THE EFFECT OF ORTHO SUBSTITUENTS IN SRN1 REACTIONS. SOME SYNTHETIC APPLICATIONS.

Article abstract of DOI:10.1016/S0040-4020(01)97188-1

Several ortho-substituted iodobenzenes were allowed to react, via the S_RNl mechanism, with mixtures of diethyl phosphite ion and pinacolone enolate ion.From product composition data, the relative reactivities of the two nucleophiles were reckoned.They represent relative reactivities in attachment to aryl radical intermediates.Most of the ortho effects are slight, but there is evidence that large ortho substituents hinder attachment of the phosphite more than the enolate nucleophile.The methoxy and diethoxyphosphoryl substituents, when para to the site of substitution, respectively favour and disfavour the phosphite with respect to the enolate ion.S_RNl reactions of ortho-substituted halobenzenes are, for some substituents, followed by other reactions which afford products of synthetic interest.