N-Amidocobalt complex

On the other hand, adding hydrido complex to excess a-phenyl or a-ethoxy acrylonitriles resulted in the formation of N-amidocobalt complexes, identified in the same way as the complex obtained from chloro-diphenylacetonitrile. Since these acrylonitriles were catalytically hydrogenated to the corresponding saturated nitriles in the presence of excess hydrido complex, it is inferred that both the hydrogenation and N-amidocobalt complex formation occur via a common radical intermediate (Reaction 23, paths b and e). 

Reduction of phenylcyanomethylenequinone oxime also resulted in the formation of an N-amidocobalt complex, presumably in the following manner ... 

It appears that the type of complex formed is determined by the structural features of the substrate. Thus, a-halonitriles, which apparently all react via a radical mechanism, may yield either 1-cyanoalkylcobalt or N-amidocobalt complexes acrylonitriles may react via a polar mechanism to form 1-cyanoalkylcobalt complexes or via a radical mechanism to form N-amidocobalt complexes. 

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