Copper-Mediated Amidation of Heterocyclic and Aromatic C−H Bonds

A copper-mediated aerobic coupling reaction enables direct amidation of heterocycles or aromatics having weakly acidic C−H bonds with a variety of nitrogen nucleophiles. These reactions provide efficient access to many biologically important skeletons, including ones with the potential to serve as inhibitors of HMTs.Chemistry and Chemical Biolog

Palladium nanoparticles supported on fluorine-doped tin oxide as an efficient heterogeneous catalyst for Suzuki coupling and 4-nitrophenol reduction

Immobilization of palladium nanoparticles onto the fluorine-doped tin oxide (FTO) as support Pd/FTO, resulted in a highly active heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions and 4-nitrophenol reduction. The Pd/FTO catalyst has been synthesized by immobilization of palladium nanoparticles onto FTO via a simple impregnation method. ICP-MS analysis confirmed that there is 0.11 mmol/g of palladium was loaded successfully on FTO support. The crystallinity, morphologies, compositions and surface properties of Pd/FTO were fully characterized by various techniques. It was further examined for its catalytic activity and robustness in Suzuki coupling reaction with different aryl halides and solvents. The yields obtained from Suzuki coupling reactions were basically over 80%. The prepared catalyst was also tested on mild reaction such as reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Pd/FTO catalyst exhibited high catalytic activity towards 4-NP reduction with a rate constant of 1.776 min(-1) and turnover frequency (TOF) value of 29.1 hr(-1). The findings revealed that Pd/FTO also maintained its high stability for five consecutive runs in Suzuki reactions and 4-NP reductions. The catalyst showed excellent catalytic activities by using a small amount of Pd/FTO for the Suzuki coupling reaction and 4-NP reduction

"Catalyst Recycling in Continuous Flow Reactors" in "Catalyst Immobilization. Methods and Applications"

This review summarizes the use of flow reactors, for the purpose of continuous catalyst separation and recycling in liquid‐phase fine chemistry organic transformations. An overview of the main separation strategies is provided, with a focus on cases where extended recycling of metal or metal‐free catalytic systems was demonstrated. Examples ranging from cross‐coupling and metathesis reactions to enantioselective transformations are discussed, trying to highlight the key factors towards the attainment of high total turnover number (TTON) and time on stream (TOS)