Green Synthesis of Pd Nanoparticles for Sustainable and Environmentally Benign Processes

Among transition metal nanoparticles, palladium nanoparticles (PdNPs) are recognized for their high catalytic activity in a wide range of organic transformations that are of academic and industrial importance. The increased interest in environmental issues has led to the development of various green approaches for the preparation of efficient, low-cost and environmentally sustainable Pd-nanocatalysts. Environmentally friendly solvents, non-toxic reducing reagents, biodegradable capping and stabilizing agents and energy-efficient synthetic methods are the main aspects that have been taken into account for the production of Pd nanoparticles in a green approach. This review provides an overview of the fundamental approaches used for the green synthesis of PdNPs and their catalytic application in sustainable processes as cross-coupling reactions and reductions with particular attention afforded to the recovery and reuse of the palladium nanocatalyst, from 2015 to the present.

Novel Recyclable Pd/H-MOR Catalyst for Suzuki-Miyaura Coupling and Application in the Synthesis of Crizotinib

In this paper, we report an effective ultrasound method for the synthesis of Pd/H-MOR, which was used as a catalyst in the Suzuki-Miyaura coupling of aryl halides with phenylboronic acid. The structure and morphology of the as-prepared catalysts were fully characterized by X-ray diffraction (XRD), N2 sorption isotherms, scanning electron microscopy (SEM), and an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The advantages of Pd/H-MOR in the coupling reaction are green solvents, high yields, absence of ligands, and recyclability. The catalysts were easily reused at least ten times without significant deterioration in catalytic activity. In addition, this protocol was used in the marketed anti-tumor drug crizotinib synthesis.

Design of a new multi-functional catalytic system Ni/SO3H@zeolite-Y for three-component synthesis of N-benzo-imidazo- or -thiazole-1,3-thiazolidinones

In this investigation, a nanoporous zeolite-NaY supported sulfonic acid was synthesized and Ni(ii) ions were successfully stabilized on SO₃H@zeolite-Y (Ni/SO₃H@zeolite-Y). This novel type of zeolitic nanocomposite was characterized using various techniques including FT-IR, FE-SEM, TGA, BET and EDX. Ni/SO₃H@zeolite-Y was used as a multi-functional and highly active nanocatalyst for the three-component synthesis of 3-benzimidazolyl-1,3-thiazolidin-4-ones and new 3-benzthiazoleyl-1,3-thiazolidin-4-ones via cyclocondensation of 2-aminobenzimidazole or 2-aminobenzothiazole, aromatic aldehydes and thioglycolic acid in acetone-H₂O at room temperature. This economical chemical procedure has advantages such as excellent yield in short reaction times, convenient manipulation and high purity of products, applicability to a broad range of substrates, and the use of a nontoxic and heterogeneous acid catalyst with good reusability.

Synthesis and Characterization of Magnetic Zeolite Y-Palladium-Nickel Ferrite by Ultrasonic Irradiation and Investigating Its Catalytic Activity in Suzuki-Miyaura Cross-Coupling Reactions

Zeolite faujasite is widely used as a catalyst in many industrial catalytic applications. In this study, synthesis and characterization of magnetic zeolite Y-palladium-nickel ferrite were studied. First, palladium nanoparticles were combined with nickel ferrite and then placed on zeolite Y by ultrasonic treatment. The structure and morphology of the synthesized magnetic zeolite Y-palladium-nickel ferrite were characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray, vibrating sample magnetometer, and inductively coupled plasma optical emission spectroscopy analysis. Also, we investigated the catalytic activity of this prepared zeolite in Suzuki-Miyaura coupling reaction between phenylboronic acid and aryl halides. Our study shows that magnetic zeolite Y-palladium-nickel ferrite is a suitable catalyst for Suzuki-Miyaura coupling reaction. Short reaction time, high yield, and easy reusability are the advantages of using this catalyst in carbon-carbon cross-coupling reactions.