Chen, Gang Sasaki, Mikio Li, Xinghan Yudin, Andrei K. Strained Enamines as Versatile Intermediates for Stereocontrolled Construction of Nitrogen Heterocycles This contribution assesses the synthetic utility of molecules that impose conformational constrains onto aziridine-derived enamines. Synthetically versatile [3.1.0] and [4.1.0] bicyclic enamines have been prepared by intramolecular oxidative cycloamination of aziridine-containing olefins. This process is initiated by <i>N</i>-bromosuccinimide followed by base-mediated elimination of HBr to afford highly strained exo-bicyclic enamines. In addition, intramolecular aziridine addition to aldehyde functionality was found to afford the [3.1.0] and [4.1.0] bicyclic hemiaminals. These routes highlight possibilities for chemoselective oxidative transformations of aziridine-containing precursors without nitrogen protection/deprotection steps. The resulting products provide straightforward synthetic entries into a wide range of pyrrolidine- and piperidine-containing heterocycles that are positioned toward subsequent transformations via aziridine ring opening. enamine;bicyclic;aldehyde functionality;aziridine ring opening;Strained Enamines;Versatile Intermediates;intramolecular aziridine addition;chemoselective oxidative transformations;Nitrogen HeterocyclesThis contribution;Stereocontrolled Construction;intramolecular oxidative cycloamination 2006-08-04
    https://acs.figshare.com/articles/journal_contribution/Strained_Enamines_as_Versatile_Intermediates_for_Stereocontrolled_Construction_of_Nitrogen_Heterocycles/3066667
10.1021/jo0607921.s003