Diphospha-Ureas from the Phosphaketene Ph3 GePCO.

The phosphaketene Ph3 GePCO is shown to react with the phosphide KP(tBu)2 to generate the anion [Ph3 GePC(O)P(tBu)2 ]- 1. This species reacts with CH3 I or ClGePh3 to give the dissymmetric diphospha-ureas (tBu)2 PC(O)P(GePh3 )(CH3 ) 2 and (Ph3 Ge)2 PC(O)P(tBu)2 3 respectively. Sequential treatment of 2 with a base and CH3 I affords a route to (tBu)2 PC(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.