General One-Pot, Three-Step Methodology Leading to an Extended Class of <i>N</i>-Heterocyclic Cations: Spontaneous Nucleophilic Addition, Cyclization, and Hydride Loss
作者:Alexis D. C. Parenty、Louise V. Smith、Alexandra L. Pickering、De-Liang Long、Leroy Cronin
DOI:10.1021/jo0495440
日期:2004.9.1
derivative has been isolated from the reaction of 2-bromoethyl-phenanthridinium bromide with a range of primary amines in excellent yields. The reaction pathway is unprecedented and proceeds via three cascade steps: nucleophilic attack of a primary amine on the iminium moiety of a heteroaromatic ring system and cyclization to form a five-membered ring, followed by hydride loss to yield a rearomatized dihydro-1H-imidazo[1
从2-溴乙基溴化菲啶鎓与一系列伯胺的反应中已分离出一类新型的菲啶鎓衍生物,收率很高。反应路径是前所未有的,通过三个级联的步骤进行:在杂芳环体系和环化的亚胺部分的伯胺的亲核攻击,以形成一个五元环,随后氢化物损失,得到rearomatized二氢ħ -咪唑并[1,2- f ]菲啶鎓衍生物。进行了一系列NMR相转移实验以阐明机理途径,并且该方法已经通过使用N-溴代琥珀酰亚胺作为助氧化剂的双相系统进一步发展。该方法也已扩展到其他N-杂环阳离子衍生物,例如喹啉鎓和喹唑啉鎓。