Diazo Transfer to Alkynes

2 Methods for the Preparation of Alkane, Alkene, and Alkyne Diazo Compounds 

If cyanogen azide or 2-azido-3-ethylbenzothiazolium tetrafluoroborate is used as diazo transfer reagent, only the diazoamidines are detected (Regitz et al., 1981a). This is consistent with the interpretation of the results of Table 2-3. 

In the context of the rearrangements of triazoles discussed previously, the thermal isomerization (2-87) of alkyl 5-azido-l,2,3-triazole-4-carboxylates (2.221) into 5-di-azoalkyl substituted tetrazoles (2.222) and the rearrangement equilibrium (2-88) of 

The reaction of ynamines of type 2.217, in which R is a diphenylphosphinyl group, their sulfur or seleno analog ((C6H5)2P(X), X = O, S, Se), corresponds to that of reaction (2-85). Again, the triazoles are in equilibrium with the diazoamidines (Himbert and Regitz, 1974). A large number of )ff-metalyl-ynamines show the same reaction pattern. The metals are trialkylated or triphenylated Si, Ge, and Sn (Himbert et al., 1976). 

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Diazo Transfer to Alkynes 11 Table 2-3. Triazole diazoamidine equilibria in additions of azides to ynamines (Scheme 2-85) in CDCI3, 40 °C (Data from Harmon et al., 1970 Himbert and Regitz, 1972 a, 1973). ... 

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