A New Route for the Preparation of Substituted 2,2-Difluorostyrenes and a Convenient Route to Substituted (2,2,2-Trifluoroethyl)benzenes

Article abstract of DOI:10.1021/jo971019w

The (2,2-difluoroethenyl)zinc reagent II is coupled with aryl iodides or bromides in the presence of Pd(PPh₃)₄ in DMF to give the corresponding 2,2-difluorostyrenes IV. The 4-substituted (tetrafluoroaryl)copper reagents are coupled with 2,2-difluoro-1-iodoethylene (I) to produce the corresponding styrene derivatives VII. Both methods provide good yields of the coupled products. These products react with wet KF in DMF or DMSO to form the (2,2,2-trifluoroethyl)benzene derivatives VIII in good yields.

Full text of DOI:10.1021/jo971019w

7758
J . Org. Chem. 1997, 62, 7758-7764
A New Rou te for th e P r ep a r a tion of Su bstitu ted
2,2-Diflu or ostyr en es a n d a Con ven ien t Rou te to Su bstitu ted
(2,2,2-Tr iflu or oeth yl)ben zen es
Ba V. Nguyen and Donald J . Burton*
Department of Chemistry, University of Iowa, Iowa City, Iowa 52242
Received J une 6, 1997X
The (2,2-difluoroethenyl)zinc reagent II is coupled with aryl iodides or bromides in the presence of
Pd(PPh3)4 in DMF to give the corresponding 2,2-difluorostyrenes IV. The 4-substituted (tetrafluo-
roaryl)copper reagents are coupled with 2,2-difluoro-1-iodoethylene (I) to produce the corresponding
styrene derivatives VII. Both methods provide good yields of the coupled products. These products
react with wet KF in DMF or DMSO to form the (2,2,2-trifluoroethyl)benzene derivatives VIII in
good yields.
1. ZnCl2, –100 °C
2. Pd(PPh3)4
In tr od u ction
s-BuLi
CF2 CH2
CF2
[CF2 CHLi]
CH
In recent years, 2,2-difluorostyrenes have been shown
–110 °C
THF/Et2O
–5 °C
N
N
to be important substances in organic synthesis and
material science.1 However, few methods for the prepa-
ration of 2,2-difluorostyrenes have been reported. One
involved the reaction of difluoromethylene ylide2 with
aldehydes.3 This Wittig reaction has limited application
because of the lack of tolerance for groups substituted
on the benzaldehyde and gives moderate yields.
I
50%
roethyl compounds, which on treatment with SbF3-SbCl5
form the trifluoroethyl compounds. This type of reaction
produces many byproducts, and the yields of the trifluo-
roethyl compounds are often low.
TG
2Ph3P + CF2Br2 + RCHO 70 °C8
t-BuONO
CCl2
CH2CCl3
57–73%
NH2 + CH2
CuCl2/CH3CN
R
R
RCHdCF2 + Ph3PO + Ph3PBr2
R: C6H5
C6F5
R: 4-NO2, 3-NO2, 3-CF3, 4-CH3, 3-Cl, 4-Cl
65%
20%
SbF3–SbCl5
An alternative method to 2,2-difluorostyrenes is via
metalation of 1,1-difluoroethylene with s-BuLi at -110
°C to form the lithium reagent,4 which undergoes ex-
change with ZnCl2 at low temperature to yield the zinc
reagent II.5 This zinc reagent is stable and readily
couples with 2-iodopyridine in the presence of a catalytic
amount of Pd(PPh3)4.6 This is the only reported reaction
with zinc reagent II for the preparation of a 2,2-
difluorostyrenes. Zinc reagents II prepared by this
method have some drawbacks, since 1,1-difluoroethylene
has a low boiling point (-83 °C) and the reaction
sequences at low temperature are difficult to monitor.
In 1988, Kumadaki and co-workers7 reported the
synthesis of (2,2,2-trifluoroethyl)aryls. In this method,
aromatic amines were treated with 1,1-dichloroethene,
t-BuONO, and CuCl2 in acetonitrile to form the trichlo-
CH2CF2Cl
CH CCl2
R
R
R
R
CH2CF3
trace–51%
CHClCF2Cl
CCl CCl2
R
byproducts
Recently, we reported the synthetic applications of
polyfluorinated vinyl zinc, cadmium, and copper re-
agents.8 We now describe two facile methods for the
preparation of 2,2-difluorostyrenes. For simple aryl
derivatives, the palladium catalyzed coupling reaction of
aromatic iodides with (2,2-difluoroethenyl)zinc (II) worked
well. For perfluoroaryl halides, (perfluoroaryl)copper
reagents were coupled with 2,2-difluoroiodoethylene (I).
A convenient route to {2,2,2-trifluoroethyl}benzenes was
developed by treatment of the 2,2-difluorostyrene deriva-
tives with wet KF in DMF or DMSO.
X Abstract published in Advance ACS Abstracts, October 1, 1997.
(1) (a) Reynolds, D. W.; Cassidy, P. E.; J ohnson, C. G.; Cameron,
M. L. J . Org. Chem. 1990, 55, 4448. (b) Emsley, J . New Scientist 1989,
122, April 22, 46.
(2) (a) Naae, D. G.; Burton, D. J . Synth. Commun. 1973, 3(3), 197.
(b) Naae, D. G.; Burton, D. J . J . Fluorine Chem. 1971/72, 1, 123. (c)
Herkes, F. E.; Burton, D. J . J . Org. Chem. 1967, 32, 1311. (d) See
Burton, D. J .; Yang, Z. Y.; Qiu, W. Chem. Rev. 1996, 96, 1641 for a
comprehensive review of this method.
Resu lts a n d Discu ssion
Cou p lin g of (2,2-Diflu or oeth en yl)zin c Rea gen t II
w ith Ar yl Iod id es III. Mono- and bis(2,2-difluoroeth-
enyl)zinc reagent II was prepared by treatment of 2,2-
difluoroiodoethylene with acid-washed zinc in dry DMF.
(3) Burton, D. J . J . Fluorine Chem. 1983, 23, 339.
(4) Sauvetre, R.; Normant, J . F. Tetrahedron Lett. 1981, 22, 957.
(5) Gillet, J . P.; Sauvetre, R.; Normant, J . F. Tetrahedron Lett. 1985,
33, 3999.
(6) Gillet, J . P.; Sauvetre, R.; Normant, J . F. Synthesis 1986, 538.
Recently, Ichikawa has proposed a zinc intermediate in the coupling
of aryl iodides with a vinylzirconium intermediate in the presence of
zinc iodide: Ichikawa, J ., Fujiwara, M., Nawata, T., Okauchi, T.,
Minami, T. Tetrahedron Lett. 1996, 37, 8799.
(8) (a) Spawn, T. D.; Burton, D. J . Bull. Soc. Chim. Fr. 1986, 6, 876.
(b) Hansen, S. W.; Spawn, T. D.; Burton, D. J . J . Fluorine Chem. 1987,
35, 415. (c) Burton, D. J .; Hansen, S. W. J . Fluorine Chem. 1986, 31,
461. (d) Burton, D. J .; Tarumi, Y.; Heinze, P. L. J . Fluorine Chem.
1990, 50, 257. (e) Burton, D. J .; Hansen, S. W. J . Am. Chem. Soc. 1986,
108, 4229.
(7) Ando, A.; Miki, T.; Kumadaki, I. J . Org. Chem. 1988, 53, 3637.
S0022-3263(97)01019-0 CCC: $14.00 © 1997 American Chemical Society

2,2-Difluorostyrenes and (2,2,2-Trifluoroethyl)benzenes
J . Org. Chem., Vol. 62, No. 22, 1997 7759
Ta ble 1. Rea ction of Ar yl Ha lid es w ith
(2,2-Diflu or oeth en yl)zin c Rea gen t
Pd(PPh3)4
CHZnX
CF2
+
X
CF2
CH
69–92%
DMF/60 °C
1-4 h
R
R
Pd(PPh3)4
X = Br, I
CHZnX
CF2
X + CF2
CH
DMF/60 °C
II
III
IV
R:
o-CH3
m-CH3 p-CH3C(O)
p-CH3 m-NO2
m-CH3O
p-NO2
o-F
m-CF3
p-CF3
H
R
R
X = I, Br
48–92%
entrya
R
product
yield, %b
NMR spectrum of the reaction mixture indicated the
presence of F2CdCHZnX [-63.0 (dd, J ) 56.8, 14.0 Hz),
-76.1 (dd, J ) 57.2, 57.2 Hz)] and F2CdCBrZnX [-69.8
(d, J ) 56.6 Hz), -85.0 (d, J ) 56.6 Hz)];10 the average
ratio of these zinc reagent signals was 40/60, respectively.
Confirmation of these assignments was obtained by
treatment of this mixture with I2 to give F2CdCHI and
F2CdCBrI, confirmed by comparison to authentic samples.
In addition, when VI was treated with iodobenzene and
a catalytic amount of Pd(PPh3)4 in DMF at 60 °C, a
mixture of F2CdCHC6H5 and F2CdCBrC6H5 was formed.
