Reaction of gem-difluorinated organozinc reagents with β-nitrostyrenes

Article abstract of DOI:10.1016/j.jfluchem.2015.06.001

A novel reactivity pattern of gem-difluorinated organozincs in copper(I) catalyzed reaction with β-nitrostyrenes is described. The reaction proceeds not as conjugate addition, but as nitro group substitution furnishing alkenes as single E-isomers in moder

Full text of DOI:10.1016/j.jfluchem.2015.06.001

Accepted Manuscript
Title: Reaction of gem-difluorinated organozinc reagents with
␤-nitrostyrenes
Author: Nikolay S. Kondratyev Vitalij V. Levin Artem A.
Zemtsov Marina I. Struchkova Alexander D. Dilman
PII:
S0022-1139(15)00152-9
DOI:
Reference:
http://dx.doi.org/doi:10.1016/j.jfluchem.2015.06.001
FLUOR 8572
To appear in:
FLUOR
Received date:
Revised date:
Accepted date:
12-5-2015
3-6-2015
4-6-2015
Please cite this article as: N.S. Kondratyev, V.V. Levin, A.A. Zemtsov,
M.I. Struchkova, A.D. Dilman, Reaction of gem-difluorinated organozinc
reagents with rmbeta-nitrostyrenes, Journal of Fluorine Chemistry (2015),
http://dx.doi.org/10.1016/j.jfluchem.2015.06.001
This is a PDF file of an unedited manuscript that has been accepted for publication.
As a service to our customers we are providing this early version of the manuscript.
The manuscript will undergo copyediting, typesetting, and review of the resulting proof
before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that
apply to the journal pertain.

*Graphical Abstract - Pictogram
F F
F F
Cu(I)
R
+ O2N
R
ZnX
Ar
Ar
Page 1 of 15

*Graphical Abstract - Synopsis
Reaction of gem-difluorinated organozinc reagents with β-nitrostyrenes
a,b
a
a
a
Nikolay S. Kondratyev, Vitalij V. Levin, Artem A. Zemtsov, Marina I. Struchkova, Alexander
a,
D. Dilman *
a
N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian
Federation, Fax: +7-499-1355328, E-mail: adil25@mail.ru
b
Higher Chemical College, Russian Academy of Sciences, 125047 Moscow, Miusskaya sq. 9,
Russian Federation
F F
ZnX
F F
Cu(I)
R
+ O2N
R
Ar
Ar
Nitro group substitution in copper-catalyzed reaction of gem-difluorinated organozinc reagents with
β-nitrostyrenes is described.
Page 2 of 15

*Highlights (for review)
Reactions of fluorinated organozinc reagents.
Reactions of β-nitrostyrenes.
Copper-catalyzed nitro group substitution.
Page 3 of 15

*Manuscript
Click here to view linked References
Reaction of gem-difluorinated organozinc reagents with β-nitrostyrenes
a,b
a
a
a
Nikolay S. Kondratyev, Vitalij V. Levin, Artem A. Zemtsov, Marina I. Struchkova, Alexander
a,
D. Dilman *
a
N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian
Federation, Fax: +7-499-1355328, E-mail: adil25@mail.ru
b
Higher Chemical College, Russian Academy of Sciences, 125047 Moscow, Miusskaya sq. 9,
Russian Federation
Abstract A novel reactivity pattern of gem-difluorinated organozincs in copper (I) catalyzed
reaction with β-nitrostyrenes is described. The reaction proceeds not as conjugate addition, but as
nitro group substitution furnishing alkenes as single E-isomers in moderate yields.
1
Page 4 of 15

