The importance of the σ*–π* orbital mixing for the nucleophilic displacement on the unsaturated carbon

Abstract

The reactivity of carbonyl and aromatic compounds for the nucleophilic displacement is investigated theoretically. LUMO (lowest unoccupied MO) obtained by the mixing of the π* MO with the σ* MO is a uniform criterion of the relative reactivity of substrates. The presence or absence of the tetrahedral intermediate is found to depend on the energy difference between the π* and σ* MO's.