Publications by authors named "Gaofeng Feng"

Enabled by electron donor-acceptor complexes, a novel visible-light-induced α-amino C-H bond arylation protocol, without a photoredox catalyst, has been disclosed. The protocol does not require any transition metal, oxidant, or exclusion of oxygen or moisture. A direct irradiation of the mixture of tertiary amines and benzonitriles with visible light in ,-diethylethanamide in the presence of CsCO afforded α-arylated amines in good to excellent yields.

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Tm-doped silica-glass preforms were fabricated by the modified chemical vapor deposition process combined with the solution doping technique. Its spectroscopic properties were evaluated according to the detected absorption spectrum and the fluorescence spectrum. The calculated maximum emission cross section of Tm ions in this core glass is 5.

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Article Synopsis
  • A new wavelength-tunable all-fiber mode-locked erbium-doped fiber laser has been created using a supermode interference filter (SMIF) made from a seven-core fiber connected to standard single-mode fibers.
  • By exciting two supermodes in the fiber, the SMIF produces a broad comb-shaped transmission spectrum, allowing for variable wavelength output.
  • The laser emits 230 fs pulses with a spectral width of 14 nm and can tune its output spectrum within a range of 22 nm while maintaining stable mode-locking operation.
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The first visible-light-mediated photoredox oxidative approach for generating carbamoyl radicals from oxamic acids is disclosed. Reaction of the generated carbamoyl radicals with electron-deficient alkenes opens efficient access to 3,4-dihydroquinolin-2(1 H)-ones under mild conditions through a sequence of intermolecular radical addition, cyclization, and aromatization. The process is compatible with a variety of oxamic acids and electron-deficient alkenes, and a wide variety of 3,4-dihydroquinolin-2(1 H)-ones were prepared.

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An efficient and high yield process for sp(3) C-H bond functionalization of N-aryl-1,2,3,4-tetrahydroisoquinolines is disclosed. This involves a visible light mediated photoredox Ugi-type reaction with carboxylic acids and isonitriles under aerobic conditions, employing Ru(bpy)3Cl2 as a photoredox catalyst and CH3CN as the solvent. CH3CN was found to be crucial for the process, and good to excellent yields were achieved for a wide variety of N-aryl-1,2,3,4-tetrahydroisoquinolines, carboxylic acids, and isonitriles.

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We report here successful synthesis of superoleophilic, nanoporous polymeric ionic liquids supported palladium acetate (PDVB-[C3vim][SO3CF3]-Pd-xs, where x stands for the weight percentage of palladium acetate), which act as efficient heterogeneous catalysts in Suzuki-Miyaura cross-coupling reaction. PDVB-[C3vim][SO3CF3] support was synthesized from solvothermal copolymerization of divinylbenzene with vinylimidazole without using any templates, followed by functionalized with ionic liquid groups. The resultant PDVB-[C3vim][SO3CF3]-Pd-xs possess large BET surface areas, good stability, homogeneous dispersion of Pd active species, and superwettability for various aromatic reactants, which result in their much improved reactants enrichment property.

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We demonstrate broadband optical amplification at 1.3 mum in silicate glass-ceramics containing beta-Ga(2)O(3):Ni(2)+ nanocrystals with 980 nm excitation for the first time. The optical gain efficiency is calculated to be about 0.

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