Reaction of gem-difluorinated organozinc reagents with β-nitrostyrenes
a,b
a
a
a
Nikolay S. Kondratyev, Vitalij V. Levin, Artem A. Zemtsov, Marina I. Struchkova, Alexander
a,
D. Dilman *
a
N. D. Zelinsky Institute of Organic Chemistry, 119991 Moscow, Leninsky prosp. 47, Russian
Federation, Fax: +7-499-1355328, E-mail: adil25@mail.ru
b
Higher Chemical College, Russian Academy of Sciences, 125047 Moscow, Miusskaya sq. 9,
Russian Federation
Abstract A novel reactivity pattern of gem-difluorinated organozincs in copper (I) catalyzed
reaction with β-nitrostyrenes is described. The reaction proceeds not as conjugate addition, but as
nitro group substitution furnishing alkenes as single E-isomers in moderate yields.
Keywords: Organozinc reagents, Nitroalkenes, gem-Difluorinated compounds, Substitution
1
. Introduction
2
Nucleophilic substitution at sp -carbon atom by fluorinated carbanions has emerged as a
powerful methodology for the synthesis of organofluorine compounds [1]. In these reactions,
halogen (typically iodine) [1], pseudo-halogen (perfluorosulfonate) [2], or diazonium [3] serve as
leaving groups, and reactions are promoted by copper(I) or palladium(0) catalysts. As far as C-
nucleophiles are concerned, fluorinated silicon [1], boron [4], and zinc reagents [5] were employed
which undergo transmetalation to generate fluorinated copper or palladium species as reactive
intermediates. Correspondingly, stoichiometric fluorinated copper reagents proved to be very
efficient in these reactions [6].
2
Page 5 of 15

Recently we reported an efficient method towards gem-difluorinated organozinc reagents 1 by
reaction of organozincs with difluorocarbene precursor [7] (Scheme 1). Herein we report, that
interaction of reagents 1 with β-nitrostyrenes in the presence of a copper catalyst provides products
of formal nitro group substitution rather than conjugate addition.
Me SiCF Br
3
2
F
F
or BrCF CO K
2
2
R
ZnBr
R
ZnBr
1
conjugate addition
1
/cat. Cu(I) +
NO2
Ar
substitution - this work
Scheme 1. Preparation of reagents 1.
While for combination of conventional non-fluorinated alkyl organozincs and β-nitrostyrenes
both conjugate addition [8] and nitro group substitution [9] processes have been described, such
reactions of fluorine-containing organozincs have not been known.
2
. Results and discussion
Since we have systematically studied conjugate addition of fluorinated nucleophiles with
Michael acceptors [10], we studied the reaction of organozinc reagents 1 with β-nitrostyrenes 2
Table 1). Reagent 1a obtained from benzylzinc bromide and Me SiCF Br [7a] was used as a model
(
3
2
nucleophile and its coupling with 2-nitrostyrene 2a was evaluated. No product formation was
1
9
observed under non-catalytic conditions ( F NMR control), and we decided to add copper(I) salts,
since they are known to mediate conjugate additions in non-fluorinated area [11] and even for
fluorinated organozinc addition [10g]. Surprisingly, when 20 mol % of copper (I) chloride was
used, compound 3a corresponding to substitution of the nitro group by the fluorinated fragment was
3
Page 6 of 15

formed, whereas the amount of expected addition product did not exceed 10% (Table 1).
Subsequent extensive variation of reaction parameters (solvent, catalyst, ligand, stoichiometry)
allowed to increase the yield of 3a to a certain extent, but in most cases several unidentified
substances were formed which greatly hampered the isolation of the desired product. Finally, the
cleanest reaction was noted with 5 mol % of СuCl·1.5PPh complex as a catalyst performing the
3
reaction in dimethylformamide (DMF), with the isolated yield of alkene 3a being 50% as a single
E-isomer (entry 7).
Table 1
Preparation of compound 3a
F
F
F F
Ph
+
O2N
Ph
ZnBr
Ph
Ph
1a
2a
3a
Entry 1a (equiv)
Cat. (equiv)
Ligand
Solv.
Temp.
°C
Time,
Yield of
a
(
equiv)
h
3a, %
1
2
3
4
5
6
1.2
1.5
2
–
–
THF/MeCN (1/1)
THF/MeCN (1/1)
THF/MeCN (1/1)
THF/Diglyme (1/1)
THF/Diglyme (1/1)
DMF
–25
–25
–25
–25
0
2
0
CuCl (0.2)
CuCl (0.2)
CuI (0.1)
CuI (0.1)
CuI (0.1)
–
2
44
52
52
49
57
–
2
2
bipy (0.15)
phen (0.15)
phen (0.15)
–
2
2
18
18
18
1.5
1.5
rt
b
7
CuCl·1.5PPh (0.05)
DMF
rt
50
3
a
Determined by NMR with internal standard.
Isolated yield
b
Under the optimized conditions, a series of organozincs 1 were coupled with β-nitrostyrenes 2
Table 2). Compounds 3 were obtained as single E-isomers, except product 3f, which contained ca.
% of a geometrical isomer.
(
3
4
Page 7 of 15

