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Volumn 74, Issue 11, 2001, Pages 2151-2160

Highly enantioselective cyclopropanation of styrenes and diazoacetates catalyzed by 3-oxobutylideneaminatocobalt(II) complexes, part 2. Semiempirical analysis of diastereo and enantioselectivities

Author keywords

[No Author keywords available]

Indexed keywords

CATALYSIS; ESTERS; OLEFINS; STABILITY;

EID: 0035788820     PISSN: 00092673     EISSN: None     Source Type: Journal    
DOI: 10.1246/bcsj.74.2151     Document Type: Article
Times cited : (22)

References (63)
  • 40
    • 85009018261 scopus 로고    scopus 로고
    • Mac Spartan Pro Ver 1.0.1 and PC Spartan Pro Ver 1.0. were released from Wavefunction, Inc., 18401, Von Karman Avenue, Suite 370, Irvine, CA 92612 U.S.A.
    • Mac Spartan Pro Ver 1.0.1 and PC Spartan Pro Ver 1.0. were released from Wavefunction, Inc., 18401, Von Karman Avenue, Suite 370, Irvine, CA 92612 U.S.A.
  • 53
    • 85009020583 scopus 로고    scopus 로고
    • note
    • -1). Though semiempirical calculation has a tendency to estimate the perpendicular and skew approach of ethylene slightly stable, the parallel approach of olefin was finally obtained as the most stable transition state (TS 15). Therefore, this tendency gave little effect on the conclusion.
  • 54
    • 85009012891 scopus 로고    scopus 로고
    • note
    • 1 as an axis (Fig. 14).
  • 55
    • 85009013830 scopus 로고    scopus 로고
    • note
    • -1), the phenyl groups attached to the ethylene bridge in the real experimental system should destabilize the structure 38 because of the steric repulsions. Therefore, it is plausible to adopt structure-11-type orientation of methoxy-carbonyl group as a basic orientation (Fig. 15).
  • 56
    • 85009020584 scopus 로고    scopus 로고
    • note
    • Nine rotational isomers were shown in Fig. 16
  • 57
    • 85009010136 scopus 로고    scopus 로고
    • note
    • To explain clearly, phenyl and acetyl groups were attached to the transition state 11 as a representative model, Any rotational isomers can be used for initial geometries and the same results were obtained.
  • 60
    • 85009019839 scopus 로고    scopus 로고
    • note
    • Direct analyses of the present cyclopropanation in real experimental system by the PM3(tm) method were very complicated, because the usual conformation search was not reliable. Too many unreasonable structures were obtained in such a large system and a slight difference in initial geometry often lead to different optimized structures. Therefore, it was required that the analyses started from a simple model system and developed into a real experimental system by step by step checking the validity of the afforded structures.
  • 61
    • 0034603013 scopus 로고    scopus 로고
    • Since the carbene carbon of the cobalt(II) carbene complex possessed a radical character, the initial bond formation preferentially occurred at the terminal carbon of styrene. Similar radical character was proposed in the salen-Mn catalyzed epoxidation by the density functional method, and it was indicated that the stereo-selectivity was dominated at the initial carbon-oxygen bond formation step. L. Cavallo and H. Jacobsen, Angew. Chem., Int. Ed. Engl., 39, 589 (2000).
    • (2000) Angew. Chem., Int. Ed. Engl. , vol.39 , pp. 589
    • Cavallo, L.1    Jacobsen, H.2
  • 62
    • 85009018526 scopus 로고    scopus 로고
    • note
    • Unreasonable transition states were omitted.
  • 63
    • 85009010825 scopus 로고    scopus 로고
    • See the preceding paper
    • See the preceding paper.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.