Design, Synthesis and Characterization of Palladium‐Functionalized Covalent Organic Framework and Its Application as Heterogeneous Catalysis for C−H Arylation of Azoles
W. T. Li, Yu‐Xuan Chen, S. K. KANG, Li‐Ping Mo, Zhan‐Hui Zhang
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 C-H arylation of azoles with aryl halides in 2-methyltetrahydrofuran. 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.