Table 2
Coupling of organozincs 1 with β-nitrostyrenes 2
CuCl·1.5PPh3
F
F
F F
(
5 mol %)
R
+ O2N
R
ZnX
(1.5 equiv)
Ar
Ar
DMF, rt, 18 h
1
2
3
entry
1
2
3
Yield of
a
3
, %
F
F
NO2
F
F
F
F
1
2
3
1a
1a
1a
2b
2c
2d
3b 65
3c 53
3d 40
Ph
Ph
ZnBr
F
F
NO2
F
Ph
Ph
MeO
MeO
NO2
F
O
O
OMe
OMe
NO2
F F
4
1a
2e
3e 37
Ph
O
O
F F
b
NO2
5
6
1a
1b
2f
3f 24
Ph
Ph
Ph
Ph
Ph
O
NO2
O
2a
3g 39
3h 28
MeO
F
F
OMe
F
F
ZnBr
c
F F
7
1c
2g
F F
ZnI
NO2
a
Isolated yield.
b 19
F NMR and GC MS analysis indicated ca. 3 % of isomeric product.
equiv of 1c was used.
c
2
5
Page 8 of 15

Concerning mechanism, we believe that the reaction starts with zinc/copper transmetalation to
generate organocopper species 4. One electron oxidation of 4 leads to free radical 5, which can add
to double bond of 2 providing radical 6 stabilized by conjugation with the aromatic group. Finally,
elimination of free NO reinstalls the double bond. Although the exact nature of oxidant is unclear,
2
we may tentatively propose that nitrostyrene 2 can play this role, with the corresponding radical
anion serving as reductant of nitrogen dioxide. At the same time, other non-radical pathways for the
product formation cannot be excluded.
F
F
Cu(I)
F
F
– e
Cu(I)
F
F
R
R
R
ZnBr
Cu
1
4
5
O N
2
O N
2
Ar
F F
Ar
2
R
R
F
Ar
F
NO2
3
6
Scheme 2. Proposed mechanism.
3
. Conclusions
In summary, an unusual reaction of fluorinated organozinc reagents with respect to electron
deficient alkenes was disclosed. Presumably, the reaction proceeds by radical mechanism leading to
products of substitution of the nitro group of nitrostyrenes. Despite the moderate yields of products,
the described process constitutes a novel reactivity pattern which may find further applications.
4
. Experimental
4
.1 General Experimental Procedures
All reactions were performed under an argon atmosphere. DMF and MeCN were distilled under
vacuum from P O and stored over MS 4Å. NMR spectra were recorded on a Bruker AM-300
2
5
instrument. Microanalyses were performed on KarloErba 1106 instrument. Nitroalkenes 2a [12],
b,c [13], 2d [14], 2e [10d], 2f [15], 2g [16] and СuCl·1.5PPh [17] were obtained according to
2
3
literature procedures. Sodium acetate was dried under vacuum (200 °C/1 Torr, 1 h). Potassium
6
Page 9 of 15

