Resumo

MADRID, Gustavo; QUIROZ, Beatriz  e  CUEVAS, Gabriel. Estudio experimental y computacional de la participación de efectos estereoelectrónicos en derivados del norbornano sustituidos en posición 2 por medio de las constantes de acoplamiento ¹J_C-C. Rev. Soc. Quím. Méx [online]. 2000, vol.44, n.1, pp.53-61. ISSN 0583-7693.

In this paper the analysis of ¹J_C-C coupling constants shown that they are good indexes for stereoelectronic effects participation in the stability of organic molecules. Within this analysis, experimental and computational data were found and allows to explain the very well known differences of the kinetic behavior in endo- and exo 2-norborneol derivatives. These coupling constants show the stereo electronic delocalization between O-R polar bonds and C-C bonds which present the appropriated stereochemical disposition to have interaction in the ground state. Experimental coupling constants were measured by INADEQUATE technique and were calculated by ab initio calculations using density functional theory (DFT). As it is showed, the endo-derivatives are stabilized by a stereoelectronic σ_C1-C7 → σ*_C2-OR type interaction whereas the corresponding exo isomers are stabilized by a σ_C1-C6 → σ*_C2-OR stereoelectronic interation.

Palavras-chave : Stereoelectronic effects; INADEQUATE; norbornanes; stabilization; coupling constants.