Electrophilic Sulfides(II) as a Novel Catalyst. V. Structure, Nucleophilicity, and Steric Compression of Stabilized Sulfur Ylides as Observed by<sup>13</sup>C-NMR Spectroscopy
作者:Haruo Matsuyama、Hiroshi Minato、Michio Kobayashi
DOI:10.1246/bcsj.50.3393
日期:1977.12
13C chemical shifts and 13C–H spin coupling constants (179.7 Hz) of the ylide carbons of two dialkylsulfonium phenacylides show that the ylide carbons are basically sp2. Large upfield shifts (−9.5–−11.8 ppm) of carbonyl carbon signals (δC 181.7 and 179.2) of the ylides from those of the corresponding salts (δC 191.2 and 191.0) suggest significant contribution of a betaine structure. The 13C-NMR spectrum
两种二烷基锍苯内酯的叶立德碳的 13C 化学位移和 13C-H 自旋耦合常数 (179.7 Hz) 表明叶立德碳基本上是 sp2。叶立德的羰基碳信号(δC 181.7 和 179.2)与相应盐(δC 191.2 和 191.0)的羰基碳信号(δC 181.7 和 179.2)的大高场偏移(-9.5–-11.8 ppm)表明甜菜碱结构的重要贡献。甲基异丙基苯甲酰锍的 13C-NMR 谱显示异丙基的两个非等价甲基信号(δC 17.9 和 18.4)。用几种烷基锍双(甲氧基羰基)甲基化物和三烷基锍盐观察到对叶立德碳化学位移的空间γ效应。