bromodifluoroacetate and Et NBr were dried at under vacuum during 10 min prior to use (for
4
BrCF CO K, 100 °C/7 Torr; for Et NBr, 170 °C/1 Torr).
2
2
4
4
4
.2. Synthesis of compounds 3a-f (General Procedure)
.2.1. Preparation of reagent 1a.
A solution of benzylzinc bromide [7a] (2.1 М in THF, 14.3 mL, 30 mmol, 1.0 equiv) was added
to a solid potassium bromodifluoroacetate (45 mmol, 9.54 g, 1.5 equiv), and the solvent was
evaporated under vacuum (7 Torr) using water bath which finally reached 30 °C. The flask was
filled with argon, and the residue was diluted with DMF (40 mL). The resulting mixture was heated
for 1 h at 50 °C with vigorous stirring, and the mixture was cooled to room temperature. The
1
9
solution was analyzed by F NMR using PhCF as a standard (0.4–0.5 M of organozinc 1a).
3
4
.2.2 Reaction of 1a with 2a-e
A reaction tube was evacuated and filled with argon (repeated twice). A solution of reagent 1a in
DMF (3.0 mmol, 1.5 equiv) was added. Then, at room temperature, nitroalkene 2 (2.0 mmol, 1.0
equiv) and СuCl·1.5PPh (49.2 mg, 0.10 mmol, 5 mol %) were successively added, and the mixture
3
was stirred for 18 h. For the work-up, water (15 mL) and H SO (2 mL of 2M aqueous solution)
2
4
were added. The mixture was extracted (35 mL) [with hexane for 3a,b,e,f; with hexane/EtOAc,
3
/1, for 3c,d]. The combined organic phases were filtered through Na SO , concentrated under
2 4
vacuum, and the residue was purified by column chromatography.
4
.2.3 [(1E)-3,3-Difluoro-4-phenylbut-1-enyl]benzene (3a).
93 mg (50%). Colorless crystals. Mp 62–63 °C. R = 0.31 (hexanes/EtOAc, 30/1). H NMR
1
2
f
(
300 MHz, CDCl ), δ: 3.36 (t, 2H, J = 14.5 Hz), 6.20 (dt, 1H, J = 16.1, 11.4 Hz), 6.89 (d, 1H, J =
3
1
3
1
2
1
6.1 Hz), 7.17–7.75 (m, 10H). C NMR (75 MHz, CDCl ), δ: 44.5 (t, J = 28.0 Hz), 120.8 (t, J =
3
41.0 Hz), 123.0 (t, J = 26.0 Hz), 127.1, 127.3, 128.4, 128.7, 128.9, 130.6, 132.8 (t, J = 4.2 Hz),
1
9
33.9 (t, J = 9.0 Hz), 134.9. F NMR (282 MHz, CDCl ), δ: –94.7 (td, 2F, J = 14.5, 11.4 Hz).
3
Calcd for C H F (244.28): C 78.67, H 5.78. Found: C 78.83, H 5.74.
1
6
14 2
4
.2.4 1-[(1E)-3,3-Difluoro-4-phenylbut-1-enyl]-4-fluorobenzene (3b).
7
Page 10 of 15

