Cyclotri(λ³-phospliazane) / Cyclotri(λ³-phosphazanes)

Abstract

<jats:title>Abstract</jats:title><jats:p> P-perhalogenated cyclotri(λ<jats:sup>3</jats:sup> -phosphazanes) 3 a, b are obtained from the reaction of 1 or 2 with excess PX<jats:sub>3</jats:sub> (X = Cl, Br). Under mild reaction conditions 4-7 are found to be intermediates. The existence of a six-membered ring trimer is proven by NMR and mass spectroscopy. No dimer (XPNMe)<jats:sub>2</jats:sub> could be detected.</jats:p>

Insights into the formation of inorganic heterocycles via cyclocondensation of primary amines with group 15 and 16 halides

“…Thus, the reactions of an excess of PX3 (X = Cl, Br) with (MeNSiMe2)3 or (Me3Si)2NMe, which can be regarded as synthetic equivalents of MeNH2, yield the cyclic trimers [XP(μ-NMe)]3 whose identities were established by 31 P NMR spectroscopy and mass spectrometry. 22 The related ring system [ClP(μ-NEt)]3 is obtained in good yield from the reaction of PCl3 with ethylamine hydrochloride [EtNH3]Cl in boiling 1,1,2,2tetrachloroethane, 23 and it has been structurally characterised as the cis isomer (Fig. 2).…”

“…the preparation of the six-membered rings (XPNMe)3 (X = Cl, Br) from PX3 and the same reagent (Section 2.2.3). 22 Importantly, the 77 Se NMR chemical shift of Se4(NMe)4 facilitated the identification of the elusive tert-butyl derivative Se4(N t Bu)4 (15, R = t Bu), which is observed as a major product of the cyclocondensation reactions.…”

Reactions of phosphorus acid halides withN-silylated organic compounds

“…Monosubstitution occurs with equimolar amounts of the reagents and at low temperature. 41,42 The resulting N-silylamidophosphorodihalidites are thermally unstable and can be transformed to cyclotriphosphazanes on heating of the reaction mixture. 42,43 The reaction of alkylphosphonous dichlorides with methylbis(trimethylsilyl)amine also affords mono-and diphosphoryla-tion products, depending on the ratio of the reagents, 44 and boiling of equimolar amounts of the reagents in acetonitrile leads to cyclotetraphosphazanes.…”

“…41,42 The resulting N-silylamidophosphorodihalidites are thermally unstable and can be transformed to cyclotriphosphazanes on heating of the reaction mixture. 42,43 The reaction of alkylphosphonous dichlorides with methylbis(trimethylsilyl)amine also affords mono-and diphosphoryla-tion products, depending on the ratio of the reagents, 44 and boiling of equimolar amounts of the reagents in acetonitrile leads to cyclotetraphosphazanes. 45,46 The synthesis of N-trimethylsilyldialkylphosphinamidites by boiling dialkylphosphinous chlorides with an excess of hexamethyldisilazane in the presence of a catalyst was also described.…”

Identification of new N–Sb topologies: understanding the sequential dehydrochloride coupling of primary amines and trichloropnictines

“…Dehydrochloride coupling reactions have been reported for AsCl 3 8 and SbCl 3 , 9 but not for BiCl 3 , although reactions of alkali metal amides with PnCl 3 have been generally applied to prepare 2,4-substituted cyclo-2,4dipnicta-1,3-diazanes (Pn 5 As, [10][11][12][13][14] Pn 5 Sb, 9,14-22 Pn 5 Bi 14,22,23 ). Cyclotripnictatriazanes 8Pn are rare, [24][25][26] but recently we have realized that the presence of the medium sized substituents 2,6dimethylphenyl-(Dmp) or 2,6-diisopropylphenyl-(Dipp) at nitrogen facilitates transformation of the dimer 7 to the trimer 8 for Pn 5 P 27 or As. 28 Imposition of this subtle substituent steric strain on the stibazane system has now allowed for the identification of the amine-stibine adduct 1Sb, the bisaminestibine adduct 4Sb, the first acyclic dipnictadiazane 6Sb and the first six-membered cyclotristibatriazane 8Sb.…”