Hydrogen imino groups

The hydrogen of the imino-group may be replaced lay acid and alkyl radicals. In the latter case the sodium compound is tieated with an alkyl iodide. 

Biaser HU, Spindler E (1999) Hydrogenation of imino groups. In Jacobsen EN, Pfaltz A, Yamamoto Y (eds) Comprehensive asymmetric catalysis, voi I. Springer, Berlin, Chapter 6.2... 

Only in the case of a, to - dicyanoalkanes hydrogenation, there is a possibility of intramolecular condensation of intermediate [1] between amino and imino group. Such a condensation leading to an aminal [2] prone to ammonia loss, gives rise to 1-aza-l-cyclo-heptene 3. Hydrogenation of this intermediate leads to azacyclo-heptane 4. 

The cis stereochemistry observed is better supported starting from 10 rather than from 11. In the first case intramolecular hydrogen bonding between amino and imino group favors the cis configuration leading to cis AMCPA as the major compound. 

It was found later [94] that aziridinyl ketones do not react with aldehydes in the absence of ammonia apparently owing to the strong intramolecular hydrogen bond [96]. Kaluski et al. [94] considered a more probable mechanism where the carbonyl group of the aziridinyl ketone is first attacked by an ammonia molecule, releasing the aziridine imino group, which reacts with the carbonyl compound and subsequently cyclizes into azirenoimidazoles (Scheme 1.22). 

The hydrogen atom of the imino group of pyrazoles is sufficiently active to take part in Mannich reactions. Thus, pyrazoles unsubstituted on nitrogen, with formaldehyde and secondary amines, react smoothly to give high yields of dialkylaminomethyl derivatives (64) which are acid labile.653-656 Pyrazoles substituted on nitrogen give... 

---