The perfluoroallylation of alkynes and transformation of the products

Article abstract of DOI:10.1016/j.jfluchem.2005.02.011

The addition of perfluoroallyl iodide to alkynes 1 initiated by AIBN in the absence of solvent 65 °C gave the corresponding 1:1 adducts (1,1,2,3,3-pentafluoro-5-iodopenta-1,4-dienes) 2. The reaction of 2 with boronic acids 3 and terminal alkynes 1 in the

Full text of DOI:10.1016/j.jfluchem.2005.02.011

Journal of Fluorine Chemistry 126 (2005) 771–778
www.elsevier.com/locate/fluor
The perfluoroallylation of alkynes and transformation
of the products
Shu Qin Liu b, Shi Wei Wang a, Feng-Ling Qing a,b,
*
a Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Science,
354, Fenglin Lu, Shanghai 200032, China
b College of Chemistry and Chemical Engineering, Donghua University, 1882 West Yanan Lu, Shanghai 200051, China
Received 24 January 2005; received in revised form 18 February 2005; accepted 21 February 2005
Available online 7 April 2005
Abstract
The addition of perfluoroallyl iodide to alkynes 1 initiated by AIBN in the absence of solvent 65 8C gave the corresponding 1:1 adducts
(1,1,2,3,3-pentafluoro-5-iodopenta-1,4-dienes) 2. The reaction of 2 with boronic acids 3 and terminal alkynes 1 in the presence of catalytic
palladium afforded the cross-coupling products 4 and 5, respectively.
# 2005 Elsevier B.V. All rights reserved.
Keywords: Perfluoroallylation; Suzuki cross-coupling reaction; Sonogashira cross-coupling reaction
1. Introduction
2. Results and discussion
There has been considerable interest in organofluorine
compounds as pharmaceutical and agrochemical agents due
to their unique properties arising from altered electron
density, acidity, and hydrogen-bonding patters [1]. Accord-
ingly, the development of methods for the synthesis of
organofluorine compounds continues to be an important area
of research [1]. Among these, the perfluoroalkylation of
organic molecules has been widely used for the synthesis of
organofluorine compounds. Although the perfluoroalkyla-
tion of alkenes [2] and alkynes [3] has been extensively
investigated with perfluoroalkyl iodides, few reports of
perfluoroallylation have been documented. To the best our
knowledge, only Burton and co-workers [4] described the
addition of perfluoroallyl iodide (F-allyl iodide) to alkenes
in the presence of copper, and there was no report on the
perfluoroallylation of alkynes. Herein, we wish to report the
addition of F-allyl iodide to alkynes initiated by AIBN and
the transformation of the 1:1 adduct products.
2.1. Addition of F-allyl iodide to alkynes
Addition of perfluoroalkyl iodide to alkynes can be
readily achieved by initiation with Na2S2O4/NaHCO3 [3b]
or Pd(PPh3)4 [3e]. We began our investigation by examining
the addition of F-allyl iodide to 1-heptyne (1a) in the
presence of Na2S2O4/NaHCO3 in CH3CN. Contrary to
perfluoroalkyl iodide [3b], we observed no reaction after 4 h
at 0–5 8C. When a mixture of F-allyl iodide, 1a and catalytic
Pd(PPh3)4 was heated at 60 8C for 8 h, the polymerization of
F-allyl iodide occurred and the adduct product was not
obtained. Fortunately, the addition of F-allyl iodide to 1a
initiated by AIBN in the absence of solvent at 65 8C
proceeded smoothly, the addition reaction was complete in
16 h and the adduct product 2a was isolated in 75% yield as a
mixture of E- and Z-isomers. The ratio of E/Z was 4/1 as
determined by 1H NMR (Scheme 1). The alkenyl hydrogen
of E-isomer appeared lower field than that of Z-isomer [3b].
To the best our knowledge, this was the first example of the
perfluoroallylation of alkynes. The generality of the reaction
was demonstrated by the addition of F-allyl iodide to a
* Corresponding author. Fax: +86 21 64166128.
