Methylbenz[e]indenyl asymmetric ansa-metallocene and silylamido zirconium complexes

Abstract

by reaction with ZrCl 4 (THF) 2 and TiCl 3 (THF) 3 and further oxidation with PbCl 2 (Ti). All of the new complexes were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of complexes 9 and 10a were studied by X-ray diffraction methods. #

Diastereoselective Insertion of Isocyanide into the Alkyl−Metal Bond of Methylbenz[e]indenyl ansa‐Zirconocene Complexes

“…[26] We also report the results found from our studies of catalytic activity of these dichloro-metallocenes in the homopolymerization of ethylene and copolymerization of ethylene/1-hexene.…”

“…The dichloro ansa-zirconocenes [Zr{(η 5 -C 5 H 5 )EMe 2 (η 5 -2-MeϪC 13 H 7 )}Me 2 ] (E ϭ C: 1a, E ϭ Si: 1b) containing the MBI ligand were isolated previously [26] by reaction in toluene of ZrCl 4 (THF) 2 with the dilithium salts of the corresponding ϪCMe 2 Ϫ and ϪSiMe 2 -bridged indenyl-cyclopentadienyl derivatives, as shown in Scheme 1.…”

“…Ellipsoid plot of compound 3 (50% probability level); hydrogen atoms have been omitted for clarity [12,26,31,32] The most remarkable difference is the orientation of the two nonequivalent benzyl ligands. One is located above the plane (torsion angle Cp MBI ϪZr(1)ϪC(1)ϪC(11) 62.6°) while the other is located below (torsion angle Cp MBI ϪZr(1)ϪC (2)ϪC (21) 158.1°), with respect to the C(1)ϪZr (1)ϪC (2) plane.…”

“…IR spectra were performed in nujol mulls on a PerkinϪElmer 883 spectrophotometer. NMR spectra, measured at 25°C, were recorded on a Varian Unity FT-300 ( 1 H NMR at 300 MHz, 13 [26] , Li(CH 2 SiMe 3 ) [40] and K(CH 2 C 6 H 5 ) [41] were prepared following the literature methods. …”

Chiral Complexes of a New Diazaallyl Ligand: Group 4 Aminooxazolinates

“…, [(ebthi)ZrCl 2 ], I , to mediate both stereoselective polymerizations and the enantioselective transformation of small molecules has been well documented. , However the drawbacks associated with the resolution of these compounds may ultimately preclude their commercial use in nonracemic form for asymmetric catalysis . One approach to this problem has been via the development of chiral cyclopentadienyl (Cp) ligands, , but apart from some notable exceptions 5c,7 this has led to limited success. We are engaged in another approach whereby chiral non-Cp ligands are used to generate stereogenic architectures directly .…”