The Endocyclic Restriction Test: The Geometries of Nucleophilic Substitutions at Sulfur(VI) and Sulfur(II)

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• 作者：Stephen G. Jarboe ; Michael S. Terrazas ; Peter Beak
• 刊名：Journal of Organic Chemistry
• 出版年：2008
• 出版时间：December 19, 2008
• 年：2008
• 卷：73
• 期：24
• 页码：9627-9632
• 全文大小：275K
• 年卷期：v.73,no.24(December 19, 2008)
• ISSN：1520-6904

文摘

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. These results are taken to be consistent with transition structures for these sulfur transfer reactions which require a large angle between the entering and leaving group, a geometry analogous to apical group positions in trigonal bipyramidal transition states.