E-mail address: flq@mail.sioc.ac.cn (F.-L. Qing).
0022-1139/$ – see front matter # 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2005.02.011

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S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
Scheme 1.
Table 1
AIBN-mediated addition of F-allyl iodide to terminal alkynes 1
Entry
R (1)
Product 2
Yield (%)a
E/Z ratiob
1
2
3
4
5
6
7
8
a
n-C5H11 (1a)
C6H5 (1b)
2a
2b
2c
2d
2e
2f
75
64
34
66
44
68
62
42
4/1
3/1
1/3
1/1
1/1
1/1
1/1
1/1
CO2CH3 (1c)
CH2OH (1d)
C6H5OCH2 (1e)
(CH3)3Si (1f)
C6H5CH2OCH2 (1g)
CH3CO2CH2 (1h)
2g
2h
Isolated yield.
Determined by 19F NMR and 1H NMR after of purification of the crude product by column chromatography.
b
variety of other terminal alkynes. All examples of the
addition reactions were summarized in Table 1. As shown in
Table 1, a variety of functionalized groups were tolerated
under the reaction conditions. The isolated yields of the
adduct products were from moderate to good, except for 2c.
The adduct products 2a–c were obtained with low levels of
stereoselectivities (entries 1–3). In the case of terminal
alkynes 1d–h, there were no stereoselectivities in the
perfluoroallylation reaction (entries 4–8). It was noteworthy
the pure E-2b, E-2h and Z-2h could be obtained by column
chromatography. Under the same reaction conditions, AIBN
also initiated the addition of F-allyl iodide to internal alkyne
such as 4-octyne (Scheme 2). However, the adduct product
2i was isolated in low yield (24%) with no stereoselectivity
(E/Z: 1/1).
3 mol% PdCl2(PPh3)2 and K2CO3 in refluxing THF) [3a, 6],
the reaction was very complex as indicated by 19F NMR of
the reaction mixture. When K3PO4 was used as base instead
of K2CO3, 19F NMR of the reaction mixture showed that
perfluoroallyl group disappeared. These results suggested
that perfluoroallyl group was labile to strong base.
Accordingly, we have chosen a weak base for this reaction.
We were pleased to find that the desired compound 4a was
obtained in 49% yield in the case of NaHCO3 being used as a
base. Finally, when KF was used as base [7], the Suzuki
cross-coupling of 2a and 3a in the presence of 3 mol%
PdCl2(PPh3)2 in toluene at 80 8C gave the desired product 4a
in 79% isolated yield (Scheme 3). The configuration of
double bond was intact in this Suzuki cross-coupling
reaction.
The cross-coupling of fluorinated electrophiles 2 with
aryl boronic acid 3 in the presence of PdCl2(PPh3)2/KF was
summarized in Table 2. As shown in Table 2, the reaction of
2a and 2b with phenyl boronic acid 3a and p-methylphenyl
boronic acid 3b gave the corresponding cross-coupling
products 4a-d in good yields (entries 1–4). However, a
mixture of 2d and 3a in the presence of PdCl2(PPh3)2/KF
resulted in polymerization and the cross-coupling product
was not detected (entry 5). This result showed that the
perfluoroallyl group could be attacked by hydroxy group
2.2. The Suzuki cross-coupling of 1,1,2,3,3-pentafluoro-5-
iodopenta-1,4-dienes 2 with boronic acids
Having the fluorinated electrophiles 2 in hand, our
attention was turned to palladium-catalyzed Suzuki cou-
pling reactions [5]. Compound 2a was chosen as a model
substrate to examine the reaction conditions. When the
reaction of 2a and phenylboronic acid 3a was carried out in
typical Suzuki cross-coupling conditions (in the presence of
Scheme 2.

S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
773
Scheme 3.
under the cross-coupling reaction conditions. It was
2.3. The Sonogashira cross-coupling of 1,1,2,3,3-
pentafluoro-5-iodopenta-1,4-dienes 2 with
terminal alkynes
noteworthy that there was no reaction in the cross-coupling
of 2a with p-methoxylphenyl boronic acid 3c (entry 6).
