Immobilized Palladium Metal-Containing Ionic Liquid-Catalyzed Alkoxycarbonylation, Phenoxycarbonylation, and Aminocarbonylation Reactions

Immobilized palladium metal-containing ionic liquid (ImmPd-IL), a structurally well-defined transition metal complex, is explored as an immobilized, phosphine-free catalyst for carbonylation reactions, including alkoxycarbonylation, phenoxycarbonylation, and aminocarbonylation reactions. The effect of various reaction parameters, such as solvent, base, time, temperature, and CO pressure on carbonylation reactions using ImmPd-IL catalyst was investigated. The optimized protocol was applied to a wide variety of substituted aryl iodides and various alcohol/phenols and amines having different steric and electronic properties and afforded the corresponding products in good to excellent yield. The developed catalytic system circumvents the use of phosphine ligands, with an additional advantage of palladium catalyst recovery and reuse for up to four consecutive cycles. The recycled catalyst was characterized using XPS analysis.