Studies on organic reactions with catalysts on mesoporous materials

Abstract

Recent interest in the development of new inert and strong mesoporous materials with high surface area (MCM series, SBA15, CMK series, mesoporous polymer) has evoked a renewed interest in developing heterogeneous catalysts and reagents for organic synthesis. We prepared various catalysts loaded on mesoporous materials, which have extraordinary activities and selectivities. Pd@MCM48 prepared by CVI method, had 10nm sized Pd particles and showed extraordinary selectivity between hydrogenolysis and hydrogenation with additive BnBr. Additional benzyl bromide increased the rate of hydrogenolysis 3 times more than Pd@MCM48. This extraordinary selectivity has not been observed with conventional Pd catalysts. Pd-Ni/CMK3 prepared by wet infiltration, had excellent performance for Heck reaction of arylchloride and arylbromide in good yield and had many advantages, which is the highly active, air-stable, less toxic and reusable. Pd/CMK-3 with Buchwald’s ligand carried out room temperature Suzuki reaction of arylchloride. The mesoporous polymer has ordered, rigid, and porous structure. Phosphine grafting and Pd loading methods on this material were developed, and the resulting Pd catalyst loaded on mesoporous polymer, showed high activity for room temperature Suzuki reaction of arylchlorides and recyclability. (s)-diphenylprolinol oaded on mesoporous polymer performed enantioselective reduction of aromatic ketones in high yield and with better enantioselectivity than homogeneous catalyst and 1% cross-linked polymer supported catalyst. Mesoporous polymer is a useful tool which can make each catalyst separate. This character influences the selectivity and activity of catalyst. We showed applications of mesoporous materials as excellent heterogeneous catalyst’s supports and a mesoporous polymer’s probability of as tools of studies on the mechanisms of homogeneous catalysts.