Synthesis and characterization of elusive cyclo-di- and -tri-phosphino-1,3-diphosphonium salts: fundamental frameworks in catena-organophosphorus chemistry.

Reaction of a cyclophosphinophosphonium cation with neat MeOTf represents a general and high-yield synthetic approach to dications enabling the isolation of the first derivatives of 2,4,5-triphosphino-1,3-diphosphonium as bis-triflate salts.