Preparation of 1,2,5-Trisubstituted 1<i>H</i>-Imidazoles from Ketenimines and Propargylic Amines by Silver-Catalyzed or Iodine-Promoted Electrophilic Cyclization Reaction of Alkynes
作者:Xiaorong Zhou、Zheng Jiang、Lexing Xue、Ping Lu、Yanguang Wang
DOI:10.1002/ejoc.201500704
日期:2015.9
From readily available propargylic amines, 1,2,5-trisubstituted imidazoles are efficiently obtained through a cascade reaction catalyzed by AgOTf or promoted by molecular iodine. The AgOTf-catalyzed reaction involves nucleophilic addition of propargylic amine to ketenimine, a silver-catalyzed electrophilic cyclization reaction of alkyne, and a tautomerism/isomerism/metal-H exchange cascade. The iodine-mediated
从容易获得的炔丙胺中,通过由 AgOTf 催化或由分子碘促进的级联反应有效地获得 1,2,5-三取代的咪唑。AgOTf 催化的反应包括炔丙胺与烯酮亚胺的亲核加成、炔烃的银催化亲电环化反应和互变异构/异构/金属-H 交换级联反应。碘介导的对应物产生 5-甲酰基-1,2-二取代咪唑,这可能包括级联水解/氧化反应。此外, 所提出的协议可以扩大规模, 所得的 1,2,5-三取代咪唑可以转化为稠合茚并 [1,2-d] 咪唑。