Bimetallic PdCu nanoparticles can be applied as catalyst in a wide range of chemical and electrochemical reactions. This review article overviews the preparation and synthetic applications of these bimetallic nanoparticles...

A new heterogeneous catalyst derived from gold (III) and supported on caffeine‐coated magnetic nanoparticles, Fe3O4@Caff‐Au, has been prepared and characterized using different techniques. This magnetic gold composite shows high catalytic activity in A3 coupling reactions of terminal alkynes, aldehydes and secondary amines. Using this green catalyst, propargylamines are obtained in high turnover frequency in short reaction times using water as solvent at room temperature. This stable and ready accessible catalyst can be easily recycled magnetically for at least nine consecutive runs without significant loss of activity and with slight aggregation of Au species.

Research Highlights  Novel magnetic nanohydrogel supported Pd NPs are synthesized and characterized.  This material showed high efficiency for selective aerobic oxidation of alcohols.

Reaction of Ag(IPr)(Cl), 1 [IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene] with sodium precursors Na(mim) [mim=dihydrobis(methimazolyl)borate] and Na(Bb) [Bb=dihydrobis(2‐mercapto‐benzothiazolyl)borate] formed two novel silver complexes [Ag(IPr)(mim)], 2 and [Ag(IPr)(Bb)], 3. These complexes catalyzed three‐component coupling reaction of a series of aldehydes with alkynes and amines. The efficiency of these novel catalysts compared with that of 1 and Au(IPr)(Cl), 4.

The product obtained by reaction of deprotonation of 2‐mercaptobenzothiazole or methimazole (2‐mercapto‐1‐methylimidazole) with copper iodide in the presence of tertiary phosphines, PR2R' (R = R' = cyclohexyl; R = R' = phenyl; R = phenyl, R' = methyl) showed high catalytic activity in A3 coupling of a series of aldehydes with phenylacetylene and piperidine, yielding propargylamines. An investigation into the nature of active species carried out mainly by electrospray ionization mass spectrometry (ESI‐MS) techniques underscores a crucial role played by organosulfur and organophosphorus compounds in the generation of active species responsible for these reactions. The coupling reactions were successfully carried out at low catalyst loadings in water/THF (20:1) and in relatively short reaction times. The scope of the reaction was also investigated with 20 examples.