A facile protocol for the convenient preparation of phosphino- and phosphono-containing trans-1,2-difluorovinylsilanes

Article abstract of DOI:10.1080/10426500600977346

Attempted preparation of phosphono containing trans-1,2-difluoro-1- phenyldimethylsilyl ethylenes R₂P(O)CF = CFSiMePh 3 by deprotonation of HFC = CFSiMe₂Ph 2 followed by acylation with R₂P(O)Cl was unsuccessful. However, a

Full text of DOI:10.1080/10426500600977346

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Phosphorus, Sulfur, and Silicon
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A Facile Protocol for the
Convenient Preparation of
Phosphino-and Phosphono-
Containing Trans-1,2-
Difluorovinylsilanes
a
a
b
Hou-Jen Tsai , Chi-Wei Hsieh & Shyi-Chen Wu
a
Department of Applied Chemistry, Chung
Cheng Institute of Technology , National Defense
University , Tahsi, Taoyuan, Taiwan, R.O.C.
b
Department of Chemistry, R.O.C. Military
Academy , Fengshan, Kaohsiung, Taiwan, R.O.C.
Published online: 18 Feb 2007.
To cite this article: Hou-Jen Tsai , Chi-Wei Hsieh & Shyi-Chen Wu (2007) A Facile
Protocol for the Convenient Preparation of Phosphino-and Phosphono-Containing
Trans-1,2-Difluorovinylsilanes, Phosphorus, Sulfur, and Silicon and the Related
Elements, 182:2, 491-501, DOI: 10.1080/10426500600977346
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Phosphorus, Sulfur, and Silicon, 182:491–501, 2007
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500600977346
A Facile Protocol for the Convenient Preparation
of Phosphino- and Phosphono-Containing
Trans-1,2-Difluorovinylsilanes
Hou-Jen Tsai
Chi-Wei Hsieh
Department of Applied Chemistry, Chung Cheng Institute of Technology,
National Defense University, Tahsi, Taoyuan, Taiwan, R.O.C.
Shyi-Chen Wu
Department of Chemistry, R.O.C. Military Academy, Fengshan,
Kaohsiung, Taiwan, R.O.C.
Attempted preparation of phosphono containing trans-1,2-difluoro-1-
phenyldimethylsilyl ethylenes R2P(O)CF=CFSiMePh
3 by deprotonation of
HFC=CFSiMe2Ph 2 followed by acylation with R2P(O)Cl was unsuccessful.
However, acylation of the lithium salt of 2 with R2PCl gave R2PCF=CFSiMe2Ph 4,
which on subsequent oxidation with hydrogen peroxide or tert-butylhydroperoxide
afforded a series of compounds trans-R2P(O)CF=CFSiMe2Ph 3 in good yields.
Keywords Acylation; deprotonation; trans-1,2-difluoroethylene; oxidation
INTRODUCTION
Fluorinated organic compounds continue to attract the interest of phar-
maceutical chemists and agrochemists due to the unique properties of
compounds, which contain one or more fluorine atoms at strategic po-
1
sitions in the molecule. Many natural products, such as pheromones
and juvenile hormones, contain double bonds and conjugated polyenes
as essential features of their structures. Synthetic and biological ac-
tivities of several fluorinated analogs have been reported.2−8 In most
cases, only hydrogens at saturated carbon atoms or one vinyl hydro-
gen have been replaced by fluorine atoms. Although the introduction
Received July 19, 2006; accepted July 28, 2006.
The authors would like to thank the National Science Council of the Republic of China
for supporting this work.
Address correspondence to Hou-Jen Tsai, Department of Applied Chemistry, Chung
Cheng Institute of Technology, National Defense University, Tahsi, Taoyuan, Taiwan,
3
35 Republic of China. E-mail: hjtsai@ccit.edu.tw
491

4
92
H.-J. Tsai et al.
of the trans-1,2-difluoroethylene unit into organic compounds using
readily available fluoromonomers as starting materials has been stud-
ied by Normant and coworkers,9 the preparation of organic com-
pounds containing the 1,2-difluoroethene unit is still a challenging
1
0−13
problem.
