3); the other
signals are identical to those of the Z-isomer. ESI-MS (m/z): calcd.
for C9H5ClF4 [M+] 224.0016, found 224.0016.
4.1.2. 1-Bromo-4-(2,3,3,3-tetrafluoroprop-1-enyl)benzene (3b)
Obtained as a 92:8 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.6; IR (nujol) 1590, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
(400 MHz, CDCl3)
J = 8.3 Hz, 2H, Ar), 7.53 (d, J = 8.3 Hz, 2H, Ar); 19F NMR (377 MHz,
CDCl3)
À130.73 (dq, J = 35.1 Hz, J = 11.2 Hz, F), À72.13 (d,
J = 11.2 Hz, CF3); 13C NMR (100 MHz, CDCl3)
110.49, 118.81
d 6.30 (d, J = 35.1 Hz, 1H, 55CH–), 7.42 (d,
d
d
(qd, JCF = 272.3 Hz, JCF = 40.5 Hz, CF3), 125.84 (d, JCF = 3.7 Hz),
129.64, 131.08 (d, JCF = 7.6 Hz), 132.14, 136.51, 145.42 (dq,
JCF = 268.1 Hz, JCF = 38.1 Hz, CF); E-isomer: 1H NMR (400 MHz,
3. Conclusion
Using one-pot COR protocol a novel efficient method for the
CDCl3)
d 6.74 (d, J = 20.5 Hz, 1H,55CH–), 7.13 (d, J = 8.1 Hz, 1H, Ar);
preparation of b-fluoro-b-(trifluoromethyl)styrenes from aromat-
19F NMR (377 MHz, CDCl3)
d
À123.36 (dq, J = 20.5 Hz, J = 9.2 Hz, F),
ic aldehydes and CF3CFBr2 was elaborated. High stereoselectivity,
good yields and simplicity are advantages of the mentioned
method. Nucleophilic vinylic substitution of the fluorine atom in
À66.76 (d, J = 9.2 Hz, CF3); the other signals are identical to those of
the Z-isomer. Anal. Calcd. for C9H5BrF4: C 40.18; H 1.87. Found: C
40.35; H 1.97.
b
-fluoro-
found that
than -chloro and
b
-(trifluoromethyl)styrenes was also investigated. We
-fluoro- -(trifluoromethyl)styrenes are less reactive
-bromo- -(trifluoromethyl)styrenes.
b
b
b
4.1.3. 2,4-Dichloro-1-(2,3,3,3-tetrafluoroprop-1-enyl)benzene (3c)
Obtained as a 94:6 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.7; IR (nujol) 1600, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
b
b
4. Experimental
(400 MHz, CDCl3)
d 6.79 (d, J = 34.6 Hz, 1H, 55CH–), 7.32 (dd,
NMR spectra were recorded on Bruker AMX Avance 400
spectrometer in CDCl3 with TMS and CCl3F as internal standards.
Mass spectra (ESI-MS) were measured on a MicroTof Bruker
Daltonics. IR spectra were recorded on ThermoNicolet IR 200.
Bruker TLC was performed using 25-DC-Alufoil with Kieselgel 60
F254 (Merck). Fluka Silica gel 60 (0.063–0.200 mm) was used for
column chromatography. Commercial reagents and solvents were
generally used as received.
J = 8.5 Hz, J = 2.0 Hz, 1H, Ar), 7.48 (d, J = 2.0 Hz, 1H, Ar), 7.77 (d,
J = 8.5 Hz, 1H, Ar); 19F NMR (377 MHz, CDCl3)
d
À129.96 (dq,
J = 34.6 Hz, J = 10.6 Hz, F), À72.25 (d, J = 10.6 Hz, CF3); 13C NMR
(100 MHz, CDCl3) d 106.52, 118.54 (qd, JCF = 271.5 Hz, JCF = 41.0 Hz,
CF3), 126.28 (d, JCF = 4.4 Hz), 127.56, 129.75, 131.38 (d,
JCF = 12.4 Hz), 134.74, 136.01, 146.35 (dq, JCF = 271.5 Hz,
JCF = 38.8 Hz, CF); E-isomer: 1H NMR (400 MHz, CDCl3)
d
6.76 (d,
J = 19.1 Hz, 1H, 55CH–); 19F NMR (377 MHz, CDCl3)
d
À121.78 (dq,
J = 19.1 Hz, J = 9.5 Hz, F), À66.71 (d, J = 9.5 Hz, CF3); the other
signals are identical to those of the Z-isomer. Anal. Calcd. for
C9H4Cl2F4: C 41.73; H 1.56. Found: C 41.58; H 1.67.
