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Electrooxidation has emerged as an increasingly viable platform in molecular syntheses that can avoid stoichiometric chemical redox agents. Despite major progress in electrochemical C−H activations, these arene functionalizations generally require directing groups to enable the C−H activation. The installation and removal of these directing groups call for additional synthesis steps, which jeopardizes the inherent efficacy of the electrochemical C−H activation approach, leading to undesired waste with reduced step and atom economy. In sharp contrast, herein we present palladium-electrochemical C−H olefinations of simple arenes devoid of exogenous directing groups. The robust electrocatalysis protocol proved amenable to a wide range of both electron-rich and electron-deficient arenes under exceedingly mild reaction conditions, avoiding chemical oxidants. This study points to an interesting approach of two electrochemical transformations for the success of outstanding levels of position-selectivities in direct olefinations of electron-rich anisoles. A physical organic parameter-based machine learning model was developed to predict position-selectivity in electrochemical C−H olefinations. Furthermore, late-stage functionalizations set the stage for the direct C−H olefinations of structurally complex pharmaceutically relevant compounds, thereby avoiding protection and directing group manipulations. Electrochemistry has emerged as an increasingly viable tool in molecular synthesis. Here the authors realize electrocatalyzed C−H activations, with the aid of data science and artificial intelligence, towards selective alkenylations for late-stage drug diversifications. [ABSTRACT FROM AUTHOR]

Promoting the development of highly efficient and long-term stable oxygen evolution reaction (OER) electrocatalysts is crucial to relieve the energy crisis. In this study, amorphous Fe–Mo–O/NF was designed as an effective and durable catalyst for OER in 1.0 M KOH aqueous solution. The OER catalytic performance of amorphous Fe–Mo–O/NF is obviously improved compared to Fe2O3/NF. The synthesized amorphous Fe–Mo–O/NF exhibits excellent catalytic activity and the current density reached 50 and 100 mA cm–2 in 1.0 M KOH aqueous solution with only overpotentials of 215 and 224 mV. This remarkable electrocatalytic activity is considered as the following: (1) The pristine catalytic performance originates from the OER catalytic activity inherent in transition-metal Fe-based oxides electrocatalysts; (2) the introduction of Mo element increases the number of active sites; (3) the coupling synergy effect between metals is more conducive to the adsorption of oxygen intermediates; and (4) the tight bonding of the amorphous Fe–Mo–O nanostructures to the conductive substrate ensures the structure rapid electron transport and ultrahigh stability. We anticipate that our research will extend the range of transition-metal-based materials as effective electrocatalysts for OER. [ABSTRACT FROM AUTHOR]

Direct C−H functionalizations by electrocatalysis is dominated by strongly coordinating N(sp2)‐directing groups. In sharp contrast, direct electrocatalytic transformations of weakly‐coordinating phenols remain underdeveloped. Herein, electrooxidative peri C−H alkenylations of challenging 1‐naphthols were achieved by versatile rhodium(III) catalysis via user‐friendly constant current electrolysis. The rhodaelectrocatalysis employed readily‐available alkenes and a protic reaction medium and features ample scope, good functional group tolerance and high site‐ and stereoselectivity. The strategy was successfully applied to high‐value, nitrogen‐containing heterocycles, thereby providing direct access to uncommon heterocyclic motifs based on the dihydropyranoquinoline skeleton. [ABSTRACT FROM AUTHOR]

