The rearrangement of allylic phosphines
Abstract
Reduction of the allylic phosphine oxides, Ph2P(O)CR1R2·CH:CH2, with phenylsilane followed by rapid distillation gives the crude allylic phosphines, Ph2P·CR1R2·CH:CH2, which rearrange at 210° to the more stable phosphines Ph2P·CH2CH:CR1R2. This rearrangement is catalysed by traces of silanes or silanols; the pure allylic phosphines do not rearrange under these conditions. Diphenyl-1(1-phenylallyl)phosphine gave with methyl iodide the prototropically rearranged methyldiphenyl-(1-phenylprop-1-enyl)phosphonium iodide.