Selective Chloride-Mediated Neat Ethanol Oxidation to 1,1-Diethoxyethane via an Electrochemically Generated Ethyl Hypochlorite Intermediate

Carbocation Mechanism Revelation of Molecular Iodine-Mediated Dehydrogenative Aromatization of Substituted Cyclic Ketones to Phenols

Dehydrogenative aromatization (DA) of cyclic ketones is central to the development of functionalized aromatic precursors and hydrogen transfer-related technologies. Traditional DA strategies require precious metals with oxidants and are typically performed at high temperatures (100-150 °C) to overcome the high energy barrier of aliphatic C-H bond activation. Recently, a mild alternative approach based on I2 has been proposed to realize DA on substituted unsaturated cyclic ketones under ambient conditions. However, depending on the solvent, the product selectivity may vary between phenol ether and phenol, and the reaction mechanisms remain unclear. Herein, based on time-resolved proton nuclear magnetic resonance, DFT calculation, and mass spectrometric analyses, we established a unified mechanism to account for the product distribution. Through substrate scope and desorption electrospray ionization-mass spectrometry, we discovered the formation of a carbocation, which has been overlooked in previous studies. An expanded substrate scope study coupled with spectroscopic observation provided strong evidence to elucidate the formation mechanism and the location of the carbocation. With a renewed understanding of the mechanism, we achieved a phenolic product yield of 17-96% while controlling the selectivity. Moreover, some reactants could undergo DA in H2O, achieving 95-96% yield at below water-boiling temperature.

Interfacial Micro-Environment of Electrocatalysis and Its Applications for Organic Electro-Oxidation Reaction

Conventional designing principal of electrocatalyst is focused on the electronic structure tuning, on which effectively promotes the electrocatalysis. However, as a typical kind of electrode-electrolyte interface reaction, the electrocatalysis performance is also closely dependent on the electrocatalyst interfacial micro-environment (IME), including pH, reactant concentration, electric field, surface geometry structure, hydrophilicity/hydrophobicity, etc. Recently, organic electro-oxidation reaction (OEOR), which simultaneously reduces the anodic polarization potential and produces value-added chemicals, has emerged as a competitive alternative to oxygen evolution reaction, and the role IME played in OEOR is receiving great interest. Thus, this article provides a timely review on IME and its applications toward OEOR. In this review, the IME for conventional gas-involving reactions, as a contrast, is first presented, and then the recent progresses of IME toward diverse typical OEOR are summarized; especially, some representative works are thoroughly discussed. Additionally, cutting-edge analytical methods and characterization techniques are introduced to comprehensively understand the role IME played in OEOR. In the last section, perspectives and challenges of IME regulation for OEOR are shared.