SciELO - Scientific Electronic Library Online

 
vol.49 número1CONSTRUCTION OF A POLYMERIC LIQUID-MEMBRANE ION-SELECTIVE ELECTRODE (ISE)AND ITS APPLICATION FOR DETERMINATION OF NITRATE IN TOMATOESIR AND 13C-NMR SPECTRAL PROPERTIES OF THE LAYERED INCLUSION COMPOUND BIS(THIOUREA)HEXAMETHYLENETETRAMINE índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Journal of the Chilean Chemical Society

versión On-line ISSN 0717-9707

Resumen

ARAYA-MATURANA, RAMIRO; HEREDIA-MOYA, JORGE; ESCOBAR, CARLOS A.  y  PEREZ, PATRICIA. ON THE REDUCTION OF 4-OXO-4H-BENZOPYRAN-3-CARBALDEHYDES: GLOBAL AND LOCAL ELECTROPHILICITY PATTERNS‡. J. Chil. Chem. Soc. [online]. 2004, vol.49, n.1, pp. 35-38. ISSN 0717-9707.  http://dx.doi.org/10.4067/S0717-97072004000100007.

The theoretical global and local electrophilicity patterns of substituted and chelated 4-oxo-4H-benzopyran-3-carbaldehydes (formylchromones) have been evaluated using the electrophilicity index proposed by Parr et al [J. Am. Chem. Soc. 1999, 121, 1922]. The complexation of formylchromones with aluminum predicts a strong electrophilic character of these compounds against nucleophiles. Local response at the active sites may also be assessed in terms of a global contribution described by the global electrophilicity, and a local contribution described by the variations in electrophilic Fukui function at those sites. The highest local electrophilicity is found at the formyl group of the chelated formylchromones, in spite of that, the highest positive charge is located on the pyrone carbonyl group. This result is consistent with the experimental observed reactivity displayed by 4-oxo-4H-benzopyran-3-carbaldehydes in the presence of 2-propanol and alumina

        · texto en Inglés