Synthesis of an ansa-Zirconocene via a NovelS4-Symmetric Spirobis(silastannaindacene) Compound
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چکیده
منابع مشابه
Cyclomagnesation of dienes catalyzed by a chiral ansa-zirconocene
The biphenyl-bridged. chiral zirconocene complex rac-2.2' -biphenyl-bis( 3.4-dimethylcyclopentadienyl I zirconium dichloride catalyzes the reaction of 1.6and 1,7 -dienes with excess dibutyl magnesium to bis( butyl-magnesio-methyl '-substituted cycloalkanederivatives. Analogous reactions occur with butyl magnesium chloride and with heteroatom-t.:Ontaining dienes. The preference of 1.6-dienes for...
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Reduction of Zr(IV) metallocenium cations with sodium amalgam (NaHg) produces EPR signals assignable to Zr(III) metallocene complexes. The chloro-bridged heterodinuclear ansa-zirconocenium cation [(SBI)Zr(μ-Cl)2AlMe2](+) (SBI = rac-dimethylsilylbis(1-indenyl)), present in toluene solution as its B(C6F5)4(-) salt, thus gives rise to an EPR signal assignable to the complex (SBI)Zr(III)(μ-Cl)2AlMe...
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Novel synthetic approaches to chiral ethylene-bridged ansa-titanocenes possessing stereogenic centers on the bridging carbon chain are described. A key step in the preparation of these compounds is the double-Skatteberl rearrangement of bis(vinyldibromocyc1opropane) intermediates derived from 1,4-disulfones. The influence of tether substitution on the diastereoselection in ansa-titanocene forma...
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Starting from 1,1'-diacetylferrocene the ortho-amino,α-dimethylamino[3]ferrocenophane system 3 was prepared. This was converted to the o-imino,α-Cp-derivative 6. Subsequent treatment with e.g. an excess of methyllithium followed by ZrCl(2)(NMe(2))(2)(thf)(2) and Me(2)SiCl(2) eventually gave the [3]ferrocenophane based Cp-amido zirconium complex 11b. In a similar way the [3]ferrocenophane derive...
متن کاملKinetic resolution of racemic -olefins with ansa-zirconocene polymerization catalysts: Enantiomorphic site vs. chain end control
Copolymerization of racemic -olefins with ethylene and propylene was carried out in the presence of enantiopure C1-symmetric ansa metallocene, {1,2-(SiMe2)2( -C5H-3,5-(CHMe2)2)( -C5H3)}ZrCl2 to probe the effect of the polymer chain end on enantioselection for the Ror S-olefin during the kinetic resolution by polymerization catalysis. Copolymerizations with ethylene revealed that the polymer cha...
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ژورنال
عنوان ژورنال: Angewandte Chemie International Edition
سال: 1998
ISSN: 1433-7851,1521-3773
DOI: 10.1002/(sici)1521-3773(19980904)37:16<2268::aid-anie2268>3.0.co;2-y