PROCESS FOR THE PREPARATION OF METALLOCENE COMPLEXES

摘要

The invention relates to a process comprising the step of (a) reacting a 2- indenylboranic acid (ester) with a bromosubstituted compound in the presence of the Pd catalyst bis(triphenylphosphin)palladium dichloride (PPh3)2PdCI2) and a base to form the corresponding bridged bis(indenyl) ligand. In case the 2-indenylboranic acid (ester) is the pinacolester of 2-indenylboranic acid, the process of the invention may further comprise the step of reacting a 2-bromo indene compound with pinacolborane in the presence of a Pd catalyst and a base, to form the corresponding 2- indenylpinacolylborane compound. With this, the invention provides an improved and easy two-step process to prepared bridged bis(indenyl)ligands, which is commercially very attractive when the Pd catalyst bis(triphenylphosphin)palladium dichloride (PPh3)2PdCI2) is used. Bridged bis(indenyl)ligands may suitably be used in the preparation of metallocene complexes, such as 2,2'-bis(2-indenyl)biphenyl ZrCI2 and 1,2-bis(2-indenyl)benzene ZrCI2. These metallocene complexes may be used for the polymerization, optionally in the presence of a cocatalyst, of one or more a-olefins, preferably for the polymerization of ethylene.