Synthesis and characterisation of bulky guanidines and phosphaguanidines: precursors for low oxidation state metallacycles
作者:Guoxia Jin、Cameron Jones、Peter C. Junk、Kai-Alexander Lippert、Richard P. Rose、Andreas Stasch
DOI:10.1039/b809120j
日期:——
Reactions of alkali metal amides or phosphides with the bulky carbodiimide, ArNCNAr (Ar = C6H3Pri2-2,6), followed by aqueous work-ups, have yielded several guanidines, ArNC(NR2)N(H)Ar (R = cyclohexyl (GisoH) or Pri (PrisoH); NR2 = cis-NC5H8Me2-2,6 (PipisoH)), a bifunctional guanidine, ArNCN(H)Ar}2μ-N(C2H4)2N} (Pip(GisoH)2), and two phosphaguanidines, ArNC(PR2)N(H)Ar (R = cyclohexyl (CyP-GisoH) or Ph (PhP-GisoH)). A very bulky guanidine, ArNCN(Ar)SiMe3}N(H)Ar (ArSi-Giso), and an aryl coupled bifunctional guanidine, ArN(H)C(NPri2)NC6H2Pri2-2,6-}2 (PrisoH)2, have been prepared by other routes. All compounds have been crystallographically characterised and shown to exist in a number of isomeric forms in the solid state. These appear to be largely retained in solution. The deprotonation of GisoH with BunLi in either hexane or THF led to crystallographically characterised dimeric and monomeric complexes respectively, viz. [LiLi(κ2-N,N′-Giso)2}] and [Li(THF)(η1-N,η3-Ar-Giso)]. Deprotonation of PrisoH and Pip(GisoH)2 with K[N(SiMe3)2] gave the unsolvated polymer, [K(η1-N,η6-Ar-Priso)}∞], and the solvated complex, [K(THF)2}Pip(Giso)2}K(THF)3}], respectively.
碱金属酰胺或磷化物与大体积碳二亚胺 ArNCNAr(Ar = C6H3Pri2-2,6)反应,然后进行水性加 工,得到了几种胍类化合物 ArNC(NR2)N(H)Ar(R = 环己基 (GisoH) 或 Pri (PrisoH));NR2=顺式-NC5H8Me2-2,6(PipisoH))、一种双官能胍,ArNCN(H)Ar}2μ-N(C2H4)2N}(Pip(GisoH)2)和两种磷胍,ArNC(PR2)N(H)Ar(R=环己基(CyP-GisoH)或 Ph(PhP-GisoH))。我们还通过其他方法制备了一种非常笨重的胍类化合物 ArNCN(Ar)SiMe3}N(H)Ar (ArSi-Giso),以及一种芳基偶联双官能胍类化合物 ArN(H)C(NPri2)NC6H2Pri2-2,6-}2 (PrisoH)2。所有化合物都经过了晶体学表征,并显示在固态下存在多种异构体。这些异构体似乎在溶液中基本保持不变。GisoH 与 BunLi 在己烷或四氢呋喃中发生去质子化反应,分别生成了具有晶体学特征的二聚体和单体复合物,即 [LiLi(κ2-N,N′-Giso)2}] 和 [Li(THF)(η1-N,η3-Ar-Giso)]。PrisoH 和 Pip(GisoH)2 与 K[N(SiMe3)2] 发生去质子化反应后,分别得到非溶解聚合物 [K(η1-N,η6-Ar-Priso)}∞] 和溶解复合物 [K(THF)2}Pip(Giso)2}K(THF)3}]。