The Lanthanide Ziegler−Natta Model:  Aluminum-Mediated Chain Transfer

C 2-symmetric tetraalkylaluminate complexes rac-[Me2Si(2-Me-C9H5)2]Y(μ-R)2AlR2 and terminal alkyl complexes rac-[Me2Si(2-Me-C9H5)2]YR(THF) (R = Me, Et, iBu) are quantitatively formed via a special silylamide elimination reaction. The “reversibility” of tetraalkylaluminate coordination gives access to the first mixed-alkyl lanthanidocene complexes, which can be discussed as models for polymer chain transfer in organoaluminum-dependent Ziegler−Natta catalysts.