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SBA-15-functionalized melamine-pyridine group-supported palladium(0) was found to serve as a heterogeneous and recyclable nanocatalyst for N-arylation of indoles with aryl iodides under a low catalyst loading (0.3 mol% of Pd) through Ullmann-type C-N coupling reactions. A variety of aryl iodides could be aminated to provide the N-arylated products in good to excellent yields without the need of an inert atmosphere. Also, this catalyst was found to be an efficient system for the N-arylation of other nitrogen-containing heterocycles with aryl iodides. The heterogeneous palladium catalyst could be recovered by simple filtration of the reaction solution and reused for six cycles without significant loss in its activity.

A novel catalyst has been afforded by attaching of a Cu­(proline)2 complex to magnetic nanoparticles through cheap, simple, and readily available chemicals. This catalyst was characterized by Fourier transform infrared, energy-dispersive X-ray, X-ray diffraction, vibrating-sample magnetometry, transmission electron microscopy, scanning electron microscopy, and inductively coupled plasma analyses. The catalytic activity of the Fe3O4@NH2@TCT@HProCu nanocatalyst was investigated in a green and effective synthesis of pyran derivatives in high yields by applying three-component reactions of malononitrile, dimedone, and aldehydes in ethanol. Conversion was high under optimal conditions. The obtained nanocatalyst could be easily separated from the mixture of the reaction and was recyclable nine times via a simple magnet without considerable reduction of its catalytic efficiency. Operational simplicity, high product yields, environmental friendliness, ecofriendliness, economical processing, and easy workup are the features of this methodology.

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Magnetic nanoparticles have been proved as a tremendously powerful synthetic tool to achieve a milder process for the organic transformations and also suggested many potentialities in biomedical applications. They have an important role in the human health, environment protection, and energy resource management. Excellent reusability, easy separation of nanosized catalysts, and stability are the significant advantages of these catalysts. Hence, detailed studies on their synthesis mechanism for both chemical transformations and biomedical applications are crucial. In this review, we described a brief introduction of the dendrimers and various methods that are used for their synthesis, followed by the discussion of the syntheses and structures of magnetic nanodendrimers and their catalytic application in organic synthesis. We accordingly embarked on the studies on their synthesis mechanism for chemical transformations especially their surface modification since 2001.

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This review provides a concise overview of the synthesis of biologically and synthetically important β-hydroxy sulfides through the direct hydroxysulfenylation of the respective alkenes.