Generation of (alkꢀ1ꢀynyl)halocarbenes
Russ.Chem.Bull., Int.Ed., Vol. 51, No. 7, July, 2002
1253
J = 7 Hz, J = 6.5 Hz); 6.11 (d, 1 H, CHCCl3, J = 15.5 Hz);
6.27 (dt, 1 H, CH2CH=, J = 15.5 Hz, J = 7.2 Hz).
1ꢀBromoꢀ1ꢀfluoroheptꢀ2ꢀyne (27). 1H NMR, δ: 0.92 (t, 3 H,
CH3 in Bu, J = 7 Hz); 1.20—1.60 (m, 4 H, 2 CH2); 2.20—2.45
(m, 2 H, CH2C≡); 6.77 (dt, 1 H, —CHFBr, JH,F = 52 Hz, J =
1.7 Hz). 19F NMR, δ (CFCl3): –121.5 (d, —CHFBr, J =
52 Hz). MS, m/z: 113 [M – Br]+.
Reaction of 1,1,3ꢀtribromoꢀ1ꢀfluoroheptane (1b) with ButOK:
identification of intermediate products. Potassium tertꢀbutoxide
(158 mg, 1.41 mmol) was added at ∼20 °C to a solution of
tetrahalide 1b (500 mg, 1.41 mmol) in 5 mL of hexane. The
reaction mixture was stirred for 15 min and then treated with
water. The organic layer was separated, and the organic mateꢀ
rial was extracted from the aqueous phase with ether (3×10 mL).
The combined organic layers were dried with magnesium sulꢀ
fate, and the solvent was evaporated. The residue contained a
mixture of the starting compound 1b, transꢀ1,1ꢀdibromoꢀ1ꢀ
fluoroheptꢀ2ꢀene (24), and isomeric Eꢀ and Zꢀ1,3ꢀdibromoꢀ1ꢀ
fluoroheptꢀ1ꢀenes (25) in the 1 : 1.8 : 0.9 : 0.75 ratio (GLC and
NMR data). The total yield was 340 mg.
This work was financially supported by the Russian
Foundation for Basic Research (Project Nos. 01ꢀ03ꢀ32674
and 00ꢀ15ꢀ97387).
References
1. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov, Izv.
Akad. Nauk, Ser. Khim., 1998, 1185 [Russ. Chem. Bull.,
1998, 47, 1154 (Engl. Transl.)].
2. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov,
Mendeleev Commun., 1997, 144.
3. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov, Izv.
Akad. Nauk, Ser. Khim., 1997, 2079 [Russ. Chem. Bull.,
1997, 46, 1973 (Engl. Transl.)].
4. K. N. Shavrin, V. D. Gvozdev, and O. M. Nefedov, Izv.
Akad. Nauk, Ser. Khim., 1992, 1128 [Bull. Russ. Acad. Sci.,
Div. Chem. Sci., 1992, 41, 885 (Engl. Transl.)].
5. K. N. Shavrin, I. V. Krylova, I. B. Shvedova, G. P.
Okonnishnikova, I. E. Dolgy, and O. M. Nefedov, J. Chem.
Soc., Perkin Trans. 2, 1991, 1875.
6. K. N. Shavrin, I. B. Shvedova, and O. M. Nefedov, Izv.
Akad. Nauk SSSR, Ser. Khim., 1991, 2559 [Bull. Acad. Sci.
USSR, Div. Chem. Sci., 1991, 40, 2235 (Engl. Transl.)].
7. M. S. Kharash, O. Reinmuth, and W. H. Urry, J. Am.
Chem. Soc., 1947, 69, 1105.
Compound 24. 1H NMR, δ: 0.88 (t, 3 H, CH3 in Bu,
J = 7 Hz); 1.20—1.55 (m, 4 H, 2 CH2); 2.06 (dt, 2 H,
—CH2CH=, J = 7 Hz, J = 6.5 Hz); 5.85—6.15 (m, 2 H,
—CH=CH—). 19F NMR, δ (CFCl3): –51.8 (d, CFBr2, J =
16.6 Hz). MS, m/z: 193, 195 [M – Br]+.
Compound Eꢀ25. 1H NMR, δ: 0.88 (t, 3 H, CH3 in Bu,
J = 7 Hz); 1.20—2.00 (m, 6 H, 3 CH2); 4.72 (dt, 1 H, CHBr,
J = 11.1 Hz, J = 7.2 Hz); 5.31 (dd, 1 H, CH=CFBr, J =
11.1 Hz, JH,F = 27.9 Hz). 19F NMR, δ (CFCl3): –69.2 (d,
=CFBr, J = 27.9 Hz). MS, m/z: 193, 195 [M – Br]+.
