DFT studies on the mechanism of base-catalyzed hydrocyanation of alpha, beta-unsaturated ketone

When it comes to creating new carbon-carbon bonds during the hydrocyanation of α, β-unsaturated ketones, catalytic Michael addition reactions are extremely effective tools. A simple method for converting α, β-unsaturated ketone to its hydrocyanic form involves using cyanohydrin acetone with a mild base and a phase transfer catalyst. This reaction stoichiometry produced a high-quality product with a high yield on the gram scale. Density functional theory (DFT) calculations have been used in a comprehensive theoretical investigation to elucidate the mechanism of base-catalyzed hydrocyanation reaction of enolizable α, β-unsaturated ketone. B3LYP-D3(BJ)/6-311+G**//B3LYP-D3(BJ)/6-311G** was used to study the genesis and reaction mechanism of asymmetric induction for conjugate addition of cyanide to the C=C bond of α, β-unsaturated ketone. Additionally taken into account are the relative stability of the investigated compounds as well as their atomic charges, electron densities, energetic characteristics, chemical thermodynamics, dipole moments, etc. The final charge transfer interaction within the investigated molecule is suggested by the narrow frontier orbital gap, which also demonstrated significant chemical reactivity. Lastly, to visualise the charge transfer between the localised bonds and lone pairs, natural bond orbital analysis is done. The current study's mechanistic insights should be helpful in the logical design of efficient catalysts with high selectivity and yield for this type of reaction.