Studies On Preparation Of Schiff Base Modified SBA-15 Mesoporous Molecular Sieves And Its Application For The Reactions With Isatin

Mesoporous molecular sieve are special nano-structured materials of pore size(2~50nm), which have many advantages, such as highly ordered pore structure, thick cell walls, high hydrothermal stability. There are many silanol groups on pore surface, these hydroxyl groups can support organic compounds in the aperture surface, which is an excellent catalyst carried. Wherein, the SBA-15 mesoporous molecular sieve has a uniform tubular channels, a large aperture(4~30nm adjustable) and pore volume. The active ingredient or active molecules are introduced to prepare heterogeneous catalyst on the inner surface, which makes SBA-15 possess catalytic activity. Thus, Mesoporous molecular sieve SBA-15 has a widespread use in the field of molecular catalysis.Schiff base are a class of organic compound containing C=N double bond. These compounds and their metal complexes have important applications in medicine, catalysis, analytical chemistry, corrosion and photochromic field. In catalysis field, effective active sites can be provided by Schiff base in organic reaction. However, Schiff base catalysts with reaction solution are formed a homogeneous system in the catalytic process, which brings the problem to many researchers in the post-processing stage due to separate difficultly. Schiff base is supported on SBA-15 mesoporous molecular sieve which provides with the excellent physical and chemical properties and structural characteristics. The method not only can improve the catalytic performance of Schiff base, but also can be reused and solved the difficult separation and recycling problems of the catalyst.This article describes 2-phenyl-1,2,3-triazole Schiff base is grafted onto mesoporous molecular sieve SBA-15, which has been prepared heterogeneous catalyst, and its structure is characterized and studied the catalytic properties in organic reactions. The thesis was made up of two important parts:The first part is literature review. The application of modification of mesoporous molecular sieve SBA-15 was reviewed. In addition, research progress in supported catalysts for Knoevenagel condensation and three-component reaction is elaborated. The second part is experiment content, four parts were included:1. The mesoporous molecular sieve SBA-15 was functionalized with Schiff base, and characterized by means of XRD, FT-IR analysis, TEM and SEM.2. Knoevenagel condensation reaction of isatins with malononitrile or ethyl cyanoacetate was catalyzed by SBA-15/Schiff bases in aqueous medium.3. Study on Knoevenagel condensation reaction of isatins with Pyrazolone was catalyzed by SBA-15/Schiff bases4. Study on one-pot three-component reaction of isatins, malononitrile and active dicarbonyl compounds was catalyzed by SBA-15/Schiff bases in aqueous medium.