Base-Catalyzed Anti-Markovnikov Hydroamination of Vinylarenes – Scope, Limitations and Computational Studies
作者:Patricia Horrillo-Martínez、Kai C. Hultzsch、Adrià Gil、Vicenç Branchadell
DOI:10.1002/ejoc.200700147
日期:2007.7
The hydroamination of vinylarenes with primary and secondary amines was studied with catalytic amounts as low as 2 mol-% of LiN(SiMe3)2/TMEDA. Reactions proceeded readily at 120 °C in the absence of solvent to give selective anti-Markovnikov addition. Slow addition was observed at 25 °C with either electron-deficient p-chlorostyrene or secondary cyclic amines such as pyrrolidine, piperidine, or morpholine
使用低至 2 mol% 的 LiN(SiMe3)2/TMEDA 的催化量研究了乙烯基芳烃与伯胺和仲胺的加氢胺化。在没有溶剂的情况下,反应在 120 °C 下很容易进行,以提供选择性的抗马尔科夫尼科夫加成物。在 25 °C 下观察到使用缺电子对氯苯乙烯或仲环胺(如吡咯烷、哌啶或吗啉)缓慢添加。伯胺易于进行二次加氢胺化反应以形成叔胺副产物。单(加氢胺化)产物的选择性可以用两倍过量的胺来提高。与 LiN(SiMe3)2 相比,KN(SiMe3)2 显示出更高的催化活性,但选择性更低,导致不希望的 C-H 活化副产物。用密度泛函理论研究了锂催化加氢胺化的机理和TMEDA的影响。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)