4.1. General procedure for synthesis of (2,3,3,3-tetrafluoroprop-1-
enyl)arenes (3a–k)
Round bottomed 100 mL flask was charged with hydrazine
hydrate (0.5 mL, 10 mmol), EtOH (10 mL) and solution of aromatic
aldehyde (10 mmol) in EtOH (20 mL) was added dropwise with
stirring. After aldehyde disappeared (overnight, TLC monitoring),
freshly purified CuCl [50] (100 mg, 1 mmol) and 1,2-ethylenedia-
mine (2 mL, 30 mmol) were added. The reaction mixture was
cooled down to 5–10 8C and CF3CFBr2 (2.2 mL, 20 mmol) was
added dropwise. After stirring at r.t. for 2 h and at 35 8C for 2 h, the
reaction mixture was quenched with 5% aq. HCl (150 mL) and the
reaction products were extracted with CH2Cl2 (3Â 50 mL).
Combined extracts were washed with water (50 mL) and dried
over Na2SO4. CH2Cl2 was removed in vacuo and the residue was
purified by column chromatography using hexane–CH2Cl2 mixture
(4:1) as eluent. E and Z isomers of alkenes could not be separated
by column chromatography. 13C NMR spectra of the minor E-
isomers are not given, because corresponding signals were not
found in 13C NMR spectra of the isomeric mixtures due to their low
concentration.
4.1.4. 1-Methyl-4-(2,3,3,3-tetrafluoroprop-1-enyl)benzene (3d)
Obtained as a 93:7 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.6; IR (nujol) 1610, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
(400 MHz, CDCl3)
7.27 (d, J = 7.8 Hz, 2H, Ar), 7.51 (d, J = 7.8 Hz, 2H, Ar); 19F NMR
(377 MHz, CDCl3)
À133.16 (dq, J = 36.0 Hz, J = 11.5 Hz, F), À71.94
(d, J = 11.5 Hz, CF3); 13C NMR (100 MHz, CDCl3)
21.28, 111.40,
d 2.44 (s, 3H, Me), 6.37 (d, J = 36.0 Hz, 1H,55CH-),
d
d
119.04 (qd, JCF = 271.5 Hz, JCF = 41.0 Hz, CF3), 126.85 (d, JCF = 3.7 Hz),
129.58, 129.62, 129.71 (d, JCF = 7.3 Hz), 139.91, 144.43 (dq,
JCF = 265.7 Hz, JCF = 38.8 Hz, CF); E-isomer: 1H NMR (400 MHz,
6.84 (d, J = 21.2 Hz, 1H,55CH–);19F NMR (377 MHz, CDCl3)
CDCl3) d d
À66.71 (d, J = 9.8 Hz, CF3); the other signals are identical to those of
the Z-isomer. NMR data are in agreement to literature [44].
