| Abstract
| - Density functional (DF) based numerical approaches for computing orbital and atomic reactivity indices wereemployed in the study of selectivity descriptors for the 1,4 Michael addition reaction. To this aim, atomicand orbital Fukui indices and atomic softnesses for 2-arylmethylene-1,4-butanolides and N,N-disubstitutedphenylacetamides were computed. Further on, these local selectivity descriptors have been rationalized interms of the Pearson's hard−soft-acid−base principle to explain the observed regioselectivity. It is shownthat the methods employed for local (atomic and orbital) reactivity index computations are useful and reliablefor prediction of the regioselectivity upon conjugate addition of ambident nucleophiles to 2,3-unsaturatedcarboxylic esters. All the results reveal similar degree of localization/hardness of the 1,4-butanolides C4 andactive α-carbon belonging to the N,N-dimethyl-phenylacetamide, while the soft α-carbon in LiCH2CN reactswith the soft C2 1,4-butanolide center.
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