Role of Zr,Al Hydride Intermediate Structure and Dynamics in Alkene Hydroalumination with XAlBui2 (X = H, Cl, Bui), Catalyzed by Zr η5 Complexes
摘要:
The zirconocene complexes L2ZrCl2 (L = C5H5, C5H4Me, Ind, C5Me5; L-2 = rac-Me2C(2-Me-4-Bu-t-C5H2)(2), meso-Me2C(2-Me-4-Bu-t-C5H2)(2), rac-Me2C(3-Bu-t-C5H3)(2), rac-Me2C(Ind)(2), rac-Me2Si(Ind)(2), and rac-C2H4(Ind)(2)) were tested as catalysts in alkene hydroalumination by the isobutylalanes XAlBu2i (X = H, Cl, Bu-i). A low-temperature NMR spectroscopy study on the structure and dynamics of Zr,Al intermediates formed in the L2ZrCl2-XAlBu2i systems showed that the intra- and intermolecular exchange in the bimetallic clusters, controlled by the steric factor of the eta(5) ligand and organoaluminum compound nature, determines the activity of the whole catalytic system.
Mechanism of Cp2ZrCl2-catalyzed olefin hydroalumination by alkylalanes
作者:L. V. Parfenova、S. V. Pechatkina、L. M. Khalilov、U. M. Dzhemilev
DOI:10.1007/s11172-005-0254-z
日期:2005.2
The composition of intermediates of the Cp2ZrCl2-catalyzed hydroalumination of α-olefins by isobutylalanes (HAlBui2, AlBui3, ClAlBui2) was studied by dynamic 1H and 13C NMR pectroscopy. The reaction of Cp2ZrCl2 with isobutylalanes affords the complex (Cp2ZrHCl·HAlBui2)2 responsible for α-olefin hydroalumination.