The cross-coupling of fluorinated electrophiles 2 with
alkenyl(alkyl) boronic acids was also investigated. Treatment
of 2a with alkenyl boronic acid 3d in the presence of
PdCl2(PPh3)2/KF resulted in no reaction. Fortunately, the
reaction of 2a with 3d in toluene at 80 8C under the catalyst of
3 mol% Pd(PPh3)4 in the presence of NaHCO3 gave the
desired product 4e in 87% yield (Scheme 4). Furthermore, the
cross-coupling of E-2b with alkyl boronic acid 3e under the
catalyst of Pd(dppf)2Cl2 in the presence of NaHCO3/Ag2O [8]
proceeded smoothly to give compound 4f (Scheme 4).
The Sonogashira coupling reaction is one of the very
useful methods for the synthesis of fluorinated conjugated
enynes [3a, 9]. We examined the Sonogashira cross-
coupling of perfluoroallyl vinyl iodides 2 with terminal
alkynes 1. When Et3N was used as both solvent and
base, treatment of 2 with 1 in the presence of Pd(PPh3)4
at 40–50 8C for 16 h gave compounds 5 in high yields. It
was noteworthy that the Sonogashira reaction in the
presence of PdCl2(PPh3)2/CuI was not complete, even the
Table 2
PdCl2(PPh3)2/KF-mediated cross-coupling of 2 with aryl boronic acid 3
Entry
1
2
Boronic acid 3
Product 4
Isolated yield (%)
79
2
3
74
72
4
87
5
6
Polymerisation
No reaction

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S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
Scheme 4.
reaction time was prolonged to 24 h. The coupling
reaction results were summarized in Table 3. As shown
in Table 3, pure E-5b, E-5c and E-5d were obtained by
column chromatography. The coupling of 2d with
terminal alkyne 1a in the presence of Pd(PPh3)4/Et3N
resulted in polymerization, which was similar to the
Suzuki coupling of 2d with boronic acid in the presence of
PdCl2(PPh3)2/KF.
Table 3
Pd(PPh3)4-mediated cross-coupling of 2 with terminal alkyne 1
Entry
1
2
Alkyne 1
Product 5
Isolated yield (%)
84
2
3
55 (75)a
48 (69)a
4
5
51 (82)a
60
6
78
7
Polymerization
a
Isolated yield of a mixture of Z and E isomers.

S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
775
3. Conclusion
4.1.3. Methyl 4,4,5,6,6-pentafluoro-2-iodohexa-2,
5-dienoate (2c)
We have developed a procedure for the first perfluor-
oallylation of alkynes. By utilizing AIBN as initiator, the
perfluoroallyl vinyl iodides was obtained in high yields.
We have also developed a facile method for the
preparation of perfluoroallyl trisubstituted olefins, dienes
and enyenes via palladium-catalyzed cross-coupling of
perfluoroallyl vinyl iodides with boronic acids and
alkynes.
1H NMR (300 MHz, CDCl3) d: 7.66 (t, J = 10.8 Hz,
0.25H), 6.61 (t, J = 12.0 Hz, 0.75H). 19F NMR (282 MHz) d:
À92.8 (m, 0.25F), À93.6 (m, 0.75F), À96.2 (m, 2F), À105.9
(m, 1F), À187.2 (m, 1F). IR: 2960, 1787, 1638, 1352,
1295 cmÀ1. MS m/z: 342 (M+, 15), 131 (100), 91 (24), 69
(27), 59(38). HRMS Calcd. for C7H4F5IO2: 342.0089,
found: 341.9196.
4.1.4. 4,4,5,6,6-Pentafluoro-2-iodohexa-2,
5-diene-1-ol (2d)
4. Experimental section
1H NMR (300 MHz, CDCl3) d: 6.77 (t, J = 10.9 Hz,
0.5H), 6.54 (t, J = 12.9 Hz, 0.5H), 4.35 (s, 1H), 4.33 (s, 1H),
2.54 (s, 0.5H), 2.28 (s, 0.5H). 19F NMR (282 MHz) d: À97.3
(m, 1F), À98.2 (m, 0.5F), À98.9 (m, 1F), À99.5 (m, 0.5F),
À111.0 (m, 1F), À191.6 (m, 1F). IR: 3367, 1786, 1654,
1346, 1295 cmÀ1. MS m/z: 314 (M+, 40), 139 (100), 131
(51), 119 (68), 69 (41). Anal. Calcd. for C6H4F5IO: C, 22.95;
H, 1.28. found: C, 23.18; H, 1.48.
