Synthesis and Reactivity of Cyclic (R₃P-PR₃)⁺⁺Dications

1,2-Dications in Organic Main Group Systems

“…Nevertheless, the fact that the electron shells of phosphorus are more diffuse compared to those of nitrogen permits milder conditions for the alkylation than in the case of hydrazinium salts. For instance, methylation of cyclic diphosphine 306 by methyl triflate proceeds rapidly at the room temperature to give diphosphonium dication 307 …”

“…For instance, methylation of cyclic diphosphine 306 by methyl triflate proceeds rapidly at the room temperature to give diphosphonium dication 307. 329 This method was used to prepare several propellane diphosphosphonium salts 309 from cyclic diphosphines 308 and bis-triflates of R,ω-alkanediols. 330 The reaction proceeds readily in a polar solvent (nitromethane) but stops at the first alkylation step when dichloromethane is used as a solvent.…”