Supported DABCO-based ionic liquids for synthesis of heterocyclic compounds through multi-component reactions: a strategic approach
摘要
This review outlines a strategic method for immobilizing DABCO-based ionic liquids (ILs) on various solid supports to facilitate multi-component reactions (MCRs). DABCO (1,4-diazabicyclo[2.2.2]octane) is a rigid, nitrogen-rich bicyclic amine that has been functionalized to create a series of task-specific ILs. The immobilization of these ILs combines the advantages of traditional ILs with the practical benefits of heterogeneous catalysis. Attaching DABCO-based ILs to solid supports enhances their recovery and reusability while maintaining consistent catalytic activity. Various studies have evaluated their performance across different MCRs, demonstrating high yields, short reaction times, and mild conditions. Spectroscopic and analytical techniques have confirmed the structural integrity and stability of these catalysts. These catalysts function as both base and acid catalysts, facilitating substrate activation and improving reaction kinetics. Recycling studies showed minimal activity loss over multiple cycles, emphasizing their sustainability. The heterogeneous nature of the catalysts allows their easy separation from the reaction mixture, aligning with green chemistry principles. This review presents a versatile and eco-friendly platform for developing recyclable DABCO-based heterogeneous catalysts suitable for a broad range of organic transformations.
Graphical Abstract