Synthesis of 3‑SCF₂H‑/3-SCF₃‑chromones via Interrupted Pummerer Reaction/Intramolecular Cyclization Mediated by Difluoromethyl or Trifluoromethyl Sulfoxide and Tf₂O

The reaction of alkynyl aryl ketones bearing an o-methoxy group with difluoromethyl sulfoxide in the presence of Tf2O was found to conveniently afford the corresponding 3-SCF2H-substituted chromones. The combining use of difluoromethyl sulfoxide/Tf2O could represent the first reagents system that can introduce the biologically important SCF2H moiety under base-free conditions via an interrupted Pummerer reaction. The same protocol could also be applied to the synthesis of 3-SCF3-substituted chromones by replacing difluoromethyl sulfoxide with trifluoromethyl sulfoxide and CH3CN with toluene

Design of Supported–Coated Structure Silicon/Carbon Composites Using Industrial Waste Micrometer-Sized Silicon for an Advanced Lithium-Ion Battery Anode

Silicon (Si) has garnered significant attention as an anode material for an advanced lithium-ion battery (LIB), but it remains challenging to design high-stability Si-based composites with low structural strain and high electrical conductivity. Here, we present a novel Si–carbon anode material (Si/G@TNS-60) derived from recycled wire-cutting polysilicon waste, featuring a unique structure with an internal anchoring load and an external wrapping of flexible two-dimensional (2D) material. The graphite (G) component serves as a conductive anchor carrier, enhancing electronic conductivity and preventing pulverization and electrical contact loss in Si particles. Additionally, the MXene (TNS) protective layer provides mechanical flexibility, isolates Si from direct contact with the electrolyte to reduce side reactions, improves ion and electron diffusion kinetics, and ensures structural stability. Consequently, the Si/G@TNS-60 electrode delivers improved initial coulombic efficiency (ICE, 78.8%), excellent rate performance with a capacity of 485.3 mAh g–1 at 2 C, and sustained durability over 500 cycles at 0.5 C with 83.5% capacity retention. The investigation into the reaction dynamics reveals the hybrid storage mechanism and rapid Li+ diffusion coefficient. Furthermore, ex situ scanning electron microscopy (SEM) demonstrates a minimal volume change and maintains the integrity of the electrode structure. Impressively, the full cell based on the Si/G@TNS-60 anode prelithiated by chemical solution technology and LiNi1/3Co1/3Mn1/3O2 as the cathode shows a raised ICE of 88.5% and maintains excellent cycle stability. This work fundamentally puts forward a facile and effective structural engineering strategy, highlighting the promising application potential of wire-cutting polysilicon waste in advanced LIB technology