作者:L. M. Khalilov、L. V. Parfenova、S. V. Rusakov、A. G. Ibragimov、U. M. Dzhemilev
DOI:10.1023/a:1009536328369
日期:——
The mechanism of cycloalumination of olefins under the action of AlEt3 in the presence of Cp2ZrCl2 giving rise to aluminacyclopentanes was investigated by dynamic H-1 and C-13 NMR spectroscopy. The bimetallic complex Cp2ZrEtCl-AlEt3 is formed initially and is converted into the bridged complex Cp2Zr(Cl)CH2CH2AlEt2 as a result of beta -hydride shift and elimination of the ethane molecule. The resulting complex adds a molecule of the initial olefin yielding aluminacyclopentanes. Under the action of Et2AlCl in the presence of an excess of AlEt3, zirconacyclopentanes give rise to intermediate bimetallic complexes stable at -70 degreesC. Under the reaction conditions, the latter compounds are converted into aluminacyclopentanes.