Benzyl triphenylphosphonium bromide is prepared by the following steps:To a solution of Ph3P (22 g, 0.084 mol) in toluene, BnBr (10 ml, 0.084 mol) was added dropwise with ice-cooling and stirred at room temperature for 2 hours. A solid was formed, which was filtered and washed with toluene and then dry pet ether to remove unreacted Ph3P. The salt was dried under vacuum (35 g, 96% yield).
Benzyltriphenylphosphonium bromide is used as a reactant for stereoselective azidolysis of vinyl epoxides, enantioselective aziridination and Friedel-Crafts cyclization for asymmetric synthesis of dihydrexidine, biomimetic iron(III) mediated oxidative dimerization for synthesis of benzoquinone parvistemin A, enantioselective synthesis of syn-diarylheptanoids from D-glucose, preparation of β-amyloid plaque ligands and decarboxylative cyclopropanation. It react with 4-methyl-oxetan-2-one to produce 4-hydroxy-1-phenyl-1-(triphenyl-l5-phosphanylidene)-pentan-2-one.
