The reactive intermediate Me3SiNPCl was trapped with dmb to form the cyclic phosphazane Me3SiN(dmb)PCl, which eventually oligomerizes to give 5. In the presence of dmb or chd (chd = 1,3-cyclohexadiene) (Me3Si)2NP(OTf)2 reacts by eliminating Me3SiOTf to yield the spirocyclic phospholenium salts [Me3SiN(dmb)P(dmb)][OTf] (7) and [Me3SiN(chd)P(chd)][OTf] (8), of which the solid state structures were successfully