Bifunctionalized Mesoporous Materials with Site-Separated Bronsted Acids and Bases: Catalyst for a Two-Step Reaction Sequence

摘要

Mesoporous silica has been regarded as an ideal support for heterogeneous catalysts because of its high surface area and tunable pore size. This interest has increased since the discovery of the ordered mesoporous material MCM-41, which led to a range of possibilities for the chemical design of novel heterogeneous catalysts. There has been rapid development of immobilized, reusable organocatalysts, and one of the major research interests is the functionalization of mesoporous silica with organic functional groups. The functionalization can be accomplished by using either postsyn-thesis grafting or co-condensation. The design and synthesis of bi- or multifunctionalized mesoporous silica containing multiple types of functional groups is appealing because these functional groups might be used as catalysts for a multistep reaction sequence requiring either a cooperative or independent catalytic performance.