Title : Mesoporous silica is a mysterious material: From viewpoints of its catalysis for direct amidation reaction of carboxylic acids and amines
Mesoporous silica is a material having a uniformed mesopore, a large specific surface area and a pore volume, and a topology reflecting its bulk architectural matrix. Almost reported catalytic reactions using mesoporous silica have been relied on the Brønsted acid site by introducing Al into the framework. We found that the siliceous mesoporous silica showed the excellent catalytic activity for direct amidation using equimolar amounts of carboxylic acids (including fatty acids) and amines, and recently reported that the catalytic activity (the initial reaction rate) uniquely depended on the pore size of the catalyst SBA-15 having P6mm topology. In this reaction, the catalyst after the calcination can be recycled and reused without loss of its catalytic activity, and successfully applied in the synthesis of procainamide. In this honorable lecture, the brief background of recent heterogeneous amidations and the selected our reported characteristic feature of this reaction system will be introduced, and unique results that we are just facing on will propose to realize not only the reason why mesoporous silica is a mysterious but also the importance of pore size when you will use mesoporous silica as a catalyst.