3-Azabicyclo[4.1.0]hepta-2,4-dienes were efficiently synthesized in a reaction of N-propargylic β-enaminones with acetylenedicarboxylates under novel and exceptional catalyst- and base-free conditions in a single step.
![Graphical abstract: Reaction of N-propargylic β-enaminones with acetylene dicarboxylates: catalyst-free synthesis of 3-azabicyclo[4.1.0]hepta-2,4-dienes](http://hg.y866.cn/compound/lib/scimg/usr/1/C4RA00136B.jpg)
