Main-Chain Organic Frameworks with Advanced Catalytic Functionalities

Abstract

Over the past 10 years, there have been remarkable advances in the development of porous organic frameworks, which include covalent organic framework (COF), conjugated microporous polymer (CMP), porous aromatic framework (PAF), and covalent triazine framework (CTF). The emergence of organic frameworks brings about tremendous possibilities for heterogeneous catalyst development. In addition to well-controlled surface chemistry and porosity, these materials possess high physicochemical stability, high density or loading of functional groups with homogeneous distribution, and high surface area. These allow the organic framework catalysts to have potentially high activity and reusability. In particular, main-chain organic frameworks (MCOFs) represent a class of organic materials whereby the functionalities are directly embedded in the framework. They are generally synthesized through the “bottom-up” approach. In catalytic MCOFs, the functional moieties can have direct interactions with the main framework, leading to unique properties beyond the general advantages associated with porous polymer heterogeneous catalysts. Higher activity, selectivity, and stability can be attained with MCOF catalyst designs. This mini Review summarizes recent developments of MCOFs that have demonstrated superior catalytic properties as compared with their homogeneous analogs. The synthesis, structure and advanced functionalities of these MCOF catalysts are discussed, along with perspectives for future development.

Trends and challenges for microporous polymers

“…Excellent and comprehensive reviews on the use of microporous polymers for catalytic applications were recently published by Rose 40 and Zhang and Ying. 80 While microporous polymers certainly provide fascinating opportunities for catalytic applications some challenges remain, which are so far not or just rarely considered in the literature. It is understandable that initial works applying microporous polymers in catalysis use more or less conventional and well-studied molecular catalysts for immobilization.…”

Solid-Supported Palladium Catalysts in Sonogashira Reactions: Recent Developments

“…The use of covalent organic frameworks (COFs) [118] and metal-organic frameworks (MOFs) [119,120] as supports of NPs has also been considered due to their good properties in terms of stability, recyclability, high surface area and high pore volume. Thus, highly dispersed PdNPs have been immobilized into the covalent organic framework TpPa-1 by a simple solution infiltration method followed by NaBH 4 reduction, providing the heterogeneous catalyst PdNPs@TpPa-1 (70).…”

Porous aromatic framework (PAF-1) as hyperstable platform for enantioselective organocatalysis

“…Among the applications, immobilization of homogeneous catalysts, especially chiral catalysts, on cavity surfaces of the solid porous materials is of great importance. In this field, the latest developments involved enantioselective catalysis based on metal-organic frameworks (MOFs) [1][2][3][4][5][6][7][8][9][10][11][12][13][14], covalent organic frameworks (COFs) [15][16][17][18][19][20][21][22][23][24] and porous organic polymers (POPs) [25][26][27][28][29][30][31][32]. Many advantages of MOFs, COFs and POPs for heterogeneous enantioselective catalysis have been elaborated by scientists.…”