4.1.5. 1-Ethyl-4-(2,3,3,3-tetrafluoroprop-1-enyl)benzene (3e)
Obtained as a 94:6 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.7; IR (nujol) 1610, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
(400 MHz, CDCl3)
d 1.31 (t, J = 7.6 Hz, 3H, Me), 2.73 (q, J = 7.6 Hz,

A.A. Goldberg et al. / Journal of Fluorine Chemistry 131 (2010) 384–388
387
2H, –CH2–), 6.38 (d, J = 36.0 Hz, 1H, 55CH–), 7.30 (d, J = 8.1 Hz, 2H,
Ar), 7.55 (d, J = 8.1 Hz, 2H, Ar); 19F NMR (377 MHz, CDCl3)
À133.17 (dq, J = 36.0 Hz, J = 11.5 Hz, F), À71.94 (d, J = 11.5 Hz, CF3);
13C NMR (100 MHz, CDCl3)
15.26, 28.78, 111.45, 119.10 (qd,
JCF = 270.8 Hz, JCF = 41.0 Hz, CF3), 127.14 (d, JCFb = 3.7 Hz), 128.44,
129.84 (d, JCF = 7.3 Hz), 145.33 (dq, JCF = 265.7 Hz, JCF = 38.8 Hz, CF),
(400 MHz, CDCl3)
d 3.84 (s, 3H, O-Me), 6.30 (d, J = 36.2 Hz, 1H,
d
55CH–), 6.93 (d, J = 8.8 Hz, 2H, Ar), 7.52 (d, J = 8.8 Hz, 2H, Ar); 19F
NMR (377 MHz, CDCl3)
d
À135.31 (dq, J = 36.2 Hz, J = 11.7 Hz, F),
d
À71.81 (d, J = 11.7 Hz, CF3); 13C NMR (100 MHz, CDCl3)
d 55.04,
111.13, 114.27, 119.26 (qd, JCF = 270.8 Hz, JCF = 41.0 Hz, CF3),
122.26 (d, JCF = 3.7 Hz), 131.34 (d, JCF = 7.3 Hz), 143.62 (dq,
JCF = 263.5 Hz, JCF = 38.0 Hz, CF), 160.64; E-isomer: 1H NMR
146.29; E-isomer: 1H NMR (400 MHz, CDCl3)
d
7.85 (d, J = 21.5 Hz,
1H, 55CH–); 19F NMR (377 MHz, CDCl3)
d
À125.58 (dq, J = 21.4 Hz,
(400 MHz, CDCl3)
(377 MHz, CDCl3)
(d, J = 9.7 Hz, CF3); the other signals are identical to those of the Z-
isomer. Anal. Calcd. for C10H8OF4: C 54.55; H 3.66. Found: C 54.68;
H 3.74.
d
6.80 (d, J = 21.5 Hz, 1H, 55CH–); 19F NMR
J = 9.8 Hz, F), À66.72 (d, J = 9.8 Hz, CF3); the other signals are
identical to those of the Z-isomer. Anal. Calcd for C11H10F4: C 60.55;
H 4.62. Found: C 60.67; H 4.53.
d
À126.49 (dq, J = 21.5 Hz, J = 9.7 Hz, F), À66.71
4.1.6. 1-Nitro-3-(2,3,3,3-tetrafluoropropen-1-yl)benzene (3f)
Obtained as a 89:11 mixture of Z/E isomers. Colorless oil; Rf
(hexane–CH2Cl2 2:1) 0.5; IR (nujol) 1350, 1540 (NO2); 1610, 1700
4.1.10. Methyl 4-(2,3,3,3-tetrafluoropropen-1-yl)benzoate (3j)
Obtained as a 97:3 mixture of Z/E isomers. White solid, m.p.
59.3–59.5 8C; Rf (hexane–CH2Cl2 2:1) 0.5; IR (nujol) 1610, 1700
(C55C) cmÀ1; Z-isomer: 1H NMR (400 MHz, CDCl3)
d 6.40 (d,
J = 34.0 Hz, 1H,55CH–), 7.61 (t, J = 8.0 Hz, 1H, Ar), 7.89 (d, J = 8.0 Hz,
1H, Ar), 8.23 (ddd, J = 8.0 Hz, J = 2.1 Hz, J = 0.9 Hz, 1H, Ar), 8.41 (s,
(C55C) cmÀ1; Z-isomer: 1H NMR (400 MHz, CDCl3)
d
3.93 (s, 3H,
O–Me), 6.39 (d, J = 35.0 Hz, 1H, 55CH–), 7.61 (d, J = 7.8 Hz, 2H,
Ar), 8.05 (d, J = 7.8 Hz, 2H, Ar); 19F NMR (377 MHz, CDCl3)
À128.75 (dq, J = 35.0 Hz, J = 10.9 Hz, F), À72.24 (d, J = 10.9 Hz,
CF3); 13C NMR (100 MHz, CDCl3)
52.12, 110.57, 118.60 (qd,
1H, Ar); 19F NMR (377 MHz, CDCl3)
d
À127.81 (dq, J = 34.0 Hz,
d
J = 10.6 Hz, F), À72.33 (d, J = 10.6 Hz, CF3); 13C NMR (100 MHz,
CDCl3)
d
109.61, 118.39 (qd, JCF = 272.3 Hz, JCF = 41.0 Hz, CF3),
d
124.21, 124.31 (d, JCF = 8.1 Hz), 130.02, 131.14 (d, JCF = 2.9 Hz),
135.22 (d, JCF = 7.3 Hz), 146.71 (dq, JCF = 271.5 Hz, JCF = 38.8 Hz, CF),
JCF = 272.3 Hz, JCF = 41.0 Hz, CF3), 129.54 (d, JCF = 7.3 Hz), 129.94,
130.88, 133.80 (d, JCF = 3.7 Hz), 146.11 (dq, JCF = 270.8 Hz,
JCF = 38.0 Hz, CF), 166.20; E-isomer: 1H NMR (400 MHz, CDCl3)
148.48; E-isomer: 1H NMR (400 MHz, CDCl3)
d
6.87 (d, J = 19.4 Hz,
1H, 55CH–); 19F NMR (377 MHz, CDCl3)
d
À120.95 (dq, J = 19.4 Hz,
d d
6.84 (d, J = 20.1 Hz, 1H, 55CH–); 19F NMR (377 MHz, CDCl3)
J = 9.2 Hz, F), À66.83 (d, J = 9.2 Hz, CF3); the other signals are
identical to those of the Z-isomer. ESI-MS (m/z): calcd. for
C9H5F4NNaO2 [M+] 258.0154, found 258.0149.
