Direct electrophilic and radical isoperfluoropropylation with i-C3F7-Iodine(III) reagent (PFPI reagent).

The isoperfluoropropyl group (i-C3F7) is an emerging motif in pharmaceuticals, agrichemicals and functional materials. However, isoperfluoropropylated compounds remain largely underexplored, presumably due to the lack of efficient access to these compounds. Herein, we disclose the practical and efficient isoperfluoropropylation of aromatic C-H bonds through the invention of a hypervalent-iodine-based reagent-PFPI reagent, that proceeds via a Ag-X coupling process. The activation of the PFPI reagent without any catalysts or additives was demonstrated in the synthesis of isoperfluoropropylated electron-rich heterocycles, while its activity under photoredox catalysis was shown in the synthesis of isoperfluoropropylated non-activated arenes. Detailed mechanistic experiments and DFT calculations revealed a SET-induced concerted mechanistic pathway in the photoredox reactions. In addition, the unique conformation of i-C3F7 in products, that involved intramolecular hydrogen bond was investigated by X-ray single-crystal diffraction and variable-temperature NMR experiments.

Influence of Plasma Treatment on Surface Characteristics of Aluminum Alloy Sheets and Bonding Performance of Glass Fiber-Reinforced Thermoplastic/Al Composites.

This study focuses on modifying the surface of an AA 5052-H32 aluminum alloy using plasma treatment. Discharge power, exposure time, and working gas were adjusted as process parameters to improve the adhesion between the aluminum alloy and glass fiber-reinforced thermoplastic (GFRTP) polycarbonate composite. The surface composition and morphology of the aluminum alloy sheet were analyzed by X-ray photoelectron spectroscopy and scanning electron microscopy, and surface roughness and wettability were evaluated using a surface roughness-measuring instrument and contact angle goniometry, respectively. The bonding performance of GFRTP/aluminum alloy was also assessed. The surface of the aluminum alloy was subjected to chemical treatment prior to plasma treatment. The results revealed that nitrogen plasma treatment led to a substantial increase (25%) in bonding strength due to the synergistic effect of rough surface mechanical bonding and chemical bonding through functional groups between the aluminum alloy and GFRTP. However, the improvement in surface wettability by plasma treatment is time dependent and may gradually diminish over time due to the re-adsorption of hydrocarbon contamination from the surrounding air.

Diverse reactivity of the gem-difluorovinyl iodonium salt for direct incorporation of the difluoroethylene group into N- and O-nucleophiles.

The synthesis of gem-difluoroethylene compounds remains a difficult task in organic synthesis. Here, the direct difluoroethylation reactions of N- and O-nucleophiles including amides and acids were realized with a hypervalent iodine reagent: gem-difluorovinyl iodonium salt (DFVI). The reactions were accomplished via a neighbouring group rearrangement. The gem-difluorovinyl iodonium salt was found to display diverse reactivity due to its unique electronic effect and was applied to the incorporation of difluoroethylene group, including difluorovinylation of carboxylic acids, difluorovinylation and 1,3-cyclic fluorovinylation of amides and 1,1-cyclic difluoroethylation of amines.