First members of a novel family of constrained geometry complexes of titanium and zirconium containing a short bridge between the amide and inden-4-yl fragments were obtained. When activated with methylaluminoxane, these complexes can be used as highly active catalysts for ethene polymerization producing high-molecular-weight polymers.
A new procedure was developed for the synthesis of a broad range of ansa -zirconocenes containing bis(2-methyl-4-arylindenyl)dimethylsilane ligands. The method is based on the palladium-catalyzed reaction of halogen-substituted bis(indenyl)dimethylsilanes with various organozinc compounds. The aryl-substituted bridging ligands thus prepared serve as the starting compounds for the synthesis of ansa -zirconocenes, which can be used as components of promising catalysts for propylene polymerization.
Substituted 4-/7-halo-1H-indenes and 5-methyl-3-bromo-4-/6H-cyclopenta[b]thiophenes were shown to be convenient starting materials for Suzuki−Miyaura, Negishi, and Murahashi protocols to give the corresponding aryl-subsituted indenes and cyclopenta[b]thiophenes of importance for further synthesis of ansa-metallocenes. Alternatively, (2-methyl-1H-inden-4-yl)boronic acid and (1-methoxy-2-methyl-2,3-dihydro-1H-inden-4-yl)boronic acid as well as the respective organozinc and -magnesium reagents can be used for synthesizing aryl-subsituted indenes via the Pd-catalyzed reactions with aryl halides. These synthetic methods were shown to have a very broad scope to afford libraries of aryl-substituted indenes. Finally, synthesis and structure characterization of several representative chiral ansa-zirconocenes, potentially useful as components of highly active and stereoselective olefin polymerization catalysts, have been performed.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.