À122.36 (dq, J = 20.10 Hz, J = 9.5 Hz, F), À66.82 (d, J = 9.5 Hz,
CF3); the other signals are identical to those of the Z-isomer. ESI-
MS (m/z): calcd. for
C
11H8F4NaO2 [M+]: 271.0358, found
271.0353.
4.1.7. 1-Nitro-2-(2,3,3,3-tetrafluoropropen-1-yl)benzene (3g)
Obtained as a 91:9 mixture of Z/E isomers. Colorless oil; Rf
(hexane–CH2Cl2, 2:1) 0.5; IR (nujol) 1610, 1700 (C55C) cmÀ1; Z-
4.1.11. 1-(2,3,3,3-Tetrafluoropropen-1-yl)-4-
(trifluoromethyl)benzene (3k)
isomer: 1H NMR (400 MHz, CDCl3)
d
7.03 (d, J = 32.5 Hz, 1H,55CH–),
Obtained as a 95:5 mixture of Z/E isomers. Colorless oil; Rf
7.59 (td, J = 8.0 Hz, J = 1.6 Hz, 1H, Ar), 7.72 (td, J = 7.7 Hz, J = 1.1 Hz,
1H, Ar), 7.78 (dd, J = 8.0 Hz, J = 1.1 Hz, 1H, Ar), 8.14 (d, J = 8.1 Hz, 1H,
(hexane) 0.5; Z-isomer: 1H NMR (400 MHz, CDCl3)
d
6.40 (d,
J = 34.8 Hz, 1H,55CH–), 7.66 (m, 4H, Ar); 19F NMR (377 MHz, CDCl3)
Ar); 19F NMR (377 MHz, CDCl3)
d
À131.30 (dq, J = 32.5 Hz,
d
À128.85 (dq, J = 34.8 Hz, J = 10.8 Hz, F), À72.31 (d, J = 10.8 Hz,
J = 10.7 Hz, F), À72.46 (dd, J = 10.7 Hz, CF3); 13C NMR (100 MHz,
CF3), À63.05 (s, CF3); 13C NMR (100 MHz, CDCl3)
d 110.12, 118.55
CDCl3)
d
107.76, 118.41 (qd, JCF = 272.3 Hz, JCF = 41.0 Hz, CF3),
(qd, JCF = 272.3 Hz, JCF = 41.3 Hz, CF3), 123.7 (q, JCF = 272.3 Hz, CF3),
125.7, 129.82 (d, JCF = 7.6 Hz), 131.05, 133.04, 146.40 (dq,
JCF = 270.6 Hz, JCF = 38.0 Hz, CF); E-isomer: 1H NMR (400 MHz,
CDCl3) d
6.84 (d, J = 20.2 Hz, 1H,55CH–); 19F NMR (377 MHz, CDCl3)
124.14, 125.15, 130.21, 131.64 (d, JCF = 8.0 Hz), 133.60, 146.30 (dq,
JCF = 269.3 Hz, JCF = 38.8 Hz, CF), 147.71; E-isomer: 1H NMR
(400 MHz, CDCl3)
J = 7.8 Hz, 2H, Ar), 8.22 (d, J = 7.8 Hz, 2H, Ar); 19F NMR (377 MHz,
CDCl3)
d
7.19 (d, J = 18.2 Hz, 1H, 55CH–), 7.42 (d,
d
À122.05 (dq, J = 20.2 Hz, J = 9.4 Hz, F), À66.84 (d, J = 9.4 Hz, CF3),
d
À123.61 (dq, J = 18.1 Hz, J = 9.7 Hz, F), À66.90 (d, J = 9.7 Hz,
À62.95 (s, CF3); 13C NMR (100 MHz, CDCl3)
d; the other signals are
CF3); the other signals are identical to those of the Z-isomer. ESI-MS
(m/z): calcd. for C9H5F4NNaO2 [M+] 258.0154, found 258.0149.
