Self-Assembly of Nanoparticles in a Modular Fashion to Prepare Multifunctional Catalysts for Cascade Reactions: From Simplicity to Complexity

ACS Omega. 2019 Jan 17;4(1):1549-1559. doi: 10.1021/acsomega.8b03098. eCollection 2019 Jan 31.

Abstract

One-pot cascade reactions can simplify the synthetic route and reduce the use of solvents and energy. The critical part of the completion of the cascade reaction is the preparation of multifunctional catalysts. In this work, a novel and simple pathway was developed to construct multifunctional catalysts with acidic, basic, and magnetic properties at the same time. Mesoporous silica materials modified with different metal oxides were used as catalytic elements. Microspheres that assembled with catalytic components have a diameter of 150 μm and a specific surface area larger than 400 m2 g-1 and can be used as catalysts for cascade reactions. The yield of the final product in the deacetalization-Knoevenagel reaction is 92%. Microspheres integrated with Fe3O4 nanoparticles have a magnetic susceptibility of 7.2 emu g-1 and can be easily removed from the reaction system by applying an external magnetic field. This multimodule assembly method fully reflects the enormous power of complexity resulting from simplicity. This method provides a reference and practical technical support for the preparation of other multifunctional materials.