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Volumn 45, Issue 46, 2006, Pages 7832-7835

Cooperative coexistence: Effective interplay of two Brønsted acids in the asymmetric synthesis of isoquinuclidines

Author keywords

Asymmetric synthesis; Ion pairs; Isoquinuclidines; Mannich bases; Michael addition

Indexed keywords

CHEMICAL ACTIVATION; NITROGEN COMPOUNDS; REACTION KINETICS; STEREOCHEMISTRY; SYNTHESIS (CHEMICAL);

EID: 33845329553     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200603199     Document Type: Article
Times cited : (174)

References (56)
  • 41
    • 33845323343 scopus 로고    scopus 로고
    • (Ed.: G. A. Cordell), Academic Press
    • R. J. Sundberg, S. Q. Smith in The Alkaloids, Vol. 59 (Ed.: G. A. Cordell), Academic Press, 2002, p. 261.
    • (2002) The Alkaloids , vol.59 , pp. 261
    • Sundberg, R.J.1    Smith, S.Q.2
  • 45
    • 0032546063 scopus 로고    scopus 로고
    • Isoquinuclidines have been obtained as products in Lewis acid catalyzed reactions and as a by-product in the Lewis base catalyzed Baylis-Hillman reaction of cyclohexenone with aldimines: a) G. Babu, P. T. Perumal, Tetrahedron 1998, 54, 1627;
    • (1998) Tetrahedron , vol.54 , pp. 1627
    • Babu, G.1    Perumal, P.T.2
  • 49
    • 33845321350 scopus 로고    scopus 로고
    • note
    • A small shift of the keto-enol equilibrium is sufficient for a reaction, as the formed dienol will be extracted directly from the equilibrium. Other cyclic enones such as cyclopentenone showed no reactivity under these conditions.
  • 50
    • 33845284475 scopus 로고    scopus 로고
    • note
    • A large number of chiral Brønsted acids were tested. Table 1 shows only the general trend of reactivity.
  • 51
    • 33845340440 scopus 로고    scopus 로고
    • note
    • The use of other binol phosphates, other chlorinated and aromatic solvents, aliphatic aldimines, as well as the variation of catalyst loading and enone concentration resulted in inferior enantioselectivities.
  • 52
    • 33845319734 scopus 로고    scopus 로고
    • note
    • The X-ray crystal structure of the exo product is shown in the Supporting Information.
  • 56
    • 33845298239 scopus 로고    scopus 로고
    • note
    • The rate-determining step of the reaction is presumably the dienol formation, as no considerable conversion was observed without the addition of Brønsted acid 2.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.