Copper salt-catalysed reaction of perfluoroalkyl halides with olefins

Article abstract of DOI:10.1070/MC2006v016n03ABEH002344

Perfluoroalkyl halides react with olefins in the presence of copper acetate and hydrazine to give 1,2-addition products.

Full text of DOI:10.1070/MC2006v016n03ABEH002344

Mendeleev
Communications
Mendeleev Commun., 2006, 16(3), 189–190
Copper salt-catalysed reaction of perfluoroalkyl halides with olefins
Sergei M. Igumnov,* Veronika L. Don, Vladimir A. Vyazkov and Karen E. Narinyan
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
Fax: +7 495 135 6509; e-mail: igumnov@fluorine.ru
DOI: 10.1070/MC2006v016n03ABEH002344
Perfluoroalkyl halides react with olefins in the presence of copper acetate and hydrazine to give 1,2-addition products.
The adducts of perfluoroalkyl halides and unsaturated com-
pounds have considerable commercial importance.1 They have
been used in the synthesis of fluorinated alcohols,2 unsaturated
compounds,3 sulfonates, thiols etc.4
viously.12 This system initiates the free radical chain addition of
perfluoroalkyl iodides to unsaturated compounds under mild
conditions (at 20–30 °C) with good yields of adducts.
Here, we present the application of this initiator to the syn-
thesis of a large number of perfluoroalkylated compounds. As
shown in Scheme 1,† the reaction of perfluoroalkyl halides 1a–g
with ethylene was carried out in an autoclave at 30 °C; addition
products 2a–g were formed in 40–80% yields.
Free radical chain additions of perfluoroalkyl iodides to
unsaturated compounds have been widely applied in the syn-
thesis of perfluoroalkyl-substituted compounds.1 Initiation of
such reactions can be induced by UV radiation or heating above
200 °C.5,6 Initiation has also been carried out using peroxides,7
azonitriles,7(g),8 or redox systems.9 The addition mechanism has
been described by Harash et al.10 However, initiation by UV
radiation or heating generally leads to low yields of products,5,6
whereas the use of azo initiators can give rise to highly toxic
decomposition products.11 The use of peroxides can result in
uncontrolled process with rapid decomposition of materials.7(b)
Thus, a more satisfactory redox initiating system involving
the use of copper acetate/hydrazine hydrate was developed pre-
RfX + CH2=CH2
RfCH2CH2X
1a–g
2a–g
a Rf = C2F5, X = I
e Rf = BrCF2, X = Br
f Rf = CF3CF2CF(CF3), X = I
g Rf = CF3(CF2)7, X = I
b Rf = C3F7, X = I
c Rf = BrCF2CF2, X = Br
d Rf = BrCF2CFCl, X = Br
Scheme 1 Reaction of perfluoroalkyl halides with ethylene.
Mendeleev Commun. 2006 189

