Design, Synthesis and Characterization of Palladium‐Functionalized Covalent Organic Framework and Its Application as Heterogeneous Catalysis for C−H Arylation of Azoles

Abstract

A novel triazine-based covalent organic framework (TFPT-Bz COF) has been constructed by the condensation of 2,4,6-tris(5-formyl-2-pyridinoxy)-1,3,5-triazine (TFPT) and benzidine (BZ) with deep eutectic solvent (DES) as the reaction medium. After the introduction of Pd ions through strong coordination to TFPT-Bz COF matrix, the constructed TFPT-Bz COF/Pd composite exhibited excellent catalytic activity for CÀ H arylation of azoles with aryl halides in 2methyltetrahydrofuran. The protocol allows the arylation of a variety of substituted azoles with diverse aryl halides in high to excellent yield. Moreover, the TFPT-Bz COF/Pd catalyst can be recycled several times without significantly reducing its activity.

Challenges in photocatalysis using covalent organic frameworks

“…COFs are generally synthesized using dynamic chemistries, and under proper synthesis conditions result in crystalline, nanoporous materials [10][11][12][13][14]. COFs are useful for a variety of applications including separations [15,16], catalysis [17,18], energy storage [19,20], ion transport [21,22], and electronics [23,24]. They are also all-organic and synthesized using relatively simple building blocks and reaction steps.…”

Utility of silver nanoparticles embedded on a covalent organic framework as a highly active catalyst for carboxylative cyclization with CO2: a sustainable route for production of tetronic acids and oxazolidinones

“…This simplifies the planned synthesis of building blocks and enables the realization of variation in structure and functioning across COFs. 30–34…”

Construction of Palladium Nanoparticles Modified Covalent Triazine Frameworks towards Highly-Efficient Dehydrogenation of Dipentene for p-Cymene Production

“…CTF is composed of aromatic N-C=N structure of triazine ring unit by covalent bond. However, most CTF materials have the problem of high exciton binding energy and weak electron transport capacity [33,34]. Nitrogen in CTF can improve the catalytic reaction performance of supported palladium nanoparticles in the following aspects: (1) The nitrogen sites (particularly sp 2 N-C=N nitrogen in the triazine unit) can provide anchoring sites for metals, so that the metal nanoparticles can be evenly dispersed and anchored on the support, and the size of the metal nanoparticles can be finely controlled; (2) The negative electrical properties presented by the nitrogen site can increase the electron density of the metal particles so that the metal can maintain a high catalytic performance; (3) nitrogen sites could remain the metal in metallic state during air contact, and metal on nitrogen sites may promote absorption of reactants or desorption of products [35][36][37][38].…”