Hydrazines from diazirines

Structural data of a diaziridine come from gas phase electron diffraction measurements (74CC397). The N—N bond of 3-methyldiaziridine (24) is longer than in hydrazine (1.449 A) the C—N bond distances in (24) and in diazirine are nearly equal (1.479 versus 1.482 A),... 

The 1-alkyl-diaziridines can easily be hydrolyzed to alkyl hydrazines. Hence alkyl hydrazines are easily available from Grignard reagents and thus from alkyl halides. The three last examples of Table XII show the yield of alkyl hydrazine calculated on the diazirine used. The reaction has preparative interest because the alkylation of hydrazine with alkyl halides only gives monoalkyl hydrazines in exceptional cases. ... 

Difluoroamine reacts with primary and secondary amines to give alkanes (32). With imines, a variety of products are obtained depending on the structure of the imine. The three types of compounds obtained are diazirines (I), a-haloazo compounds (II), and a-fluoroalkylidine-hydrazines (III) (138, 139). The reaction of HNF2 with formaldehyde imines or negatively substituted aromatic imines yields diazirines in fair yield as the principal product, whereas with imines derived from aliphatic aldehydes the reaction gives a mixture of the corresponding diazirine derivative and a-fluoroazo compound. 

Thermolysis and/or photolysis of tosylhydrazone salts, accessible by condensation of p-toluene-sulfonyl-hydrazine with aldehydes or ketone, gives rise to elimination of the sulfinate salts and forms the intermediate diazo compound (Scheme 18). Generation of free carbenes by this method is sometimes in doubt and, as a consequence, this method is not included in this chapter except when generation of a carbene from the diazirine or diazo compound is not available. 

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