1
3
62 mg (65%). Colorless crystals. Mp 69–70 °C. R
f
= 0.30 (hexanes/EtOAc, 30/1). H NMR
(300 MHz, CDCl
3
), δ: 3.35 (t, 2H, J = 15.4 Hz), 6.11 (dt, 1H, J = 16.0, 11.4 Hz), 6.84 (d, 1H, J =
1
3
1
2
1
2
4
6.0 Hz), 7.06 (t, 2H, J = 8.3 Hz), 7.23–7.50 (m, 7H). C NMR (75 MHz, CDCl ) δ: 44.5 (t, J =
3
8.0 Hz), 115.7 (d, J = 21.8 Hz), 120.7 (t, J = 240.9 Hz), 122.8 (dt, J = 26.2, 2.1 Hz), 127.4, 128.4,
28.7, 128.8, 130.6, 131.1 (d, J = 2.65 Hz) 132.7 (t, J = 9.3 Hz), 132.8 (t, J = 5.0 Hz), 163.0 (d, J =
1
9
48.8 Hz). F NMR (282 MHz, CDCl
3
) δ: –94.7 (td, 2F, J = 15.4, 11.4 Hz), –113.0 (tt, 1F, J = 8.3,
.2 Hz). Calcd for C H F (262.27): C 73.27, H 5.00. Found: C 73.21, H 4.98.
1
6
13 3
4
.2.4 1-[(1E)-3,3-Difluoro-4-phenylbut-1-enyl]-4-methoxybenzene (3c).
90 mg (53%). Colorless crystals. Mp 72–73 °C. R = 0.28 (hexanes/EtOAc, 15/1). H NMR
1
2
f
(
300 MHz, CD CN), δ: 3.26 (t, 2H, J = 16.1 Hz), 3.71 (s, 3H) 6.21 (dt, 1H, J = 16.2, 11.5 Hz), 6.72
3
(dt, 1H, J = 16.2 Hz, 2.34 Hz), 6.82 (d, 2H, J = 8.7 Hz), 7.30–7.36 (m, 5H), 7.31 (d, 2H, J = 8.7
1
3
Hz). C NMR (75 MHz, CD CN) δ: 44.6 (t, J = 27.5 Hz), 56.1, 115.3, 121.9 (t, J = 26.0 Hz), 122.5
3
(t, J = 238.9 Hz), 128.3, 128.5, 129.3, 129.6, 131.7, 134.4 (t, J = 9.2 Hz), 134.4 (t, J = 4.4 Hz),
19
1
61.5. F NMR (282 MHz, CD CN) δ: –94.5 (td, 2F, J = 16.1, 11.5 Hz). Calcd for C H F O
3 17 16 2
(
274.31): C 74.44, H 5.88. Found: C 74.21, H 5.84.
.2.5 Methyl 4-[(1E)-3,3-difluoro-4-phenylbut-1-enyl]benzoate (3d).
42 mg (40%). Colorless crystals. Mp 86–88 °C. R = 0.31 (hexanes/EtOAc, 8/1). H NMR (300
MHz, CDCl ), δ: 3.33 (t, 2H, J = 15.5 Hz), 3.93 (s, 3H) 6.26 (dt, 1H, J = 16.2, 11.3 Hz), 6.87 (dt,
H, J = 16.2, 2.3 Hz), 7.26–7.39 (m, 5H), 7.42, (d, 2H, J = 8.4), 8.02 (d, 2H, J = 8.4 Hz). C NMR
75 MHz, CDCl ) δ: 44.5 (t, J = 27.6 Hz), 52.1, 120.4 (t, J = 240.1 Hz), 125.4 (t, J = 26.4 Hz),
27.0, 127.4, 128.4, 130.0, 130.3, 130.5, 132.5 (t, J = 4.6 Hz), 132.9 (t, J = 9.2 Hz), 139.2, 166.5.
4
1
2
f
3
1
3
1
(
3
1
1
9
F NMR (282 MHz, CDCl
3
) δ: –95.4 (td, 2F, J = 15.5, 11.3 Hz). Calcd for C H F O (302.32): C
18 16 2 2
7
1.51, H 5.33. Found: C 71.44, H 5.41.
4
.2.6 2-[(1E)-3,3-Difluoro-4-phenylbut-1-enyl]furan (3e).
1
1
3
80 mg (37%). Pale yellow oil. R = 0.26 (hexanes/EtOAc, 30/1). H NMR (300 MHz, CDCl ), δ:
3
f
.32 (t, 2H, J = 15.5 Hz), 6.14 (dt, 1H, J = 15.9, 11.9 Hz), 6.34 (d, 1H, J = 3.4 Hz), 6.38 (dd, 1H, J
8
Page 11 of 15