The first successful preparation of 1,2-difluoro-1-alkenes
through the fluorination of bromoketones with potassium fluoride and
sulfur tetrafluoride followed by dehydrofluorination of trifluoroalkanes
1
0
with potassium tert-butoxide was reported by Leroy, but this method
required toxic or expensive fluorinating agents. However, there are
no reports in the literature concerning the synthesis of phosphino-
and phosphono-containing trans-1,2-difluorovinylsilanes. Herein, we
present a novel and convenient method for the preparation of a se-
ries of phosphino-containing trans-1,2-difluoro-1-phenyl-dimethylsilyl
ethylenes R2PCF=CFSiMe2Ph and phosphono-containing trans-1,2-
difluoro-1-phenyldimethylsilyl ethylenes R2P(O)CF=CFSiMe2Ph.
RESULTS AND DISCUSSION
Phenyldimethylsilyl trifluoroethylene F2C=CFSiMe2Ph 1 was pre-
pared from chlorotrifluoroethylene and phenyldimethylsilyl chloride in
1
4
the presence of n-butyllithium at a low temperature. Figure 1 shows
the reaction apparatus for the preparation of 1.
1
5
Treatment of 1 with lithium aluminum hydride resulted in the for-
mation of trans-1,2-difluoro-1-phenyl-dimethylsilyl ethylene 2 as the
Dry ice + IPA
N2
2
.5 M n-BuLi
Mineral Oil
in Hexane
CF =CFCl
2
gas tank
Septum
Dry ice + IPA
Dry ice + IPA
PhMe SiCl/THF
2
Dewar
Dewar
FIGURE 1 Reaction apparatus for the preparation of F
2
2
C=CFSiMe Ph.

Phosphino- and Phosphono-Containing Trans-1,2- Difluorovinylsilanes
493
predominant isomer (trans:cis = 96:4 by 19F NMR analysis). The two
19
isomers were easily identified by F NMR spectroscopy due to the
2
16
large difference in the JFF coupling constants between the cis isomer
(
0–20 Hz) and the trans isomer (120–140 Hz).
n-BuLi/THF
F2C CFCl + PhMe2SiCl
−→ F2C CFSiMe2Ph
◦
−
78 C to R.T.
THF
1
+ LiA1H4
−→ HFC FSiMe2Ph
◦
−
5 C to R.T.
Observations in our laboratory indicate that direct conversion of
HFC=CFSiMe2Ph 2 to trans-(EtO)2P(O)CF=CFSiMe2Ph 3a proceeds
with very low yields when deprotonation and acylation is performed
with n-butyllithium and diethyl chlorophosphate (EtO)2P(O)Cl, respec-
tively (Scheme 1). The use of different bulky alkyl lithium reagents such
as sec-butyllithium and tert-BuLi and of a proton-selective base such
as lithium 2,2,6,6-tetramethyl piperidide (LTMP) at different tempera-
tures and with different solvent ratios did not improve the yield of the
conversion of 2 to 3a. Before work-up, 19F NMR analysis of the reac-
tion mixture indicated the complete consumption of 2 and the presence
of 3a as a minor product. Some unexpected byproducts could not be
isolated and identified. After work-up, only trace amounts of trans-
(
EtO)2P(O)CF=CFSiMe2Ph 3a were isolated.
o
o
(
1) Base/-110 C or -140 C
THF/Ether
(
EtO) P(O)
F
2
2
(
2) (EtO) P(O)Cl
F
SiMe Ph
2
2
3
a
o
o
-
110 C or -140 C to r.t.
Isolated yield < 10%
Li
N
Base = n-BuLi, sec-BuLi, t-BuLi,
SCHEME 1
Deprotonation of HFC=CFSiMe2Ph 2 afforded the lithium salt
−
+
[
PhMe2SiCF=CF] Li 2a, which could not be isolated at r.t. In the acy-
lation of 2a with (EtO)2P(O)Cl, the lithium salt was stable in THF/Et2O
◦
solvent below −110 C, but if the reaction temperature was allowed to
◦
rise to −90 C, it rapidly produced a white material. In this situation,
the potential instability of the lithium salt can be explained by the

4
94
H.-J. Tsai et al.