1H NMR spectra were recorded on a Bruker AM 300
(300 MHz) spectrometer with Me4Si as internal standard.
19F NMR spectra were obtained on Bruker AM 300
(282 MHz) spectrometer in CDCl3 with CFCl3 as external
standard, downfield shifts being designated as negative. All
chemical shifts (d) are expressed in ppm, coupling constants
(J) are given in Hz. Mass spectra were recorded on a
Finnigan-MAT-8430 instrument using EI ionization at
70 eV. IR spectra were recorded on a Shimadzu IR-440
spectrometer. Perfluoroallyl iodide was prepared according
to the literature procedure [10].
4.1.5. 1,1,2,3,3-Pentafluoro-5-iodo-6-phenoxhexa-2,
5-diene (2e)
1H NMR (300 MHz, CDCl3) d: 7.34–6.89 (m, 5H), 6.79
(t, J = 10.5 Hz, 0.5H), 6.68 (t, J = 13.2 Hz, 0.5H), 4.78 (s,
1H), 4.73 (s, 1H). 19F NMR (282 MHz) d: À92.9 (m, 1F),
À93.8 (m, 1F), À94.1 (m, 1F), À105.9 (m, 1F), À186.3 (m,
1F). IR: 1786, 1641, 1600, 1349, 1294. MS m/z: 390 (M+,
25), 263 (80), 131 (60), 94 (91), 65 (100). Anal. Calcd. for
C12H8F5IO: C, 36.95; H, 2.07. found: C, 36.45; H, 2.21.
4.1. General procedure for addition of F-allyl iodide
to alkyne
Under nitrogen atmosphere, a mixture of F-allyl iodide
(5.0 mmol), alkyne 1 (6.0 mmol) and AIBN (100 mg) was
stirred at 65 8C for 16 h. The reaction mixture was directly
purified by flash column chromatography (silica gel, eluting
with hexane) to give 2.
4.1.6. 1,1,2,3,3-Pentafluoro-5-iodo-5-trimethylsilylpenta-
2,5-diene (2f)
1H NMR (300 MHz, CDCl3) d: 7.38 (t, J = 15.9 Hz,
0.4H), 6.80 (t, J = 10.2 Hz, 0.6H), 0.32 (s, 3.5H), 0.26 (s,
5.5H). 19F NMR (282 MHz) d: À93.4 (m, 3F), À105.8 (m,
1F), À186.4 (m, 1F). IR: 2961, 1784, 1587, 1348, 1291. MS
m/z: 356 (M+, 13), 245 (100), 137 (28), 77 (44). HRMS
Calcd. for C8H10F5ISi: 356.1490, found: 355.9485.
4.1.1. 1,1,2,3,3-Pentafluoro-5-iododeca-1,4-diene (2a)
1H NMR (300 MHz, CDCl3) d: 6.40 (t, J = 12.6 Hz,
0.8H), 6.30 (t, J = 10.6 Hz, 0.2H), 2.56 (t, J = 15.0 Hz,
1.6H), 2.63 (t, J = 3.6 Hz, 0.4H), 1.62–1.28 (m, 6H), 0.92 (t,
J = 7.1 Hz, 3H). 19F NMR (282 MHz) d: À93.0 (m, 2F),
À94.7 (m, 1F), À106.6 (m, 1F), À185.9 (m, 1F). IR: 1784,
1635, 1346, 1292 cmÀ1. MS m/z: 171 (17), 147 (100), 105
(67), 77 (34). HRMS Calcd. For C10H12F5I: 354.1012,
found: 353.9953.