Large-scale electrolysis of water to produce hydrogen is an effective way to obtain clean renewable energy. The first-row transition-metal-based oxygen evolution reaction (OER) catalysts with high activity have been developed to replace the noble-metal catalysts, e.g., RuO 2 and IrO 2. In the work reported in this paper, we developed the Ni–Fe Prussian-blue analog (PBA) on the Ni foam surface (PBA/NF) via an in situ electrodeposition method and transferred the PBA/NF into bimetallic phosphides (NiFeP x /NF) through the phosphidation process as highly active OER electrocatalysts in alkaline medium. The in situ electrodeposition method could not only precisely control the nucleation and growth processes of PBA on the surface of nickel foam, as well as the purity, structures, and morphologies of the deposits obtained, but also provide sufficient adhesive force between catalysts and Ni foam substrates without further use of poorly conductive binder material, which guaranteed robust electrode stability. When applying for OER, NiFeP x /NF presented excellent catalytic activity. Upon screening a wide electrodeposition time range, results demonstrate that NiFeP x -80/NF (deposition time 80 min) possessed the best OER catalytic activity with only 224 mV to deliver a current density of 10 mA cm−2 as well as a Tafel slope of 29 mV dec−1 in 1 M KOH, which shows that the use of electrodeposition methods to directly grow PBA nanomaterials on conductive substrates may be an effective method for the preparation of multifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]

Developing highly active and robust oxygen evolution reaction electrocatalysts is indispensable to relieve energy crisis. Herein, firstly, the Ni nanocubes precursor as a self-sustaining template is synthesized through a reflow method. Afterward, the nanocubic NiFe bimetallic organic frameworks was formed under the self-assembly approach between the exogenous Fe2+ and released Ni2+ from Ni nanocubes with terephthalic acid organic ligand on the Ni nanocubes precursor, i.e Ni nanocubes@MIL-53(NiFe). The synthesized Ni nanocubes@MIL-53(NiFe) exhibit excellent activity, which only requires the overpotential of 271 and 388 mV to deliver the current density of 20 and 100 mA cm−2 in alkaline solution (1.0 M KOH). The noticeable catalytic performance can be ascribed to the aspects as following: 1) Ni nanocubes as a template provides a Ni source during the self-assembled process; 2) the metal-metal coupling effect arisen within the Ni and Fe atom is substantially contributed to the oxygen evolution reaction performance; 3) the abundant active sites, enhanced electron transport ability also endow the superior electrocatalytic oxygen evolution reaction activity; 4) rich carboxyl groups in the metal-organic frameworks structure could enhance the hydrophilicity of the catalysts. We anticipate that our study would extend the design and exploration of active metal-organic frameworks on energy conversion field. • The self-templated strategy is proposed to design a bimetallic blocky MOF. • The Fe-Ni metal-metal coupling effect boosts the OER performance. • The Ni NCs control the morphology and prevent the accumulation of catalyst. [ABSTRACT FROM AUTHOR]

Developing highly-efficient and robust electrocatalysts for oxygen evolution reaction (OER) is crucial to relieve energy crisis. Herein, a facile two-step method involving Prussian blue nanocubes as template is introduced to synthesize coral-like Ni 3 S 2 @MIL-53(NiFeCo) core-shell nanowires array as an excellent OER electrocatalyst. The metal sulfides as a core in the core-shell structure could effectively adjust the morphology of the metal-organic frameworks (MOFs) in the shell layer forming ultrathin 2D MOFs nanosheets. The synthesized Ni 3 S 2 @MIL-53(NiFeCo)/NF nanowires exhibit excellent activity, which needs overpotential of only 236 mV to drive high current density of 50 mA cm−2 in 1.0 M KOH. This excellent catalytic performance can be attributed to the following aspects: 1) The synergy between the metal sulfides and the MOF contributes substantially to the OER performance. 2) The compact three-dimensional nano-array structure increases the electrochemically active surface area of Ni 3 S 2 @MIL-53(NiFeCo)/NF nanowires, which promotes electrolyte permeation and gas overflow. 3) The tight integration of the vertically aligned nanowires structure with the conductive substrate ensures rapid electron transport and ultra-high structural stability of the electrode material. We anticipate that our research will extend the strategy for assembling advanced materials as an effective electrocatalyst for OER. • The core-shell nanowire array structure is synthesized by a two-step process. • The synergistic advantage is contributed to the catalytic activity for OER. • 3D nano-array facilitates the penetration of electrolyte and the release of gases. • The combination of nanowire and substrate ensures electron transport and stability. [ABSTRACT FROM AUTHOR]