Preparation of non-racemic single-stereocentre α-aminonitriles and a study of their fate in Bruylants reactions
作者:Virginie Beaufort-Droal、Elisabeth Pereira、Vincent Théry、David J. Aitken
DOI:10.1016/j.tet.2006.09.087
日期:2006.12
for the preparation of four representative enantiomerically enriched α-aminonitriles possessing only one stereogenic centre; best results were observed using Burgess' salt (yield up to 87%, er up to 92/8) or the trifluoroacetic anhydride–triethylamine combination (yield up to 98%, er up to 86/14). Two of the aminonitriles thus obtained were subjected to Bruylants reactions with a methyl Grignard reagent
研究了许多手性羧酰胺脱水方法,以制备仅具有一个立体生成中心的四个代表性的对映异构体富集的α-氨基腈。使用Burgess盐(产率高达87%,er高达92/8)或三氟乙酸酐-三乙胺组合(产率高达98%,er高达86/14)观察到最佳结果。将如此获得的两个氨基腈与甲基格氏试剂进行Bruylants反应,得到相应的叔胺;这些产物以及任何未反应的起始原料基本上以外消旋形式获得。根据该反应的公认机理,镁元素与亚胺的形成有关,亚胺是化学转化和外消旋过程的常用中间体。