<i>N</i>-Aminomethylation vs. <i>C</i>-Aminomethylation of Indole and Pyrrole with an <i>N</i>,<i>O</i>-Acetal Controlled by the Hardness of a Counter Ion of an Iminium Compound
作者:Norio Sakai、Hidetoshi Okano、Kazuyori Shimamura、Takeo Konakahara
DOI:10.1246/cl.131116
日期:2014.4.5
Under relatively strong Lewis acidic conditions (a softer counter ion) using TMSOTf and TMSI, the aminomethylation of indole or pyrrole with a typical N,O-acetal preferentially produced the kinetically favored N-aminomethylated indole or pyrrole derivative. Use of a relatively weak Lewis acid (a harder counter ion), such as TMSCl and TMSBr, preferentially produced the thermodynamically favored C-aminomethylated indole and pyrrole derivative.
在使用 TMSOTf 和 TMSI 的相对较强的路易斯酸条件下(较软的反离子),吲哚或吡咯与典型的 N,O-缩醛的氨基甲基化反应优先产生动力学上有利的 N-氨基甲基化吲哚或吡咯衍生物。使用相对较弱的路易斯酸(较硬的反离子),如 TMSCl 和 TMSBr,优先产生热力学上有利的 C-氨基甲基化吲哚和吡咯衍生物。