Magnetically separable mixed metal oxide nanocomposite (Pd/MnFe₂O₄) for Suzuki cross-coupling in aqueous medium

Magnetically separable Pd/MnFe₂O₄ nanocomposite has been synthesized by coupling palladium with MnFe₂O₄ via citrate gel auto combustion and deposition precipitation method. The physicochemical and microscopic study of Pd/MnFe₂O₄ was investigated using various characterization techniques. The zeta potential of the prepared nanocomposite Pd/MnFe₂O₄ was found to be highly negative value of -36.7 mV, which stabilizes the particle in its dispersed state and also helps to polarize the aryl-halide bond. The catalytic activity of Pd/MnFe₂O₄ was explored for Suzuki cross-coupling of aryl boronic acids and aryl halides (I, Cl, Br) in an aqueous medium. Interestingly, the rate of the slow oxidative addition step of the reaction is enhanced due to the high negative surface charge of the catalyst. It is worth mentioning that high turnover number (TON) and turnover frequency (TOF), thermal stability, ease of handling, nontoxic, magnetically separable, and recyclable are the remarkable properties of the present catalyst. Moreover, the protocol was found to be significant with respect to reaction time, substrate scope, the yield of products, and solvent used for the reaction.