Oximes as Nucleophiles in the Reaction with Acetylenes Literature Analysis

1 Oximes as Nucleophiles in the Reaction with Acetylenes Literature Analysis 

The results of early works on the interaction of oximes with acetylenes are contradictory and often are inconsistent among themselves. Oximes, that is, tridentate 0-, N-, and C-nucleophiles, theoretically can add to the triple C-C bond via any of these nucleophilic centers. 

SCHEME 1.185 Ketoximes as O-nucleophiles in the reaction with ethoxyacetylene. 

SCHEME 1.187 Formation of nitriles from aldoximes and l-(N,N-diethylamino)propyne. 

It is presumed [306-308] that addition across the C=C bond generates a zwit-terion, in which intramolecular proton transfer occurs through the five-membered intermediate to give nitrone. The latter enters the 1,3-dipolar addition reaction with the second molecule of dimethyl acetylenedicarboxylate affording oxazole derivative. 

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