Application of Mesoporous Membrane Catalyst containing Chiral Salen Complexes for the Synthesis of Optically Pure Epoxides

초록

The nanosciences have recently evolved as a major research direction of our modern society resulting from an ongoing effort to miniaturize at the nanoscale processes that currently use microsystems. The heterogene-ous chiral catalysts offer potential advantages of the facile separation from the reactants and products, as well as recovery and reuse. By the limitation of microporous zeolites as catalysts in processing large molecules of nanometer-scale sizes, the mesoporous materials have expanded the application areas, e.g. selective catalysts for large molecules and cooperative complexes for enantioselective catalytic reactions. Amphiphilic block copolymers, which are structurally analogous to low molecular weight nonionic surfactants, can be used as a structure-directing agent to produce nanostructures with a larger pore size.[1] In this work, mesoporous silica film fabricated from SBA-15, -16 sol was coated porous SiO2 matrix to make membrane catalyst, and the chiral salen compexes were immobilized into the porous silica films. This heterogeneous salen in the membrane system showed a high activity in asymmetric hydrolitic kinetic resolution(HKR) reaction of terminal epoxides with water.