Spin-state control of electrochemical catalyst for selective Oxygen-Atom transfer and Hydrogen Abstraction

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In the modern chemical industry, epoxides have been regarded as pivotal ingredients for chemical synthesis. In general, the reactive three-membered heterocyclic ring in epoxides can be opened by nucleophilic groups, thus easily introducing diverse functionality. Currently, thermochemical routes are employed to epoxide target olefins under elevated temperature and high pressure. Given that the whole country aims to build a carbon-neutral society, it would be essential to exploit sustainable methodologies to replace the current route.

Herein, we report electrocatalytic epoxidation via the generation of Co-oxo intermediate in Co-TAML(tetraamido macrocyclic ligand) molecular catalysts. 

Electrochemical Nitric Oxide Synthesis via Cobalt Oxide Nanocatalysts

 Studies on the reactions of biological molecules in cells are crucial to reveal the molecular mechanisms behind biological processes. Nitric oxide (NO) is a significant gaseous signaling molecule with diverse physiological roles, including neuronal signal transmission and maintaining biological system homeostasis. Interestingly, the role of NO has been debated, as it can have both anti-tumor and pro-tumor effects depending on its concentration. The diffusive nature of NO and its rapid decaying have posed challenges in studying its role. In this study, we developed an electrochemical platform to regulate NO gas supply to cells and explore its effects on tumor cells.

  Our study aims to systematically investigate the role of NO through spatiotemporal regulation. The platform employs metal oxide nanocatalysts, with iron oxide (Fe3O4) nanoparticles exhibiting selective NO generation under low overpotentials. Using our spatio-temporal electrochemical platform ESCoRT(Electrochemical System for Conveyance of Radicals to Tumor cell), we systematically investigated the role of NO by studying cellular responses in A549 tumor cell lines under specific electrochemical conditions. Notably, we observed distinct trends in cell viability depending on the applied voltage, distance, and exposure time from the electrode. Parameters such as effective distance range, chronoamperometry duration, and NO yield rate were found to be critical factors influencing cell death. This standardized electrochemical device provides valuable insights into the reactivity of cells to external radical gases, enhancing our understanding of the biological response to gas molecules in both intra- and extra-cellular microenvironments.

Selective amine preparation pathways using electrochemical reductive amination

The selective construction of carbon-nitrogen bonds has been considered as one of the central tasks of chemical synthesis, as they are basic structural units that constitute various natural products, pharmaceuticals, and bioactive molecules. For instance, amine functional groups can be found in methyl orange (pH indicator), chlorpheniramine (antihistamine), and adrenaline (hormone). A commonly employed method to prepare amines is reductive amination, which exhibits high chemo-selectivity and is cost-effective.

In this study, we demonstrated a new strategy to catalyze the reductive amination process. Moreover, we suggested selective pathways for the preparation of various amines using electrochemistry.