4.1.7. 6-Benzyloxy-1,1,2,3,3-pentafluoro-5-iodohexa-2,
5-diene (2g)
1H NMR (300 MHz, CDCl3) d: 7.45–7.20 (m, 5H), 6.75
(t, J = 10.8 Hz, 0.5H), 6.63 (t, J = 12.9 Hz, 0.5H), 4.54 (d,
J = 3.6 Hz, 1H), 4.49 (d, J = 4.8 Hz, 1H), 4.26–4.17 (m, 2H).
19F NMR (282 MHz) d: À92.2 (m, 1F), À93.2 (m, 0.5F),
À93.6 (m, 1F), À94.2 (m, 0.5F), À106.2 (m, 1F), À186.0
(m, 1F). IR: 3067, 1785, 1639, 1348, 1293 cmÀ1. MS m/z:
404 (M+, 1), 171 (14), 105 (10), 91 (100), 77(12). Anal.
Calcd. for C13H10F5IO: C, 38.64; H, 2.49, found: C, 38.69;
H, 2.65.
4.1.2. 1,1,2,3,3-Pentafluoro-5-iodo-5-phenylpenta-1,
4-diene (2b)
1H NMR (300 MHz, CDCl3) d: 7.49–7.27 (m, 5H), 6.71
(t, J = 9.3 Hz, 0.75H), 6.50 (t, J = 10.5 Hz, 0.25H). 19F
NMR (282 MHz) d: À90.5 (m, 1.5F), À93.5 (m, 0.5F),
À94.4 (m, 1F), À106.4 (m, 1F), À185.4 (m, 1F). IR: 3062,
1787, 1631, 1348, 1299 cmÀ1. MS m/z: 360 (M+, 9), 233
(100), 213 (49), 133 (33), 102 (30). HRMS Calcd. for
C11H6F5I: 360.0649, found: 359.9415.
4.1.8. E-4,4,5,6,6-Pentafluoro-2-iodohexa-2,5-dienyl
acetate (2h)
1H NMR (300 MHz, CDCl3) d: 6.62 (t, J = 12.60 Hz,
1H), 4.84 (s, 2H), 2.15 (s, 3H). 19F NMR (282 MHz, CDCl3)

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S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
d: À92.7 to À92.6 (m, 2F), À92.9 to À92.7 (m, 1F), À105.9
to À105.4 (m, 1F), À187.2 to À186.7 (m, 1F). IR: 2980,
1784, 1750, 1347, 1292, 1218, 1163, 1041, 984 cmÀ1. MS
m/z: 229 (46), 131 (25), 119 (10), 43 (100). Anal. Calcd. for
C8H6F5IO2: C, 26.69; H, 1.69; F, 26.97, found: C, 26.97; H,
1.85; F, 26.86.
(m, 1F). IR: 3062, 3034, 1786, 1633, 1494, 1347,
1304 cmÀ1. MS m/z: 311 (M+ + 1, 4), 310 (M+, 22), 197
(100), 165 (36), 77 (44), 51 (56). HRMS. Calcd. for
C17H11F5: 310.2659, found: 310.0766.
4.2.3. 1,1,2,3,3-Pentafluoro-5-(4-methyphenyl)deca-1,4-
diene (4c)
4.1.9. Z-4,4,5,6,6-Pentafluoro-2-iodohexa-2,
1H NMR (300 MHz, CDCl3) d: 7.35–7.01 (m, 4H), 5.73
(t, J = 13.20 Hz, 1H), 2.62–2.59 (m, 2H), 2.38 (s, 1.4H), 2.36
(s, 0.6H), 1.35–1.26 (m, 4H), 0.9–0.79 (m, 6H). 19F NMR
(282 MHz) d: À88.3 (t, J = 22.84 Hz, 0.4F), À91.5 (m,
1.6F), À95.7 (m, 0.8F), À96.8 (m, 0.2F), À107.6 (m, 1F),
À183.4 (m, 0.8F), À185.4 (m, 0.8F). IR: 3030, 2961, 1784,
1646, 1468, 1376, 1344, 1293 cmÀ1. MS m/z: 318 (M+, 9),
262 (100), 247 (48), 211 (13), 91 (11). HRMS. Calcd. for
C17H19F5: 318.3291, found: 318.1421.
