ansa-metallocene derivatives XXXIX biphenyl-bridged metallocene complexes of titanium, zirconium, and vanadium: Syntheses, crystal structures and enantioseparation
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چکیده
منابع مشابه
ansa-Metallocene derivatives XXI *. Syntheses of etheno-bridged ansa-titanocene derivatives by the McMurry reaction
207 Novel olefin-linked biscylopentadienylligands have been prepared by McMurry coupling reactions of benzoyland acetyl-cyclopentadienyl sodium. Reactions of the disodium salts with TiC1 4 or TiCl 3 • 3THF afford the alkene-bridged ansa-titanocene dichlorides. 13C-NMR shifts of the bridge carbon atoms do not indicate any interaction between the olefin 'IT-system and the metal.
متن کاملansa - Metallocene derivatives XXIII * .
9 Titanocene and zirconocene complexes with a phenyl or I-naphthyl substituent in one ,B-position of each Cs-ring ligand and with an interannular tetramethylethanoor dimethylsilano-bridge have been prepared. Racemic complex isomers, which are formed together with varying amounts of their meso isomers, were separated from the latter and characterised by lH NMR spectroscopy and X-ray crystallogra...
متن کاملAnsa-tris(allyl) complexes of alkali metals: tripodal analogues of cyclopentadienyl and ansa-metallocene ligands.
Alkali metal complexes of two types of ansa-tris(allyl) ligand are reported; a monoanionic ansa-tris(allyl) ligand containing tin(II) is formally valence isoelectronic to the cyclopentadienyl ligand and a trianionic ansa-tris(allyl) ligand containing silicon(IV) is formally valence isoelectronic to an ansa-metallocene ligand; the potential wider use of these tripodal ligands in coordination che...
متن کاملUnique sigma-bond metathesis of silylalkynes promoted by an ansa-dimethylsilyl and oxo-bridged uranium metallocene.
The tetrachloride salt of uranium reacts with 1 equiv of the lithium ligand Li2[(C5Me4)2SiMe2] in DME to form the complex [eta5-(C5Me4)2SiMe2]UCl2.2LiCl.2DME (1), which undergoes a rapid hydrolysis in toluene to yield the dimeric bridged monochloride, monooxide complex [{[eta5-(C5Me4)2SiMe2]UCl}2(mu-O)(mu-Cl)*Li*1/2DME]2 (2). Metathesis of 2 with BuLi in DME gives the mono-bridged dibutyl compl...
متن کاملAnsa-metallocene polymerization catalysts derived from [2+2]cycloaddition reactions of bis(1-methylethenyl-cyclopentadienyl)zirconium systems.
Bis(1-methylethenyl-cyclopentadienyl)zirconium dichloride (7a) was prepared by a fulvene route. Photolysis at 0 degrees C with Pyrex-filtered UV light resulted in a rapid and complete intramolecular [2+2]cycloaddition reaction to yield the corresponding cyclobutylene-bridged ansa-zirconocene dichloride isomer (8a). This is one of the rare examples of an organic functional group chemistry that l...
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ژورنال
عنوان ژورنال: Journal of Organometallic Chemistry
سال: 1997
ISSN: 0022-328X
DOI: 10.1016/s0022-328x(97)00064-8