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Volumn 65, Issue 7, 2000, Pages 2030-2042

Epoxidation of acyclic chiral allylic alcohols with peroxy acids: Spiro or planar butterfly transition structures? A computational DFT answer

Author keywords

[No Author keywords available]

Indexed keywords

ALLYL ALCOHOL; EPOXIDE; PERACETIC ACID; PERACID; SPIRO COMPOUND; UNCLASSIFIED DRUG;

EID: 0034616182     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo991530k     Document Type: Article
Times cited : (33)

References (54)
  • 30
    • 0032822880 scopus 로고    scopus 로고
    • Adam et al., while maintaining a "planar" geometry for peroxy acid epoxidation TSs, adopt a "Bach" model for hydrogen bonding; i.e., they now prefer hydrogen bond to peroxy acid carbonyl oxygen
    • (n) Note added in proof: in a recent review (Adam, W.; Wirth, T. Acc. Chem. Res. 1999, 32, 703) Adam et al., while maintaining a "planar" geometry for peroxy acid epoxidation TSs, adopt a "Bach" model for hydrogen bonding; i.e., they now prefer hydrogen bond to peroxy acid carbonyl oxygen.
    • (1999) Acc. Chem. Res. , vol.32 , pp. 703
    • Adam, W.1    Wirth, T.2
  • 36
    • 0342786638 scopus 로고    scopus 로고
    • note
    • For previous PM3 and B3LYP studies, respectively, on facial selectivity of cyclic alkenes see ref 20a and 20b.
  • 45
    • 0343221137 scopus 로고    scopus 로고
    • note
    • The cc-pVTZ basis sets have been suggested by a reviewer to be "proper" for hydrogen bonding description. However, they are highly time-consuming, specially after inclusion of diffuse functions, and out of reach, at least for us, for relatively large systems such as those studied in this work. For this reason, we used the B3LYP/6-311+G** level for single-point calculations on B3LYP/6-31G* geometries as an acceptable compromise between reliability and time request. However, the reader should keep in mind that this basis set might slightly overestimate (see Table 1) the stability of exo-TS (with hydrogen bonding to peroxy oxygens) as compared to that of their endo counterpart (with hydrogen bonding to carbonyl oxygen).
  • 48
    • 0343656834 scopus 로고    scopus 로고
    • note
    • 7 plane by ≥55° and ≥11°, respectively). This distortion obviously compounds the spiro/planar TS classification.
  • 50
    • 0343221141 scopus 로고    scopus 로고
    • note
    • Solvent effects (both absolute and relative) evaluated by this method are smaller than those obtained with the Tomasi method (as implemented in Gaussian 94) previously used by us. Because the performance of methods in evaluating the solvent effects is not, to date, satisfactorily assessed the "computed solvent effect" should be taken with some caution.
  • 51
    • 0342786629 scopus 로고    scopus 로고
    • note
    • We did not try to locate the related conformational minima with the hydroxylic hydrogen pointing away from the π bond. Conformational analysis of 2-propenol clearly demonstrated that conformers of this type (without hydrogen bonding interactions and with repulsive closed shell interactions between lone pairs and the π bond) are definitely less stable than those in which hydrogen bonding operates.
  • 52
    • 0343221134 scopus 로고    scopus 로고
    • note
    • Obviously our system behaves as a Curtin-Hammett system. The conformational equilibrium of the starting alcohols is very fast and product distribution is only determined by the relative TS energies. Thus, to calculate theoretical face selectivity one does not need to know which conformer each TS originates from.
  • 53
    • 0343221135 scopus 로고    scopus 로고
    • note
    • 9 as a whole = +0.07 (+0.04). Electron transfer, from olefin to PFA, according to CHelpG analisys is -0.29 and -0.31 in syn,exo,threo-15a and syn,exo,erythro-22d, respectively.
  • 54
    • 0342351767 scopus 로고    scopus 로고
    • note
    • 6 peroxy acid plane is always very close to being orthogonal to C=C bond.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.