13
=
3.4, 1.8 Hz), 6.61 (dt, 1H, J = 15.9, 2.4 Hz), 7.25–7.43 (m, 6H). C NMR (75 MHz, CDCl ) δ:
3
4
4.5 (t, J = 28.1 Hz), 111.3, 111.7, 120.6 (t, J = 240.5 Hz), 121.1 (t, J = 26.4 Hz), 121.8 (t, J = 9.9
19
Hz), 127.4, 128.4, 130.7, 132.8 (t, J = 4.1 Hz), 142.3, 150.9. F NMR (282 MHz, CDCl ) δ: –95.0
3
(
td, 2F, J = 15.5, 11.9 Hz). Calcd for C H F O (234.24): C 71.78, H 5.16. Found: C 71.77, H 5.30.
14 12 2
4
.2.7 [(1E,3E)-5,5-Difluoro-6-phenylhexa-1,3-dienyl]benzene (3f).
29 mg (24%) Colorless crystals. Mp 59–60 °C. R = 0.20 (hexanes/EtOAc, 40/1). H NMR (300
1
1
f
MHz, CDCl ), δ: 3.31 (t, 2H, J = 15.4 Hz), 5.79 (dt, 1H, J = 15.2, 11.8 Hz), 6.58–6.84 (m, 3H),
3
1
3
7
1
9
.25–7.48 (m, 10H). C NMR (75 MHz, CDCl ) δ: 44.5 (t, J = 28.0 Hz), 120.6 (t, J = 240.3 Hz),
3
26.1 (t, J = 26.1 Hz), 126.4, 126.8, 127.4, 128.5, 128.8, 130.6, 132.9 (t, J = 4.3 Hz), 134.1 (t, J =
19
.6 Hz), 136.45, 136.50, 136.53. F NMR (282 MHz, CDCl ) δ: –94.3 (tq, 2F, J = 15.4, 11.8 Hz);
3
minor isomer (ca 3 %): –88.7 (q, J = 15.3 Hz). Calcd for C H F O (270.32): C 79.98, H 5.97.
1
8
16
2
2
Found: C 80.04, H 5.84.
4
.3. Synthesis of methyl 4-[(3E)-2,2-difluoro-4-phenylbut-3-enyl]benzoate (3g).
A solution of organozinc bromide 4-MeO CC H CH ZnBr [7a] (0.95 М in THF, 4.9 mL, 4.65
2
6
4
2
mmol, 1.5 equiv) and the solvent was evaporated under vacuum (7 Torr) using water bath which
finally reached 30 °C. The flask was filled with argon, and the residue was diluted with MeCN (4.6
mL) to give colorless solution. Then, sodium acetate was added (5.59 mmol, 458 mg, 1.8 equiv),
and the resulting solution was cooled to –30 °C. TMSCF Br (5.59 mmol, 1.134 g, 1.8 equiv) was
2
added dropwise over 10 min, and the mixture was stirred for 18 h at –30 °C. DMF (4.6 mL) was
added, and the cooling bath was removed. The volatile components (mainly MeCN) were
evaporated under vacuum at 30 °C/7 Torr leading to a clear solution. The mixture was cooled to
room temperature. Nitroalkene 2a (462 mg, 3.1 mmol, 1.0 equiv) and СuCl·1.5PPh (76.3 mg,
3
0
.155 mmol, 5 mol %) were successively added, and the mixture was stirred for 18 h. For the work-
up, water (15 mL) and H SO (2 mL of 2M aqueous solution) were added, and the mixture was
2
4
extracted with hexane/tert-butyl methyl ether, 1/1 (35 mL). The combined organic phases were
filtered through Na SO , concentrated under vacuum, and the residue was purified by column
2
4
9
Page 12 of 15

