SUBJECTS triazenes

The subject of this chapter is the replacement of protons in primary and secondary aromatic and aliphatic amines by arenediazonium ions. In these reaction (Scheme 13-1) derivatives of the unknown substance triazene, HN = N-NH2, are formed. ... 

Triazenes obtained from arenediazonium ions with secondary aliphatic or aromatic amines are not subject to tautomerism. They are used as stable sources of arenediazonium ion in organic synthesis and in technological applications. 

To conduct the substitution reactions of Figure 5.56, one neutralizes an acidic solution of the aromatic diazonium salt with diethylamine. This forms the diazoamino compound B (called a triazene ). It is isolated and subjected to the substitution reactions in an organic solvent. In each case, at first a leaving group is generated from the NIT, moiety of the dia-... 

Diazonium ions react with all known nucleophiles. The addition of hydroxide, alkoxide, cyanide and sulfite ions does not belong to the subject of this review, but the formation of diazoamino compounds (1,3-triazenes) formed with ammonia, primary and secondary amines does. In analogy with the other reactions discussed in this paper, where carbon atoms are the site of attack by diazonium ions (C-coupling), these reactions are called N-coupling reactions. 

Pyrazolylpyrimidines (pzpm) also provide a method for detecting the Pd-N bond rupture (see equation 16). This has been extended to tri-substituted triazines, wherein Pd-N bond rupture can be detected, but which also allows the metal to pass around the entire ligand via a series of (1) metallotropic shifts involving retention of the triazene N-Pd bond and (2) pyrazolyl ligand assisted metal hurdling from one triazene N to another (see equation 17). The subject of metals shuttling... 

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