Preparation of metallacyclic titanocene hydrocarbyl complexes and their use in propene polymerization reactions

Article abstract of DOI:10.1016/0022-328X(91)86406-G

A series of differently-substituted bis(cyclopentadienyl)titanaindan complexes has been prepared, characterized, and employed as transition metal components of homogeneous titanocene/alumoxane Ziegler-type catalysts for propene polymerization reactions.The titanaindan systems 3a and 3b were synthesized via an aryne titanocene intermediate by means of thermolysis of Cp2TiPh2 (1a) or (H3CC5H4)2TiPh2 (1b) in the presence of ethylene.The analogous reactions of 1a, b with propene, 1-pentene or 1-decene gave the corresponding 3-substituted 1,1-bis(cyclopentadienyl)titanaindan systems (4a-d).The t-butyl Cp-substituted diphenyltitanocene complexes <(H3C)3CC5H4>CpTiPh2 (1c) and <(H3C)5CC5H4>2TiPh2 (1d) reacted in a different way.Their thermolysis proceeded cleanly by means of intramolecular C-H activation at the t-butyl substituent by the reactive aryne ligand to give the metallacyclic systems (RC5H4)Ph (5) (a: R = H; b: R = CMe3).The titanaindan complex 3a has been characterized by X-ray diffraction.