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首页> 外文期刊>Chemistry: A European journal >Stereoelectronic Effects in Cyclic Sulfoxides,Sulfones,and Sulfilimines:Application of the Perlin Effect to Conformational Analysis
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Stereoelectronic Effects in Cyclic Sulfoxides,Sulfones,and Sulfilimines:Application of the Perlin Effect to Conformational Analysis

机译：环亚砜，砜和亚硫亚胺中的立体电子效应：Perlin效应在构象分析中的应用

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摘要

The 1J_(C-H)coupling constants in conformationally constrained sulfox ides,bissulfoxides,sulfoxide-sulfones,and sulfilimines derived from 2-benzyl-idene-1,3-dithiane and 2-(2,2-dimethyl-propylidene)-1,3-dithiolane were mea sured by means of HMQC and HSQC NMR experiments and the Perlin ef fects were calculated.The type and the relative configuration of S=X groups(X=O,NTos)in these compounds have a strong influence on the magni tude of coupling constants for axial and equatorial C-H bonds,respectively.Axial S=O bonds give rise to a stereo-electronic effect on antiperiplanar axial C-H bonds.The resultant weakening of the respective C-H bonds leads to a smaller coupling constant than for a re spective equatorial C-H bond.Equato rial S=O groups have an influence on(beta-C-H bonds through a homoanomeric effect.Here,the axial C-H bond is weakened and a smaller coupling con stant is measured.Sulfilimine groups show similar effects to sulfoxide groups.
机译：构象受限的亚砜，二亚砜，亚砜砜和由2-苄叉基-1,3-二噻吩和2-（2,2-二甲基丙叉基）-1,3衍生的亚胺亚胺中的1J_（CH）耦合常数通过HMQC和HSQC NMR实验测定了二硫烷的含量，计算了Perlin效应。这些化合物中S = X（X = O，NTos）基的类型和相对构型对甲酰胺的影响很大。轴向和赤道CH键的耦合常数分别为。轴向S = O键对反平面的轴向CH键产生立体电子效应。由此导致的各个CH键的弱化导致耦合常数小于相应的耦合常数。赤道CH =基团通过同分异构效应对β-CH键产生影响。此处，轴向CH键被削弱，偶合常数较小。亚硫亚胺基团的作用与亚砜基相似。

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