2-Lithioindenyllithium: An Easily Accessible Intermediate for the One-Pot Synthesis of Single- and Double-Functionalised 2-Indene Derivatives

We found that double-silicon-bridged bisindenyl complexes of early transition metals of group 4 are able to produce polyethylenes with high molecular weights and narrow molecular-weight distributions having high α-olefin incorporation. The bottle-neck for the synthesis of these complexes is the ligand synthesis. The corresponding ligands could be obtained via a three-step procedure with low (15%) overall yields. We found that the use of the new 2-lithioindenyllithium enhanced the overall yield to 50% in a one-pot procedure.