NMR and x-ray evidence for the chair conformation of six-membered rings attached diequatorially to five-coordinate phosphorus. Implications for reported transition-state analogs of nucleoside cyclic 3',5'-monophosphate hydrolysis
作者:Yande Huang、Alan E. Sopchik、Atta M. Arif、Wesley G. Bentrude
DOI:10.1021/ja00063a024
日期:1993.5
A series of phosphoranes, 5, 6a, 6b, and 7a, has been prepared and structurally characterized by 1 H NMR spectroscopy and/or X-ray crystallography. In the crystalline state, 5a, 6a, and 6b feature five-coordinate phosphorus bonded in a somewhat distorted, trigonal bipyramidal fashion. The phosphorus-containing six-membered ring is attached to phosphorus diequatoially and is in the chair conformation
已经制备了一系列正膦,5、6a、6b 和 7a,并通过 1 H NMR 光谱和/或 X 射线晶体学对其进行了结构表征。在结晶状态下,5a、6a 和 6b 的特征是五配位磷以稍微扭曲的三角双锥体方式键合。含磷六元环与磷二等位连接,呈椅子构象。1 H NMR 耦合常数表明,对于所有四种磷烷,在溶液中也存在椅子形环,而不是船形或扭曲构象