These two products were not easily separated by column
chromatography, but F2CdCHC6H5 could be selectively
removed under full vacuum at 60 °C to give pure F2Cd
CBrC6H5.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
o-CH3
o-CH3C6H4CHdCF2
m-CH3C6H4CHdCF2
p-CH3C6H4CHdCF2
m-CH3OC6H4CHdCF2
p-CH3C(O)C6H4CHdCF2
m-NO2C6H4CHdCF2
p-NO2C6H4CHdCF2
o-FC6H4CHdCF2
m-CF3C6H4CHdCF2
p-CF3C6H4CHdCF2
1,4-CF2dCHC6H4CHdCF2
C6H5CBrdCF2
71
78
75
88
78
92
86
69
62
80
69
48
81c
71d
m-CH3
p-CH3
m-CH3O
p-CH3C(O)
m-NO2
p-NO2
o-F
m-CF3
p-CF3
1,4-diiodo
C6H5
C6H5
C6H5
C6H5CHdCF2
C6H5CHdCF2
a
b
The entry number is the product number. Isolated yield is
based on aryl halides. c Isolated yield is based on iodobenzene.
d
Isolated yield is based on bromobenzene.
The formation of F2CdCBrZnX can be rationalized as
shown below. The initially formed F2CdCHZnX under-
goes an acid-base exchange reaction with F2CdCHBr
to form F2CdCBrZnX. Similar exchange did not occur
with F2CdCHI (no F2CdCIZnX detected), and we have
no explanation for this unusual result.
The reaction mixture was heated to 60 °C to initiate the
reaction. When the reaction started, the heating was
discontinued. The reaction gave a 60-80% yield of II in
1 h on the basis of 19F NMR (vs internal R,R,R-trifluoro-
toluene). The reaction gave the best yield of the zinc
reagent II when the temperature was maintained be-
tween 50 and 60 °C: 19F NMR (internal standard CFCl3)
-63.0 (dd, J ) 56.2, 14.0 Hz), -76.4 (dd, J ) 56.8, 56.8
Hz), -63.1 (dd, J ) 55.6, 13.3 Hz), -76.4 (dd, J ) 55.7,
55.7 Hz).
DMF
CF2 CHBr + Zn
CF2 CBrZnX
CF2 CH2
CF2 CHZnX
CF2 CHBr
When this reaction was repeated and the low-boiling
gas condensed (at -110 °C) into Br2, we obtained a 29%
yield of CF2BrCH2Br, confirmed by comparison to an
authentic sample. Subsequent quenching of the zinc
reagents formed in this reaction gave F2CdCHI and
F2CdCBrI11 in 21% and 30% isolated yields, respectively.
DMF
CF2 CHI + Zn
CHZnX
CF2
60 °C
I
II
60–80%
CH
X = I or CF2
The zinc reagent II reacted smoothly with aryl iodides
or bromides III in DMF in the presence of 5 mol % of
Pd(PPh3)4 at 60 °C to give 2,2-difluorostyrenes IV (Table
1). In cases where the aryl iodides were substituted with
electron-donating groups, such as methyl and methoxy,
the reaction required 4 h. When the aryl iodides were
substituted with electron-withdrawing groups, such as
fluorine and trifluoromethyl, the reaction was completed
in 2 h. Typical conditions for complete consumption of
III involved stirring a 1.4:1 ratio of II to III at 60 °C for
1-6 h with 5 mol % of the Pd(PPh3)4 catalyst. The
reaction of 1,4-diiodobenzene with 2.5 equiv of II in DMF
and a catalytic amount of Pd(PPh3)4 at 60 °C for 2 h gave
a 69% yield of 1,4-bis(2,2-difluoroethenyl)benzene (entry
11). In the presence of Pd(PPh3)4 the reaction of 4′-
iodoacetophenone can be accomplished at 60 °C in 3 h to
give a 78% isolated yield. The aceto group on the benzene
ring is preserved under these conditions, and the product
is readily isolated by chromatography (entry 5, Table 1).
When F2CdCHBr (V) was utilized as a precursor to
the vinylzinc reagent, less satisfactory results were
obtained, and a novel acid-base reaction was observed.
Thus, when V in DMF was heated at 90 °C for 1 h with
zinc previously activated with ClSiMe3 and CH2I2,9 a 60%
average yield of two different zinc reagents, VI, was
observed by 19F NMR analysis of the reaction mixture
and a continuous evolution of gas was noted. The 19F
Cd/DMF
CuBr
CHI
75 °C
F
F
X
CdX
F
CH CF2
CF2
R
R
R
VII
X = Br, I
73–89%
CH3
N–
R = F, CF3, (CH3)2N, Br,
O
N–,
H3C
N
Rea ction of (P er flu or oa r yl)cop p er Rea gen t w ith
I. The 4-substituted (tetrafluoroaryl)copper reagent was
prepared by treatment of the 4-substituted tetrafluoro-
aryl iodide (or bromide) with acid-washed cadmium (or
zinc powder) in DMF at room temperature under a
nitrogen atmosphere to form the (perfluoroaryl)cadmium
or zinc reagents in quantitative yield.12 The cadmium
or zinc reagents undergo metathesis with CuBr at room
temperature to give the corresponding copper reagent.
(9) Rao, S. A.; Knochel, P. J . Am. Chem. Soc. 1991, 113, 5735. (b)
Knoess, H. P.; Furlong, M. T.; Rozema, M. J .; Knochel, P. J . Org. Chem.
1991, 56, 5974. (c) Rao, S. A.; Knochel, P. J . Org. Chem. 1991, 56,
4591.
(10) Prepared independently from F2CdCBr2 and Zn.
(11) Prepared independently by quenching the zinc reagent from
10
F2CdCBr2 with I2.
(12) Nguyen, B. V.; Burton. D. J . J . Fluorine Chem. 1994, 67, 205.

7760 J . Org. Chem., Vol. 62, No. 22, 1997
Nguyen and Burton
Ta ble 2. Cou p lin g betw een th e Su bstitu ted
(4-Tetr a flu or oa r yl)cop p er Rea gen t w ith
2,2-Diflu or o-1-iod oeth en e
Ta ble 3. Rea ction of 1,1-Diflu or ostyr en es w ith KF
KF (wet)
RCHdCF2 DMSO or DMF8 RCH2CF3
83-95%
1. Cd, DMF, rt
CF2
R
X
R
CH
F
F
2. CuBr, rt
3. CF2
CHI, 75 °C
73–89%
86
a
b
The entry number is the product number. Isolated yield is
based on 1,1-difluoroalkene.
H+
H
–
N
F
N
F
CHCF3
N
F
CH2CF3
a
b
The entry number is the product number. Isolated yield is
F
based on the substituted (4-tetrafluoroaryl)copper reagent.
F
48%
F–
The copper reagent readily undergoes coupling with I at
75 °C to give high yields of the expected coupled products
VII. The results of this study are summarized in Table
2. The coupling reaction proceeded without metal-
halogen exchange as determined by 19F NMR analysis
of the reaction mixture. For example, treatment of 1,4-
dibromotetrafluorobenzene with excess acid-washed
cadmium in DMF at 80 °C for 2 h produced the
(4-bromotetrafluorophenyl)cadmium reagent,13 which sub-
sequently undergoes a quantitative metathesis reaction
with cuprous bromide at room temperature. The copper
reagent coupled with I at 75 °C in 3 h to afford an 89%
isolated yield of 1-bromo-4-(2,2-difluoroethenyl)tetrafluo-
robenzene (entry 20).
the 2,2,2-trifluoroethyl group into organic molecules.7 In
entry 25 (Table 3), 4-(2,2-difluoroethenyl)-1-acetophenone
added HF across the 2,2-difluoroethenyl group when it
was treated with wet KF in DMF at 60 °C for 2 h to give
a 90% isolated yield of the addition product. 1,4-Bis(2,2-
difluoroethenyl)benzene reacted with excess wet KF in
DMSO at 100 °C for 12 h and gave complete addition of
HF to both 2,2-difluoroethenyl groups in 83% yield (entry
26).
KF
RCH2CF3
RCH
VII
CF2
DMSO or DMF
VIII
83–95%
NO2
Cd/DMF
CuBr
CHI
75 °C
F
F
X
CdX
F
CH CF2
CF2
R
R
R
,
,
,
R = CH3C(O)
O2N
VII
X = Br, I
73–89%
CH3
,
O
N
F
N–
R = F, CF3, (CH3)2N, Br,
O
N–,
H3C
In conclusion, we have presented a new method for the
preparation of 2,2-difluorostyrenes via the Pd(PPh3)4-
catalyzed coupling reaction with the (2,2-difluoroethen-
yl)zinc reagent, or the coupling of tetrafluoroaryl copper
reagents with iododifluoroethylene. The availability of
the catalysts and substituted aryl halide precursors, the
simplicity of the experimental procedure, and the high
yields obtained make this approach a facile method to
(2,2-difluoroethenyl)benzenes and should provide a con-
venient entry for the introduction of the CF3CH2 group
into organic molecules.
N
Under the same conditions, (4-tetrafluoropyridyl)cop-
per reagent reacts with I at 75 °C in 4 h to give only
4-(2,2,2-trifluoroethyl)tetrafluoropyridine in 48% isolated
yield. This product may be explained by attack of
fluoride ion in the reaction mixture on the vinyl group
of the initially formed coupled product to form an anion
which abstracts a proton from solvent to produce the
4-(2,2,2-trifluoroethyl)tetrafluoropyridine.
Rea ction of Styr en e Der iva tives w ith Wet KF .
2,2-Difluorostyrenes react with wet KF in DMF or DMSO
to give (2,2,2-trifluoroethyl)benzene in good yield. This
method can be used as an alternative route to introduce
Exp er im en ta l Section
Gen er a l. All reactions were monitored by 19F NMR analy-
sis of the reaction mixtures on a 90-MHz spectrometer. The
1H, 19F, and 13C NMR spectra of final products were obtained
on a 300-MHz spectrometer (CDCl3, CFCl3, or TMS internal
(13) Burton, D. J .; Yang, Z. Y.; MacNeil, K. J . J . Fluorine Chem.
