作者:Sophia A. Solomon、Lucy K. Allen、Sarah B. J. Dane、Dominic S. Wright
DOI:10.1002/ejic.201301203
日期:2014.4
3-sigmatropic rearrangement occurs to give new benzylic phosphonium salts [(3,5-Me2C6H3)CH2PR3]+I– (R = Me, 6; R = Et, 7), in which the phosphonium centre, the R3P group, is transferred to an ortho-CH3 group. In situ 31P NMR spectroscopic studies show that the reaction is base-activated and stoichiometric with respect to tBuLi. DFT calculations support the conclusion that the rearrangement is thermodynamically
尝试通过甲基碘化鏻反应合成叶立德二价阴离子 [2,4,6-Me3C6H2P(CHR)3]2– (2,4,6-Me3C6H2 = mesityl, R = H 或 Me) [2,4,6 -Me3C6H2PR3]+I– (R = Me, 1; R = Et, 2) 与 tBuLi 回流不会导致磷键合 R 基团的预期去质子化。相反,发生定量的 1,3-σ 重排以产生新的苄基鏻盐 [(3,5-Me2C6H3)CH2PR3]+I– (R = Me, 6; R = Et, 7),其中鏻中心、 R3P 基团,被转移到邻位 CH3 基团。原位 31P NMR 光谱研究表明,该反应是碱活化的,并且与 tBuLi 是化学计量的。DFT 计算支持以下结论:在气相和 THF 中重排在热力学上是有利的,并表明重排是由焓驱动的。