Some reactions of vinylphosphonium salts

Abstract

Methods for the preparation of alkyldiphenylvinylphosphonium salts have been investigated. Addition of unchanged phosphine to vinyl phosphonium salts frequently complicates these reactions and leads to either bis- or polymeric phosphonium salts. The addition of nucleophiles to the alkylvinyl salts to generate, after proton transfer, alkylidenephosphoranes has been investigated. Ylides have been formed from the salts Ph₂[graphic omitted] (CH₂R¹)·CR²:CH₂Br^–(R¹,R²= H; R¹= Ph, R²= H; R¹= C₆H₄Me-m, R²= Ph) : there is no evidence in their reactions of cyclisation to phosphetanes. The alkaline hydrolysis of triphenylvinylphosphonium bromide gives 1,2-bis(diphenyl-phosphinyl)ethane and diphenyl-1-phenylethylphosphine oxide.