1991, 52, 251.

2,2-Difluorostyrenes and (2,2,2-Trifluoroethyl)benzenes
J . Org. Chem., Vol. 62, No. 22, 1997 7761
references). FT-IR spectra were recorded as CCl4 solutions
in a 0.1 cm path length cell. Low-resolution mass spectra
analyses were performed at 70 eV in the electron-impact mode
on a single quadrapole instrument interfaced to a gas chro-
matograph fitted with an OV-101 column. High-resolution
mass spectral analyses were performed by the University of
Iowa High Resolution Mass Spectroscopy Facility at 70 eV in
the electron impact mode. GLPC analyses were performed on
a 5% OV-101 column and thermal conductivity detector, except
for the viscous liquids. Melting points were obtained on a
capillary melting point apparatus in open-ended capillaries
and are uncorrected. F2CdCHBr is available commercially,14
and F2CdCHI can be prepared by the method of Park.15 All
aromatic iodides were obtained from commercial sources and
used directly.
P r ep a r a tion of CF 2dCHZn X. A 100 mL two-necked,
round-bottomed flask equipped with a septum, a Teflon-coated
magnetic stir bar, and a dry ice condenser which was connected
to N2 and a mineral oil bubbler was charged with 1.9 g (30
mmol) of acid-washed zinc, 20 mL of dry DMF, and 0.8 g of
CF2dCHI. The reaction mixture was heated to 60 °C to
initiate the reaction. When the reaction started, the heating
was stopped, 2 g of CF2dCHI was added slowly, and the
temperature was maintained at 50-60 °C. 19F NMR (internal
standard CFCl3): δ -63.0 (dd, J ) 56.2, 14.0 Hz), -76.4 (dd,
J ) 56.8, 56.8 Hz), -63.1 (dd, J ) 55.6, 13.3 Hz), -76.4 (dd,
J ) 55.7, 55.7 Hz). The yield of the mono- and biszinc reagents
was 80% and the ratio of mono-/biszinc was 90/10.
P r ep a r a tion of 2-(2,2-Diflu or oeth en yl)tolu en e (1). In
a typical experimental procedure, a 50 mL two-necked, round-
bottomed flask equipped with a septum, a Teflon-coated
magnetic stir-bar, and an N2 inlet which was connected to a
mineral oil bubbler was charged with 2.2 g (10 mmol) of
2-iodotoluene, 14.2 mmol (7.5 mL × 1.9 M) of CF2dCHZnX
reagent in DMF, and 5 mol % of Pd(PPh3)4. The reaction
mixture was stirred at 60 °C under an N2 atmosphere for 4 h.
19F NMR analysis showed the reaction was completed. The
reaction mixture was introduced onto a silica gel column and
eluted with hexane to give 1.1 g (71%) of clear liquid 1: GLPC
purity 100.0%; 19F NMR δ -84.8 (d, J ) 31.6 Hz, 1F), -85.7
(dd, J ) 31.4, 25.9 Hz, 1F); 1H NMR δ 7.4 (m, 1H), 7.1 (m,
3H), 5.3 (dd, J ) 25.4, J ) 3.9 Hz, 1H), 2.3 (s, 3H); 13C NMR
δ 156.8 (dd, J ) 296.6, 287.4 Hz), 136.5 (d, J ) 4.3 Hz), 130.5
(s), 129.3 (t, J ) 5.7 Hz), 128.6 (d, J ) 7.7 Hz), 127.7 (s), 126.5
(s), 79.7 (dd, J ) 28.8, 14.9 Hz), 19.5 (s); FT-IR (cm-1) 3080.5
(w), 3036.1 (w), 2958.9 (w), 2935.8 (w), 2864.5 (w), 2669.6 (w),
1736.0 (s), 1498.7 (w), 1460.2 (m), 1354.1 (s), 1294.3 (w), 1249.9
(s), 1226.8 (s), 1176.6 (s), 1111.1 (w); GCMS 155 (M+ + 1, 10.0),
154 (100.0), 139 (1.5), 135 (5.8), 134 (28.3), 133 (53.3), 127
(11.1), 119 (2.1), 104 (15.7), 91 (3.5), 77 (13.9), 76 (5.3), 75 (7.2),
63 (10.6); HRMS calcd for C9H8F2 154.0594, found 154.0601.
P r epar ation of 3-(2,2-Diflu or oeth en yl)tolu en e (2). Simi-
larly, 2 was prepared from 2.2 g (10 mmol) of 3-iodotoluene,
14.2 mmol (7.5 mL × 1.9 M) of CF2dCHZnX reagent in DMF,
and 5 mol % of Pd(PPh3)4 at 60 °C for 4 h. Usual workup with
hexane as eluent gave 1.2 g (78%) of clear liquid 2: GLPC
purity 97.5%; 19F NMR δ -83.1 (dd, J ) 31.9, 26.9 Hz, 1F),
-85.3 (d, J ) 32.8 Hz, 1F); 1H NMR δ 7.2 (m, 1H), 7.1 (m,
2H), 7.0 (t, J ) 7.4 Hz, 1H), 5.2 (dd, J ) 26.3, 3.9 Hz, 1H), 2.3
(s, 2H); 13C NMR δ 156.8 (dd, J ) 297.7, 287.3 Hz), 138.6 (s),
130.7 (t, J ) 5.9 Hz), 128.9 (s), 128.8 (s), 128.2 (s), 125.2 (s),
82.5 (dd, J ) 28.8, 13.6 Hz), 21.3 (s); FT-IR (cm-1) 3041.9 (w),
2922.3 (w), 2870.2 (w), 1734.1 (s), 1604.9 (w), 1489.1 (w), 1338.7
(m), 1265.4 (m), 1188.2 (m), 1167.0 (w); GCMS 155 (M+ + 1,
18.1), 154 (100.0), 153 (93.9), 139 (3.2), 135 (12.5), 134 (60.2),
133 (96.9), 127 (26.4), 119 (4.0), 104 (31.7), 103 (20.8), 102
(10.9), 101 (10.8), 89 (12.4), 77 (32.6), 76 (13.5), 75 (18.4), 63
(28.3), 62 (13.1); HRMS calcd for C9H8F2 154.0594, found
154.0588.
and 5 mol % of Pd(PPh3)4 at 60 °C for 4 h. Usual workup with
hexane as eluent gave 1.15g (75%) of clear liquid 3: GLPC
purity 97.2%; 19F NMR δ -83.8 (dd, J ) 34.1, 26.3 Hz, 1F),
1
-85.4 (d, J ) 33.5 Hz, 1F); H NMR δ 7.2 (dm, J ) 8.2 Hz,
2H), 7.1 (dm, J ) 8.1 Hz, 2H), 5.2 (dd, J ) 26.4, 3.9 Hz, 1H),
2.3 (s, 3H); 13C NMR δ 156.7 (dd, J ) 297.5, 286.9 Hz), 137.1
(m), 129.7 (s), 127.9 (m), 82.3 (dd, J ) 29.1, 14.2 Hz), 21.1 (s);
FT-IR (cm-1) 3099.8 (w), 3030.4 (w), 2920.4 (w), 2862.5 (w),
1722.5 (s), 1512.3 (w), 1344.5 (w), 1244.2 (m), 1165.1 (m), 949.0
(m); GCMS 155 (M+ + 1, 9.5), 154 (100.0), 153 (55.6), 151 (7.6),
135 (5.8), 134 (26.9), 133 (48.1), 127 (10.8), 115 (2.7), 104 (17.5),
103 (9.2), 89 (5.6), 78 (6.2), 77 (18.6), 76 (6.7), 75 (9.8), 63 (12.0);
HRMS calcd for C9H8F2 154.0594, found 154.0593.
P r epar ation of 3-(2,2-Diflu or oeth en yl)an isole (4). Simi-
larly, 4 was prepared from 2.3 g (10 mmol) of 3-iodoanisole,
14.2 mmol (7.5 mL × 1.9 M) of CF2dCHZnX reagent in DMF,
and 5 mol % of Pd(PPh3)4 at 60 °C for 4 h. Usual workup with
hexane as eluent gave 1.5 g (88%) of clear liquid 4: GLPC
purity 98%; 19F NMR δ -82.4 (dd, J ) 30.0, 26.7 Hz, 1F), -84.7
(d, J ) 31.5 Hz, 1F); 1H NMR δ 7.2 (t, J ) 7.9 Hz, 1H), 6.9 (m,
2H), 6.8 (dd, J ) 8.2, 2.4 Hz, 1H), 5.2 (dd, J ) 26.0, 3.9 Hz,
1H), 3.8 (s, 3H); 13C NMR δ 160.4 (s), 156.8 (dd, J ) 297.9,
288.0 Hz), 132.0 (t, J ) 6.5 Hz), 129.9 (s), 120.5 (dd, J ) 6.0,
3.6 Hz), 113.7 (dd, J ) 6.1, 3.6 Hz), 112.9 (m), 82.5 (dd, J )
29.3, 13.3 Hz), 55.1 (s); FT-IR (cm-1) 3036.1 (w), 3005.3 (w),
2955.1 (w), 2827.8 (w), 1739.9 (s), 1599.1 (m), 1583.6 (m),
1489.1 (m), 1458.3 (m), 1427.4 (m), 1348.3 (m), 1292.4 (m),
1267.3 (s), 1211.4 (m), 1151.6 (m), 1045.5 (m); GCMS 171 (M+
+ 1, 10.2), 170 (100.0), 141 (8.8), 140 (36.2), 139 (11.8), 127
(44.7), 119 (6.6), 107 (6.4), 101 (11.6), 99 (4.9), 91 (6.9), 77
(14.1), 75 (5.2), 63 (5.5); HRMS calcd for C9H8F2O 170.0543,
found 170.0518.
