Synthesis and characterization of 1-and 2-(omega-alken-1-yl)indenes, theirlithium salts and dichlorozirconium(IV) complexes

A series of new 1-, 2-, and multi-substituted indenes has been synthesized and characterized. The reaction of indenyl lithium or 4,7-dimethylindenyl l ithium with alkenyl bromides yielded a mixture of 1- and 3-allylindene (1), 3-(3-buten-1-yl)indene (2), 3-(4-penten-1-yl)indene (3), 3-allyl-4,7-dimet hylindene (4), 3-(3-buten-1-yl)-3,7-dimethylindene (5), as well as 3-(4-pen ten-1-yl)-4,7-dimethylindene (6). The 2-substituted indenes 2-allylindene ( 7), 2-(3-buten-1-yl)indene (8), 2-(4-penten-1-yl)indene (9), 2-allyl-4,7-di methylindene (10), 2-(3-buten-1-yl)-4,7-dimethylindene (11), and 2-(4-pente n-1-yl)-3,7-dimethylindene (12) were prepared by PdCl2(DPPF) or NiCl2(DPPE) catalyzed cross-coupling reactions of the appropriate Grignard reagents wi th 2-bromoindene or 2-bromo-4,7-dimethylindene. Alkenylation of 3-methylind enyl lithium and 2,3,7-trimethylindenyl lithium produced 1-(3-buten-1-yl)-3 -methylindene (13) or 1-(3-buten-1-yl)-2,4,7-trimethylindene (14), respecti vely. The indene derivatives 1-14 react with n-butyl lithium in hexane yiel ding the corresponding lithium salts 1a-14a. Zirconium tetrachloride reacts with 1a, 2a, 4a-6a and 11a-14a under formation of the corresponding bis(in denyl)zirconium dichloride complexes 1b, 2b, 4b-6b and 11b-14b. All compoun ds were characterized by elemental analysis, H-1 and C-13{H-1}-NMR spectros copy and mass spectrometry, 5b and 12b also by single crystal X-ray structu ral analysis. 1b, 4b-6b and 11b-13b are active catalysts for the polymeriza tion of ethene and propene. (C) 1999 Elsevier Science S.A. All rights reser ved.