Coles Simon J, Davies David B, Eaton Robert J, Hursthouse Michael B, Kiliç Adem, Shaw Robert A, Uslu Aylin
Department of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BG, UK.
Dalton Trans. 2006 Mar 14(10):1302-12. doi: 10.1039/b512854d. Epub 2005 Nov 18.
Reactions of pentaerythritol with hexachlorocyclotriphosphazene, N3P3Cl6, and gem-disubstituted cyclotriphosphazene derivatives, N3P3Cl4R2 [R = Ph, NHBu(t) or (OCH2CF2CF2CH2O)0.5] gave a series of pentaerythritol-bridged derivatives linked spiro-spiro, spiro-ansa and ansa-ansa. The structures and stereogenic properties of the products were characterised by X-ray crystallography and 31P NMR spectroscopy on addition of the chiral solvating agent, (S)-(+)-2,2,2-trifluoro-1-(9-anthryl)ethanol. Molecules with spiro-spiro and spiro-ansa bridged gem-disubstituted cyclophosphazenes [R = Ph, NHBu(t) or (OCH2CF2CF2CH2O)0.5] are found to be chiral and exist as racemates. Molecules with ansa-ansa bridged cyclophosphazenes [R = Cl or (OCH2CF2CF2CH2O)0.5] have been characterised for the first time and are shown to have meso configurations. Analysis of crystal structure data shows that the six-membered chair form of the spiro rings and the eight-membered boat-chair form of the ansa rings in the bridged compounds are similar to analogous spiro and ansa exocyclic ring conformations of 1,3-propanedioxy-derivatives of cyclophosphazenes.
季戊四醇与六氯环三磷腈（N₃P₃Cl₆）以及偕二取代环三磷腈衍生物N₃P₃Cl₄R₂[R = Ph、NHBu(t) 或 (OCH₂CF₂CF₂CH₂O)₀.₅]反应，得到了一系列通过螺-螺、螺-ansa和ansa-ansa连接的季戊四醇桥连衍生物。通过X射线晶体学以及在手性溶剂化剂（S）-（+）-2,2,2-三氟-1-（9-蒽基）乙醇存在下的³¹P NMR光谱对产物的结构和立体化学性质进行了表征。发现具有螺-螺和螺-ansa桥连的偕二取代环磷腈[R = Ph、NHBu(t) 或 (OCH₂CF₂CF₂CH₂O)₀.₅]的分子是手性的，以外消旋体形式存在。具有ansa-ansa桥连环磷腈[R = Cl或 (OCH₂CF₂CF₂CH₂O)₀.₅]的分子首次得到表征，显示具有内消旋构型。晶体结构数据分析表明，桥连化合物中螺环的六元椅式构象和ansa环的八元船-椅式构象与环磷腈的1,3-丙二氧基衍生物的类似螺环和ansa外环构象相似。