2 2
TABLE I Preparation of Trans-(EtO) P(O)CF CFSiMe Ph
3a From 2 and (EtO)
2
P(O)Cl
Base
Solvent (THF/Et2O)
Temperature ( C) Isolated Yield (%)a
◦
n-BuLi
s-BuLi
t-BuLi
LTMP
1:1
1:2
2:1
3:1
−110 to r. t.
−110 to r. t.
−140 to r. t.
−140 to r.t.
<5
<10
<10
<8
aIsolated yields are based on HCF=CFSiMe2Ph.
possibility of lithium fluoride elimination 15 leading initially to alkynes,
which may then react further.
Results for the direct synthesis of trans-(EtO)2P(O)CF=CFSiMe2Ph
3
a from HFC=CFSiMe2Ph 2 and (EtO)2P(O)Cl with different bases
and at different temperatures and solvents are summarized in Table I.
Cooling was accomplished with an external dewar bath consisting of an
◦
ethanol/liquid N2 mixture at −110 C or an isopentane/liquid N2mixture
◦
at −140 C.
However, we found that if chlorophosphines such as diethyl
chlorophosphite (EtO)2PCl, diphenyl chlorophosphine Ph2PCl, bis(di-
ethylamino) chlorophosphine (Et2N)2PCl, dicyclohexyl chlorophos-
phine (c-C6H11)2PCl, diethyl chlorophosphine Et2PCl, diisopropyl
chlorophosphine (i-C3H7)2PCl, di-tert-butyl chlorophosphine t-Bu2PCl,
or 1,2-phenylene phosphorochloridate (C6H4O2)PCl were used as acy-
lating reagents to react with the lithium salt of HFC=CFSiMe2Ph
2
, the phosphino-containing trans-1,2-difluoro-1-phenyl dimethylsilyl
ethylenes R2PCF=CFSiMe2Ph 4 were obtained (Scheme 2) in 90–94%
yields (according to 19F NMR).
Yields of products 4 obtained using different bases and different
◦
THF/Et2O solvent ratios at −110 C are given in Table II.
o
(
1) Base/-110 C
THF/Ether
R2P
F
F
2
(
2) R PCl
2
SiMe Ph
2
o
-
110 C to r.t.
4
Base = n-BuLi, sec-BuLi, t-BuLi
R = EtO (4a), Ph (4b), Et N (4c), c-C H (4d),
2 6 11
Et (4e), i-C H (4f), t-Bu (4g), -OC H O- (4h)
3
7
6 4
SCHEME 2

Phosphino- and Phosphono-Containing Trans-1,2- Difluorovinylsilanes
495
2 2
TABLE II Preparation of Trans-R PCF CFSiMe Ph 4
R
Base
Solvent (THF/Et2O)
Yield (%)a
4
4
4
4
4
4
4
4
a
b
c
d
e
f
EtO
Ph
Et2N
c-C6H11
Et
i-C3H7
t-Bu
n-BuLi
n-BuLi
s-BuLi
t-BuLi
n-BuLi
t-BuLi
n-BuLi
s-BuLi
3:1
2:1
3:1
3:1
2:1
1:1
2:1
1:1
92
90
94
91
88
84
80
82
g
h
-OC6H4O-
aDetermined by 19F NMR; C6H5CF3 as internal standard.
19F NMR and 31
P NMR data of compounds R2PCF CFSiMe2Ph 4
are shown in Table III.
Trans-1,2-difluoro-1-phenyldimethylsilyl ethylenes 4 can be di-
rectly oxidized to afford trans-R2P(O)CF=CFSiMe2Ph 3. In situ
oxidation of R2PCF=CFSiMe2Ph 4 with hydrogen peroxide or
tert-butylhydroperoxide afforded trans-3 in 80–85% isolated yields
(
Scheme 3). The results illustrate that this methodology can be used
to prepare difluoro ethylenes 3 in good yields.
3
0% H O , r.t.
