New chiral heterogeneous catalysts based on mesoporous silica: Asymmetric diethylzinc addition to benzaldehyde

Abstract

New heterogeneous catalyst systems have been developed employing a proline-derived ligand immobilized on mesoporous silicas; asymmetric diethylzinc addition to benzaldehyde was carried out using the catalyst systems; the reaction enantioselectivity was found to be largely dependent upon the pore size of the mesoporous silicas, capping of free silanol moieties with trimethylsilyl group and employment of (BuLi)-Li-n.