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Volumn 11, Issue 18, 2005, Pages 5419-5425

The barton reaction: Can a more tenable pathway be hypothesized for the formation of nitrosoalkyl derivatives?

Author keywords

Barton reaction; EPR spectroscopy; Radicals; Reaction mechanisms; Spin trapping

Indexed keywords

CONCENTRATION (PROCESS); DERIVATIVES; NITROGEN COMPOUNDS; PARAMAGNETIC RESONANCE; THERMODYNAMICS;

EID: 24644438635     PISSN: 09476539     EISSN: None     Source Type: Journal    
DOI: 10.1002/chem.200500079     Document Type: Article
Times cited : (9)

References (40)
  • 13
    • 84890282826 scopus 로고
    • (Eds.: J. N. Pitts, Jr., G. S. Hammond, W. A. Noyes, Jr.), Wiley-Interscience, New York
    • a) J. Heicklen in Advances in Photochemistry, Vol. 14 (Eds.: J. N. Pitts, Jr., G. S. Hammond, W. A. Noyes, Jr.), Wiley-Interscience, New York 1988, pp. 177-272;
    • (1988) Advances in Photochemistry , vol.14 , pp. 177-272
    • Heicklen, J.1
  • 23
    • 24644471362 scopus 로고    scopus 로고
    • note
    • A third radical species is evident in the spectrum; however, even though its structure could not be identified, the spectroscopic parameter would ascribe it to an alkyl alkoxy nitroxide-type.
  • 25
    • 24644497512 scopus 로고    scopus 로고
    • note
    • Actually, primary nitrosoalkyl compounds can tautomerize to the corresponding oximes, which easily donate an H atom to lead to an iminoxyl radical RCH=NO(̇), a persistent a radical detectable by EPR spectroscopy; whereas, no evidence of this species was obtained in any of the experiments in which primary nitrosoalkyls were involved.
  • 28
    • 33748407078 scopus 로고
    • Spin trapping
    • (Eds.: V. Gold, D. Bethell), Academic Press, London
    • c) M. J. Perkins in "Spin Trapping", Advances in Physical Organic Chemistry, Vol. 17 (Eds.: V. Gold, D. Bethell), Academic Press, London, 1980, pp. 1-64.
    • (1980) Advances in Physical Organic Chemistry , vol.17 , pp. 1-64
    • Perkins, M.J.1
  • 29
    • 24644476871 scopus 로고    scopus 로고
    • note
    • [15c] strongly stress that the fragmentation of tert-butoxy-tert-butyl nitroxides to give tert-butoxyl radicals is more rapid than that which gives tert-butyl radicals, by a factor of 100 (at 40°C).
  • 32
    • 24644524950 scopus 로고    scopus 로고
    • note
    • In ref. [17a], it is reported that "a second radical has spin density on a nitrogen atom of ∼ 25-30 G, and its EPR signal is predominant over that of the ordinary dialkyl nitroxide at temperature below -40 °C." In ref. [17b] it is reported that "the photolysis of the tBuONO in toluene would lead to the tert-butoxy benzyl nitroxide and dibenzyl nitroxide; but, at -40°C the alkoxy alkyl nitroxide is formed exclusively." Actually, it is interesting to note that these au thors had already noted the same behavior that we report, but could not account for it.
  • 37
    • 24644485886 scopus 로고    scopus 로고
    • note
    • 2N(Ȯ)-OtBu was detectable and to account for it, the intermediacy of the tBuONO has to be assumed.
  • 38
    • 24644523500 scopus 로고    scopus 로고
    • note
    • |21| of the intermediate 4-pentenyloxyl radical led us to the conclusion that the reverse reaction of Equation (35) is negligible, thus supporting an ultimate quantum yield of ≈ 1 for nitrite 16.
  • 39
    • 0001544986 scopus 로고
    • Wiley, New York
    • W. A. Noyes, Organic Syntheses, Vol. III, Wiley, New York, 1943, pp. 108-109.
    • (1943) Organic Syntheses , vol.3 , pp. 108-109
    • Noyes, W.A.1
  • 40
    • 24644449040 scopus 로고    scopus 로고
    • note
    • Hβ = 10.75 G) was also evident. This proves, once again, the efficiency of alkyl nitrite as a spin trap.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.