Effects of<i>para</i>-Substituents on the Rates of Inversion of Biphenyl Derivatives. I. 5,7-Dihydrodibenzo[<i>c</i>,<i>e</i>]thiepins
作者:Michinori Oki、Hiizu Iwamura、Gaku Yamamoto
DOI:10.1246/bcsj.44.262
日期:1971.1
Several 3,9-disubstituted 5,7-dihydrodibenzo[c,e]thiepins were synthesized and temperature dependence of their NMR spectra was examined. All the substituted derivatives showed a lower energy barrier to inversion than the unsubstituted one. The effects of the substituents on the energy barrier may be interpreted in terms of resonance stabilization and/or out-of-plane bending of the axis bond at the transition state.
我们合成了几种 3,9 二取代的 5,7 二氢二苯并[c,e]硫杂卓,并研究了它们的核磁共振光谱的温度依赖性。与未取代的衍生物相比,所有取代的衍生物都显示出较低的反转能垒。取代基对能障的影响可以从共振稳定和/或过渡态轴键平面外弯曲的角度来解释。