R2P(O)
F
F
2
2
4
or 90% t-BuOOH
SiMe Ph
2
3
R = EtO (3a), Ph (3b),
Et N (3c), c-C H11(3d)
2
6
SCHEME 3
TABLE III 19F and 31P NMR Data of R
2
2
PCF CFSiMe Ph
(
4); Coupling Constants J in Hz
19F (ppm)
δ
1-F
2-F
3JFF
2JPF
3JPF
δ
31P (ppm)
4
4
4
4
4
4
4
4
a
b
c
d
e
f
−157.0 (dd)
−170.9 (dd)
−171.1 (dd)
−151.9 (dd)
−152.9 (dd)
−145.9 (d)
−170.9 (d)
−144.3 (dd)
−162.9 (dd)
−179.5 (dd)
−179.4 (dd)
−157.9 (dd)
−154.9 (dd)
−150.4 (dd)
−179.4 (d)
−147.5 (dd)
139.2
132.3
130.7
136.9
144.3
147.1
130.6
144.2
77.9
78.4
81.6
56.9
78.0
83.2
30.9
90.1
22.4
11.9
11.3
6.0
3.2
0.0
134.6 (dd)
29.0 (dd)
−4.6 (dd)
46.3 (dd)
−32.1 (dd)
−7.4 (d)
66.8 (d)
g
h
0.0
6.7
1.4 (d)

4
96
H.-J. Tsai et al.
TABLE IV Preparation of
Trans-R P(O)CF CFSiMe Ph 3
2 2
R
Oxidation Reagent
Isolated Yield (%)a
3
3
3
3
3
a
b
c
d
h
EtO
Ph
Et2N
c-C6H11
-OC6H4O-
30% H2O2
95% t-BuOOH
30% H2O2
95% t-BuOOH
95% t-BuOOH
85
84
80
84
b
46
a
b
Isolated yields are based on R2PC=CFSiMe2Ph.
19
Determined by F NMR; C6H5CF3 as internal standard.
Results for the synthesis of trans-R2P(O)CF=CFSiMe2Ph 3 by oxi-
dation of trans-R2PCF=CFSiMe2Ph 4 with hydrogen peroxide or tert-
butylhydroperoxide are summarized in Table IV.
Additional work is in progress to explore the possible application of
difluoro ethylenes 3 and 4 in organic synthesis.
In conclusion, deprotonation of HFC=CFSiMe2Ph 2 followed
−
+
by acylation of the lithium salt [PhMe2SiCF=CF] Li 2a with
R2PCl gave trans-R2PCF=CFSiMe2Ph 4. Oxidation of the resulting
phosphino-substituted ethylenes
4 with hydrogen peroxide or
tert-butylhydroperoxide afforded trans-R2P(O)CF=CFSiMe2Ph 3 in
good yields.
EXPERIMENTAL
3
1
1
13
P, H, and C NMR spectra were recorded on a Bruker AM-300WB
1
9
spectrometer. F NMR spectra were recorded on a Bruker MSL-
00 spectrometer. All chemical shifts are reported in ppm down-
3
19
field (positive) from the standard. F NMR spectra are referenced
1
13
against internal CFCl3. H, and C NMR spectra are referenced
against internal (CH3)4Si, and 31P NMR spectra are referenced against
an external 85% H3PO4 capillary. Mass spectra were recorded with
a Finingan MAT TSQ-46C spectrometer. GLPC analyses were per-
formed on a 5% OV-101 column with a thermal conductivity de-
tector. Tetrahydrofuran was dried by distillation from sodium ben-
zophenone ketyl. Diethyl chlorophosphate (EtO)2P(O)Cl and diethyl
chlorophosphite (EtO)2PCl were distilled from calcium hydride (CaH2)
under reduced pressure. LTMP was prepared from n-butyl lithium
and 2,2,6,6-tetramethyl piperidine. Phenyldimethylsilyl chloride, 1,2-
phenylene phosphorochloridate (C6H4O2)PCl, diisopropyl chlorophos-
phine (i-C3H7)2PCl, diethyl chlorophosphine Et2PCl, bis(diethylamino)
chlorophosphine (Et2N)2PCl, di-tert-butyl chlorophosphine t-Bu2PCl,

Phosphino- and Phosphono-Containing Trans-1,2- Difluorovinylsilanes
497
dicyclohexyl chlorophosphine (c-C6H11)2PCl, lithium aluminum hy-
dride (LiAlH4), dry ether, tert-butylhydroperoxide (t-BuOOH), and the
lithium reagents (n-BuLi, sec-BuLi, t-BuLi) were obtained from com-
mercial sources and were used without further purification.