5-dienyl acetate (2h)
1H NMR (300 MHz, CDCl3) d: 6.60 (t, J = 12.60 Hz,
1H), 4.82 (s, 2H), 2.08 (s, 3H). 19F NMR (282 MHz, CDCl3)
d: À94.4 to À94.1 (m, 3F), À106.3 to À105.5 (m, 1F),
À186.6 to À185.9 (m, 1F). IR: 2988, 1785, 1751, 1653,
1430, 1347, 1296, 1213, 1161, 1048, 998 cmÀ1. MS m/z: 229
(46), 131 (25), 119 (10), 43 (100). Anal. Calcd. for
C8H6O2F5I: C, 26.69; H, 1.69, found: C, 26.97; H, 1.85.
4.1.10. 1,1,2,3,3-Pentafluoro-5-iodo-4-propylocta-1,
4-diene (2i)
4.2.4. 1,1,2,3,3-Pentafluoro-5-(4-methylphenyl)5-
phenylpenta–1,4-diene (4d)
1H NMR (300 MHz, CDCl3) d: 2.69 (t, J = 7.50 Hz, 1H),
2.62 (t, J = 7.8 Hz, 1H), 2.24–2.34 (m, 1H), 2.30–2.25 (m,
1H), 1.71–1.48 (m, 4H), 1.22–0.91 (m, 6H). 19F NMR
(282 MHz) d: À91.3 (m, 2F), À94.6 (m, 1F), À106.6 (m,
1F), À184.8 (m, 1F). IR: 2966, 1782, 1618, 1466, 1342,
1289 cmÀ1. MS m/z: 368 (M+, 24), 127 (24), 109 (100), 81
(55), 79 (41), 55 (63), 41 (82). Anal. Calcd. for C11H14F5I:
C, 35.89; H, 3.83, found: C, 35.61; H, 3.83.
1H NMR (300MHz, CDCl3) d: 7.35–7.11 (m, 9H), 6.18 (t,
J = 10.50 Hz, 1H), 2.36 (s, 0.8H), 2.32 (s, 2.2H). 19F NMR
(282 MHz) d: À87.1 (m, 2F), À95.8 (m, 1F), À107.1 (m,
1F), À183.1 (m, 1F). IR: 3029, 1680, 1609, 1494 cmÀ1. MS
m/z: 325 (M+ + 1, 9), 324 (M+, 46), 255 (100), 240 (55), 220
(45). HRMS. Calcd. for C18H13F5: 324.2927, found:
324.0950.
4.2.5. 1,1,2,3,3-Pentafluoro-5-pentyltrideca-1,4,6-triene
(4e)
4.2. General procedure for the cross-coupling of 2 with
with aryl boronic acid 3
Under nitrogen atmosphere, a mixture of 2a (0.5 mmol),
alkenyl boronic acid 3d (0.8 mmol), Pd(PPh3)4
(0.015 mmol), NaHCO3 (1.0 mmol) and toluene (2 mL)
was stirred at 80 8C for 14 h. Then ether (20 mL) was added
to the reaction mixture. The mixture was washed with water
and brine. After removal of the solvent, the residue was
purified by flash column chromatography (silica gel, eluting
with hexane) to give 4e. 1H NMR (300MHz, CDCl3) d: 6.39
(td, J = 12.6 Hz, 0.9 Hz, 2.25H), 6.25 (t, J = 10.56 Hz,
0.75H). 2.62–2.53 (m, 4H), 1.61–1.28 (m, 14H), 0.93–0.88
(m, 6H). 19F NMR (282MHz) d: À92.6 (m, 1.5F), À93.0 (m,
0.5F), À94.2 (m, 0.75F), À094.5 (m, 0.25F), À106.8 (m,
1F), À186.1 (m, 1F). IR: 2961, 2933, 1784, 1468,
1347 cmÀ1. MS m/z: 339 (M+ + 1, 2), 338 (M+, 11), 71
(72), 55 (91), 43 (100). HRMS. Calcd. for C18H27F5:
338.4033, found: 338.1987.
