STEREOSELECTIVE PROPENE POLYMERIZATION AT A METALLOCENE ALUMOXANE CATALYST DERIVED FROM THE CHIRALLY-SUBSTITUTED MESO-LIKE (P-R,P-S)-BIS[1-(NEOISOPINOCAMPHYL)-4,5,6,7-TETRAHYDROINDENYL]-ZIRCONIUM DICHLORIDE

Isopinocamphyl-tosylate (2) was treated with indenyllithium to yield 3-(neoisopinocamphyl)-indene (3). Treatment of 3 with methyllithium gave 1-(neoisopinocamphyl)indenyllithium (4) which was then treated with 0.5 molar equivalents of ZrCl4(thf)2 to give a 52:48 mixture of one of the ''racemic-like'' isomers of bis[1-(neoisopinocamphyl)indenyl]ZrCl2 (5A) and its ''meso-like'' diastereomer 5C. Hydrogenation of the 5A/5C mixture (50 bar H-2, Pt) furnished a mixture of the corresponding tetrahydroindenylzirconium complexes 6A and 6C, from which the ''meso-like'' bis[1-(neoisopinocamphyl)-4,5,6,7-tetrahydroindenyl]zirconium dichloride diastereoisomer (6C) was isolated. Treatment of 6C with an excess of methylalumoxane in toluene/propene generated an active alpha-olefin polymerization catalyst. At -30-degrees-C partly isotactic polypropylene (M(eta)BAR = 39000) was obtained. The catalyst derived from the chirally-substituted ''meso-like'' metallocene complex 6C produced polypropylene predominantly under enantiomorphic site control.