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New methods and strategies for the direct oxidation of benzylic C-H bonds are highly desirable, owing to the importance of ketone motifs in significant organic transformations and the synthesis of valuable molecules, including pharmaceuticals, pesticides, and fine chemicals. Herein, we describe an electrochemical benzylic C-H oxidation strategy for the synthesis of ketones using MeOH as an oxygen source. Inexpensive and safe KBr serves as both an electrolyte and a bromide radical precursor in the reaction. This transformation also offers several advantages such as mild conditions, broad functional group tolerance, and operational simplicity. Mechanistic investigations by control experiments, radical scavenging experiments, electron paramagnetic resonance (EPR), kinetic studies, cyclic voltammetry (CV), and in-situ Fourier transform infrared (FTIR) spectroscopy support a pathway involving the formation and transformation of benzyl methyl ether via hydrogen atom transfer (HAT) and single-electron transfer (SET). The practical application of our strategy is highlighted by the successful synthesis of five pharmaceuticals, namely lenperone, melperone, diphenhydramine, cinnarizine, and flunarizine., (© 2024 Wiley-VCH GmbH.)

Developing hydrogen evolution reaction (HER) electrocatalysts with high activity, durability and moderate price is essential for sustainable hydrogen energy utilization. Here, the facile coupling of carbon dots (CDs, 0D carbon materials) and carbon fibres (CFs, 1D carbon materials) for enhanced electrochemical hydrogen production was demonstrated. Electrochemical tests revealed that the CD/CF catalysts showed outstanding catalytic activity with a small overpotential of 280 mV at the current density of 10 mA cm -2 , a small Tafel slope of 87 mV dec -1 and prominent durability. Percolation theory was for the first time introduced to interpret the catalytic mechanism of the CD/CF catalysts. The special morphology assembled by the 0D carbons constituted the percolating clusters and promoted electron transport throughout the 1D carbons. The strategy and theory can be adapted to general electrocatalytic applications for achieving and interpreting precise tuning on highly efficient electron transfer in electrocatalysts., (© 2020 Wiley-VCH GmbH.)