The Mechanism of the ortho-Methylation of Nitrobenzenes by Dimethylsulfonium Methylide
作者:Peter Haiss、Klaus-Peter Zeller
DOI:10.1002/ejoc.201001091
日期:2011.1
with dimethylsulfonium methylide. The importance of the ortho substituent is demonstrated by the failure of the methylation of nitrobenzene and 3- and 4-nitroanisole. This is explained by the out-of-plane geometry of the nitro group in the ortho-substituted derivative, which enables a specific interaction between the ylide and the nitro group favourable for attack of the methylide C atom at the neighbouring
带有邻位取代基的硝基苯通过与二甲基锍甲基化物反应在游离邻位选择性甲基化。硝基苯和 3- 和 4- 硝基苯甲醚的甲基化失败证明了邻位取代基的重要性。这是通过邻位取代衍生物中硝基的平面外几何结构来解释的,这使得叶立德和硝基之间发生特定的相互作用,有利于攻击相邻自由邻位的甲基化 C 原子。如适当的氘标记研究所示,添加之后是 E1 样 β-消除,二甲基硫醚被置换,随后消除产物质子化。
Concerning the deprotonation of the trimethylsulfonium ion by the dimethylsulfinyl anion
作者:Peter Haiss、Klaus-Peter Zeller
DOI:10.1039/c1ob05889d
日期:——
side and dimethylsulfonium methylide (2) and DMSO on the other side, because for thermodynamic reasons this process is irreversible due to the limited life-time of 2. Therefore, the isotopic exchange that accompanies the deprotonation is an indicator of a more complex deprotonation process. It is suggested that in a kinetically controlled reaction, a proton of 1 is transferred to the O-atom of 8 rather