Unexpected Behavior of the Reaction between 1,2-Diaza-1,3-Butadienes and 3-Dimethylaminopropenoates: A Useful Entry to New Pyrrolines, Pyrroles, and Oxazolines
作者:Orazio A. Attanasi、Gianfranco Favi、Paolino Filippone、Amalija Golobič、Branko Stanovnik、Jurij Svete
DOI:10.1021/jo0480343
日期:2005.5.1
We observed a nucleophilicattack by the ene-amino carbon of 3-dimethylaminopropenoates at the terminal carbon of the azo-ene system of 1,2-diaza-1,3-butadienes. In tetrahydrofuran at 65 °C, this attack produced 1-aminopyrrolines with a high degree of cis-stereoselectivity by means of an unusual zwitterionic adduct intermediate followed by intramolecular ring closure. In toluene under reflux, 1-aminopyrrolines