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چکیده
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In this study, a novel heterogeneous palladium catalyst based on natural asphalt was designed and synthesized via stepwise construction of a 1-aza-15-crown-5 ether ligand followed by selective immobilization of palladium species. The synthetic route involved sonobromination of natural asphalt, subsequent functionalization with diethanolamine through reaction with alkyl bromide sites, and its sequential S N 2 and ring-closure reactions with 1,2-dichloroethane and dichloroethane to generate the aza-crown ether framework, which served as a multidentate coordination site for Pd incorporation. The resulting natural asphalt supported 1-aza-15-crown-5 ether-Pd catalyst was thoroughly characterized and evaluated in the Suzuki–Miyaura cross-coupling reaction of various aryl halides with phenylboronic acid using ethanol as a green solvent. The catalyst exhibited excellent activity, affording biaryl products in high …
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