Electro-organic reactions. Part IV. Preparative aspects of the cathodic hydrogenation of activated carbon–carbon double bonds
Compounds of the type Ph(R)C:C(CN)X(R = Ph or But, X = CN or CO2Et) undergo smooth, efficient, and specific cathodic hydrogenation of the carbon–carbon double bond in aprotic solvents in the presence of added proton donors. For R = But and X = CN, cathodic reduction in the presence of chiral proton donors gives a racemic product which implies that, for established cases of asymmetric electrochemical reduction, protonation is not the stereochemistry-determining step.
Mixtures of stereoisomeric cyclic hydro-dimers are the only products of similar reductions of compounds with R = Me or H and X = CN.