Recent progress on functional mesoporous materials as catalysts in organic synthesis

The heterogenization of homogeneous catalysts has attracted great attention owing to their increasing environmental and economic considerations. Mesoporous materials are a kind of attractive candidates due to their unique structural features, such as high surface areas, uniform and tunable pore sizes and shapes, large pore volumes, and easy to be functionalized. Therefore, mesoporous materials have been used as catalysts or their supports for homogeneous catalysis in the past decades. This review concerns the very recent development in this area, including the catalyst design, the types of active species, and the reaction catalyst by this kind of catalysts. Mesoporous catalysts can be classified as supported catalyst and bulk one. The supported catalyst includes active site in the pore wall framework, the active site on the pore wall surface, and the active site encapsulated in the mesopores. The bulk one can be directly used as catalyst, which includes metal oxides and carbon nitrides. Next, four different types of active sites, nanoparticles, highly distributed metals, anchored organic catalysts, and immobilized enzymes, are summarized in this review. Then five types of organic reactions are summarized. With the development of electrochemistry in organic synthesis in recent years, a brief outlook is also discussed.