A practical synthesis of chiral and achiral phosphonium salts from phosphine borane complexes

Article abstract of DOI:10.1016/S0040-4039(97)00647-3

Phosphine borane complexes are transformed under mild conditions, in presence of an olefin, into quaternary phosphonium salts by reaction with an alkyl (or aryl) halide. In the case of the reaction of (R)-PAMP.BH₃ 1e with benzyl bromide, the enantiomerically pure phosphonium salt 3h is obtained.