Preparation of Phenyldimethylsilyl Trifluoroethylene
F C CFSiMe Ph (1)
2
2
A 500-mL three-necked, round-bottomed flask equipped with a sep-
tum port, a low temperature thermometer, a telflon-coated magnetic
stirring bar, and a dry-ice isopropyl alcohol condenser topped with a
nitrogen T-tube leading to a source of nitrogen and mineral-oil bub-
bler was charged sequentially with 180-mL dry THF and 293 mmol
(
50.0 g) phenyldimethylsilyl chloride. The contents of the flask were
◦
cooled to −78 C in a dry ice/i-PrOH slush bath, and then 343 mmol
◦
(
40.0 g, 31 mL, b.p. = −27 C) of chlorotrifluoroethylene was condensed
into the solution. To the cooled solution, 315 mmol (126 mL) of a 2.5 M
n-hexane solution of n-butyllithium was added dropwise via a syringe,
◦
maintaining an internal temperature below −75 C. After the addition
◦
was complete, the resulting mixture was stirred at −78 C for 2 h, was
allowed to warm to r. t. over a time of 5 h, and it was stirred at that
temperature overnight. 19F NMR analysis of the reaction mixture indi-
cated the formation of 1. The reaction mixture was poured into water
(
80 mL), and the water layer was extracted with ether (3 × 120 mL). The
combined organic phases were washed with diluted HCl until the wash-
ings were neutral to litmus paper. The resulting solution was washed
successively with brine (60 mL) and water (80 mL), dried over MgSO4,
filtered, and concentrated on a rotary evaporator. The crude residue
then was fractionally distilled through a 6-cm Vigreux column at 80–
◦
8
2 C and 9.0 mm Hg to yield 58.2 g (92%) of F2C=CFSiMe2Ph (97% pure
19
3
by GLPC analysis). F NMR (CDCl3): δ −190.7 (dd, JFF = 117.3 Hz,
3
3
3
JFF = 25.6 Hz), −115.3 (dd, JFF = 117.3 Hz, JFF = 65.9 Hz), −86.3
3
3
1
(
2
dd, JFF = 65.9 Hz, JFF = 25.6 Hz); H NMR (CDCl3): δ 7.55–7.52 (m,
4
13
H), 7.36–7.30 (m, 3H), 0.47 (d, JFH = 1.3 Hz, 6H); C NMR (CDCl3):
1 1 2
δ 161.7 (ddd, JCF = 310.0 Hz, JCF = 277.0 Hz, JCF = 40.0 Hz), 134.3 (s),
2
9
1
1
2
33.8 (s), 132.5 (m), 130.1 (s), 128.2 (s), −4.8 (s, Si satellites, JSiC =
8.1 Hz).
Preparation of Trans-1,2-Difluoro-1-Phenyldimethylsilyl
Ethylene HFC CFSiMe Ph (2)
2
A 500-mL three-necked, round-bottomed flask was charged with 150 mL
of dry THF and 187 mmol (7.1 g) of powder lithium aluminum hydride.

4
98
H.-J. Tsai et al.
◦
The contents of the flask were cooled to −5 C in an ice/salt bath. To
the cooled solution, 231 mmol (50.0 g) of phenyldimethylsilyl trifluo-
roethylene in 150 mL of dry THF was added via a pressure-equalizing
◦
funnel maintaining an internal temperature of 0 C. After the addi-
tion, the resulting mixture was allowed to warm to r. t. over a time
1
9
of 3 h. F NMR analysis of the reaction mixture revealed the com-
plete consumption of F2C=CFSiMe2Ph and the presence of product 2.
