Synthesis and structures of unsymmetrical bis- and tris-cyclotriphosphazenes

Abstract

Synthesis and characterization of several unsymmetrical bis- and tris-spirocyclic cyclotriphosphazenes that include the ones with chiral 1,1'-bi-2-naphthol are reported. Specifically, the compounds N₃P₃(OCH₂CMe₂CH₂O)(HNCH₂CMe₂CH₂NH)Cl₂ (1), N₃P₃(OCH₂CMe₂CH₂O)(HNCH₂CMe₂CH₂NH)[(2,2'-OC₆H₄)₂] (2), N₃P₃(OCH₂CMe₂CH₂O)[(2-OC₁₀H₆)₂CH₂]Cl₂ (3), N₃P₃(OCH₂CMe₂CH₂O)[1,1'-O₂(C₁₀H₆)₂]Cl₂ (4), N₃P₃(OCH₂CMe₂CH₂O)(HNCH₂CMe₂CH₂NH) (1,1'-O₂(C₁₀H₆)₂) (5) and N₃P₃(OCH₂CMe₂CH₂O)[1,1'-O₂(C₁₀H₆)₂]₂ (6) are prepared by starting with the mono-spiro compound N₃P₃(OCH₂CMe₂CH₂O)Cl₄. No ansa type of compound was isolated from these reactions. X-ray structures of 1 and 2 have been determined. Synthesis of the tris-spiro compound N₃P₃[1,1'-O₂(C₁₀H₆)₂]₃ (7), possessing the 1,1'-bi-2-naphthoxy residue is also reported. Synthesis and structures of an unsymmetrical bis-spirocyclic (1) and the first example of an unsymmetrical tris-spirocyclic (2) cyclotriphosphazene is reported. In addition, several chiral cyclotriphosphazenes (e.g., 5 and 6) using 1,1'-bi-2-naphthol have been synthesized.