Palladated composite of MOF and cyclodextrin nanosponge: A novel catalyst for hydrogenation reaction

Abstract

In attempt to develop green protocols for organic transformations, a novel catalyst is prepared by combination of the features of metal-organic frameworks and polymers of cyclic carbohydrates. In detail, cyclodextrin nanosponge was synthesized from β-cyclodextrin that is a cyclic carbohydrate with capability of formation of inclusion complex and then hybridized with the as-prepared iron based metal-organic framework. The composite was then palladated to furnish a catalyst for hydrogenation of nitroarenes in aqueous media at ambient temperature. It was postulated that cyclodextrin nanosponge in the catalyst backbone can act as a nanoreactor to encapsulate and transfer nitroarenes in aqueous media and control the growth of Pd nanoparticles by acting as a capping agent. The results approved high efficiency of the catalyst, superior to the palladated CDNS and metal-organic framework. Using this catalyst, steric substrates with low solubility in water as well as substrates with competing functionalities could efficiently be hydrogenated. Moreover, the catalyst could be recycled several times with low Pd leaching and loss of activity.