An Expedient Synthesis of Dialkylphosphane-Borane Complexes from Sodium Phosphide, and Their Alkylation under Phase-Transfer Conditions

Abstract

A group of seven achiral, α- and β-chiral dialkylphosphanes were synthesized in one step from sodium phosphide and alkyl sulfonates or sulfates. The corresponding borane complexes were further alkylated with alkyl, allyl, and benzyl bromides and mesylates to give tertiary mono- and diphosphanes, either via lithium phosphide-borane complexes at low temperature (45-78%) or under phase-transfer conditions (79-91%).