chromatography. 365 mg (39%). Colorless crystals. Mp 100–101 °C. R = 0.30 (hexanes/EtOAc,
f
1
8
1
/1). H NMR (300 MHz, CDCl ), δ: 3.38 (t, 2H, J = 15.3 Hz), 3.93 (s, 3H), 6.16 (dt, 1H, J = 16.2,
3
13
1.4 Hz), 6.86 (dt, 1H, J = 16.2, 2.4 Hz), 7.24–7.48 (m, 7H), 8.03 (d, 2H, J = 8.2 Hz). C NMR (75
MHz, CDCl ), δ: 44.5 (t, J = 28.3 Hz), 52.1, 120.4 (t, J = 240.1 Hz), 122.6 (t, J = 26.1 Hz), 127.1,
3
1
9
1
28.8, 129.1, 129.4, 129.6, 130.6, 134.3 (t, J = 9.2 Hz), 134.7, 138.0 (t, J = 4.0 Hz), 166.8. F
NMR (282 MHz, CDCl ), δ: –94.6 (td, 2F, J = 15.3, 11.4 Hz). Calcd for C H F O (302.32): C
3
18 16
2
2
7
1.51, H 5.33. Found: C 71.32, H 5.35.
4
.5. Synthesis of 1-[(1E)-3,3-difluorobut-1-enyl]naphthalene (3h).
A solution of MeZnI (1.9 М in THF, 2.1 mL, 4.0 mmol, 2.0 equiv) was added to a solid
potassium bromodifluoroacetate (6.0 mmol, 1.278 g, 3.0 equiv), and the solvent was evaporated
under vacuum (7 Torr) using water bath which finally reached 30 °C. The flask was filled with
argon, and the residue was diluted with DMF (6 mL), and Et NBr (420 mg, 2.0 mmol, 1 equiv) was
4
added. The resulting mixture was heated at 50 °C with vigorous stirring for 1 h. The mixture was
cooled to room temperature that cased the formation of the precipitant. Nitroalkene 2f (398 mg, 2.0
mmol, 1.0 equiv) and СuCl·1.5PPh (49.2 mg, 0.10 mmol, 5 mol %) were successively added, and
3
the mixture was stirred for 18 h. For the work-up, water (15 mL) and H SO (2 mL of 2M aqueous
2
4
solution) were added, and the mixture was extracted with hexane (35 mL). The combined organic
phases were filtered through Na SO , concentrated under vacuum, and the residue was purified by
2
4
1
column chromatography. 120 mg (28%). Colorless oil. R = 0.20 (hexanes/EtOAc, 50/1). H NMR
f
(
300 MHz, CDCl ), δ: 1.90 (t, 3H, J = 17.9 Hz), 6.31 (dt, 1H, J = 15.6, 10.1 Hz), 7.50–7.80 (m,
3
1
3
5
H), 7.84–7.98 (m, 2H), 8.09–8.20 (m, 1H). C NMR (75 MHz, CDCl ), δ: 24.5 (t, J = 29.2 Hz),
3
1
20.8 (t, J = 236.0 Hz), 123.5, 124.4, 125.5, 126.0, 126.5, 127.5 (t, J = 27.2 Hz), 128.7, 129.2,
19
1
30.6 (t, J = 9.9 Hz), 131.3, 132.6, 133.6. F NMR (282 MHz, CDCl ), δ: –88.2 (qd, 2F, J = 17.9,
3
1
0.1 Hz ). Calcd for C H F (218.24): C 77.05, H 5.54. Found: C 76.94, H 5.50.
1
4
12 2
Acknowledgments
This work was supported by the Russian Science Foundation (project 14-50-00126).
1
0
Page 13 of 15

References and Notes
[
1] (a) T. Liu, Q. Shen, Eur. J. Org. Chem. 2012 (2012) 6679–6687. (b) S. Roy, B.T. Gregg,
G.W. Gribble, V.-D. Le, S. Roy, Tetrahedron. 67 (2011) 2161–2195. (c) O.A. Tomashenko,
V.V. Grushin, Chem. Rev. 111 (2011) 4475–4521.
[
[
2] E.J. Cho, S.L. Buchwald, Org. Lett. 13 (2011) 6552–6555.
3] (a) J.-J. Dai, C. Fang, B. Xiao, J. Yi, J. Xu, Z.-J. Liu, X. Lu, L. Liu, Y. Fu, J. Am. Chem. Soc.
1
35 (2013) 8436–8439. (b) G. Danoun, B. Bayarmagnai, M.F. Grünberg, L.J. Gooßen,
Angew. Chem. Int. Ed. 52 (2013) 7972–7975. (c) A. Lishchynskyi, G. Berthon, V.V. Grushin,
Chem. Commun. 50 (2014) 10237–10240.
[
[
4] T. Knauber, F. Arikan, G.-V. Röschenthaler, L.J. Gooßen, Chem. Eur. J. 17 (2011) 2689–
2
697.
5] (a) I. Popov, S. Lindeman, O. Daugulis, J. Am. Chem. Soc. 133 (2011) 9286–9289. (b) Y.
Nakamura, M. Fujiu, T. Murase, Y. Itoh, H. Serizawa, K. Aikawa, K. Mikami, Beilstein J.
Org. Chem. 9 (2013) 2404–2409.
[
[
6] (a) G.G. Dubinina, H. Furutachi, D.A. Vicic, J. Am. Chem. Soc. 130 (2008) 8600–8601. (b)
H. Morimoto, T. Tsubogo, N.D. Litvinas, J.F. Hartwig, Angew. Chem. Int. Ed. 50 (2011)
3
793–3798. (c) A. Lishchynskyi, M.A. Novikov, E. Martin, E.C. Escudero-Adan, P. Novak,
V.V. Grushin, J. Org. Chem. 78 (2013) 11126–11146.
7] (a) V.V. Levin, A.A. Zemtsov, M.I. Struchkova, A.D. Dilman, Org. Lett. 15 (2013) 917–919.
(b) A.A. Zemtsov, N.S. Kondratyev, V.V. Levin, M.I. Struchkova, A.D. Dilman, J. Org.
Chem. 79 (2014) 818–822. (c) V.O. Smirnov, M.I. Struchkova, D.E. Arkhipov, A.A.
Korlyukov, A.D. Dilman, J. Org. Chem. 79 (2014) 11819–11823. (d) V.V. Levin, A.A.
Zemtsov, M.I. Struchkova, A.D. Dilman, J. Fluorine Chem. 171 (2015) 97–101.
[
8] (a) F. Valleix, K. Nagai, T. Soeta, M. Kuriyama, K. Yamada, K. Tomioka, Tetrahedron. 61
(2005) 7420–7424. (b) A. Rimkus, N. Sewald, Org. Lett. 4 (2002) 3289–3291. (c) A.R.M.
1
1
Page 14 of 15

