The first substitution reactions of N,N-spiro bridged octachlorobiscyclotriphosphazene

Unexpected Ring Expansion of a Four-Membered Cyclophosphazane

“…Then, a second phenoxy nucleophile in the medium attacks the bridgehead phosphorus atom, [P­(NR)­Cl], which is more reactive than the remaining PCl 2 groups presumably because of the involvement in the ansa ring resulting in the phenoxy group arrayed in a nongeminal fashion (Scheme b). The nucleophilic substitution reactions of compound 1 with mono- and difunctional amines, amino alcohols (unpublished work), and 1,2-ethanediol, which gives only spiro products, progress without rearrangement, and normal substituted derivatives form, in contrast to the results reported above.…”

“…Investigations of the reactions of these novel fused ring systems open up opportunities to uncover previously unexplored reactivity pathways and new fused ring architectures in phosphazene chemistry. We have reported the nucleophilic substitution reactions of N (R), N (R)-spiro-bridged octachlorobis­(cyclotriphosphazene) {N 3 P 3 Cl 4 [N­(CH 2 ) 5 CH 3 ] 2 N 3 P 3 Cl 4 } ( 1 ) with the sodium salt of 1,2-ethanediol in different stoichiometries and obtained only the spiro derivative products monospiro, dispiro (ipsilateral, cis , and trans ), and tetraspiro derivatives . In this investigation, the nucleophilic substitution reactions of compound 1 with two longer-chain diols (1,3-propanediol and 2,2,3,3,4,4-hexafluoro-1,5-pentanediol), both of which can give spiro and ansa products, is presented.…”

“…The unsubstituted cyclotriphosphazene rings (A) in compounds 3 and 4 are approximately planar, and the bond lengths and bond angles in these rings are found within the normal range for many cyclotriphosphazenes. − However, the substituted cyclotriphosphazene rings (C) containing phenoxy or fluorodioxy groups exhibit distortion and compression.…”