Mesoporous hollow silicon dioxide nanospheres loaded with prolinol catalyst as well as preparation method and application of mesoporous hollow silicon dioxide nanospheres

Abstract

The invention discloses mesoporous hollow silicon dioxide nanospheres loaded with a prolinol catalyst as well as a preparation method and application of the mesoporous hollow silicon dioxide nanospheres. Mesoporous silicon dioxide with an ultra-large specific surface area is firstly prepared, a shell layer is very thin, and the maximization of the loading capacity is ensured. The mesoporous hollowsilicon dioxide nanospheres are effectively combined with the prolinol catalyst, and the defect that silicon dioxide is not easy to activate is overcome. The hollow silicon dioxide nanospheres and the prolinol catalyst are effectively combined and successfully applied to Michael / Michael / aldol cascade reaction with strict catalytic requirements, and a good result (ee is close to 100%, and Dr is 98: 2) is obtained. The catalytic effect is decreased progressively only after the catalyst is recycled for 8 times, which indicates that the structure of the silicon dioxide spheres is stable and a method for combining a hydrolysis method and an organic group is very suitable.

Description

technical field [0001] The invention belongs to the field of macromolecular materials and heterogeneous catalysis, and relates to a mesoporous hollow silicon dioxide nanosphere with a super large specific surface area loaded with a catalyst, a preparation method, and an application in an asymmetric series reaction. Background technique [0002] In recent years, hollow nanospheres have attracted increasing attention and research due to their unique properties, such as low density, good thermal stability and surface permeability, and large internal space. Many materials such as inorganic materials (zeolite, hydroxyapatite, titanium dioxide, alumina, gallium oxide, gallium nitride, etc.), organic polymer materials (polystyrene, etc.), have been made into hollow spherical structures and present conventional The special functions that materials do not have, are widely used in many fields such as drug sustained / controlled release systems, chromatographic separation, catalysts, coa...

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Problems solved by technology

[0004] Silica mesoporous nanospheres can provide a specific surface area of ​​30-150m2 g-1, for Catalytic reactions with large loading requirements are far from enough. In order to increase its specific surface area, reducing the shell thickness is also a common method in addition to passing through mesopores. However, the support force of nanospheres is limited, and the shell thickness is too thin. its collapse or rupture

Because the amount of prolinol catalyst added in the catalytic reaction is large (10-30mol%), it is difficult to separate, recycle and reuse the prolinol catalyst after the reaction, which increases the subsequent separation cost, pollutes the environment, and plays an important role in the development of green chemistry. to hinder

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