Oliveira, J.A.F.P. Villar, F. Simonelli, R.A. Gariani, C.L. Wosch, P.H.G. Zarbin, Tetrahedron
Lett. 48 (2007) 1507–1509.
[
[
9] (a) D. Seebach, H. Schäfer, B. Schmidt, M. Schreiber, Angew. Chem. Int. Ed. 31 (1992)
1
587–1588. (b) Y. Hu, J. Yu, S. Yang, J.-X. Wang, Y. Yin, Synlett. 1998 (1998) 1213–1214.
(c) Y. Hu, J. Yu, S. Yang, J.-X. Wang, Y. Yin, Synth. Commun. 29 (1999) 1157–1164.
10] (a) A.D. Dilman, V.V. Levin, P.A. Belyakov, M.I. Struchkova, V.A. Tartakovsky,
Tetrahedron Lett. 49 (2008) 4352–4354. (b) A.A. Zemtsov, V.V. Levin, A.D. Dilman, M.I.
Struchkova, P.A. Belyakov, V.A. Tartakovsky, Tetrahedron Lett. 50 (2009) 2998–3000. (c)
A.A. Zemtsov, V.V. Levin, A.D. Dilman, M.I. Struchkova, V.A. Tartakovsky, J. Fluorine
Chem. 132 (2011) 378–381. (d) N.S. Kondratyev, A.A. Zemtsov, V.V. Levin, A.D. Dilman,
M.I. Struchkova, Synthesis. 44 (2012) 2436–2440. (e) V.V. Levin, A.L. Trifonov, A.A.
Zemtsov, M.I. Struchkova, D.E. Arkhipov, A.D. Dilman, Org. Lett. 16 (2014) 6256–6259. (g)
A.D. Volodin, A.A. Zemtsov, V.V. Levin, M.I. Struchkova, A.D. Dilman, J. Fluorine Chem.
submitted.
[
[
11] B.H. Lipshutz, S. Sengupta, Org. React. (N.Y.). 41 (1992) 135–631.
12] M.-Y. Wu, K. Li, T. He, X.-W. Feng, N. Wang, X.-Y. Wang, X.-Q. Yu, Tetrahedron. 67
(
2011) 2681–2688.
13] M.-Y. Wu, M.-Q. Wang, K. Li, X.-W. Feng, T. He, N. Wang, X.-Q. Yu, Tetrahedron Lett. 52
2011) 679–683.
[
(
[
[
14] E.C. Taylor, B. Liu, J. Fluorine Chem. 68 (2003) 9938–9947.
15] C. Dockendorff, S. Sahli, M. Olsen, L. Milhau, M. Lautens, J. Am. Chem. Soc. 127 (2005)
1
5028–15029.
[
[
16] C. Keene, L. Kürti, Synthesis. 45 (2013) 1719–1729.
17] K. Paizanos, D. Charalampou, N. Kourkoumelis, D. Kalpogiannaki, L. Hadjiarapoglou, A.
Spanopoulou, K. Lazarou, M.J. Manos, A.J. Tasiopoulos, M. Kubicki, S.K. Hadjikakou,
Inorg. Chem. 51 (2012) 12248–12259.
1
2
Page 15 of 15