Compound Zꢀ25. 1H NMR, δ: 0.88 (t, 3 H, CH3 in Bu,
J = 7 Hz); 1.20—2.00 (m, 6 H, 3 CH2); 4.48 (dtd, 1 H, CHBr,
J = 10.9 Hz, J = 7.1 Hz, JH,F = 2.5 Hz); 5.71 (dd, 1 H,
CH=CFBr, J = 10.9 Hz, JH,F = 10.9 Hz). 19F NMR, δ (CFCl3):
–68.3 (dd, =CFBr, J = 10.9 Hz, J = 2.5 Hz). MS, m/z: 193,
195 [M – Br]+.
The mixture of the halides obtained (340 mg) was dissolved
in 5 mL of hexane, and ButOK (120 mg, 1.07 mmol) was added
at ∼20 °C. After 30 min, the starting tetrahalide 1b was comꢀ
pletely consumed (GLC data), and the reaction gave, along
with trihalides 24 and 25, two new products identified as
dihalides 26 and 27 in 12 and 5% yields, respectively. After
60 min, the reaction mixture contained transꢀ24 (45%), the
Eꢀisomer of 25 (25%), the Zꢀisomer of 25 (3%), allene 26
(15%), and alkyne 27 (5.5%) (GLC data). When the mixture
reacted with ButOK for 90 min, the relative content of prodꢀ
ucts 26 and 27 decreased to 12 and 5%, respectively. The reacꢀ
tion mixture was treated with water. The organic layer was
separated, and the organic material was extracted from the
aqueous phase with ether (3×10 mL). The combined organic
layers were dried with magnesium sulfate, and the solvent was
evaporated in vacuo at a bath temperature of no higher than
40 °C. The residue (164 mg) was analyzed by NMR spectrosꢀ
copy and GLꢀMS spectrometry.
8. M. Asscher and D. Vosfi, J. Chem. Soc., 1963, 1887.
9. H. Günther, NMR Spectroscopy, an Introduction, J. Wiley
and Sons, Chichester—New York—Brisbane—Toronꢀ
to, 1972.
10. Matsui Kiyohide, Negishi Akira, Takahatake Yuriko,
Sugimoto Kikuo, Fujimoto Tamotsu, Takashima Toshiyuki,
and Kondo Kiyosi, Bull. Chem. Soc. Jpn., 1986, 59, 221.
11. R. A. Moss, Acc. Chem. Res., 1980, 13, 58.
12. H. D. Harzler, J. Am. Chem. Soc., 1961, 83, 4990.
13. P. J. Stang, in Methoden der organischen Chemie (Houbenꢀ
Weyl), Stuttgart, Georg Thieme, 1989, B. E19b, Teil 1, 138.
14. A. Roedig, in Methoden der organischen Chemie (Houbenꢀ
Weyl), Stuttgart, Georg Thieme, 1960, B. V/4, 773.
15. J. M. Birchall and R. N. Hasseldine, J. Chem. Soc., 1956, 16.
16. G. Lehnmann, J. Prakt. Chem., 1963, 22, 230.
17. A. J. Gordon and R. A. Ford, The Chemist´s Companion,
J. Wiley and Sons, New York—London—Sydney—Toronꢀ
to, 1972.
1ꢀBromoꢀ1ꢀfluoroheptaꢀ1,2ꢀdiene (26). 1H NMR, δ: 0.92
(t, 3 H, CH3 in Bu, J = 7 Hz); 1.20—1.60 (m, 4 H, 2 CH2);
2.20—2.45 (m, 2 H, CH2CH=); 5.97 (dt, 1 H, —CH=, J =
6.5 Hz, JH,F = 1.6 Hz). 19F NMR, δ (CFCl3): –95.4 (d, =CFBr,
J = 1.6 Hz). MS, m/z: 150, 152 [M – C3H6]+.
Received December 21, 2001;
in revised form March 14, 2002