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Volumn 128, Issue 26, 2006, Pages 8671-8677

Nucleophilic additions of trimethylsilyl cyanide to cyclic oxocarbenium ions: Evidence for the loss of stereoselectivity at the limits of diffusion control

Author keywords

[No Author keywords available]

Indexed keywords

DIFFUSION; RATE CONSTANTS; SUBSTITUTION REACTIONS;

EID: 33745714287     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja061110u     Document Type: Article
Times cited : (54)

References (80)
  • 16
    • 33745707996 scopus 로고    scopus 로고
    • note
    • The numbering used in this paper considers the carbocationic carbon as C-1
  • 17
    • 0029838260 scopus 로고    scopus 로고
    • For examples of other nonstereoselective additions of trimethylsilylcyanide to oxocarbenium ions, see: (a) Rychnovsky, S. D.; Dahanukar, V. H. J. Org. Chem. 1996, 61, 7648-7649.
    • (1996) J. Org. Chem. , vol.61 , pp. 7648-7649
    • Rychnovsky, S.D.1    Dahanukar, V.H.2
  • 23
    • 33745722116 scopus 로고    scopus 로고
    • note
    • A similar situation can also arise if nucleophilic addition to one diastereotopic face of a cationic intermediate proceeds at the diffusion control rate, whereas addition to the other face does not.
  • 27
    • 0345114077 scopus 로고
    • The reactivity of ambident nucleophiles has traditionally been rationalized on the basis of the hard-soft acid-base principle: (a) Pearson, R. G. J. Am. Chem. Soc. 1963, 85, 3533-3539.
    • (1963) J. Am. Chem. Soc. , vol.85 , pp. 3533-3539
    • Pearson, R.G.1
  • 29
    • 33847089332 scopus 로고
    • For examples of the loss of selectivity in the addition reactions of nucleophiles to highly reactive cationic intermediates at the rates of diffusion in aqueous media, see: (a) Young, P. R.; Jencks, W. P. J. Am. Chem. Soc. 1977, 99, 8238-8248.
    • (1977) J. Am. Chem. Soc. , vol.99 , pp. 8238-8248
    • Young, P.R.1    Jencks, W.P.2
  • 44
    • 33745707994 scopus 로고    scopus 로고
    • note
    • 1H NMR spectrum of the unpurified reaction mixture. Product diastereoselectivities were determined by GC analysis of the unpurified reaction mixture.
  • 45
    • 33745707993 scopus 로고    scopus 로고
    • note
    • The diastereoselectivities of nucleophilic substitutions obtained from the competition experiments were identical to those obtained from the individual reactions.
  • 63
    • 33745707990 scopus 로고    scopus 로고
    • note
    • 3SiCN by itself is not the nucleophile.
  • 64
    • 33745693831 scopus 로고    scopus 로고
    • note
    • 3SiNC serving as the nucleophile.
  • 69
    • 33748227722 scopus 로고
    • 3SiCN with oxocarbenium ions involves the initial formation of an isonitrile, which can be converted to the nitrile through a subsequent isomerization. Although the interconversion between alkyl isocyanides and alkyl cyanides has been reported, this process requires high temperatures. See, for example: (a) Rüchardt, C.; Meier, M.; Haaf, K.; Pakusch, J.; Wolber, E. K. A.; Müller, B. Angew. Chem., Int. Ed. Engl. 1991, 30, 893-901.
    • (1991) Angew. Chem., Int. Ed. Engl. , vol.30 , pp. 893-901
    • Rüchardt, C.1    Meier, M.2    Haaf, K.3    Pakusch, J.4    Wolber, E.K.A.5    Müller, B.6
  • 80
    • 33745722109 scopus 로고    scopus 로고
    • note
    • 4NCN gave the cleanest reactions.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.