IV-Cyclopropylimines

Scheme 11.41 Photochemical rearrangement of iV-cyclopropylimines under direct sensitized conditions.

Scheme 11.42 Diradical mechanism for iV-cyclopropylimine-pyrroline rearrangement.

The aza-di-TT-methane (ADPM) rearrangement of aza-1,4-dienes via radical-cat-ions suggests the possibility that other radical-ion intermediates (e.g., radical-anions) could also be responsible for this rearrangement reaction. In order to test this proposal, the azadiene 101 was irradiated for 20 min in acetonitrile using A,iV-dimethylaniline (DMA) as an electron-donor sensitizer. The reaction leads to formation of the cyclopropylimine 102. Separation of product mixture by column chromatography on silica gel affords the aldehyde 34 (21%) resulting from hydrolysis of the imine 102, (Scheme 18) [70]. 

AT-Cyclopropylimines afford JV-cyclopropylamines on treatment with borohy-drides, whereas ring-cleavage to iV-propylamines is seen with lithium aluminium hydride. ... 

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