P r ep a r a tion of 4′-(2,2-Diflu or oeth en yl)a cetop h en on e
(5). Similarly, 5 was prepared from 2.5 g (10 mmol) of 4′-
iodoacetophenone, 13.2 mmol (15 mL × 0.88 M) of CF2d
CHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C
for 3 h. Usual workup with a mixture of hexane/ether (10/2)
as eluent gave 1.4 g (78%) of white solid 5, mp 38-39 °C: 19F
NMR δ -79.6 (td, J ) 25.3, 5.9 Hz, 1F), -81.3 (d, J ) 24.2
1
Hz, 1F); H NMR δ 7.9 (dd, J ) 8.6, 2.1 Hz, 2H), 7.4 (dd, J )
8.4, 2.1 Hz, 2H), 5.3 (dm, J ) 26.0 Hz, 1H), 2.5 (d, J ) 2.6 Hz,
3H); 13C NMR δ 197.0 (s), 157.3 (dd, J ) 300.3, 290.5 Hz), 136
(m), 135.5 (t, J ) 12.3 Hz), 129 (s), 127.9 (dd, J ) 6.7, 3.6 Hz),
82.7 (dd, J ) 29.5, 12.4 Hz), 26.4 (s); FT-IR (cm-1) 3352.5 (w),
3094.0 (w), 3030.4 (w), 2999.5 (w), 2958.9 (w), 1730.2 (s), 1689.7
(s), 1606.0 (m), 1413.9 (w), 1357.9 (m), 1275.0 (s), 1180.5 (m),
958.6 (m); GCMS 183 (M+ + 1, 4.1), 182 (39.4), 168 (10.0), 167
(100.0), 140 (4.0), 139 (45.9), 138 (7.0), 120 (5.4), 119 (41.6),
99 (13.1), 89 (6.8), 88 (6.4), 75 (5.2), 63 (15.1), 62 (6.8); HRMS
calcd for C10H8F2O 182.0543, found 182.0554.
P r ep a r a t ion of 3-(2,2-Diflu or oet h en yl)n it r ob en zen e
(6). Similarly, 6 was prepared from 2.5 g (10 mmol) of
3-iodonitrobenzene, 12.2 mmol (17 mL × 0.72 M) of CF2d
CHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C
for 4 h. Usual workup with a mixture of hexane/ether (9.5/
0.5) as eluent gave 1.7 g (92%) of white solid 6: mp 32-33 °C;
19F NMR δ -79.5 (dd, J ) 24.6, 5.9 Hz, 1F), -81.2 (d, J )
1
23.7 Hz, 1F); H NMR δ 8.2 (t, J ) 1.7 Hz, 1H), 8.1 (dm, J )
8.1 Hz, 1H), 7.7 (dm, J ) 7.8 Hz, 1H), 7.5 (t, J ) 8.0 Hz, 1H),
5.4 (dd, J ) 25.2, 3.2 Hz, 1H); 13C NMR δ 157.1 (dd, J ) 299.1,
290.6 Hz), 148.7 (s), 133.5 (dd, J ) 6.1, 3.6 Hz), 132.4 (dd, J )
6.7, 6.7 Hz), 129.8 (s), 122.4 (dd, J ) 7.0, 3.6 Hz), 121.9 (m),
81.3 (dd, J ) 31.3, 13.1 Hz); FT-IR (cm-1) 3076.6 (w), 2972.5
(w), 2945.5 (w), 2866.4 (w), 1563.4 (m), 1479.5 (w), 1442.8 (w),
1348.3 (s), 1315.5 (w), 1253.8 (m), 1201.7 (w), 1138.1 (s), 1095.6
(m); GCMS 186 (M+ + 1, 8.4), 185 (94.3), 169 (7.3), 155 (33.2),
139 (78.7), 127 (19.7), 119 (100.0), 113 (5.4), 99 (24.8), 89 (9.5),
77 (5.5), 75 (6.0), 63 (17.1); HRMS calcd for C8H5F2NO2
185.0288, found 185.0294.
P r epar ation of 4-(2,2-Diflu or oeth en yl)tolu en e (3). Simi-
larly, 3 was prepared from 2.2 g (10 mmol) of 4-iodotoluene,
14.2 mmol (7.5 mL × 1.9 M) of CF2dCHZnX reagent in DMF,
P r ep a r a t ion of 4-(2,2-Diflu or oet h en yl)n it r ob en zen e
(7). Similarly, 7 was prepared from 2.5 g (10 mmol) of
4-iodonitrobenzene, 13.2 mmol (15 mL × 0.88 M) of CF2d
CHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C
for 1 h. Usual workup with a mixture of hexane/ether (10/2)
as eluent gave 1.6 g (86%) of white solid 7; mp 35-36 °C; 19F
NMR δ -77.9 (dd, J ) 25.1, 18.7 Hz, 1F), -79.2 (d, J ) 18.2
(14) PCR, Gainesville, FL.
(15) Park, J . D.; Abramo, J .; Hein, M.; Gray, D. N.; Lacher, J . R. J .
Org. Chem. 1958, 23, 1661.

7762 J . Org. Chem., Vol. 62, No. 22, 1997
Nguyen and Burton
Hz, 1F); 1H NMR δ 8.2 (dm, J ) 8.9 Hz, 2H), 7.5 (dm, J ) 8.9
Hz, 2H), 5.4 (dd, J ) 25.5, 3.3 Hz, 1H); 13C NMR δ 157.3 (dd,
J ) 301.6, 292.9 Hz), 146.6 (s), 137.5 (t, J ) 7.2 Hz), 128.2
(dd, J ) 6.5, 3.4 Hz), 124.1 (s), 81.8 (dd, J ) 30.6, 13.1 Hz);
FT-IR (cm-1) 3078.6 (w), 3040.0 (w), 2945.5 (w), 2856.7 (w),
2654.2 (w), 1734.1 (s), 1602.9 (m), 1514.2 (s), 1350.2 (s), 1305.9
(w), 1255.7 (m), 1172.8 (m), 1107.2 (w), 941.3 (m), 860.3 (m);
GCMS 186 (M+ + 1, 6.1), 185 (80.5), 169 (2.2), 156 (3.3), 155
(47.7), 139 (25.8), 138 (19.5), 128 (3.0), 127 (47.1), 120 (10.8),
119 (100.0), 101 (7.8), 99 (37.6), 89 (15.9), 88 (17.9), 77 (10.9),
76 (3.3), 75 (12.4), 74 (8.6), 69 (2.5), 63 (37.4), 62 (16.9), 51
(18.4), 50 (17.9); HRMS calcd for C8H5F2NO2 185.0288, found
185.0287.
298.1, 288.7 Hz), 129.8 (m), 128.4 (m), 82.4 (dd, J ) 29.6, 13.6
Hz); FT-IR (cm-1) 3099.8 (w), 3040.0 (w), 2669.6 (w), 1865.3
(w), 1743.7 (s), 1512.3 (w), 1423.5 (w), 1357.9 (m), 1292.4 (w),
1269.2 (m), 1192.1 (s), 1093.7 (w), 949.0 (m), 868.0 (m); GCMS
203 (M+ + 1, 11.0), 202 (100.0), 201 (5.2), 182 (14.6), 163 (3.2),
152 (10.9), 151 (62.0), 133 (28.6), 125 (4.7), 114 (5.9), 101 (17.3),
99 (5.5), 88 (7.2), 75 (8.2), 63 (9.5); HRMS calcd for C10H6F4
202.0406, found 202.0419.
P r ep a r a tion of r-Br om o-â,â-d iflu or ostyr en e (12).
A
100 mL two-necked, round-bottomed flask equipped with a
septum, a Teflon-coated magnetic stir bar, and a dry ice
condenser which was connected to N2 and a mineral oil bubbler
was charged with 1.9 g (30 mmol) of acid-washed zinc, 0.3 g
(1.1 mmol) of diiodomethane, 0.12 mL (1.2 mmol) of ClSiMe3
and 10 mL of dry THF. The reaction mixture was heated to
reflux and then cooled to room temperature. The THF was
removed via syringe, and full vacuum was applied to remove
the remaining liquid. Then 20 mL of dry DMF and 2.9 g (20
mmol) of CF2dCHBr were added to the reaction flask. The
reaction mixture was heated to 60-90 °C for 30 min. 19F NMR
analysis showed two types of zinc reagents, which were
CF2dCHZnX [-63.0 (dd, J ) 56.8, 14.0 Hz), -76.1 (dd, J )
57.2, 57.2 Hz)] and CF2dCBrZnX [-69.8 (d, J ) 56.6 Hz),
-85.0 (d, J ) 56.6 Hz)]. The average ratio of these zinc
reagents was 40/60, respectively. The total yield of both zinc
reagents was 60%. The zinc reagent was syringed into a flask
which contained 5 mol % of Pd(PPh3)4 and 2 g (20 mmol) of
iodobenzene. The reaction mixture was heated at 60 °C for 4
h to give (2,2-difluoroethenyl)benzene and (1-bromo-2,2-difluo-
roethenyl)benzene in a 40/60 ratio based on 19F NMR. The
reaction mixture was introduced onto a silica gel column and
eluted with hexane to give a mixture of the two products. â,â-
Difluorostyrene was removed under full vacuum at 60 °C, and
the R-bromo-â,â-difluorostyrene, 1.8 g (48%), remained in the
flask: 19F NMR δ -78.9 (d, J ) 31.2 Hz, 1F), -85.2 (d, J )
31.2 Hz, 1F); 1H NMR δ 7.4 (m, 2H), 7.3-7.2 (m, 3H); 13C NMR
δ 153.4 (dd, J ) 294.2, 285.9 Hz), 131.8 (d, J ) 3.6 Hz), 129.0
(m), 128.6 (s), 80.2 (dd, J ) 34.3, 25.8 Hz); FT-IR (cm-1) 3084.4
(w), 3061.2 (w), 3038.1 (w), 1728.3 (s), 1435.1 (w), 1282.7 (m),
1259.6 (m), 995.3 (s), 910.5 (w); GCMS 221 (M+ + 1, 5.2), 220
(64.0), 219 (5.8), 218 (71.0), 140 (8.5), 139 (100.0), 138 (12.5),
120 (10.5), 119 (78.5), 112 (4.7), 99 (21.0), 89 (12.4), 87 (10.1),
75 (4.8), 69 (10.6), 63 (18.0); HRMS calcd for C8H5F2Br
218.9532, found 218.9738.
