[Enthalpy]

[...] Alkenes can make cis-1,2-cyclobutanes by photoaddition. I haven't seen the equivalent reaction with imines, so the appended tentative syntheses need luck. [...]

Irradiation knowingly enlarges cyclopropylimines to 5-membered aza-enes rings. Whether some conditions favor the cycloaddition?

[Enthalpy]

More ramblings... As a synthesis for N,N'-diisopropyl-diazetidine is known, but C+N=10 is only as reluctant to flame as turpentine, I imagine di(cyclopropylaza)bicyclopentane with one cycle more would bring wow performance and raise the flash point. I fully ignore how toxic and explosive this hydrazine is.

• Cis-dihalocyclopropane exposes the halogens simultaneously to the N-H, which may help this step.
• But the N-N bond is more strained than in diazetidine. Ouch.

The recycling of HBr is displayed too, because many people claim that bromine compounds are expensive. Electrolysis produces HOBr which acts even on cyclopropane.

I didn't see a cis-dihalocyclopropane synthesis. If someone knows, please tell! Cyclise tri- or tetrahalopropane with a metal, hoping it stops before cyclopropene?

Marc Schaefer, aka Enthalpy