Under nitrogen atmosphere, a mixture of 2 (0.5 mmol),
aryl boronic acid 3 (0.8 mmol), PdCl2(PPh3)2 (0.015 mmol),
KF.2H2O (1.0 mmol) and toluene (2 mL) was stirred at
80 8C for 16 h. Then ether (20 mL) was added to the reaction
mixture. The mixture was washed with water and brine.
After removal of the solvent, the residue was purified by
flash column chromatography (silica gel, eluting with
hexane) to give 4.
4.2.1. 1,1,2,3,3-Pentafluoro-5-phenyldeca-1,4-diene (4a)
1H NMR (300 MHz, CDCl3) d: 7.36–7.12 (m, 5H), 5.73
(t, J = 13.5 Hz, 1H), 2.61 (d, J = 7.5 Hz, 1.6H), 2.38 (d,
J = 6.3 Hz, 0.4H), 1.62–1.17 (m, 6H), 0.89–0.8 (t,
J = 7.60 Hz, 3H). 19F NMR (282 MHz) d: À88.3 (m,
0.4F), À91.5 (m, 1.6F), À95.5 (m, 0.8F), À96.4 (m, 0.2F),
À107.3 (m, 1F), À183.0 (m, 1F). IR: 2962, 1784, 1646,
1344, 1293 cmÀ1. MS m/z: 305 (M+ + 1, 14), 248 (100), 197
(45), 179 (62), 159 (37), 115 (40), 77 (23). Anal. Calcd. For
C16H17F5: C, 63.15; H, 5.63, found: C, 62.99; H, 5.61.
4.2.6. 1,1,2,3,3-Pentafluoro-5-phenylundeca-1,4-diene (4f)
Under nitrogen atmosphere,
a mixture of E-2b
(0.5 mmol), alkyl boronic acid 3e (0.8 mmol), Pd(dppf)Cl2
(0.025 mmol), NaHCO3 (1.0 mmol), Ag2O (1.0 mmol) and
THF (2 mL) was stirred at 50 8C for 18 h. Then ether
(20 mL) was added to the reaction mixture. The mixture was
washed with water and brine. After removal of the solvent,
the residue was purified by flash column chromatography
(silica gel, eluting with hexane) to give 4f. 1H NMR
(300 MHz, CDCl3) d: 7.37–7.12 (m, 5H), 5.73 (t, J = 9.9 Hz,
4.2.2. 1,1,2,3,3-Pentafluoro-5,5-diphenylpenta-1,4-diene
(4b)
1H NMR (300 MHz, CDCl3) d: 7.65–6.24 (m, 10H), 6.27
(t, J = 10.50 Hz, 1H). 19F NMR (282 MHz) d: À87.6 (m,
2F), À95.8 (q, J = 35.80 Hz, 1F), À107.2 (m, 1F), À183.5

S.Q. Liu et al. / Journal of Fluorine Chemistry 126 (2005) 771–778
777
1H), 2.42 (d, J = 7.5 Hz, 2H), 1.42–1.32 (m, 4H), 0.90 (t,
J = 6.6 Hz, 3H). 19F NMR (282 MHz) d: À88.2 (m, 2F),
À96.3 (m, 1F), À107.4 (m, 1F), À183.2 (m, 1F). IR: 2962,
1784, 1646, 1344, 1293 cmÀ1. MS m/z: 291 (M+ + 1, 2), 290
(M+, 3), 248 (89), 177 (100), 57 (89). HRMS. Calcd. for
C15H15F5: 290.2755, found: 290.1111.
2225, 1784, 1630, 1468 cmÀ1. MS m/z: 322 (M+), 238 (38),
91 (42), 55 (87), 41 (100). HRMS. Calcd. for C17H23F5:
322.3607, found: 322.1672.
