Hansen Kerstin, Szilvási Tibor, Blom Burgert, Irran Elisabeth, Driess Matthias
Department of Chemistry, Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, 10623 Berlin (Germany), Fax: (+49) 30-314-29734.
Chemistry. 2014 Feb 10;20(7):1947-56. doi: 10.1002/chem.201303906. Epub 2014 Jan 16.
The stabilization of the labile, zwitterionic "half-parent" phosphasilene 4 L'Si=PH (L'=CH[(C=CH2)CMe(NAr)2]; Ar=2,6-iPr2C6H3) could now be accomplished by coordination with two different donor ligands (4-dimethylaminopyridine (DMAP) and 1,3,4,5-tetramethylimidazol-2-ylidene), affording the adducts 8 and 9, respectively. The DMAP-stabilized zwitterionic "half-parent" phosphasilene 8 is capable of transferring the elusive parent phosphinidene moiety (:PH) to an unsaturated organic substrate, in analogy to the "free" phosphasilene 4. Furthermore, compounds 4 and 8 show an unusual reactivity of the Si=P moiety towards small molecules. They are capable of adding dimethylzinc and of activating the S-H bonds in H2S and the N-H bonds in ammonia and several organoamines. Interestingly, the DMAP donor ligand of 8 has the propensity to act as a leaving group at the phosphasilene during the reaction. Accordingly, treatment of 8 with H2S affords, under liberation of DMAP, the unprecedented thiosilanoic phosphane LSi=S(PH2) 16 (L=HC(CMe[2,6-iPr2C6H3N])2). Compounds 4 and 8 react with ammonia both affording L'Si(NH2)PH2 17, respectively. In addition, the reaction of 8 with isoproylamine, p-toluidine, and pentafluorophenylhydrazine lead to the corresponding phosphanylsilanes L'Si(PH2)NHR (R=iPr 18 a; R=C6H5-CH3 18 b, R=NH(C6F5) 18 c), respectively.
不稳定的两性离子型“半母体”磷硅烯4 L'Si=PH（L'=CH[(C=CH2)CMe(NAr)2]；Ar=2,6-iPr2C6H3）现在可以通过与两种不同的给体配体（4-二甲基氨基吡啶（DMAP）和1,3,4,5-四甲基咪唑-2-亚基）配位来实现稳定，分别得到加合物8和9。DMAP稳定的两性离子型“半母体”磷硅烯8能够将难以捉摸的母体磷烯部分（:PH）转移到不饱和有机底物上，这与“游离”磷硅烯4类似。此外，化合物4和8的Si=P部分对小分子表现出异常的反应性。它们能够添加二甲基锌，并能活化H2S中的S-H键以及氨和几种有机胺中的N-H键。有趣的是，8的DMAP给体配体在反应过程中倾向于在磷硅烯处作为离去基团。因此，用H2S处理8，在释放DMAP的情况下，得到了前所未有的硫代硅烷膦LSi=S(PH2) 16（L=HC(CMe[2,6-iPr2C6H3N])2）。化合物4和8与氨反应分别都得到L'Si(NH2)PH2 17。此外，8与异丙胺、对甲苯胺和五氟苯肼的反应分别导致相应的膦基硅烷L'Si(PH2)NHR（R=异丙基18 a；R=苯甲酰基甲基18 b，R=NH(C6F5) 18 c）。
