Herein, we describe the first example of copper-catalyzed oxidative thioamination of maleimides with secondary amines and Bunte salts with the achievement of C–N and C–S bonds in a single flask. The protocol showcases a prominently broad substrate scope and is also efficient for the late-stage modification of an array of pharmaceuticals. Preliminary mechanistic investigation indicates copper-catalyzed oxidative amination of maleimides with amines to form reactive enaminone and subsequent intermolecular alkenyl C–H thiolation.

Arguments regarding the biocompatibility of graphene-based materials (GBMs) have never ceased. Particularly, the genotoxicity (e.g., DNA damage) of GBMs has been considered the greatest risk to healthy cells. Detailed genotoxicity studies of GBMs are necessary and essential. Herein, we present our recent studies on the genotoxicity of most widely used GBMs such as graphene oxide (GO) and the chemically reduced graphene oxide (RGO) toward human retinal pigment epithelium (RPE) cells. The genotoxicity of GO and RGOs against ARPE-19 (a typical RPE cell line) cells was investigated using the alkaline comet assay, the expression level of phosphorylated p53 determined via Western blots, and the release level of reactive oxygen species (ROS). Our results suggested that both GO and RGOs induced ROS-dependent DNA damage. However, the DNA damage was enhanced following the reduction of the saturated C–O bonds in GO, suggesting that surface oxygen-containing groups played essential roles in the reduced genotoxicity of graphene and had the potential possibility to reduce the toxicity of GBMs via chemical modification.

A copper-catalyzed decarboxylative alkylselenation of propiolic acids with Se powder and epoxides leading to alkynyl selenides is developed. This protocol not only provides an approach to obtain alkynyl selenides with the formation of double CÀ Se bonds, but also expands the applicability of alkynyl carboxylic acid.

A copper-catalyzed oxidative carboamination of maleimides with alkyl amines and α-bromo carboxylates is described. These multicomponent reactions show good functional group compatibility and are suitable for the late-stage modification of a series of neuroprotective agents, providing a direct path for the library synthesis of 3-carbo-4-amino maleimides. The initial copper-catalyzed oxidative amination of maleimides with amines to form enamines intermediate, followed by copper-catalyzed radical alkylation with α-bromo carboxylate compounds, triggers a relayed catalytic reaction to achieve the carboamination process.

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