Steric effects in [2.2] metaparacyclophanes. Steric isotope effect, remote substituent effect on a steric barrier, and other steric phenomena

SA Sherrod, RL Da Costa, RA Barnes…

文献索引：Sherrod,S.A. et al. Journal of the American Chemical Society, 1974 , vol. 96, p. 1565 - 1577

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被引用次数: 71

摘要

Abstract: The conformational flipping of [2.2] metaparacyclophanes requires intrusion by the substituent at the 8 position into the s-electron cloud of the para-bridged ring. It is shown that the kinetics of this process can readily be followed by a double irradiation nmr technique. The Arrhenius factors observed for the conformational flipping of [2.2] metaparacyclophane itself are AH*= 17.0 f 0.5 kcal/mol and AS*=-8.8 f 2.4 eu. Substitution of deuterium for ...