Hydrido complexes zirconium

Zirconium(iv) and Hafnium(iV) Hydrido-complexes.—Yields of up to 95% of Zr(BH4)4 were obtained by grinding solid ZrCl4 with UBH4. Zirconium tetra-... 

Zirconocene derivatives are used to catalyse a range of organic hydrogenation and C—C bond-forming reactions. In the presence of methylaluminoxane, chiral complex A catalyses asymmetric hydrogenations (see Section 26.4), with the active species being a cationic zirconium hydrido complex. 

In their early studies, Schwartz and co-workers [5, 80] reported the zirconocene hydrido chloride [Cp2Zr(H)Cl] (1) as a reagent capable of reacting under mild conditions with a variey of non-functionalized alkenes to form isolable alkylzirconi-um(lV) complexes Cp2Zr(R)Cl in which the zirconium is attached to the least-hindered terminal primary carbon, irrespective of the original location of the double bond in the olefin chain. As an example, at room temperature in benzene, 1-octene, cis-4-octene and trows-4-octene all yield the n-octylzirconocene derivative (Scheme 8-6) [80]. 

Along similar lines, Schwartz and Gell later reported that tertiary phosphines would also induce reductive elimination in bis(i7-cyclopenta-dienyl) (cyclohexylmethyl) (hydrido)zirconium resulting in high yields of zirconocene bis(phosphine) complexes (53-55). Carbon monoxide was found to readily react with a benzene solution of Cp2Zr(PMePh2)2... 

Choukroun, R.. Iraqi, A.. Gervais, D., Daran, f.C. and Jeannin, Y. (1987) A semibridging hydrido zirconium-rhodium complex A possible way to catalytic hydrogen transfer on do-de systems. Organometallics. 6. 1197-1201. 

The unsymmetrical silyl-hydrido zirconium dimer, Cp2Zr(SiPhMeH) (p-H)2(SiPhMe2) ZrCp2, similar to the above-mentioned complex 6, was isolated from the dehydrogenative coupling reaction of phenylmethylsilane with dimethylzirconocene. The X-ray analysis of the dimer shows a disorder which is produced by the ordered superposition of two... 

In most mixed alkyl silyl zirconium derivatives, CO insertion occurs preferentially into the Zr-C bond83,85,252,253. However, in sterically congested complexes, insertion occurs into the Zr-Si bond to give silaacyl alkyl compounds such as CpJZr [q2-COSiHMes2]Me (48)85 and CpCp Zr[ 2-COSi(SiMe3)3]Me (49)250,253. Complexes 48 and 49 readily and cleanly isomerize to the hydrido, silyl-substituted enolates... 

HClZrC oH, ), Zirconium, chlorobis(Ti -cyclopentadienyl)hydrido-, 28 259 HF2O2P, Phosphorodifluoridic acid, rhenium complex, 26 83 HFj04P2PtSC 4H34, Platinum(II), hydrido-(methanol)bis(triethylphosphine)-, trans-, trifluoromethanesulfonate, 26 135... 

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