1.2.4- Triazole - from carbodiimides

Triazolines resulting from the addition of diazoalkanes to ketenimines and carbodiimides generally isomerize spontaneously to triazoles (see Scheme 104).367-371 Similarly, diazo compounds with carbodiimides also lead to triazoles (Scheme 16)368 369-371 the migratory aptitude of substituent groups R1 and R2 is of the order, Me3Sn > Me3Si > H.368... 

Curtius-type behaviour is followed on irradiation of the azide 610 at 10 K when methoxyisocyanate is obtained by migration of the methoxy group from carbon to nitrogen" . Carbamoyl azide is also photolabile under similar conditions and provides a route to aminonitrene The substituted amide derivative 611 also undergoes conversion to the corresponding isocyanate and, if this is brought about in the presence of carbodiimides, cycloaddition results in the formation of triazoles. ... 

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