Preparation of Tetrasubstituted Bis(3-indolyl)methanes from Indoles and Acetophenes Using 1,3-Dibromo-5,5-dimehtylhydantoin as an Efficient Catalyst

A new process that could efficiently prepare tetrasubstituted bis(3-indolyl)methanes from various indoles and acetophenones with 1,3-Dibromo-5,5-dimehtylhydantoin(DBDMH) as a catalyst was reported. The effects of catalysts, solvents, and reaction temperature were investigated. Under the optimal condition, most of the tetrasubstituted bis(3-indolyl)methanes were obtained in 90–99% yields.

Photocatalytic Degradation of Fluoroquinolone Antibiotics in Solution

The photocatalytic degradation of two quinolone-type antibiotics (ciprofloxacin and levofloxacin) in aqueous solution was studied, using catalysts based on ZnO nanoparticles, which were synthesized by a thermal procedure. The efficiency of ZnO was subsequently optimized by incorporating different co-catalysts of gC3N4, reduced graphene oxide and nanoparticles of gold. The catalysts were fully characterized by electron microscopy (TEM and SEM), XPS, XRD, Raman, and BET surface area. The most efficient catalyst was 10%Au@ZnONPs-3%rGO-3%gC3N4, allowing to obtain degradations of both pollutants above 96%. This catalyst has the largest specific area, and its activity has been related to a synergistic effect, involving factors as relevant as the surface of the material and the ability to absorb radiation in the visible region, mainly produced by the incorporation of rGO and gC3N4 to the semiconductor. The use of different scavengers during the catalytic process, was used to establish the possible photodegradation mechanism of both antibiotics.

Copper(II)-Bis-Cyclen Intercalated Graphene Oxide as an Efficient Two-Dimensional Nanocomposite Material for Copper-Catalyzed Azide–Alkyne Cycloaddition Reaction

We report stable and heterogeneous graphene oxide (GO)–intercalated copper as an efficient catalyst for the organic transformations in green solvents. The GO-intercalated copper(II) complex of bis(1,4,7,10-tetraazacyclododecane) [Cu(II)-bis-cyclen] was prepared by a facile synthetic approach with a high dilution technique. The as-prepared GO-Cu(II)-bis-cyclen nanocomposite was used as a click catalyst for the 1,3 dipolar Huisgen cycloaddition reaction of terminal alkyne and azide substrates. On directing a great deal of attention toward the feasibility of the rapid electron transfer rate of the catalyst in proliferating the yield of 1,2,3-triazole products, the click catalyst GO-Cu(II)-bis-cyclen nanocomposite was designed and synthesized via non-covalent functionalization. The presence of a higher coordination site in an efficient 2D nanocomposite promotes the stabilization of Cu(I) L-acetylide intermediate during the catalytic cycle initiated by the addition of reductants. From the XRD analysis, the enhancement in the d-interlayer spacing of 1.04 nm was observed due to the intercalation of the Cu(II)-bis-cyclen complex in between the GO basal planes. It was also characterized by XPS, FT-IR, RAMAN, UV, SEM, AFM, and TGA techniques. The recyclability of the heterogeneous catalyst [GO-Cu(II)-cyclen] with the solvent effect has also been studied. This class of GO-Cu(II)-bis-cyclen nanocomposite paves the way for bioconjugation of macromolecules through the click chemistry approach.

NiSe2/FeSe2 heterostructured nanoparticles supported on rGO for efficient catalyst towards water electrolysis

To develop a cost-effective and highly abundant catalyst for overall water splitting is highly desirable. Herein, we report a feasible approach to fabricate a catalyst based on phase-separated heterointerfaces in...

Copper and palladium bimetallic sub-nanoparticles were stabilized on modified polyaniline materials as an efficient catalyst to promote C-C coupling reactions in aqueous solution

The modified polyaniline self-stabilizing Cu/Pd bimetallic sub-nanocluster Composite materials (Cu/Pd@Mod-PANI-3OH) are obtained through three steps of oxidative polymerization, structural modification, and metal self-trapping. Palladium and copper are confined and coordinated...