◦
The solution was cooled to −20 C and was quenched cautiously by a
dropwise addition of 80 mL 2N HCl. After the addition of the acid was
completed, the solution was allowed to slowly warm up to r. t. and the
liquid fraction was decanted from the solids. The solids were rinsed with
ether (3 × 150 mL), and any remaining solid in the organic layer was
filtered by water aspiration. The combined organic phases were washed
with aqueous NaHCO3 until the washings were neutral to litmus pa-
per. The resulting solution was washed successively with brine (50 mL)
and water (40 mL), dried over MgSO4, filtered, and concentrated on
a rotary evaporator. The crude residue then was fractionally distilled
◦
through a 6-cm Vigreux column at 80–81 C and 7.2 mm Hg to yield
3
9.3 g (86%) of trans and cis-1,2- difluoro-1-phenyldimethylsilyl ethy-
1
9
lene (99% pure by GLPC analysis). Trans/cis = 96/4. F NMR (CDCl3):
3
3
trans isomer: δ −179.2 (dd, JFF = 131.8 Hz, JFH = 12.2 Hz), −170.8 (dd,
3
3
2
3
JFF = 131.8 Hz, JFH = 78.1 Hz), cis isomer: −157.4 (dd, JFH = 21.9 Hz,
JFF = 19.5 Hz), −143.9 (dd, JFH = 75.7 Hz, JFF = 19.5 Hz); H NMR
2
3
1
2
3
(
CDCl3): δ 7.57 (dd, JFH = 79.1 Hz, JFH = 10.8 Hz, 1H), 7.59–7.54 (m,
4
4
2
H), 7.38–7.31 (m, 3H), 0.51 (dd, JFH = 1.25 Hz, JFH = 0.78 Hz, 6H);
1
3
1 2
C NMR (CDCl3): δ 160.6 (dd, JCF = 260.0 Hz, JCF = 56.0 Hz), 154.2
dd, JCF = 244.0 Hz, JCF = 56.0 Hz), 134.8 (s), 133.8 (s), 129.9(s), 128.1
1
2
(
(
2
9
1
s), −4.1 (s, Si satellites, JSiC = 28.1 Hz).
Attempted Preparation of Trans-(EtO) P(O)CF CFSiMe Ph (3a)
2
2
from (EtO) P(O)Cl and HFC CFSiMe Ph (2)
2
2
A 500-mL three-necked, round-bottomed flask was charged with
6
0 mL of dry THF, 60 mL of dry ether, and 50.0 mmol (9.90 g)
◦
HFC=CFSiMe2Ph. The contents of the flask were cooled to −110 C in
a pentane/liquid nitrogen slush bath. To the cooled solution, 55 mmol
(
22 mL) of a 2.5 M n-hexane solution of n-butyllithium was added drop-
wise via a syringe, maintaining the temperature of the reaction mix-
◦
ture at −90 to –110 C. After the addition was complete, the result-
◦
ing mixture was stirred at −110 C for 40 min, and then 60.0 mmol
(
10.4 g) of freshly distilled diethyl chlorophosphate in 20 mL of dry
THF was added dropwise via a pressure-equalizing funnel. The result-
◦
ing mixture was stirred at −110 C for 1 h and then allowed to warm

Phosphino- and Phosphono-Containing Trans-1,2- Difluorovinylsilanes
499
up to r. t. over a time of 4 h. The reaction mixture was poured into
water (80 mL), and the water layer was extracted with ether (3 × 80
mL). The combined organic phases were washed with diluted HCl until
the washings were neutral to litmus paper. The resulting solution was
washed successively with brine (60 mL) and water (50 mL), dried over
MgSO4, filtered, and concentrated on a rotary evaporator. The residue
was purified by flash chromatography (120 g silica gel, 200–425 mesh)
1
9
eluting with n-hexane/ethyl acetate (3/1) to give 0.69 g (4%) of 3a.
F
3
2
NMR (CDCl3): δ −162.2 (dd, JFF = 139.2 Hz, JPF = 96.7 Hz), −150.6 (d,
3
31
2
1
JFF = 139.2 Hz); P NMR (CDCl3): δ 0.41 (d, JPF = 96.7 Hz); H NMR
3
(
4
(
CDCl3): δ 7.57–7.54 (m, 2H), 7.42–7.33 (m, 3H), 4.16 (q, JHH = 7.4 Hz,
3
13
H), 1.31 (t, JHH = 7.4 Hz, 6H), 0.58 (s, 6H); C NMR (CDCl3): δ 133.9
1 1 2
s), 133.6 (s), 133.0 (ddd, JCF = 187.4 Hz, JCF = 116.6 Hz, JCF = 5.5
1
2
Hz), 131.6 (dd, JCF = 210.6 Hz, JCF = 4.9 Hz), 128.2 (s), 127.7 (s),
2
9
1
6
3.4 (s), 16.2 (s), −4.14 (s, Si satellites, JSiC = 28.1 Hz); GC-MS m/z
+
+
(
(
(
relative intensity): 319 (M −CH3, 1.4), 258 (M −C6H5+ H, 1.6), 245
+
+
M −2 C2H5O + H, 10.8), 243 (M −C6H5−CH3+ H, 7.0), 137
(C2H5O)2P(O), 11.0), 135 (Si(CH3)2C6H5, 7.9), 62 (C2F5, 2.5); FTIR:
3
095 (m), 3054 (m, Ar H), 2908 (m), 2870 (m, C H), 1741 (m), 1653
−
1
(
m, C=C), 1456, 1336 (m, C F), 1202 (s, P=O), 1164 (s), 1052 (m) cm
.