P r ep a r a tion of 1-(2,2-Diflu or oeth en yl)-2-flu or oben -
zen e (8). Similarly, 8 was prepared from 2.2 g (10 mmol) of
2-fluoro-1-iodobenzene, 12.5 mmol (10 mL × 1.25 M) of
CF2dCHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60
°C for 2 h. Usual workup with pentane as eluent gave 1.1 g
(69%) of clear liquid 8: GLPC purity >99%; 19F NMR δ -81.8
(dd, J ) 26.2, 26.2 Hz, 1F), -82.3 (d, J ) 26.9 Hz, 1F), -117.8
1
(s, 1F); H NMR δ 7.5 (m, 1H), 7.2 (m, 1H), 7.1 (m, 1H), 7.0
(m, 1H), 5.4 (dd, J ) 25.9, 3.7 Hz, 1H); 13C NMR δ 159.9 (dd,
J ) 248.6, 3.8 Hz), 157.0 (dd, J ) 298.1, 288.7 Hz), 128.9 (d,
J ) 7.8 Hz), 124.5 (d, J ) 3.5 Hz), 118.6 (dt, J ) 12.8, 6.4 Hz),
115.7 (d, J ) 21.8 Hz), 74.9 (ddd, J ) 32.3, 13.5, 7.4 Hz); FT-
IR (cm-1) 3103.7 (w), 3047.7 (w), 2951.3 (w), 2667.7 (w), 1734.1
(s), 1574.0 (w), 1487.2 (m), 1462.1 (m), 1354.1 (m), 1246.1 (m),
1224.9 (m), 1168.9 (w), 949.0 (m); GCMS 159 (M+ + 1, 8.2),
158 (100.0), 157 (10.7), 139 (6.2), 138 (15.1), 137 (6.2), 132 (8.4),
119 (4.4), 114 (3.4), 108 (14.5), 107 (25.0), 106 (2.1), 99 (3.2),
89 (11.9), 81 (6.9), 75 (4.6), 69 (3.7), 63 (8.8), 57 (8.8); HRMS
calcd for C8H5F3 158.0343, found 158.0350.
P r ep a r a tion of 3-(2,2-Diflu or oeth en yl)ben zotr iflu o-
r id e (9). Similarly, 9 was prepared from 2.7 g (10 mmol) of
3-iodobenzotrifluoride, 12.5 mmol (10 mL × 1.25 M) of
CF2dCHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60
°C for 2 h. Usual workup with hexane as eluent gave 1.3 g
(62%) of clear liquid 9: GLPC purity >99%; 19F NMR δ -63.5
(s, 3F), -81.0 (dd, J ) 26.5, 26.5 Hz, 1F), -82.7 (d, 26.5 Hz,
1F); 1H NMR δ 7.6 (s, 1H), 7.5-7.4 (m, 3H), 5.3 (dd, J ) 25.6,
3.4 Hz, 1H); 13C NMR δ 157.5 (dd, J ) 298.9, 290.5 Hz), 132.0
(t, J ) 6.7 Hz), 131.2 (m), 130.0 (q, J ) 32.3 Hz), 129.6 (s),
124.8 (m), 124.7 (q, J ) 272.2 Hz), 124.2 (m), 81.9 (dd, J )
30.5, 13.5 Hz); FT-IR (cm-1) 3068.9 (w), 3036.1 (w), 2859.5 (w),
1730.2 (m), 1438.9 (w), 1352.2 (m), 1330.9 (m), 1234.5 (m),
1180.5 (s), 1141.9 (s), 1099.5 (m), 1078.3 (m); GCMS 209 (M+
+ 1, 9.3), 208 (100.0), 207 (9.1), 189 (22.3), 187 (9.1), 169 (9.3),
158 (30.8), 145 (2.7), 139 (14.7), 138 (12.0), 119 (15.5), 107 (4.5),
99 (8.5), 94 (2.5), 89 (4.9), 88 (7.0), 75 (7.8), 69 (7.4), 63 (9.1);
HRMS calcd for C9H5F5 208.0311, found 208.0302.
P r ep a r a tion of â,â-Diflu or ostyr en e fr om Iod oben zen e
(13). Similarly, 13 was prepared from 1.02 g (5 mmol) of
iodobenzene, 7 mmol (10 mL × 0.7 M) of CF2dCHZnX reagent
in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C for 4 h. Usual
workup with pentane as eluent gave 0.57 g (81%) of clear liquid
13: GLPC purity 97%; 19F NMR δ -82.9 (dd, J ) 30.8, 26.4
1
Hz, 1F), -84.8 (d, J ) 33.9 Hz, 1F); H NMR δ 7.3-7.2 (m,
P r ep a r a tion of 4-(2,2-Diflu or oeth en yl)ben zotr iflu o-
r id e (10). Similarly, 10 was prepared from 2.0 g (7.3 mmol)
of 4-iodobenzotrifluoride, 10 mmol (8 mL × 1.25 M) of
CF2dCHZnX reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60
°C for 2 h. Usual workup with pentane as eluent gave 1.2 g
(80%) of clear liquid 10: GLPC purity >99%; 19F NMR δ -63.2
(s, 3F), -80.4 (dd, J ) 25.4, 25.4 Hz, 1F), -82.0 (d, J 25.3 Hz,
1F); 1H NMR δ 7.5 (d, J ) 8.3 Hz, 2H), 7.4 (d, J ) 8.3 Hz, 2H),
5.3 (dd, J ) 25.7, 3.5 Hz, 1H); 13C NMR δ 157.7 (dd, J ) 299.8,
290.4 Hz), 134.9 (t, J ) 6.6 Hz), 129.8 (qm, J ) 32.7 Hz), 128.3
(dd, J ) 6.9, 3.5 Hz), 126.1 (m), 124.8 (q, J ) 271.8 Hz), 82.0
(dd, J ) 30.2, 13.4 Hz); FT-IR (cm-1) 3047.7 (w), 2665.8 (w),
1736.0 (s), 1608.7 (w), 1411.9 (w), 1354.1 (w), 1327.1 (s), 1248.0
(m), 1174.7 (s), 1141.9 (s), 1062.8 (m), 1020.4 (w), 935.5 (m);
GCMS 209 (M+ + 1, 9.9), 208 (100.0), 207 (8.9), 189 (35.7),
187 (9.9), 169 (12.9), 158 (46.1), 139 (18.4), 138 (14.1), 119
(14.9), 107 (5.7), 99 (10,0), 88 (8.0), 87 (6.4), 79 (7.0), 75 (7.5),
63 (10.4); HRMS calcd for C9H5F5 208.0311, found 208.0316.
P r ep a r a t ion of 1,4-Bis(2,2-d iflu or oet h en yl)b en zen e
(11). Similarly, 11 was prepared from 3.3 g (10 mmol) of 1,4-
diiodobenzene, 25 mmol (20 mL × 1.25 M) of CF2dCHZnX
reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C for 2 h.
Usual workup with pentane as eluent gave 1.1 g (69%) of clear
liquid 11: GLPC purity >99%; 19F NMR δ -82.2 (dd, J ) 28.4,
28.4 Hz, 1F), -84.3 (d, J ) 30.3 Hz, 1F); 1H NMR δ 7.3 (s,
4H), 5.2 (dd, J ) 26.1, 3.6 Hz, 2H); 13C NMR δ 157.2 (dd, J )
5H), 5.3 (dd, J ) 26.3, 3.9 Hz, 1H); 13C NMR δ 156.6 (dd, J )
297.9, 288.4 Hz), 130.6 (t, J ) 6.1 Hz), 128.9 (s), 127.8 (dd, J
) 5.9, 3.7 Hz), 127.2 (s), 82.4 (dd, J ) 29.2, 13.5 Hz); FT-IR
(cm-1) 3088.2 (w), 3063.1 (w), 3032.3 (w), 2660.0 (w), 1716.7
(s), 1491.1 (w), 1438.9 (w), 1346.4 (m), 1238.4 (m), 1161.2 (m),
939.4 (m), 902.7 (m); GCMS 142 (M+ + 2, 0.2), 141 (5.4), 140
(100.0), 121 (3.2), 120 (8.9), 119 (9.0), 114 (13.9), 101 (4.5), 100
(1.5), 99 (4.3), 90 (56.4), 89 (12.9), 88 (5.9), 77 (1.1).
P r ep a r a tion of â,â-Diflu or ostyr en e fr om Br om oben -
zen e (14). Similarly, 14 was prepared from 0.78 g (5 mmol)
of bromobenzene, 7 mmol (10 mL × 0.7 M) of CF2dCHZnX
reagent in DMF, and 5 mol % of Pd(PPh3)4 at 60 °C for 6 h.
