Diphospha-Ureas from the Phosphaketene Ph3GePCO

The phosphaketene Ph₃GePCO is shown to react with the phosphide KP(tBu)₂ to generate the anion [Ph₃GePC(O)P(tBu)₂]⁻ 1 . This species reacts with CH₃I or ClGePh₃ to give the dissymmetric diphospha-ureas (tBu)₂PC(O)P(GePh₃)(CH₃) 2 and (Ph₃Ge)₂PC(O)P(tBu)₂ 3 respectively. Sequential treatment of 2 with a base and CH₃I affords a route to (tBu)₂PC(O)P(CH₃)₂ 5 . These species are products of the first modular diphospha-urea synthesis. The subsequent thermal and photochemical reactivity of these species was also probed and described.