Tetramethylphosphonium bromide is an organophosphorus compound with the formula (CH3)4PBr. It is a white, water-soluble solid, the salt of the cation tetramethylphosphonium and the bromide anion. It is prepared by treating trimethylphosphine with methyl bromide.
Reactions
Deprotonation gives methylenetrimethylphosphine ylide, which can sustain a second deprotonation: (CH3)4PBr + BuLi → (CH3)3P=CH2 + LiBr + BuH (CH3)3P=CH2 + BuLi → (CH3)2P(CH2)2Li + BuH
The latter is a precursor to many coordination complexes, e.g., the dicuprous complex Cu2[(Me2P(CH2)2]2.
References