Reactions du Phenyl-1 dimethyl-3,4 phosphole avec divers chlorures d'acides aromatiques

Abstract

1-Phenyl-3,4-dimethylphosphole with water and substituted benzoyl chlorides or 2- and 3-thienyl chlorides is expanded into 2-hydroxy-l,2-dihydrophosphorines. This reaction is particularly affected by steric effects. It fails with aliphatic acid chlorides. These results are not fully explained by a competition between the expansion reaction and the hydrolysis of the chlorides. A complementary explanation is proposed. The 2-hydroxy-1,2-dihydrophosphorines are in turn expanded into 1-oxa-2-phosphacyclohepta-4,6 dienes with catalytic amounts of NaH. This other expansion reaction seems to be only weakly affected by steric but more strongly by electronic effects. It fails with thienyl derivatives. Nuclear magnetic resonance data are given and discussed for all the new products. Large P–C–OH couplings in hydroxydihydrophosphorines are noteworthy.