In Situ Dearomatisation/Alkylation of Arylphosphane Derivatives

The dearomatisation of aryldialkylphosphane–boranes and aryldialkylphosphane oxides under Birch reduction conditions, followed by treatment with reactive alkyl halides, provides the corresponding α-functionalised (cyclohexa-1,4-dien-3-yl)phosphane derivatives. This reaction offers a method of choice for the synthesis of bulky (cyclohexadienyl)phosphanes.