General Procedure for Preparation of
Trans-R PCF CFSiMe Ph (4)
2
2
A solution of 5.0 mmol (0.99 g) HFC=CFSiMe2Ph with 12 mL of dry
◦
THF and 3 mL of dry ether was cooled to −110 C via a pentane/liquid
nitrogen slush bath under nitrogen. To the cooled solution, 5.5 mmol
(
2.2 mL) of a 2.5 M n-hexane solution of n-butyllithium was added drop-
◦
wise via a syringe, maintaining the reaction mixture at −90 to –110 C.
After the addition was completed, the resulting mixture was stirred at
◦
–
110 C for 40 min, and then 5.7 mmol of freshly distilled R2PCl was
added dropwise via a pressure-equalizing funnel. The resulting mix-
◦
ture was stirred at –110 C for 1 h and then was allowed to warm up
to r. t. over a time of 4 h. 19F NMR analysis of the reaction mixture
revealed the complete consumption of HFC=CFSiMe2Ph. The reaction
mixture was filtered through a Schlenck funnel to give the products of
19
31
trans-R2PCF=CFSiMe2Ph 4. F and P NMR data of 4a–4h in the
solvent of THF/Et2O are given in Table III.
General Procedure for Preparation of
Trans-R P(O)CF CFSiMe Ph (3)
2
2
A prepared solution of 5.0 mmol trans-R2PCF CFSiMe2Ph in 15 mL of
◦
dry THF and 3 mL of dry ether was cooled to 0 C via an ice-water bath

5
00
H.-J. Tsai et al.
under nitrogen. To the cooled solution, 7.0 mmol of a 90% t-BuOOH so-
lution or a 30% H2O2 was added dropwise via a syringe, maintaining the
◦
reaction mixture at 0 C. After the addition was completed, the resulting
mixture was stirred at r. t. for 4 h. The reaction mixture was quenched
by the addition of water (20 mL), and the water layer was extracted
with ether (3 × 20 mL), dried over MgSO4, filtered, and concentrated
on a rotary evaporator. The residue was purified by flash chromatogra-
phy (60 g silica gel, 200–425 mesh) eluting with n-hexane/ethyl acetate
to give trans-R2P(O)CF=CFSiMe2Ph 3.
Trans-Ph P(O)CF CFSiMe Ph (3b)
2
2
1
9
3
Yield: 84%;
F NMR (CDCl3): δ −155.8 (dd, JFF = 144.0 Hz,
2
3 31
JFP = 75.0 Hz), −145.6 (d, JFF = 144.0 Hz); P NMR (CDCl3): δ 16.5
2
1
(
d, JPF = 75.0 Hz); H NMR (CDCl3): δ 7.77–7.70 (m, 4H), 7.62–7.45
13
(
m, 6H), 7.43–7.34 (m, 5H), 0.58 (s, 6H); C NMR (CDCl3): δ 133.9 (s),
1
2
1
1
1
32.6 (s), 131.7 (s), 131.5 (s), 130.8 (dd, JCF = 222.1 Hz, JCF = 12.9 Hz),
1 1 2
30.3 (s), 129.3 (ddd, JCF = 211.8 Hz, JCP = 166.9 Hz, JCF = 9.8 Hz),
28.7 (s), 128.5 (s), 128.1 (s), −4.1 (s, Si satellites, JSiC = 28.1 Hz);
29
1
+
+
GC-MS m/z (relative intensity): 400 (M +1, 0.3), 399 (M , 0.9), 398
+
+
+
(
(
M − 1, 3.3), 322 (M − C6H5, 0.6), 263 (M − Si(CH3)2Ph, 0.6), 201
+
+
Ph2P(O), 11.0), 186 (M − Si(CH3)2Ph − C6H5, 12.5), 77 (C6H , 14.0);
5
FTIR: 3061 (m), 3003 (m, Ar-H), 2964 (m), 2904 (m, C H), 2360 (m),
1
950 (m), 1620 (m, C C), 1438 (m, C F), 1254 (s, P O), 1028 (m,
−1
P-O-C) cm
.
