Attempts at immobilization of chiral ferrocene ligands on inorganic carriers I. A model study with rac-1-ferrocenylethyl acetate

Five different ways for anchoring of 1-ferrocenylethyl group via a spacer o nto silica and alumina were examined. The most promising route was found to be the step by step synthesis of ferrocenylethyl group linked to the space r having a terminal triethoxysilyl group followed by anchoring it onto the inorganic support. Modified silica and alumina were obtained as yellowish p owders. The loading of the ferrocenyl units on the resulting solids was det ermined by AAS and found to be 0.09 mmol/g for silica and 0.05 mmol/g for a lumina. The 1-ferrocenylethyl group modified silica was characterized by C- 13-CPMAS-NMR and diffuse reflectance FTIR spectra. The specific surface are a of this material was determined by nitrogen adsorption.