Usual workup with pentane as eluent gave 0.5 g (71%) of clear
liquid 14: GLPC purity >98%; 19F NMR δ -82.9 (dd, J ) 30.8,
1
26.3 Hz, 1F), -84.8 (d, J ) 33.8 Hz, 1F); H NMR δ 7.3-7.2
(m, 5H), 5.3 (dd, J ) 26.3, 3.9 Hz, 1H); 13C NMR δ 156.6 (dd,
J ) 297.9, 288.1 Hz), 130.6 (t, J ) 6.1 Hz), 128.9 (s), 127.8
(dd, J ) 5.9, 3.7 Hz), 127.2 (s), 82.4 (dd, J ) 29.3, 13.5 Hz);
FT-IR (cm-1) 3082.4 (w), 3065.1 (w), 3028.4 (w), 2660.0 (w),
1734.1 (s), 1494.9 (w), 1440.9 (w), 1350.2 (m), 1242.2 (m),
1168.9 (m), 943.2 (m), 906.6 (w); GCMS 142 (M+ + 2, 0.1), 141
(5.3), 140 (100.0), 121 (2.8), 120 (8.0), 119 (7.9), 114 (12.4), 101
(4.1), 100 (1.4), 99 (3.9), 90 (5.2), 89 (10.6), 88 (5.0), 77 (0.8).
P r ep a r a tion of (2,2-Diflu or oeth en yl)p en ta flu or oben -
zen e (15). A 50 mL, two-necked, round-bottomed flask

2,2-Difluorostyrenes and (2,2,2-Trifluoroethyl)benzenes
J . Org. Chem., Vol. 62, No. 22, 1997 7763
equipped with a septum, a Teflon-coated magnetic stir bar,
and an N2 inlet which was connected to a mineral oil bubbler
was charged with 2.9 g (10 mmol) of iodopentafluorobenzene,
1.7 g (15 mmol) of cadmium, and 10 mL of DMF. Then the
reaction mixture was stirred at room temperature under an
N2 atmosphere for 30 min. The reaction mixture was trans-
ferred via syringe to a 100 mL, two-necked, round-bottomed
flask equipped with a septum, a Teflon-coated magnetic stir
bar, and a dry ice condenser connected to a nitrogen inlet, and
the flask was charged with 1.4 g (10 mmol) of CuBr. The
reaction mixture was stirred at room temperature under an
N2 atmosphere for 5 min, then 2.8 g (15 mmol) of CF2dCHI
was added via syringe, and the reaction mixture was stirred
for 3 h at 75 °C. The product was flash distilled, washed with
water, and then extracted with ether. The organic layer was
dried over MgSO4, filtered, and distilled to give 1.9 g (84%) of
15: bp 90 °C; GLPC purity >97%; 19F NMR δ -74.6 (m, 1F),
-78.7 (s, 1F), -139.5 (t, J ) 19.9 Hz, 2F), -155.0 (t, J ) 20.6
reaction mixture was filtered through a short silica gel column.
The filtrate was concentrated via rotary evaporation, then
introduced onto a silica gel column, and eluted with hexane
to give 1.3 g (86%) of clear solid 18: 19F NMR δ -76.0 (m,
1F), -80.5 (d, J ) 15.0 Hz, 1F), -141.9 (tm, J ) 32.4 Hz, 2F),
-152.0 (dd, J ) 19.7, 8.2 Hz, 2F); 1H NMR δ 5.2 (dm, J )
25.5 Hz, 1H), 3.8 (t, J ) 4.8 Hz, 4H), 3.3 (m, 4H); 13C NMR δ
156.9 (dd, J ) 299.8, 289.7 Hz), 144.9 (dm, J ) 248.3 Hz),
142.8 (ddt, J ) 245.1, 13.8, 4.8 Hz), 129.9 (tm, J ) 10.7 Hz),
103.1 (tdd, J ) 17.9, 8.0, 3.9 Hz), 68.9 (dd, J ) 38.3, 18.1 Hz),
67.7 (s), 51.6 (t, J ) 3.1 Hz); FT-IR (cm-1) 3101.7 (w), 3047.7
(w), 2953.2 (w), 2901.1 (w), 2891.5 (w), 2843.2 (w), 1734.1 (m),
1633.8 (w), 1492.9 (s), 1444.7 (w), 1346.4 (w), 1325.2 (w), 1267.3
(m), 1213.3 (m), 1155.4 (w), 1114.9 (m), 987.6 (m), 908.5 (m);
GCMS 298 (M+ + 1, 5.7), 297 (45.5), 296 (5.2), 240 (11.4), 239
(100.0), 238 (69.1), 225 (5.9), 218 (4.8), 168 (4.2), 161 (22.6),
143 (4.4), 141 (2.9), 123 (2.9), 119 (2.5), 117 (2.4); HRMS calcd
for C12H9F6NO 297.0588, found 297.0567.
1
Hz, 1F), -162.6 (m, 2F); H NMR δ 5.2 (d, J ) 25.1 Hz); 13C
P r ep a r a tion of 1-(2,2-Diflu or oeth en yl)-4-(3,5-d im eth -
ylp yr a zoyl)tetr a flu or oben zen e (19). Similarly, 19 was
prepared from 1.1 g (2.9 mmol) of 4-(3,5-dimethylpyrazoyl)-1-
iodotetrafluorobenzene and 0.7 g (6 mmol) of cadmium, 10 mL
of DMF, 0.7 g (5 mmol) CuBr, and 0.7 g (4 mmol) of CF2dCHI
at 75 °C for 4 h. The reaction mixture was filtered through a
short silica gel column. The filtrate was concentrated via
rotary evaporation, then introduced onto a silica gel column,
and eluted with hexane to give 0.8 g (89%) of clear liquid 19:
GLPC purity >99%; 19F NMR δ -73.1 (m, 1F), -77.7 (s, 2F),
NMR δ 157.8 (dd, J ) 300.1, 291.4 Hz), 145.2 (d, J ) 252.4
Hz), 141.7 (dm, J ) 259.9 Hz), 138.7 (dm, J ) 224.6 Hz), 106.1
(m), 68.5 (dd, J ) 38.9, 18.3 Hz); FT-IR (cm-1) 3101.7 (w),
3051.6 (w), 2634.9 (w), 1726.4 (s), 1516.1 (s), 1487.2 (s), 1421.6
(w), 1336.7 (w), 1298.2 (m), 1209.4 (m), 1126.5 (w), 1003.0 (m),
981.8 (m), 902.7 (m); GCMS 230 (M+, 100.0), 211 (10.5), 199
(4.0), 180 (24.8), 161 (84.9), 141 (8.1), 130 (10.6), 117 (6.2), 111
(5.0), 99 (4.6), 93 (8.6); HRMS calcd for C8H5F7 229.9966, found
229.9963.
P r ep a r a t ion of 1-(2,2-Diflu or oet h en yl)-4-(t r iflu or o-
m eth yl)tetr a flu or oben zen e (16). Similarly, 16 was pre-
pared from 3.0 g (10 mmol) of 4-bromoheptafluorotoluene and
1.7 g (15 mmol) of cadmium, 10 mL of DMF, 1.4 g (10 mmol)
CuBr, and 1.9 g (10 mmol) of CF2dCHI at 75 °C for 3 h. Usual
workup gave 2.1 g (73%) of 16: bp 90 °C; GLPC purity >99%;
19F NMR δ -56.9 (t, J ) 21.7 Hz, 3F), -71.1 (qm, J ) 24.1
Hz, 1F), -76.0 (s, 1F), -137.9 (m, 2F), -141.3 (m, 2F); 1H NMR
δ 5.3 (d, J ) 25.1 Hz); 13C NMR δ 157.6 (dd, J ) 302.6, 293.1
Hz), 144.6 (dm, J ) 247.9 Hz), 144.4 (dm, J ) 258.9 Hz), 121.1
(q, J ) 274.5 Hz), 114.9 (m), 109.2 (qt, J ) 35.2, 13.1 Hz),
68.5 (dd, J ) 39.8, 17.8 Hz); FT-IR (cm-1) 3107.5 (w), 3061.2
(w), 1739.9 (s), 1666.6 (m), 1489.1 (s), 1321.3 (s), 1253.8 (m),
1207.5 (s), 1159.3 (s), 1070.5 (m), 981.8 (m), 925.9 (m), 871.9
(m); GCMS 281 (M+ + 1, 9.3), 280 (100.0), 261 (69.9), 241 (6.6),
230 (85.5), 211 (26.4), 192 (27.8), 180 (16.9), 161 (76.2), 142
(14.1), 141 (20.8), 123 (20.9), 117 (14.9), 93 (15.0), 69 (32.4);
HRMS calcd for C9HF9 279.9934, found 279.9920.
