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Volumn 71, Issue 8, 2006, Pages 2982-2986

Cooperative and competitive effects of substituents at C1 and C4 on the barriers to ring inversion of 5,5-difluorobicyclo[2.1.0]pentanes

Author keywords

[No Author keywords available]

Indexed keywords

FLUORINE; MOLECULAR STRUCTURE; PARAFFINS;

EID: 33645766260     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo052538z     Document Type: Article
Times cited : (9)

References (31)
  • 7
    • 33645791234 scopus 로고    scopus 로고
    • note
    • The experiments were actually performed on 3,3-difluoro-2,4-diphenyl- bicyclo[3,3,0]octan-2,4,-diyl. Subsequent experiments showed 3,3-dialkoxy derivatives of this diyl also have singlet ground states.
  • 14
    • 33645760670 scopus 로고    scopus 로고
    • in press. We thank Professor Lemal for informing us of his results and providing us with a preprint of his manuscript
    • Wei, Y.; Liu, Y.; Wong, T.; Lemal, D. M. J. Fluorine Chem., in press. We thank Professor Lemal for informing us of his results and providing us with a preprint of his manuscript.
    • J. Fluorine Chem.
    • Wei, Y.1    Liu, Y.2    Wong, T.3    Lemal, D.M.4
  • 15
    • 0346731129 scopus 로고    scopus 로고
    • Many other reviews of fluorocarbon chemistry have been written, and they are cited in this review
    • Review: Lemal, D. M. J. Org. Chem. 2004, 69, 1. Many other reviews of fluorocarbon chemistry have been written, and they are cited in this review.
    • (2004) J. Org. Chem. , vol.69 , pp. 1
    • Lemal, D.M.1
  • 26
    • 33645755840 scopus 로고    scopus 로고
    • note
    • (a) The CASSCF geometries of 1a-f and of the singlet and triplet states of 2a-f are available as Supporting Information. Also available are the optimized geometries and energies of the singlet diradical intermediates that were located for 2a,c, and e.
  • 27
    • 33645782239 scopus 로고    scopus 로고
    • note
    • 2 symmetry, with radical centers, especially those in 2c, that are more highly pyramidalized than the radical centers in the diradical TSs for ring inversion. The energies of the singlet diradical intermediate and the TSs differ most for 2c, for which the CASPT2/6-311G* energy difference is 2.0 kcal/mol. Because of the one fewer real vibrational frequency in the TS than in the intermediate, the CASPT2/6-311G* enthalpies of these two species differ by only 1.3 kcal/mol.
  • 28
    • 33645789783 scopus 로고    scopus 로고
    • note
    • The dominant configuration in the CASSCF wave function has the A NBMO doubly occupied; however, there is a second configuration, of smaller weight, in which the S NBMO is doubly occupied.
  • 29
    • 33845377664 scopus 로고
    • There is an obvious analogy between the cooperative stabilization of singlet diradical 2d and the captodative stabilization of a monoradical by a π donor and a π acceptor attached to the radical center. For a review of the captodative effect, see: Viehe, H. G.; Janousek, Z.; Merenyi, R.; Stella, L. Acc. Chem. Res. 1985, 18, 148.
    • (1985) Acc. Chem. Res. , vol.18 , pp. 148
    • Viehe, H.G.1    Janousek, Z.2    Merenyi, R.3    Stella, L.4
  • 30
    • 33645782967 scopus 로고    scopus 로고
    • note
    • 2 carbon is anomalously short (1.330 Å), 0.008 Å shorter than the radical center that does not undergo inversion in the TS.
  • 31
    • 0003691438 scopus 로고
    • Wiley: New York
    • See, for example: Borden, W. T. Diradicals; Wiley: New York, 1982; pp 1-61.
    • (1982) Diradicals , pp. 1-61
    • Borden, W.T.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.