Transformation of <i>N</i>,<i>N</i>-Dimethylaniline <i>N</i>-Oxides into Diverse Tetrahydroquinoline Scaffolds via Formal Povarov Reactions
作者:Timothy S. Bush、Glenn P. A. Yap、William J. Chain
DOI:10.1021/acs.orglett.8b02318
日期:2018.9.7
A one-pot protocol for the assembly of diversely functionalized tetrahydro-, hexahydrofuro-, hexahydropyrano-, and tetrahydrobenzofuroquinolines from N,N-dimethylaniline N-oxides and various electron-rich olefins in a tandem Polonovski–Povarov sequence is reported. Following activation of the N–O bond with Boc2O, an exocyclic iminium ion is unveiled upon exposure to tin(IV) chloride. A formal inverse-electron-demand
的单釜协议的组件的不同地从官能四氢,六氢呋喃并,hexahydropyrano-,和tetrahydrobenzofuroquinolines Ñ,Ñ二甲基苯胺Ñ在串联-oxides和各种富电子烯烃Polonovski-Povarov序列报道。在用Boc 2 O激活N–O键后,暴露于氯化锡(IV)时,露出了环外亚胺离子。正式的反电子需求aza-Diels-Alder环化反应可生成29个实例的四氢喹啉核心,收率高达92%。