1
-139.4 (s, 2F), -146.9 (dd, J ) 20.3, 9.7 Hz, 2F); H NMR δ
6.1 (s, 1H), 5.3 (d, J ) 25.2 Hz, 1H), 2.3 (s, 3H), 2.2 (s, 3H);
13C NMR δ 157.4 (dd, J ) 301.5, 292.0 Hz), 152.1 (s), 144.5
(dm, J ) 252.5 Hz), 143.9 (ddm, J ) 254.9, 11.9 Hz), 142.7 (s),
119.2 (tm, J ) 13.7 Hz), 111.2 (tdd, J ) 17.2, 8.2, 3.8 Hz),
107.3 (s), 69.0 (ddm, J ) 38.9, 17.4 Hz), 13.7 (s), 10.8 (s); FT-
IR (cm-1) 3119.1 (w), 3057.4 (w), 2997.6 (w), 2931.9 (w), 1736.0
(s), 1566.3 (w), 1527.7 (m), 1494.9 (s), 1435.1 (w), 1406.2 (w),
1352.2 (w), 1302.0 (m), 1242.2 (m), 1120.7 (w), 1064.8 (w), 993.4
(m), 922.0 (m); GCMS 307 (M+ + 1, 15.0), 306 (100.0), 305
(33.8), 291 (7.0), 287 (11.6), 264 (20.9), 252 (29.2), 250 (10.6),
246 (6.6), 238 (16.5), 237 (18.8), 225 (5.1), 215 (4.9), 211 (4.7),
205 (4.8), 199 (5.1), 187 (4.1), 175 (5.2), 168 (7.9), 161 (34.3),
69 (5.2), 65 (4.4); HRMS calcd for C13H8F6N2 306.0592, found
306.0582.
P r ep a r a tion of 1-Br om o-4-(2,2-d iflu or oeth en yl)tetr a -
flu or oben zen e (20). A 50 mL, two-necked, round-bottomed
flask equipped with a septum, a Teflon-coated magnetic stir
bar, and an N2 inlet which was connected to a mineral oil
bubbler was charged with 3.1 g (10 mmol) of 1,4-dibromotet-
rafluorobenzene, 2.8 g (25 mmol) of cadmium, and 10 mL of
DMF. The reaction mixture was stirred at 80 °C under an N2
atmosphere for 2 h. The 19F NMR showed that only the
monocadmium reagent was formed. The reaction mixture was
transferred via syringe to a 100 mL, two-necked, round-
bottomed flask equipped with a septum, a Teflon-coated
magnetic stir bar, and a dry ice condenser connected to a
nitrogen inlet, and the flask was charged with 1.4 g (10 mmol)
of CuBr. The reaction mixture was stirred at room temper-
ature under an N2 atmosphere for 5 min, then 2.3 g (12 mmol)
of CF2dCHI was added via syringe, and the reaction mixture
was stirred for 3 h at 70 °C. The reaction mixture was filtered
through a short silica gel column. The filtrate was concen-
trated via rotary evaporation, then introduced onto a silica
gel column, and eluted with hexane to give 2.6 g (89%) of 20:
GLPC purity 98%; 19F NMR δ -77.5 (m, 1F), -78.1 (m, 1F),
P r ep a r a tion of 1-(2,2-Diflu or oeth en yl)-4-(N,N-d im eth -
yla m in o)tetr a flu or oben zen e (17). Similarly, 17 was pre-
pared from 3.2 g (10 mmol) of 4-(N,N-dimethylamino)-1-
iodotetrafluorobenzene and 1.7 g (15 mmol) of cadmium, 10
mL of DMF, 1.4 g (10 mmol) CuBr, and 2.3 g (12 mmol) of
CF2dCHI at 75 °C for 5 h. The reaction mixture was filtered
through a short silica gel column. The filtrate was concen-
trated via rotary evaporation, then introduced onto a silica
gel column, and eluted with hexane to give 1.8 g (73%) of clear
liquid 17: GLPC purity >99%; 19F NMR δ -76.6 (m, 1F),
-81.2 (d, J ) 16.3 Hz, 1F), -142.6 (tm, J ) 20.3 Hz, 2F),
1
-152.6 (dm, J ) 13.7 Hz, 2F); H NMR δ 5.2 (dm, J ) 25.6
Hz, 1H), 3.0 (t, J ) 2.1 Hz, 6H); 13C NMR δ 157.2 (dd, J )
299.4, 289.2 Hz), 144.8 (dm, J ) 244.6 Hz), 142.7 (dddd, J )
244.1, 14.6, 5.7, 3.8 Hz), 131.6 (tm, J ) 10.9 Hz), 101.7 (tdd,
J ) 18.0, 8.2, 4.5 Hz), 69.1 (ddm, J ) 38.7, 18.5 Hz), 43.4 (t,
J ) 4.1 Hz); FT-IR (cm-1) 3045.8 (w), 2982.1 (w), 2933.9 (w),
2881.8 (w), 2791.1 (w), 1736.0 (s), 1639.6 (w), 1506.5 (w), 1475.6
(s), 1421.6 (w), 1346.4 (w), 1255.7 (m), 1197.8 (m), 1097.5 (w),
1010.7 (w), 974.1 (m), 910.5 (m); GCMS 256 (M+ + 1, 6.9), 255
(71.0), 254 (100.0), 239 (18.4), 238 (28.4), 226 (3.5), 225 (5.3),
218 (3.8), 211 (2.6), 207 (3.1), 184 (3.9), 170 (3.7), 168 (4.7),
161 (23.6), 143 (9.7), 127 (11.9), 119 (7.4), 99 (4.6), 93 (4.6), 75
(4.8), 69 (5.1); HRMS calcd for C10H7F6N 255.0482, found
255.0459.
1
-133.9 (m, 2F), -138.5 (m, 2F); H NMR δ 5.3 (d, J ) 25.1
Hz); 13C NMR δ 157.9 (dd, J ) 301.5, 291.7 Hz), 145.9 (ddm,
J ) 250.9, 20.1 Hz), 144.9 (dm, J ) 253.1 Hz), 110.6 (tdd, J )
17.0, 8.5, 3.7 Hz), 100.0 (t, J ) 22.5 Hz), 69.3 (ddm, J ) 39.2,
18.1 Hz); FT-IR (cm-1) 3107.5 (w), 3059.3 (w), 2654.2 (w),
1730.3 (s), 1487.2 (s), 1396.5 (w), 1338.7 (w), 1275.0 (s), 1201.7
(m), 1074.4 (w), 974.1 (m), 916.2 (m), 831.4 (m); GCMS 293
(M+ + 2, 3.1), 292 (43.2), 291 (5.3), 290 (47.1), 223 (13.1), 221
(14.3), 211 (18.4), 192 (13.5), 161 (100.0), 142 (16.2), 141 (19.4),
123 (15.8), 117 (10.4), 98 (8.6), 93 (13.1), 92 (14.5), 75 (10.0),
69 (12.1); HRMS calcd for C8H79BrF6 290.9155, found 290.9209.
P r ep a r a tion of 1-(2,2-Diflu or oeth en yl)-4-m or p h olin o-
tetr a flu or oben zen e (18). Similarly, 18 was prepared from
1.8 g (5 mmol) of 4-morpholino-1-iodotetrafluorobenzene and
0.9 g (8 mmol) of cadmium, 10 mL of DMF, 0.8 g (5 mmol)
CuBr, and 1.1 g (6 mmol) of CF2dCHI at 75 °C for 5 h. The

7764 J . Org. Chem., Vol. 62, No. 22, 1997
Nguyen and Burton
P r ep a r a tion of 4-(2,2,2-Tr iflu or oeth yl)tetr a flu or op yr -
id in e (21). A 50 mL, two-necked, round-bottomed flask
equipped with a septum, a Teflon-coated magnetic stir bar,
and an N2 inlet which was connected to a mineral oil bubbler
was charged with 7.7 mL of a 1.3 M solution in DMF (10 mmol)
of 4-iodotetrafluoropyridine and 1.7 g (15 mmol) of cadmium.
The reaction mixture was stirred at room temperature under
an N2 atmosphere for 30 min. The reaction mixture was
transferred to a 100 mL, two-necked, round-bottomed flask
equipped with a septum, a Teflon-coated magnetic stir-bar,
and a dry-ice condenser connected with a nitrogen inlet, and
the flask was charged with 1.4 g (10 mmol) of CuBr. The
reaction mixture was stirred at room temperature under an
N2 atmosphere for 5 min, then 1.9 g (10 mmol) of CF2dCHI
was added via syringe, and the reaction mixture was stirred
for 4 h at 75 °C. The reaction mixture was poured into 100
mL of water, and product was extracted with 3 × 50 mL of
diethyl ether. The organic layer was collected, dried over
MgSO4, filtered, and distilled to give 1.1 g (48%) of 21: bp 120
°C; GLPC purity 99%; 19F NMR δ -65.4 (m, 3F), -89.8 (m,
2F), -142.9 (m, 2F); 1H NMR δ 3.7 (qm, J ) 9.7 Hz); 13C NMR
δ 144.1 (dm, J ) 245.7 Hz), 141.8 (dm, J ) 261.5 Hz), 124.6
(q, J ) 277.7 Hz), 123.8 (tm, J ) 15.9 Hz), 29.2 (q, J ) 33.9
Hz); FT-IR (cm-1) 1730.2 (w), 1687.8 (w), 1647.3 (w), 1547.0
(w), 1491.0 (m), 1469.8 (s), 1356.0 (m), 1267.3 (m), 1236.4 (m),
1153.5 (m), 1095.6 (m), 1018.5 (w), 967.0 (w); GCMS 234 (M+
+ 1, 4.0), 233 (57.9), 214 (19.3), 194 (6.8), 182 (5.4), 165 (5.9),
164 (100.0), 144 (8.8), 138 (8.2), 137 (7.2), 133 (3.3), 119 (11.4),
114 (8.1), 99 (10.5), 93 (7.1), 75 (5.0), 69 (34.1); HRMS calcd
for C7H2F7N 233.0075, found 233.0061.
