The Endocyclic Restriction Test: The Geometries of Nucleophilic Substitutions at Sulfur(VI) and Sulfur(II)
作者:Stephen G. Jarboe、Michael S. Terrazas、Peter Beak
DOI:10.1021/jo8016428
日期:2008.12.19
The trajectories for nucleophilic substitutions at sulfur(VI) and sulfur(II) have been investigated by the endocyclic restriction test. On the basis of double-labeling experiments, the sulfur(VI) transfer in the conversion of 1 to 2 is found to be intramolecular, while the sulfur(VI) transfer in the conversion of 3 to 4 and the sulfur(II) transfer in the conversion of 5 to 6 are found to be intermolecular
硫(VI)和硫(II)的亲核取代的轨迹已通过内环限制性试验进行了研究。在双标记实验的基础上,发现硫(VI)以1到2的转化是分子内转移,而硫(VI)以3到4的转化以及硫(II)的转移是分子内的。发现5到6的转化是分子间的。这些结果被认为与用于这些硫转移反应的过渡结构一致,所述过渡结构在进入和离开的基团之间需要大角度,该几何结构类似于三角双锥体过渡态中的顶端基团位置。