In this article, we have developed a new protocol for the thioarylation of structurally diverse alkyl bromides such as benzyl, cinnamyl, n-octyl, cyclohexyl, cyclopentyl, and tert-butyl bromides with aryl iodides, bromides and an activated chloride using thiourea catalyzed by copper(I) iodide in wet polyethylene glycol (PEG 200) as an eco-friendly medium in the presence of potassium carbonate at 80 and 100 8C under an inert atmosphere. The process is free from foul-smelling thiols which makes this method more practical for the thioetherification of aryl halides. Another important feature of this method is the variety of alkyl bromides which are commercially available for the in situ generation of thiolate ions with respect to the existing protocols in which the less commercially available thiols are directly used for the preparation of arylthio ethers.

No abstract

A new polymer containing phosphorus and nitrogen ligands was successfully synthesized, characterized and used for the stabilization of highly monodispersed palladium nanoparticles having an average diameter of 2-3 nm. The thermally stable heterogeneous catalyst was successfully applied in Suzuki-Miyaura and copper-free Sonogashira-Hagihara coupling reactions of aryl halides under low palladium loading conditions. Reactions were proceeded in neat water without using any organic co-solvents. The catalyst was successfully recycled for the sample Suzuki-Miyaura reaction nine consecutive times with small drop in catalytic activity.

Magnetic Fe3O4 nanoparticles (NPs) functionalized with carbon dots (C‐dots) that contain carboxylic acid and hydroxyl groups were synthesized successfully and used for the reduction of PdII and the formation of Pd NPs. The new material was characterized by SEM, TEM, energy‐dispersive spectroscopy, solid UV spectroscopy, vibrating sample magnetometry, XRD, and X‐ray photoelectron spectroscopy and was used as a very efficient catalyst in the Suzuki–Miyaura cross‐coupling reaction of aryl bromides and chlorides with arylboronic acids in aqueous media. Design of experiments indicates that the use of 0.22 mol % of Pd, K2CO3 as the base, and aqueous ethanol are the best reaction conditions. The reactions of aryl bromides take place at room temperature, and aryl chlorides react at 80 °C. The easily synthesized and air‐stable catalyst Pd@C‐dots@Fe3O4 NPs could be separated from the reaction mixture by using an external magnet and reused in eight consecutive runs with no significant loss of catalytic activity.

No abstract

No abstract

No abstract

In this article, palladium nanoparticles supported on agarose were used as an efficient catalyst for Heck-Matsuda and Suzuki-Miyaura coupling reactions of structurally different aryldiazonium tetrafluoroborate substrates in aqueous media. Heck-Matsuda reactions proceeded at 40 C whereas Suzuki-Miyaura reactions were carried out at room temperature. Both reactions required low catalyst loading. The catalyst was also recycled for the model reaction for three runs.