Trans-(Et N) P(O)CF CFSiMe Ph (3c)
2
2
2
1
9
3
Yield: 80%;
F NMR (CDCl3): δ −171.3 (dd, JFF = 147.0 Hz,
2
3 31
JFP = 70.8 Hz), −158.7 (d, JFF = 147.0 Hz); P NMR (CDCl3): δ 14.0
2
1
(
(
(
d, JPF = 70.8 Hz); H NMR (CDCl3): δ 7.49–7.43 (m, 2H), 7.34–7.24
3
3
m, 3H), 3.00 (q, JHH = 7.2 Hz, 8H), 0.99 (t, JHH = 7.2 Hz, 12H), 0.81
1
3
1
s, 6H); C NMR (CDCl3): δ 149.8 (s), 149.6 (dd, JCF = 216.3 Hz,
2
2
1
1
JCF = 11.7 Hz), 149.3 (s), 149.1 (ddd, JCF = 201.2 Hz, JCP = 156.1 Hz,
29
JCF = 10.2 Hz), 148.1 (s), 147.9 (s), 37.9 (s), 13.4 (s), −4.1 (s, Si satel-
1
+
lites, JSiC = 28.1 Hz); GC-MS m/z (relative intensity): 358 (M −2CH3,
+
+
1
.6), 253 (M −Si(CH3)2C6H5, 7.2), 239 (M −Si(CH3)2C6H5− CH3−
H, 20.8), 196 ((Et2N)2P(O), 9.3), 72 ((Et2N)2, 43.0); FTIR : 3450 (s),
2
974 (s), 2874 (m), 1654 (m), 1464 (m), 1382 (m), 1239 (s), 1128 (m),
−
1
1022 (m) cm
.
Trans-(c-C H ) P(O)CF CFSiMe Ph (3d)
6
11 2
2
1
9
3
Yield: 84%;
F NMR (CDCl3): δ − 158.0 (dd, JFF = 145.0 Hz,
2
3 31
JFP = 60.3 Hz), −151.8 (d, JFF = 145.0 Hz); P NMR: δ 46.5 (d,

Phosphino- and Phosphono-Containing Trans-1,2- Difluorovinylsilanes
501
2
JPF = 60.3 Hz); 1H NMR (CDCl3): δ 7.53–7.51 (m, 2H), 7.37–7.31
(
m, 3H), 1.98–1.80 (m, 2H), 1.77–1.64 (m, 8H), 1.36–1.15 (m, 12H),
1
3
1
0
.51 (s, 6H); C NMR (CDCl3): δ 133.9 (s), 133.6 (dd, JCF = 213.8
2
1
1
Hz, JCF = 9.6 Hz), 133.0 (s), 129.9 (ddd, JCF = 224.9 Hz, JCP = 139.8
2
Hz, JCF = 11.3 Hz), 127.9 (s), 127.8 (s), 34.7 (s), 34.4 (s), 26.2 (s),
2
9
1
2
5.8 (s), −4.2 (s, Si satellites, JSiC = 28.1 Hz); GC-MS m/z (relative
+
+
intensity): 333 (M −C6H5, 4.5), 275 (M −Si(CH3)2C6H5, 12.0), 197
+
(
:
M −(C6H11)2P(O), 7.5), 135 (Si(CH3)2C6H5, 13.5), 77 (C6H5, 10); FTIR
2920 (m), 2878 (m), 1920 (m), 1648 (m), 1430 (m), 1320 (m), 1248 (m),
−
1
1
121 (m), 1031 (m) cm .
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