Mendeleev Commun., 2006, 16(3), 189–190
References
RfX + CH2=CHY
1d,h,i 3a–c
RfCH2CHXY
1
2
3
4
N. O. Brace, J. Fluorine Chem., 1999, 93, 1.
4a–e
T. Hayashi and M. Matsuo, U.S. Patent 4 001 309, January, 1997
G. Santini, M. leBlanc and J. G. Riers, Tetrahedron, 1973, 29, 2411.
(a) W. R. Dolbier Jr., Chem. Rev., 1996, 96, 1567; (b) G. Van Dyke
Tiers, J. Org. Chem., 1962, 27, 2261.
1d Rf = BrCF2CFCl, X = Br
1h Rf = ClCF2CFCl, X = Br
1i Rf = BrCF2CF2, X = I
3a Y = Bu
3b Y = Me(CH2)5
3c Y = CH2OH
5
(a) L. D. Park, F. E. Rogers and J. R. Lancher, J. Org. Chem., 1961, 26,
2089; (b) L. D. Moore, J. Chem. Eng./Date 1964, 251.
N. O. Brace, J. Fluorine Chem., 1993, 62, 217.
(a) N. O. Brace, J. Fluorine Chem., 1995, 70, 145; (b) C. G. Overberger
M. T. O’Shaughnessy and H. Shalit, J. Am. Chem. Soc., 1949, 71,
2661; (c) R. N. Haszeldine, J. Chem. Soc. (London), 1949, 2856;
(d) N. Haszeldine, J. Chem. Soc. (London), 1952, 2504; (e) R. N.
Haszeldine and B. R. Steele, J. Chem. Soc. (London), 1953, 1199;
(f) R. N. Haszeldine, J. Chem. Soc. (London), 1954, 1923; (g) R. N.
Haszeldine, J. Chem. Soc. (London), 1957, 2193.
4a Rf = BrCF2CFCl, X = Br, Y = Bu
4b Rf = BrCF2CFCl, X = Br, Y = Me(CH2)5
4c Rf = BrCF2CFCl, X = Br, Y = CH2OH
4d Rf = ClCF2CFCl, X = Br, Y = CH2OH
4e Rf = BrCF2CF2, X = I, Y = CH2OH
6
7
Scheme 2 Reactions of perfluoroalkyl halides with olefins.
Reactions of perfluoroalkyl halides 1d,h,i with hex-1-ene,
oct-1-ene, and allyl alcohol were carried out at atmospheric
pressure (Scheme 2);‡ adducts 4 were obtained in good yields.
8
9
(a) R. N. Haszeldine, J. Chem. Soc. (London), 1957, 2800; (b) N. O. Brace,
J. Org. Chem., 1962, 27, 4491; (c) N. O. Brace, J. Org. Chem., 1963,
28, 3093.
R. Takeyama, Y. Jchinose, K. Oshima and K. Unimoto, Tetrahedron
Lett., 1989, 30, 3159.
All products were characterised by H and 19F NMR spectro-
1
scopy, and the purity was confirmed by GLC analysis.
Thus, a simple and highly effective procedure was developed
for the reaction of perfluoroalkyl halides and olefins to form
perfluoroalkyl-substituted haloalkanes.
10 M. S. Kharasch, E. V. Jensen and W. H. Urry, Science, 1945, 102, 128.
11 W. A. Pryor, Free Radicals, McGraw–Hill, New York, 1966, ch. 10.
12 The 2nd International Conference ‘CTAF 97’, St. Peterburg, Russia,
September 23–26, 1997, pp. 2–35.
†
General procedure for the preparation of products 2a–g. A stirred
steel autoclave with a needle valve was charged with isopropanol,
perfluoroalkyl halides 1a–g, copper acetate hydrate and hydrazine
hydrate, and the autoclave was closed. After cooling with liquid nitrogen,
the autoclave was charged with ethylene to an appropriate pressure,
and the reaction mixture was stirred for 4–6 h at 30 °C. Residual gas
from the autoclave was trapped into a trap cooled to –70 °C, and the
liquid products were poured into an equal volume of cold aqueous
5% HCl. The lower layer was isolated, washed with water, dried with
MgSO4 and distilled. The products, reaction conditions (quantity of
perfluoroalkyl halides, copper acetate, hydrazine hydrate; volume of iso-
propanol, ethylene pressure, autoclave volume and reaction time); yield
of the product, conversion and bp of the products are given below.
2a: (4.47 mol, 0.63 mol, 4.48 mol, 600 ml, 30 atm, 2 dm3, 4 h), 69%,
100%, 100 °C.
Received: 22nd February 2006; Com. 06/2687
‡
General procedure for the preparation of 4a–e. A flask equipped
with a stirrer, a thermometer, a dropping funnel and a reflux condenser
was charged with isopropanol and a perfluoroalkyl halide (1d,h,i). Olefin
(3a–c) and copper acetate monohydrate were added and hydrazine was
carefully added with heat evolved. Then the mixture was stirred for 3–8 h
at 20 °C and kept overnight. The reaction mixture was then poured into
aqueous HCl; the lower layer was isolated, washed with water, dried with
MgSO4 and distilled. The products, reaction conditions (flask volume,
volume of isopropanol, quantity of perfluoroalkyl halide, olefins, copper
acetate monohydrate and hydrazine hydrate), yield of the product, con-
version and bp are given below.
2b: (0.51 mol, 0.07 mol, 0.51 mol, 75 ml, 15 atm, 0.5 dm3, 6 h), 70%,
60%, 118 °C.
2c: (1.15 mol, 0.16 mol, 1.16 mol, 25 atm, 1 dm3, 6 h), 70%, 50%,
145 °C.
4a: (4 dm3, 1.5 dm3, 5.43 mol, 5 mol, 0.8 mol, 5.39 mol), 82%, 100%,
130–132 °C (20 Torr).
2d: (2.9 mol, 0.41 mol, 2.9 mol, 400 ml, 30 atm, 2 dm3, 4 h), 39%,
100%, 163–165 °C.
4b: (4 dm3, 675 ml, 2.44 mol, 2.23 mol, 0.38 mol, 2.65 mol), 75%,
100%, 125–130 °C (12 Torr).
2e: (1.43 mol, 0.19 mol, 1.44 mol, 150 ml, 30 atm, 1 dm3, 6 h), 70%,
40%, 122–123 °C.
4c: (2 dm3, 1.45 mole, 1.52 mol, 0.18 mol, 1.46 mol), 73%, 53%,
135–138 °C (17 Torr).
2f: (0.43 mol, 0.06 mol, 0.44 mol, 35 atm, 0.5 dm3, 6 h), 81%, 100%,
130 °C.
4d: (2 dm3, 800 ml, 2.41 mol, 3.01 mol, 0.37 mol, 2.88 mol), 69%,
100%, 132–135 °C (12 Torr).
2g: (2.2 mol, 0.33 mol, 2.2 mol, 35 atm, 2 dm3, 6 h), 80%, 100%,
97 °C (14 Torr).
4e: (2 dm3, 700 ml, 2.2 mol, 2.9 mol, 0.3 mol, 2.3 mol), 68%, 100%,
123 °C (18 Torr).
190 Mendeleev Commun. 2006