57297-30-0Relevant articles and documents
Organophosphorous chemistry: Selective transformation of benzoin to benzil, desyl bromide, or benzyl phenyl ketone
Furukawa, Isao,Sasaki, Mitsuhiro,Inoue, Takeshi,Ohta, Tetsuo
, p. 85 - 99 (1998)
Reaction of benzoin with dibromotriphenylphosphorane under various conditions has been closely investigated. Benzoin was selectively converted to desyl bromide by treatment with dibromotriphenylphosphorane in the presence of triethylamine, while benzyl phenyl ketone was formed in the presence of an excess amount of triphenylphosphine. On the other hand, benzoin was effectively oxidized to benzil by treatment with only bromine. The mechanism of producing these was also proposed. Desyl bromide was formed from the reaction of benzoin with dibromotriphenylphosphorane as a primary product and converted to benzyl phenyl ketone via the Perkow reaction, and benzil was formed by the oxidation of benzoin by bromine. When triethylamine or triphenylphosphine was used as an added base, these bases trapped free bromine, and the oxidation product, benzil, was formed in low yield. In the presence of triphenylphosphine as a base, the Perkow reaction of desyl bromide proceeded smoothly to give benzyl phenyl ketone preferentially, while in the presence of triethylamine, replacement of the hydroxy group to bromide occurred mainly.