4.3.5. 1,1,2,3,3-Pentafluoro-5-phenylpentadeaca-1,
4-dien-6-yne (5e)
1H NMR (300 MHz, CDCl3) d: 7.36–7.25 (m, 5H), 6.12
(t, J = 10.8 Hz, 1H), 2.34 (t, J = 6.9 Hz, 2H), 1.56–1.27 (m,
12H), 0.88 (t, J = 6.3 Hz, 3H). 19F NMR (282 MHz) d:
À88.2 (m, 2F), À95.3 (m, 1F), À106.5 (m, 1F), À183.8 (m,
1F). IR: 2220, 1786, 1618, 1495 cmÀ1. MS m/z: 272 (100),
251 (59), 201 (91), 183 (53). HRMS. Calcd. for C21H23F5:
370.4047, found: 370.1695.
4.3. General procedure for the cross-coupling of 2 with
terminal alkyne 1
Under nitrogen atmosphere, a mixture of 2 (0.5 mmol),
alkyne
1 (0.8 mmol), Pd(PPh3)4 (0.015 mmol), CuI
(0.1 mmol) and Et3N (2 mL) was stirred at 50 8C for
16 h. After removal of the solvent in vacuo, the residue was
purified by flash column chromatography (silica gel, eluting
with hexane) to give 5.
4.3.6. 1,1,2,3,3-Pentafluoro-5-phenyldedeca-1,
4-dien-6-yne (5f)
1H NMR (300 MHz, CDCl3) d: 7.37 (t, J = 3.6 Hz, 5H),
6.14 (t, J = 11.1 Hz, 1H), 2.36 (t, J = 6.9 Hz, 2H), 1.59–1.32
(m, 6H), 0.89 (t, J = 6.9 Hz, 3H). 19F NMR (282 MHz) d:
À88.5 (m, 2F), À95.7 (m, 1F), À107.0 (m, 1F), À184.1 (m,
1F). IR: 3087, 2220, 1786, 1618, 1495 cmÀ1. MS m/z: 251
(39), 201 (59), 41 (100). HRMS. Calcd. for C18H17F5:
328.3243, found: 328.1278.
4.3.1. 5,5,6,7,7-Pentafluoro-3-pentyl-1-phenylhepta-3,
6-dien-1-yne (5a)
1H NMR (300 MHz, CDCl3) d: 7.49–7.27 (m, 5H), 6.26
(t, J = 10.8 Hz, 0.2H), 6.00 (t, J = 13.5 Hz, 0.8H), 2.38 (t,
J = 7.8 Hz, 2H), 1.69–1.28 (m, 6H), 0.92 (t, J = 5.7 Hz, 3H).
19F NMR (282 MHz) d: À92.7 (m, 1.6F), À93.5 (m, 0.4F),
À95.1 (m, 1F), À107.3 (m, 1F), À186.0 (m, 1F). IR: 1784,
1627, 1492 cmÀ1. MS m/z: 328 (M+, 6), 272 (97), 201 (100),
183 (87), 127 (84), 91 (50). HRMS. Calcd. for C18H17F5:
328.3243, found: 328.1210.
Acknowledgment
We thank the National Natural Science Foundation of
China, Ministry of Education of China and Shanghai
Municipal Scientific Committee for funding this work.
4.3.2. 6,6,7,8,8-Pentafluoro-4-pentyl-1-phenoxyocta-4,
7-dien-2-yne (5b)
1H NMR (300 MHz, CDCl3) d: 7.32–6.96 (m, 5H), 5.89
(t, J = 13.5 Hz, 1H), 4.83 (s, 2H), 2.34 (t, J = 3.6 Hz, 2H),
1.56–1.21 (m, 6H), 0.87 (t, J = 6.9 Hz, 3H). 19F NMR
(282 MHz) d: À92.8 (m, 2F), À94.5 (m, 1F), À106.8 (m,
1F), À185.8 (m, 1F). IR: 3067, 1784, 1633, 1496,
1346 cmÀ1. MS m/z: 358 (M+, 5), 302 (100), 94 (46), 77
(34), 55 (54). Anal. Calcd. for C19H19F5O: C: 63.68; H, 5.34,
found: C, 63.71; H, 5.33.
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