Electrochemical synthesis has been rapidly developed over the past few years, while a vast majority of the reactions proceed through a radical pathway. Understanding the properties of radical intermediates is crucial in the mechanistic study of electrochemical transformations and will be beneficial for developing new reactions. Nevertheless, it is rather difficult to determine the “live” radical intermediates due to their high reactivity. In this work, the formation and structure of sulfonamide N-centered radicals have been researched directly by using the time-resolved electron paramagnetic resonance (EPR) technique under electrochemical conditions. Supported by the EPR results, the reactivity of N-centered radicals as a mediator in the hydrogen atom transfer (HAT) approach has been discussed. Subsequently, these mechanistic study results have been successfully utilized in the discovery of an unactivated C­(sp3)–H arylation reaction. The kinetic experiments have revealed the rate-determined step is the anodic oxidation of sulfonamides.

A novel electrochemical radical selenylation of alkenes and activated arenes without external oxidants is reported. The diselenide was fully transformed into Se-centered radicals through electrochemical Se−Se bond activation. Three-component radical carbonselenation was successfully realized using styrenes to trap the RSe radical. Besides, the direct coupling of RSe radicals with activated arenes was further developed. Using this atom-economic protocol, diversity of unsymmetric aryl−aryl, aryl-alkyl, and alkyl−alkyl selenoethers was obtained regioselectively, which has potential application in biological chemistry.

The heterocycles containing N and O are important structures in pharmaceuticals, agrochemicals and functional molecules. The synthesis of these compounds usually needs complex substrates and harsh reaction conditions. Herein, we...

In this study, polyetherimide‐graphene composites (PEI/G) were prepared and investigated as corrosion inhibition coatings on copper substrates. Various loadings of graphene were incorporated in the polyetherimide matrix using an in situ polymerization approach, and the composite coatings were cured by thermal imidization. The effect of graphene loading on corrosion inhibition and the long‐term performance of the PEI/G coatings were investigated. The dispersion of graphene in the polymer matrix was examined using SEM and TEM. The study demonstrated that PEI/G nanocomposites provide advanced corrosion inhibition of copper. This conclusion was supported by the results of various electrochemical techniques such as Tafel polarization and electrochemical impedance spectroscopy (EIS). In addition to corrosion protection, the long‐term performance of the coatings was confirmed by testing the adhesion of PEI/G composites to copper substrates before conducting the electrochemical tests and after 15 days of exposure to the corrosive medium.

In this article, polyurethane/graphene nano-platelet (PU/GnP) composites were fabricated via planetary centrifugal mixer (PCM) and cast on polyethylene terephthalate (PET) and copper substrates.

The synthesis of diarylamine is extremely important in organic chemistry. Herein, a novel electrochemical reductive arylation of nitroarenes with arylboronic acids was developed. A variety of diarylamines were synthesized without the need for transition‐metal catalysts. The reaction could be scaled up efficiently in a flow cell and several derivatization reactions were carried out smoothly. Cyclic voltammetry experiments and mechanism studies showed that acetonitrile, formic acid, and triethyl phosphite all played a role in promoting this reductive arylation transformation.

Organoselenium compounds are important structures in medicinal chemistry, material chemistry and biochemistry. The selenation of pharmaceutical molecules is a promising way to find new drugs. Herein, we introduced an electrochemical...

Abstract. Epoxy-Graphene (E/G) nanocomposites with different loading of graphene were prepared via in situ prepolymerization and evaluated as protective coating for Stainless Steel 304 (SS304). The prepolymer composites were spin coated on SS304 substrates and thermally cured. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were utilized to examine the dispersion of graphene in the epoxy matrix. Epoxy and E/G nanocomposites were characterized using X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) techniques and the thermal behavior of the prepared coatings is analyzed using Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The corrosion protection properties of the prepared coatings were evaluated using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) measurements. In addition to corrosion mitigation properties, the long-term adhesion performance of the coatings was evaluated by measuring the adhesion of the coatings to the SS304 substrate after 60 days of exposure to 3.5 wt% NaCl medium. The effects of graphene loading on the impact resistance, flexibility, and UV stability of the coating are analyzed and discussed. SEM was utilized to evaluate post adhesion and UV stability results. The results indicate that very low graphene loading up to 0.5 wt % significantly enhances the corrosion protection, UV stability, and impact resistance of epoxy coatings.