identical to those of the Z-isomer. Anal. Calcd. for C10H5F7: C 46.53;
H 1.95. Found: C 46.65; H 2.09.
4.1.8. 1-Butoxy-4-(2,3,3,3-tetrafluoropropen-1-yl)benzene (3h)
Obtained as a 94:6 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.4; IR (nujol) 1610, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR
4.1.12. 1-Nitro-4-(2,3,3,3-tetrafluoropropen-1-yl)benzene (3l)
Obtained as a 90:10 mixture of Z/E isomers. Colorless solid, m.p.
60.5–61.3 8C; Rf (hexane–CH2Cl2 2:1) 0.4; Z-isomer: 1H NMR
(400 MHz, CDCl3)
d
1.04 (t, J = 7.4 Hz, 3H, Me), 1.56 (m, 2H, –CH2–),
(400 MHz, CDCl3)
J = 8.8 Hz, 2H, Ar), 8.29 (d, J = 8.9 Hz, 2H, Ar); 13C NMR (100 MHz,
CDCl3) 109.66, 118.34 (qd, JCF = 271.5 Hz, JCF = 40.5 Hz, CF3),
123.91, 130.39 (d, JCF = 7.6 Hz), 135.76, 147.96 (dq, JCF = 273.2 Hz,
JCF = 38.8 Hz, CF), 147.90; E-isomer: 1H NMR (400 MHz, CDCl3)
6.89 (d, J = 19.5 Hz, 1H, 55CH–); the other signals are identical to
those of the Z-isomer. Anal. Calcd. for C9H5NO2F4: C 45.97; H 2.14.
Found: C 45.85; H 2.03.
d 6.50 (d, J = 34.0 Hz, 1H, 55CH–), 7.76 (d,
1.83 (m, 2H, –CH2–), 4.03 (t, J = 6.5 Hz, 2H, O–CH2–), 6.32 (d,
J = 36.3 Hz, 1H,55CH–), 6.95 (d, J = 8.5 Hz, 2H, Ar), 7.54 (d, J = 8.5 Hz,
d
2H, Ar); 19F NMR (377 MHz, CDCl3)
d
À135.53 (dq, J = 36.3 Hz,
J = 11.8 Hz, F), À71.79 (d, J = 11.8 Hz, CF3); 13C NMR (100 MHz,
d
CDCl3)
d
13.77, 19.23, 31.23, 67.76, 111.15, 114.79, 119.20 (qd,
JCF = 270.8 Hz, JCF = 41.0 Hz, CF3), 122.02 (d, JCF = 3.7 Hz), 131.31 (d,
JCF = 7.3 Hz), 146.71 (dq, JCF = 263.5 Hz, JCF = 38.8 Hz, CF), 160.17;
E-isomer: 1H NMR (400 MHz, CDCl3)
d
6.79 (d, J = 21.6 Hz, 1H,
55CH–), 7.24 (d, J = 8.4 Hz, 1H, Ar); 19F NMR (377 MHz, CDCl3)
d
4.2. Reactions of styrene 3l with nucleophiles
À126.71 (dq, J = 21.6 Hz, J = 9.7 Hz, F), À66.77 (d, J = 9.7 Hz, CF3);
the other signals are identical to those of the Z-isomer. Anal. Calcd.
for C13H14OF4: C 59.54; H 5.38. Found: C 59.75; H 5.49.
Reactions with nucleophiles were carried out according to our
previously reported procedures for the substitution of chlorine in
styrene 7 by pyrrolidine [49], 4-methylphenylthiolate [47] and
potassium tert-butoxide [48]. Identification of the reaction
products were performed by comparison with spectroscopic data
reported in mentioned references.
