The diverse behaviour of the P–Cl bonds in the spiro–cis–ansa spermidine derivative cyclotriphosphazene towards mono-functional nucleophilic reagents

A number of new spiro–ansa spermidine derivative cyclotriphosphazenes (2–10) is synthesized in order to provide insight into the reaction mechanism for nucleophilic substitution. The structures of the compounds were determined by elemental analysis, mass (MS), ¹H, ¹⁹F (for 9) and ³¹P NMR spectroscopies. Compounds (2–8) and 9, 10 can be formed by a proton abstraction–chloride elimination and both the and reaction mechanisms, respectively.