Synthesis of a novel ethylene-bis(tetrahydroindenyl) ligand containing a functionalized four-carbon tether

In this work we present an efficient synthesis of a novel ethylene-bis(2-methyl-tetrahydroindenyl) ligand, 2b, containing a tethered functional group. The tethered functional group may enable heterogenization of the homogeneous ligand on various solid supports. This strategy is the first attempt of incorporating a functional tether into a bridged metallocene ligand without disrupting the ethane bridge and represents a new approach to heterogenizing metallocene ligands. A practical synthesis was achieved by selective alkylation of the starting material and the Pauson–Khand cyclization. In addition, this strategy offers a new synthetic pathway for the preparation of the ethylene-bis(2-methyl-tetrahydroindenyl) ligand, 1b.