4.1.9. 1-Methoxy-4-(2,3,3,3-tetrafluoropropen-1-yl)benzene (3i)
Obtained as a 95:5 mixture of Z/E isomers. Colorless oil; Rf
(hexane) 0.3; IR (nujol) 1610, 1700 (C55C) cmÀ1; Z-isomer: 1H NMR

388
A.A. Goldberg et al. / Journal of Fluorine Chemistry 131 (2010) 384–388
[22] V.G. Nenajdenko, V.N. Korotchenko, A.V. Shastin, E.S. Balenkova, Russ. Chem. Bull.
Acknowledgement
53 (2004) 1034–1064.
[23] V.N. Korotchenko, A.V. Shastin, V.G. Nenajdenko, E.S. Balenkova, Tetrahedron 57
(2001) 7519–7527.
[24] V.G. Nenajdenko, A.V. Shastin, V.N. Korotchenko, G.N. Varseev, E.S. Balenkova, Eur.
J. Org. Chem. (2003) 302–308.
This project was supported by the Russian Foundation for Basic
Research (grant no. 08-03-00736-a).
[25] V.G. Nenajdenko, G.N. Varseev, V.N. Korotchenko, A.V. Shastin, E.S. Balenkova, J.
Fluorine Chem. 124 (2003) 115–118.
References
[26] V.G. Nenajdenko, G.N. Varseev, A.V. Shastin, E.S. Balenkova, J. Fluorine Chem. 126
(2005) 907–913.
[27] A.V. Shastin, V.M. Muzalevsky, E.S. Balenkova, V.G. Nenajdenko, Mendeleev
Commun. 16 (2006) 179–180.
[28] V.G. Nenajdenko, G.N. Varseev, V.N. Korotchenko, A.V. Shastin, E.S. Balenkova, J.
Fluorine Chem. 125 (2004) 1339–1345.
[29] W. Peng, S. Zhu, G. Jin, Tetrahedron 57 (2001) 5781–5784.
[30] X.-Q. Tang, C.-M. Hu, J. Chem. Soc., Perkin Trans. 1 (1994) 2161–2163.
[31] E. Bosone, F. Gozzo, Ger. Offen. DE 3244641 (1983).
[32] G. Caprara, F. Gozzo, G. Paparatto, L. Roberti, Fr. Demande FR 2499070
(1982).
[33] P. Piccardi, F. Corda, F. Gozzo, A. Menconi, A. Longoni, Belg. BE 874515 (1979).
[34] S. Peng, F.-L. Qing, J. Chem. Soc., Perkin Trans. 1 (1999) 3345–3348.
[35] X. Tang, C. Hu, Chin. Chem. Lett. 5 (1994) 183–186.
[36] W. Huang, Y. Xie, Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1097190
(1995).
[1] P. Kirsch, Modern Fluoroorganic Chemistry: Synthesis, Reactivity, Applications,
Wiley-VCH, Weinheim, 2004.
[2] K. Uneyama, Organofluorine Chemistry, Blackwell, Oxford, 2006.
[3] G. Theodoridis, Fluorine-containing agrochemicals: an overview of recent devel-
opments, in: A. Tressaud (Ed.), Advances in Fluorine Science, vol. 2, Elsevier,
Amsterdam, 2006, pp. 121–175.
[4] J.P. Be´gue´, D. Bonnet-Delpon, Bioorganic and Medicinal Chemistry of Fluorine,
John Wiley & Sons, Hoboken, 2008.
[5] A. Tressaud, G. Haufe (Eds.), Fluorine and Health. Molecular Imaging, Biomedical
Materials and Pharmaceuticals, Elsevier, Amsterdam, 2008, pp. 553–778.
[6] M. Hudlicky´, A.P. Pavlath, Chemistry of Organic Fluorine Compounds II, ACS
Symposium Series 187, American Chemical Society, Washington, 1995.
[7] V.A. Soloshonok (Ed.), Fluorine-Containing Synthons, ACS Symposium Series
911American Chemical Society, Washington, 2005.
[8] V.A. Soloshonok, K. Mikami, T. Yamazaki, J.T. Welch, J.F. Honek (Eds.), Current
Fluoroorganic Chemistry. New Synthetic Directions, Technologies, Materials, and
Biological Applications, ACS Symposium Series 949American Chemical Society,
Washington, 2006.
