Reactions of 4-Halo-2-alken(arylen )ylphosphonium Salts with Binucleophiles

摘要

Phosphonium salts with a 4-bromo-3-chlorobut-2-enyl or a 3-chlorobuta-l,3-dienyl group react with phenylhydrazine to give phenylhydrazones of corresponding 4-phospohonio-substituted 2-chloro-2-butenals.Reactions of phosphonium salts containing a 4-bromo-3-chlorobut-2-enyl group with a series of binucleophiles were studied.Under the action of urea,1,4- dehydrobromination takes place to form a salt with a conjugated diene group,which undergoes partial 3,4-3,4-cyclization under the reaction conditions.Nucleophilic substitution reactions of [o-(bromomethyl)benzyl]triphenylphosphonium bromide with binucleophiles were also carried out.