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Organic and Biomolecular Chemistry
Volumn 7, Issue 8, 2009, Pages 1619-1626
Steric effects which determine the conformational preferences and stereodynamic processes of aryl fluorenyl ketones
Author keywords

[No Author keywords available]
Indexed keywords

ARYL RINGS; ARYL SUBSTITUENTS; CONFORMATIONAL PREFERENCES; DFT CALCULATIONS; DYNAMIC NMR; FLUORENE; FLUORENYL; METHYL GROUPS; ORTHO POSITIONS; STERIC EFFECTS; X- RAY DIFFRACTIONS;
EID: 64149096640     PISSN: 14770520     EISSN: None     Source Type: Journal    
DOI: 10.1039/b822874d     Document Type: Article
Times cited : (4)
References (53)
  • 11
    • 0003550821 scopus 로고    scopus 로고
    • ortho). In 1-syn the same distances are 3.07 and 4.08 Å, respectively. Their ratios (elevated to the 6th power) are 6.4:1 in 1-anti whereas they are reversed to 1:5.5 in 1-syn The 94:6 ratio measured at -147 °C (Fig. 1) corresponds, approximately, to a 86:14 ratio at -80 °C. Therefore, the observed NOE effects at -80 °C are mainly due to the geometry of the more populated conformer. However, the presence of a non-negligible amount of the minor conformer should account for the difference between the calculated NOE ratio for a 100% population of 1-anti (i.e. 6.4:1) and the experimental value (i.e. 3.1:1). In particular, the observed 3.1 NOE ratio would be accounted for by an anti-to-syn proportion of 73:27: such a proportion is in acceptable agreement with the above mentioned 86:14 ratio
    • ortho). In 1-syn the same distances are 3.07 and 4.08 Å, respectively. Their ratios (elevated to the 6th power) are 6.4:1 in 1-anti whereas they are reversed to 1:5.5 in 1-syn
    • (1987) High-Resolution NMR Techniques in Organic Chemistry
    • Claridge, T.D.W.1
  • 22
    • 57049167560 scopus 로고    scopus 로고
    • On further lowering of the temperature, the viscosity makes the intrinsic line width too broad to detect the possible splitting of the lines in the minor conformer As proof of this feature the simulation of Fig. 3 could be obtained using solely the rate constant for the interconversion of the major into the minor signals, without the introduction of a rate constant which directly exchanges the 1:1 signals of the major conformer, so the latter rate cannot be determined by NMR -11500
    • M. D. Wodrich D. F. Jana P. v. R. Schleyer C. Corminbouef J. Phys. Chem. A 2008 112 11495 11500
    • (2008) J. Phys. Chem. A , vol.112 , pp. 11495
    • Wodrich, M.D.1    Jana, D.F.2    Schleyer, V.P.R.3    Corminbouef, C.4
  • 29
    • 0002307799 scopus 로고
    • The computed angles are 1° and 90°; 0° and 90°; 21° and 68° in 1, 2 and 3, respectively The mesityl derivative corresponding to 1 could not be studied because on synthesis it immediately forms its 9,9′-dimer
    • E. L. Eliel J. Chem. Ed. 1980 57 52
    • (1980) J. Chem. Ed. , vol.57 , pp. 52
    • Eliel, E.L.1
  • 30
    • 45449095658 scopus 로고    scopus 로고
    • Semichem, Inc., Shawnee Mission, KS, The expected third 10% signal is not observed because it is overlapped by the line at 2.28 ppm. A satisfactory line shape simulation could be obtained only if the 90% Me(para) line at 2.02 ppm exchanges with the hidden 10% line at 2.28 ppm, and the downfield 90% Me(ortho) line at 2.28 ppm exchanges with the 10% line at 1.82 ppm. The major signal at 2.54 ppm is that of the methine hydrogen, which exchanges with the corresponding minor signal at 3.10 ppm (Fig. 7)
    • This results from a visual inspection of the normal mode by an appropriate computer program: R. Dennington II, T. Keith and J. Millam, GaussView (Version 4.1), Semichem, Inc., Shawnee Mission, KS, 2007
    • (2007) GaussView (Version 4.1)

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.