Rationale for the acidity of Meldrum's acid.Consistent relation of C-H acidities to the properties of localized reactive orbital

DOI
  • Ohwada Tomohiko
    Graduate School of Pharmaceutical Sciences,The University of Tokyo
  • Nakamura Satoshi
    Graduate School of Pharmaceutical Sciences,The University of Tokyo
  • Hirao Hajime
    Graduate School of Pharmaceutical Sciences,The University of Tokyo

Bibliographic Information

Other Title
  • メルドラム酸の酸性度の理論的解析-CH酸の酸性度と局在化反応軌道の性質の関係-

Description

0rds153701el**p1033Detailed investigation on the origin of the acidity of the a-protons of a set of the carbonyl molecules were carried out on the basis of properties of the localized molecular orbital. An anomalously high acidity of Meldrum's acid, as compared with those of dimedone and dimethyl malonate, is one of the well-known but unresolved issues. The well-localized s orbitals of the C-H bonds at the a-position of the carbonyl groups can be obtained with the reactive hybrid orbital (RHO) theory. We found that the energysid10911196 levels of the unoccupiedRHOs of the C-H moiety of Meldrum's acid and other carbonyl compounds showed a good linear correlation with the experimental deprotonation energies. This is probably because the deprotonation reaction to form the proposed naked anions in a polar solvent is a highly endothermic process, in which the thermodynamic energy differences between the neutral molecules and the corresponding anions approximately coincide with the activation energies.

Journal

Keywords

Details 詳細情報について

  • CRID
    1390282680713317504
  • NII Article ID
    130004574797
  • DOI
    10.11545/ciqs.2004.0.j16.0
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

Report a problem

Back to top