ChemInform Abstract: 1,2,5-Azadiphospholium and 1,3-Diphospholium Ions.

Abstract

Abstract Our attempt to synthesize 1,2λ5,5λ5-azadiphospholium ions by a cycloaddition reaction analogous to that leading to 1,2λ5-azaphospholines1 was not successful. An effective route is provided by the reaction of the bis(diphenylphosphino)amine and a haloacetylene as demonstrated for the phenylbromoacetylene. As an intermediate the alkynylphosphonium bromide is observed in the 31P NMR spectrum. An intramolecular nucleophilic attack of the second phosphino group onto the carbon β to the phosphonium center and a 1,3-proton shift completes the reaction.