Azides nitrogen exchange reactions

Unstable amines and amines containing functional groups unstable under acidic reduction conditions can be obtained directly as the hydrochlorides by hydrogenation of nitriles, nitro compounds, azides, or oximes in the presence of chloroform A new type of basic amide hydrolysis, characterized by alkyl-nitrogen fission, has been reported Semisynthetic cephalosporins have been prepared via a novel acyl exchange reaction... 

Triazenes can be prepared by the following three methods (Scheme 1) (1) redox reactions (reduction of azides, oxidation of triazanes), (2) building or splitting of nitrogen chains, and (3) exchange of substituents (mutual transformation of triazenes). 

Mechanistically most of these transformations correspond to 5N2-type substitutions chiral substrates react with inversion. In certain cases, however, azides may also be obtained under 5n1 condi-tions." " " Some di- and tri-arylmethanols for instance (Scheme 32) react with HN3 in the presence of trichloroacetic acid via the corresponding carbenium ions. Sulfuric acid seems to be inferior for these transformations." " Under highly acidic conditions the intermediate (20) obviously tends to decompose with the elimination of nitrogen (c/. Schmidt reaction "). SnI substitution is also highly probable in the reaction of a-halo ethers and sulfides with azide ions." " In some cases even SRNl-type substitution was observed for the halogen/azide exchange." ... 

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