Sulfuranes Lacking Benzoannelation. Sulfuranes and Other Hypervalent Molecules Studied by <sup>17</sup>O-NMR
作者:Zwei-Chang Ho、Peter Livant、William B. Lott、Thomas R. Webb
DOI:10.1021/jo9909608
日期:1999.10.1
The rates of hydrolysis of benzoannelated vs nonbenzoannelated sulfuranes, viz. 5 vs 3 or 5 vs 4, were compared. Benzoannelation was found to provide very modest kinetic stabilization. Crystal structures of sulfuranes 3 and 4 were obtained and compared with each other, with a dibenzoannelated sulfurane, 17, and with a non-sulfurane analogue of 4. Bond length variations could be understood in the context
苯甲酰化的与非苯甲酰化的硫烷的水解速率,即。比较5对3或5对4。发现苯甲酰化提供非常适度的动力学稳定性。获得了硫烷3和4的晶体结构,并将它们与二苯甲酰胺化的硫烷17和非硫烷类似物4进行了比较。键长的变化可以通过简单的共振论证来理解。3-5的(17)O NMR研究表明,该技术确实对硫烷结构敏感。例如,两个4的羰基氧的化学位移相差20 ppm以上。通过(17)O NMR研究了其他高价体系,主要是碘烷。对各种理论方法进行了调查,以测试它们可以很好地再现3的几何形状。在MP2 / 3-21G()级别上,密度泛函理论计算的性能超过了从头开始的几何优化。最后,研究了11的双键和10的两个双键之一的顺反异构化。