[9] I.N. Martyanov, K.J. Klabunde, J. Catal. 224 (2004) 340–346.
[10] Z. Ma, W.M. Hua, Y. Tang, Z. Gao, J. Mol. Catal. A: Chem. 159 (2000) 335–345.
[11] P. Hohener, D. Werner, C. Balsiger, G. Pasteris, Crit. Rev. Environ. Sci. Technol. 33
(2003) 1–29.
[12] V.V. Lunin, E.S. Lokteva, Russ. Chem. Bull. 45 (1996) 1519–1534.
[13] F. Alonso, I.P. Beletskaya, M. Yus, Chem. Rev. 102 (2002) 4009–4091.
[14] K.I. Petko, L.M. Yagupolskii, Synth. Commun. 36 (2006) 1967–1972.
[15] V.G. Koshechko, V.D. Pokhodenko, Russ. Chem. Bull. 50 (2001) 1929–1935.
[16] A.V. Shastin, V.N. Korotchenko, V.G. Nenajdenko, E.S. Balenkova, Russ. Chem. Bull.
48 (1999) 2184–2185.
[37] C. Hu, M. Tu, F. Qing, Faming Zhuanli Shenqing Gongkai Shuomingshu CN
1056864 (1991).
[38] W. Fu, X. Zhang, X. Jiang, Sci. Chin. Ser. B: Chem. 44 (2001) 337–343.
[39] I. Hemer, A. Posta, V. Dedek, J. Fluorine Chem. 26 (1984) 467–479.
[40] W. Dmowski, J. Fluorine Chem. 29 (1985) 273–286.
[41] I.H. Jeong, Y.S. Park, M.S. Kim, Y.S. Song, J. Fluorine Chem. 120 (2003) 195–209.
[42] G.E. Carr, R.D. Chambers, T.F. Holmes, D.G. Parker, J. Chem. Soc., Perkin Trans. 1
(1988) 921–926.
[43] W.R.J. Dolbier, T.A. Gray, K. Onishi, Synthesis (1987) 956–958.
[44] N.V. Kirij, D.A. Dontsova, N.V. Pavlenko, Y.L. Yagupolskii, H. Scherer, W. Tyrra, D.
Naumann, Eur. J. Org. Chem. (2008) 2267–2272.
[45] V.G. Nenajdenko, V.M. Muzalevskiy, A.V. Shastin, E.S. Balenkova, G. Haufe, J.
Fluorine Chem. 128 (2007) 818–826.
[17] A.V. Shastin, V.N. Korotchenko, V.G. Nenajdenko, E.S. Balenkova, Tetrahedron 56
(2000) 6557–6563.
[46] A.V. Shastin, V.M. Muzalevskiy, E.S. Balenkova, V.G. Nenajdenko, R. Fro¨hlich, G.
Haufe, Tetrahedron 64 (2008) 9725–9732.
[18] A.V. Shastin, V.N. Korotchenko, V.G. Nenajdenko, E.S. Balenkova, Synthesis (2001)
2081–2084.
[47] V.M. Muzalevskiy, A.V. Shastin, E.S. Balenkova, V.G. Nenajdenko, Russ. Chem. Bull.
56 (2007) 1526–1533.
[19] V.N. Korotchenko, A.V. Shastin, V.G. Nenajdenko, E.S. Balenkova, J. Chem. Soc.,
Perkin Trans. 1 (2002) 883–887.
[48] V.M. Muzalevskiy, V.G. Nenajdenko, A.V. Shastin, E.S. Balenkova, G. Haufe, Syn-
thesis (2009) 2249–2259.
[20] A.V. Shastin, V.N. Korotchenko, V.G. Nenajdenko, E.S. Balenkova, Russ. Chem. Bull.
50 (2001) 1401–1404.
[49] V.M. Muzalevskiy, V.G. Nenajdenko, A.V. Shastin, E.S. Balenkova, G. Haufe, Tetra-
hedron 65 (2009) 6991–7000.
[21] V.N. Korotchenko, A.V. Shastin, V.G. Nenajdenko, E.S. Balenkova, Org. Biomol.
Chem. 1 (2003) 1906–1908.
[50] D.D. Perrin, W.L.F. Armaredo, Purification of Laboratory Chemicals, Pergamon
Press, New York, 1988, p. 322.