The CH by N Replacement Effects on the Aromaticity and Reactivity of Phosphinines

Abstract : Geometries, aromatic character, Mulliken charge distribution, and MO diagrams of 1,2-aza-, 1,3,2- diaza-, 1,3-aza-, and 1,3,5-diazaphosphinines have been calculated and compared to those of phosphinine and pyridine. This study reveals that the introduction of nitrogen atoms at the position adjacent to phosphorus significantly reduces the aromatic delocalization and induces a [1,4] dipolar character through an increase of the positive charge on the P atom. This phenomenon does not occur in 1,3-aza- and 1,3,5-diazaphosphinines, which exhibit a poor dipolar character. This comparison confirms the high reactivity of 1,3,2-diazaphosphinines toward alkynes. A [4 + 2] cycloaddition reaction between these two types of diazaphosphinines and acetylene has been modelized. Calculated geometries of the resultant [4 + 2] diazabarrelene cycloadducts and that of their respective transition states reveal that, especially with 1,3,2-diaza isomers, the cycloaddition proceeds via a disymmetrical pathway that involves the preliminary formation of the P-C bond.
Type de document :
Article dans une revue
Liste complète des métadonnées
Contributeur : Gilles Frison <>
Soumis le : mardi 9 mars 2010 - 00:19:36
Dernière modification le : vendredi 22 mars 2019 - 01:39:12

Lien texte intégral



Gilles Frison, Alain Sevin, Narcis Avarvari, François Mathey, Pascal Le Floch. The CH by N Replacement Effects on the Aromaticity and Reactivity of Phosphinines. Journal of Organic Chemistry, American Chemical Society, 1999, 64, pp.5524-5529. ⟨10.1021/jo9903611⟩. ⟨hal-00462246⟩



Consultations de la notice