Deprotonated P-ylides As Templates for Novel Cyclopentadienyl Phosphonioalkyl, -alkylidene, and -alkylidyne (CpPC) Constrained-Geometry Complexes

作者：Schroeder Fabian G; Lichtenberg Crispin; Elfferding Michael; Sundermeyer Joerg^*

来源：Organometallics, 2013, 32(18): 5082-5091.

DOI：10.1021/om4005548

Cyclopentadienylidene phosphoranes of the general formula Cp-x-PR2-CH3 (1a-d) and anionic derivatives thereof have been investigated as ligands in the coordination sphere of zirconium (R = NMe2, tBu, Ph; Cp-x = C5H4, C5Me4, C5H2(CMe2)(2)CH2). The ligand set includes a full series of neutral and mono-, di-, and trianionic phosphonium ylides, which are formed by successive deprotonation of the PCH3 group. The degree of deprotonation can be controlled by choice of the ylides 1a-d and the zirconium precursor. The resulting zirconium complexes have been analyzed by NMR spectroscopy, elemental analyses, and single-crystal X-ray diffraction analyses. Our findings include the first fully characterized zirconium complex bearing a neutral cyclopentadienylidene phosphorane ligand, [Zr(H3C-P(NMe2)(2)-C5Me4)(CH2SiMe3)Cl-3] (3a). New constrained-geometry complexes with chelating Cp-x-phosphonio-alkyl ([Zr(CH2-PtBu2-C5H4)R%26apos;(3)]: 4b, R%26apos; = Bn; 4b%26apos;, R%26apos; = CH2SiMe3)) and Cp-x-phosphonio-alkylidene ligands ([Zr(CH-PR2-Cp-x)(CH2SiMe3)(2)]: 5a, R = NMe2, Cp-x = C5Me4; 5c, R = Ph, Cp-x = C5H2(CMe2)(2)CH2; 5d, R = Ph, Cp-x = C5Me4) have been isolated and characterized. [Zr(C-PR2-C5Me4)Bn](2) (6a, R = NMe2) is a rare example of a compound featuring a bridging trianionic phosphonium ylide (phosphonio-alkylidyne) ligand.

• 出版日期2013-9-23