α,β- and β,γ-unsaturated phosphonium salts in reactions with halogenating agents

Abstract

Reaction of 1,4-bisphosphonium salts containing common buta-1,3-dienylene group with the halogenating agenst such as halogens and copper halides is studied. It was found than in all the cases instead of the expected products of the 1,2- or 1,4-addition to the above-mentioned salts the adducts with complex anions were formed quantitatively. According to the X-ray studies of bis(tributylphosphonio)buta-1,3-dienotribromocuprate the positive charge on phosphorus is compensated with the complex [Cu2Br6]2− anion.