Reduction of a,-Unsaturated Nitriles

Because of the oft-encountered overreduction to the amine, reduction to saturated nitriles is a difficult problem. A mixture prepared from CuBr, NaAl(OCH2—CH2—0CH3)2H2 (vitride) and sec-butyl alcohol do that work nicely. In contrast to the Mg—CH3OH method, no coupling was observed [26]. The mechanism of the reactions is largely speculative. 

Moreover, in analogy with the alkyl—Cu chemistry, hydrido—Cu reagents might provide selective conjugate addition of hydride and compatibility with most functional groups. Two Cu complexes seem to be efficient for that purpose [27]  

Selective reduction of the olefin unit in conjugated ketones and esters was observed. However, the reactions are often accompanied by side reactions and the reactivity of the complexes toward common functional groups limits their applicability. 

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Reductions. Magnesium methanol has been used for selective reduction of a,/ -unsaturated nitriles (6, 351) and amides1 and of 1,1- and 1,2-diphenyl-substituted ethylenes.2... 

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