Ab Initio Molecular Orbital Study of Reactivity of Active Alkyl Groups. I. Deprotonation of Acetaldehyde with Amide, Hydroxide or Fluoride Ions

Abstract

The reactions of acetaldehyde with amide (NH^-₂), hydroxide (OH^-) or fluoride (F^-) ions were investigated by ab initio calculations. Acetaldehyde, which has an active methyl group, was taken as the model compound. The hydrogen-abstraction steps were studied in detail in terms of the energies and the structures of all the complexes in the reaction process. It became clear that the order of the deprotonation ability, i.e., NH ^-₂ > OH^-> F ^- can be reasonably explained when deformation energy is taken into account in the calculation of the energies of the complexes in each reaction pathway. The reactions of methane with these three anions are also discussed as reference reactions.