1523.8 (m), 1498.8 (w), 1421.6 (w), 1359.9 (s), 1267.3 (m),
1199.8 (w), 1149.6 (s), 1118.8 (m), 1076.3 (m); GCMS 206 (M+
+ 1, 2.6), 205 (32.3), 186 (4.1), 175 (11.2), 159 (17.2), 147 (3.5),
139 (10.6), 127 (13.8), 119 (16.1), 110 (6.7), 109 (100.0), 99 (4.4),
90 (6.6), 89 (21.6), 83 (18.7), 69 (7.5), 63 (22.0); HRMS calcd
for C8H6F3NO2 205.0351, found 205.0340.
P r ep a r a t ion of 3-(2,2,2-Tr iflu or oet h yl)n it r ob en zen e
(24). Similarly, 24 was prepared from 0.92 g (5 mmol) of
3-(2,2-difluoroethenyl)nitrobenzene, 0.6 g (6 mmol) of potas-
sium fluoride, 10 mL of DMF, and 0.5 mL of H2O at 70 °C for
5 h. Usual workup with a mixture of hexane/ether (9.5/0.5)
as eluent gave 0.98 g (95%) of white solid 24: mp 45-46 °C;
1
19F NMR δ -66.3 (t, J ) 10.5 Hz); H NMR δ 8.2 (s, 1H), 8.1
(dm, J ) 8.1 Hz, 1H), 7.7 (d, J ) 7.6 Hz, 1H), 7.6 (t, J ) 7.9
Hz, 1H), 3.6 (q, J ) 10.7 Hz, 2H); 13C NMR δ 148.9 (s), 137.0
(s), 132.8 (q, J ) 3.2 Hz), 130.3 (s), 126.1 (q, J ) 276.9 Hz),
125.5 (s), 123.6 (s), 39.9 (q, J ) 30.4 Hz); FT-IR (cm-1) 3097.9
(w), 3051.6 (w), 2879.9 (w), 1745.7 (s), 1537.4 (m), 1359.9 (s),
1292.4 (w), 1255.7 (m), 1182.4 (w), 1095.6 (w), 970.2 (w), 918.2
(w); GCMS 206 (M+ + 1, 4.5), 205 (51.8), 189 (4.5), 175 (11.1),
159 (50.4), 139 (19.4), 127 (8.3), 119 (17.0), 109 (100.0), 89
(12.2), 83 (9.4), 75 (4.4), 69 (2.9), 63 (9.9); HRMS calcd for
C8H6F3NO2 205.035, found 205.0344.
P r ep a r a tion of 4′-(2,2,2-Tr iflu or oeth yl)a cetop h en on e
(25). Similarly, 25 was prepared from 1.1 g (6 mmol) of 4′-
(2,2-difluoroethenyl)-1-acetophenone, 0.6 g (10 mmol) of potas-
sium fluoride, 10 mL of DMF, and 0.5 mL of H2O at 60 °C for
2 h. Usual workup with a mixture of hexane/dichloromethane
(10/2) as eluent gave 1.1 g (90%) of white solid 25: mp 37-38
°C; 19F NMR δ -66.0 (t, J ) 10.6 Hz); 1H NMR δ 7.9 (dm, J )
8.3 Hz, 2H), 7.4 (d, J ) 8.0 Hz, 2H), 3.4 (q, J ) 10.7 Hz, 2H),
2.6 (s, 3H); 13C NMR δ 197.6 (s), 137.2 (s), 135.7 (m), 130.8
(s), 128.9 (s), 126.0 (q, J ) 276.9 Hz), 40.1 (q, J ) 29.8 Hz);
FT-IR (cm-1) 3354.4 (w), 3088.2 (w), 3045.8 (w), 2993.7 (w),
2931.9 (w), 1685.9 (s), 1602.9 (w), 1419.7 (w), 1352.2 (s), 1263.4
(s), 1199.8 (w), 1170.6 (w), 1138.1 (s), 1080.2 (m), 1012.7 (w),
960.6 (w), 902.7 (w); GCMS 202 (M+, 16.3), 188 (9.7), 187
(100.0), 159 (29.0), 139 (16.4), 119 (14.4), 109 (100.0), 99 (4.6),
91 (6.0), 90 (16.8), 89 (31.6), 83 (12.7), 75 (9.8), 69 (16.6), 63
(36.5); HRMS calcd for C10H9F3O 202.0605, found 202.0595.
P r ep a r a tion of 1-(2,2,2-Tr iflu or oeth yl)-4-m or p h olin o-
tetr a flu or oben zen e (22). A 50 mL, two-necked, round-
bottomed flask equipped with a septum, a Teflon-coated
magnetic stir bar, and an N2 inlet which was connected to a
mineral oil bubbler was charged with 1.0 g (3.36 mmol) of
1-(2,2-difluoroethenyl)-4-morpholino-2,3,5,6-tetrafluoroben-
zene, 0.6 g (10 mmol) of potassium fluoride, 10 mL of DMSO,
and 0.5 mL of H2O. The reaction was stirred at 60 °C for 2 h,
and the NMR showed that the reaction was finished. The
reaction mixture was filtered through a short silica gel column.
The filtrate was concentrated via rotary evaporation with some
silica gel; then the dry silica gel and product were introduced
onto a silica gel column and eluted with hexane/ether (9/1) to
give 1.0 g (94%) of white solid: mp 48-49 °C; 19F NMR δ -66.7
P r epar ation of 1,4-Bis(2,2,2-tr iflu or oeth yl)ben zen e (26).
Similarly, 26 was prepared from 0.5 g (2.5 mmol) of 1,4-bis-
(2,2-difluoroethenyl)benzene, 0.6 g (10 mmol) of potassium
fluoride, 10 mL of DMSO, and 0.5 mL of H2O at 100 °C for 12
h. Usual workup with hexane as eluent gave 0.5 g (83%) of
white solid 25: 19F NMR δ -66.4 (t, J ) 10.4 Hz); 1H NMR δ
7.3 (s, 4H), 3.3 (q, J ) 10.8 Hz, 4H); 13C NMR δ 131.5 (m),
1
(m, 3F), -144.1 (m, 2F), -151.5 (m, 2F); H NMR δ 3.8 (m,
4H), 3.5 (qm, J ) 10.1 Hz, 2H), 3.3 (m, 4H); 13C NMR δ 146.6
(dddd, J ) 246.9, 14.4, 8.4, 3.7 Hz), 142.6 (dddd, J ) 245.4,
14.2, 4.6, 4.6 Hz), 131.0 (tm, J ) 10.4 Hz), 125.2 (q, J ) 277.4
Hz), 102.0 (tm, J ) 18.4 Hz), 67.6 (s), 51.6 (t, J ) 3.3 Hz),
27.7 (q, J ) 33.2 Hz); FT-IR (cm-1) 2968.6 (w), 2910.7 (w),
2895.3 (w), 2856.7 (w), 1668.5 (w), 1502.6 (s), 1438.9 (w), 1365.7
(w), 1269.2 (m), 1257.7 (m), 1163.1 (s), 1118.8 (m), 1103.3 (m),
985.7 (m); GCMS 318 (M+ + 1, 4.4), 317 (52.3), 298 (6.7), 260
(10.0), 259 (100.0), 245 (2.3), 208 (2.8), 191 (7.9), 190 (78.9),
189 (31.9), 181 (8.7), 162 (10.0), 143 (4.6), 117 (2.5), 69 (5.7);
HRMS calcd for C12H10F7NO 317.0651, found 317.0672.
P r ep a r a t ion of 4-(2,2,2-Tr iflu or oet h yl)n it r ob en zen e
(23). Similarly, 23 was prepared from 1.1 g (6 mmol) of 4-(2,2-
difluoroethenyl)nitrobenzene, 0.6 g (10 mmol) of potassium
fluoride, 10 mL of DMF, and 0.5 mL of H2O at room temper-
ature for 10 h. Usual workup with a mixture of hexane/
dichloromethane (10/2) as eluent gave 1.1 g (92%) of white solid
23: mp 67-68 °C; 19F NMR δ -65.9 (t, J ) 10.2 Hz); 1H NMR
δ 8.2 (dm, J ) 8.8 Hz, 2H), 7.5 (d, J ) 8.5 Hz, 2H), 3.5 (q, J )
10.5 Hz, 2H); 13C NMR δ 148.2 (s), 137.8 (m), 131.6 (s), 125.6
127.2 (q, J ) 375.9 Hz), 39.9 (q, J ) 29.4 Hz); FT-IR (cm-1
)
3061.2 (w), 3040.0 (w), 2943.5 (w), 1520.0 (w), 1425.5 (w),
1356.0 (m), 1292.4 (w), 1261.5 (s), 1209.4 (w), 1145.8 (s), 1076.3
(m); GCMS 243 (M+ + 1, 4.2), 242 (38.6), 223 (7.0), 203 (2.7),
191 (3.4), 174 (12.5), 173 (100.0), 153 (10.4), 133 (12.5), 122
(5.9), 109 (12.3), 104 (16.6), 103 (6.9), 89 (2.3), 77 (6.7), 69 (5.3);
HRMS calcd for C10H8F6 242.0530, found 242.0521.
Ack n ow led gm en t. We thank the National Science
Foundation for support of this work. We also thank Dr.
Lee Sprague for assistance with F2CdCHI.
Su p p or tin g In for m a tion Ava ila ble: 13C NMR spectra of
all compounds (26 pages). This material is contained in
libraries on microfiche, immediately follows this article in the
microfilm version of the journal, and can be ordered from the
ACS; see any current masthead page for ordering information.
(q, J ) 277.0 Hz), 124.0 (s), 40.1 (q, J ) 30.3 Hz); FT-IR (cm-1
3078.6 (w), 2949.3 (w), 2862.5 (w), 1923.1 (w), 1604.8 (w),
)
J O971019W