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Volumn , Issue 9, 2000, Pages 1961-1968

Fragmentation of methyl hydrogen α-hydroxyiminobenzyl-phosphonates-kinetics, mechanism and the question of metaphosphate formation

Author keywords

[No Author keywords available]

Indexed keywords

ACIDITY; CHEMICAL ACTIVATION; COMPOSITION EFFECTS; DISSOCIATION; ESTERS; NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY; NUMERICAL ANALYSIS; PH EFFECTS; REACTION KINETICS; SOLVENTS; THERMODYNAMIC PROPERTIES; ULTRAVIOLET SPECTROSCOPY;

EID: 0034286430     PISSN: 03009580     EISSN: None     Source Type: Journal    
DOI: 10.1039/b002267p     Document Type: Article
Times cited : (7)

References (69)
  • 15
    • 0010781187 scopus 로고
    • eds. A. Streitwieser and R. W. Taft, Jr., John Wiley & Sons., New York
    • (b) E. H. Cordes, in Progress in Physical Organic Chemistry, Vol. 4, eds. A. Streitwieser and R. W. Taft, Jr., John Wiley & Sons., New York, 1967, p. 14.
    • (1967) Progress in Physical Organic Chemistry , vol.4 , pp. 14
    • Cordes, E.H.1
  • 16
    • 0010785005 scopus 로고    scopus 로고
    • note
    • a2 = 10.94) at pH = 9.23. No effect on the fragmentation was observed.
  • 17
    • 0010777064 scopus 로고    scopus 로고
    • note
    • 1b. Assuming a similar ratio for 1a we can conclude that, with specific acid catalysis in methanol, the fragmentation of (E)-1a is 14 times faster than its isomerization.
  • 24
    • 0010778859 scopus 로고    scopus 로고
    • In phosphorus chemistry, developments in american science
    • eds. E. N. Walsh, E. J. Griffith, R. P. Parry and L. D. Quin; ch. 8
    • (b) W. P. Jencks, in Phosphorus Chemistry, Developments in American Science, eds. E. N. Walsh, E. J. Griffith, R. W. Parry and L. D. Quin, ACS Symposium Series, 1991, 486, ch. 8 p. 103.
    • ACS Symposium Series, 1991 , vol.486 , pp. 103
    • Jencks, W.P.1
  • 30
  • 57
    • 85087242289 scopus 로고    scopus 로고
    • note
    • -1 at 50°C.
  • 58
    • 85087243466 scopus 로고    scopus 로고
    • note
    • 2.
  • 59
    • 0010854309 scopus 로고    scopus 로고
    • note
    • In contrast, the fragmentation is not blocked for the unionizable alkyl hydroxyiminophosphonamidates, in which, presumably, back-donation from N to P supplies electrons for C-P bond cleavage. This paper reports that methyl α-hydroxyiminobenzyl-N-tert-butylphosphonamidate underwent Beckmann rearrangement when refluxed in toluene, but fragmentation to a phosphoramidate when refluxed in a high boiling alcohol, e.g. butan-1-ol or pentan-3-ol. Fragmentation carried out in a 1 : 1 mixture of the two alcohols gave the two products in a 65:35 molar ratio, resulting in the selectivity value of ≈ 0.54 (consistent with the value of 0.46-0.66 found in the present work for pentan-3-ol, while assuming a selectivity value of 1 for 1-BuOH), thus compatible with a metaphosphoramidate intermediate. These and other results reported in this paper were interpreted in terms of similar transition states for the rearrangement and the fragmentation.
  • 65
    • 0002725547 scopus 로고
    • Other recent references to reviews of the Beckmann reactions are cited in ref. 32
    • R. E. Gawley, Org. React., 1988, 35, 1. Other recent references to reviews of the Beckmann reactions are cited in ref. 32.
    • (1988) Org. React. , vol.35 , pp. 1
    • Gawley, R.E.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.