Further reactions of some bis(vinylidene)diruthenium complexes

Complexes containing 1-ruthena-2,4-diphosphabicyclo[1.1.1]pentane moieties, such as 3 and 4, have been obtained by treatment of bis(vinylidene)diruthenium complexes containing dppm with KOBut, by intramolecular attack of the deprotonated dppm ligand at C(1) of the vinylidene ligand.