4208
Y.-J. Chen, J.-Y. Shen / Tetrahedron Letters 46 (2005) 4205–4208
Synthesis 1998, 1238; (m) Fraile, J. M.; Garcia, J. I.; of viscous solid, which was unsuccessful to be purified, but
1
could be studied by NMR method directly. F NMR
9
Lazaro, B.; Mayoral, J. A. Chem. Commun. 1998, 1807; (n)
Firouzabadi, H.; Iranpoor, N.; Zolfigol, M. A. Synth.
Commun. 1998, 28, 1179; (o) Hirano, M.; Yakabe, S.; Itoh,
S.; Clark, J. H.; Moromoto, T. Synthesis 1997, 1161; (p)
Lupattelli, P.; Ruzziconi, R.; Scafato, P.; DeglꢀInnocenti,
A. D.; Paolobelli, A. B. Synth. Commun. 1997, 27, 441; (q)
Khurana, J. M.; Panda, A. K.; Gogia, A. Org. Prep.
Proced. Int. 1996, 28, 234; (r) Orito, K.; Hatakeyama, T.;
Take, M.; Suginome, H. Synthesis 1995, 1357; (s) Breton,
G. W.; Fields, J. D.; Kropp, P. J. Tetrahedron Lett. 1995,
(400 MHz, CD OD) spectrum of this mixture shows two
3
peaks appeared at d À152.48 and À152.54 ppm. Among
them, one appeared at d À152.54 ppm is assigned to be as
4
the signal of KBF compared with that for an authentic
sample (À152.56 ppm), while the other one appeared at d
À152.48 ppm is still remained unclear. On the other hand,
1
1
3
B NMR (400 MHz, CD CN) spectrum of the above
viscous mixture appears only one new peak at
d
À0.376 ppm, which might be appropriate to be assigned
36, 3825; (t) Hirano, M.; Kudo, H.; Morimoto, T. Bull.
as the signal of tetrafluorodiboronperoxide, while the
Chem. Soc. Jpn. 1994, 67, 1492; (u) Folsom, H. E.;
Castrillon, J. Synth. Commun. 1992, 22, 1799.
signal of BF
noted that the signal of KBF was not observed probably
3
Æ OEt appears at d À0.613 ppm. It should be
4
4
. Halliwell, B.; Gutteridge, J. M. C. Free Radicals in Biology
and Medicine; Clarendon Press: Oxford, 1989, pp 136–179.
. (a) Kim, Y. H.; Jung, J. C.; Choi, H. C.; Yang, S. G. Pure
Appl. Chem. 1999, 71, 377; (b) Primer, A. A. In The
Chemistry of Funtional Groups, Peroxides; Patai, S.,
Rappoport, Z., Stirling, C., Eds.; John Wiley & Sons
Ltd: Chichester, 1983, Chapter 14; (c) Sawyer, D. T.;
Valentine, J. S. Acc. Chem. Res. 1981, 14, 393.
due to its low solubility in acetonitrile. According to our
results from this study, a low concentration of tetrafluoro-
diboronperoxide solution in acetonitrile (ꢀ0.12 M)
formed in situ could be handled with safety and perform
the reasonable stability and reactivity for use in the course
of reaction studied under nitrogen at 0–4 ꢁC. However,
much more works for the identification of tetrafluoro-
diboronperoxide existing in the course of reaction are still
needed.
5
6
. Ortiz de Montellano, P. R.; Kunze, K. L. J. Am. Chem.
Soc. 1980, 102, 7373.
11. Sauka, J.; Martinsons, V.; Bruners, V. Chem. Abstr. 1969,
71, 45273, BF3 reacts with KO2 at the temperature of
7
. (a) Kim, Y. H.. In Organic Peroxides; Ando, W., Ed.;
John Wiley & Sons Ltd, 1992, Chapter 8; (b) Lim, S. C.;
Kim, Y. H. Heteroat. Chem. 1990, 1, 261; (c) Kim, Y. H.;
Yoon, D. C. Synth. Commun. 1989, 19, 1569; (d) Lee, H.
K.; Kim, Y. H. Sulfur Lett. 1987, 7, 1.
liquid N
approximately, corresponds to 3KO
BF vapor reacts with KO to form KBF
4
2
to form a very unstable product, which,
Æ BF . At 160 ꢁC,
and O.
2
3
3
2
12. Holliday, A. K.; Taylor, F. B. J. Chem. Soc. 1962, 2767.
13. (a) The Chemistry of Sulfones and Sulfoxides; Patai, S.,
Rappoport, Z., Stirling, C., Eds.; John Wiley & Sons Ltd:
Chichester, 1988; (b) Uemura, S. In Comprehensive
Organic Synthesis; Trost, B. M., Fleming, I., Eds.;
Academic Press: Oxford, 1991; Vol. 7, pp 757–787; (c)
Hudlicky, M. Oxidation in Organic Chemistry; American
Chemical Society: Washington, DC, 1990, pp 252–263; (d)
Hajipour, A. R.; Mallakpour, S. E.; Adibi, H. J. Org.
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D.; Akamanchi, K. G. J. Org. Chem. 2003, 68, 5422; (f)
Shaabani, A.; Bazgir, A.; Soleimani, K.; Salehi, P. Synth.
Commun. 2003, 33, 2935.
8
. Chen, Y. J.; Huang, Y. P. Tetrahedron Lett. 2000, 41,
5233.
9
. Potassium superoxide is a commercially available inor-
ganic salt. It, generally acted as an oxidizer, is corrosive
and moisture sensitive. Manipulation of this salt must be
very careful without contacting with skin directly.
Although potassium superoxide is generally insoluble in
aprotic organic solvents, it is slightly soluble in those of
higher polar aprotic solvents such as DMSO and
acetonitrile.
1
0. Tetrafluorodiboronperoxide can be formed from the
reaction of potassium superoxide with boron trifluoride
in acetonitrile at ice-water bath. After evaporated under
reduced pressure, the reaction solution afforded a mixture
14. Adam, W.; Hass, W.; Sieker, G. J. Am. Chem. Soc. 1984,
106, 5020.