Chemistry - An Asian Journal最新文献

A new set of C1-symmetric chiral bisphosphine ligands was developed from hydroxybenzothiol, 2-(diphenylphosphaneyl)-benzoic acid and chiral aziridine. These ligands were utilized for the Pd-catalyzed asymmetric allylic substitution reaction. Under the optimal conditions, structurally diverse hard/soft nucleophiles, such as activated methylene compounds, amines, alcohols, and indole were investigated, and the corresponding products were obtained in good yields and excellent ees. Even under low catalyst loading and gram-scale reaction conditions, the product was obtained in good yield with excellent enantioselectivity, which further validated the promising practical application potential of this ligand.

Tricyclic lactone compounds featuring a vinyl bromide tether were investigated for intramolecular radical cyclization. α-Aminoalkyl radicals, generated through the translocation of an initially generated vinyl radical, underwent cyclization or cyclization/1,5-hydrogen transfer, C─O bond fragmentation, and further cyclization to construct the nitrogen-containing heterocyclic rings. When two diastereomers with substituents in opposite stereochemical configurations underwent radical reactions separately, they yielded distinct products. Density functional theory (DFT) calculation studies were carried out to unravel mechanistic insights in this process.

The regulation strategy to tune the recovery of cathode from sodium-ion batteries (SIBs) is of great significance. However, traditional strategies involving temperature, duration, and additives often lead to high energy demands, time deficiencies, notable environmental pollution, or complicated separation processes. Here, we propose a sustainable strategy based on the synergistic regulation of basicity and hydrophobicity to regulate the cathode recycling from SIBs using amino acid-based deep eutectic solvents (DESs) with low energy consumption, high time efficiency and simple process. The metal leaching efficiency from SIBs cathode could be tuned by dual-regulation of high basicity and moderate hydrophobicity. The basicity of amino acid-based DESs shows a weak positive correlation with the metal leaching efficiency, while hydrophobicity of amino acid exhibits a trend of initially increasing and then decreasing with metal leaching efficiency. After reasonable tunability of basicity and hydrophobicity, DESs glycine:lactic acid (1:12) is capable of recycling 87.5% Na and 83.3% Fe from the sodium iron phosphate cathode of SIBs at a mild temperature of 80°C for 24 h with a liquid-to-solid ratio of 50:1.

A radical addition to sterically congested ketimines, specifically 2H-benzoxazin-2-one derivatives with a substituent at the 3-position was developed by a photochemical reaction utilizing benzyltrimethylsilane derivatives as donor molecules. An efficient protocol for accessing unnatural amino acid derivatives having a tetra-substituted carbon center at the α-position was demonstrated through further manipulation of the product. Me₃SiOTf was used as a Lewis acid catalyst to accelerate the reaction. Additionally, acridinium salt functioned as an efficient photocatalyst in the present photochemical transformation, affording the desired radical addition product in moderate to high yield. Plausible catalytic cycles were proposed based on control experiments.

Lingjie Meng, Chuanlong Fu, Zhaofu Fei, Qinghua Lu, and Paul J. Dyson (2010). Photochemical Behavior of High Quantum Yield SWNTs Functionalized With Anthracene Salts. Chemistry – An Asian Journal 5: 1988–1991. https://doi.org/10.1002/asia.201000236.

The authors regret that an error appeared in Figure 2b of the printed version of the article. The correct version of Figure 2b is provided below.

The authors would like to emphasize that no changes have been made to the main text, and the correction does not affect the results, discussion, or conclusions presented in the original publication.

We apologize for this error.

Hexaazatrinaphthylene (HATNA) has recently been a subject of great interest as a polycyclic heteroaromatic scaffold in materials science, specifically in the field of discotic liquid crystals (DLCs), battery cathodes, n-type semiconductors, and so on. However, little is known about the photophysical properties of HATNA derivatives. Here we report the synthesis of a new class of hexa(arylethynyl) HATNA derivatives via consecutive Sonogashira coupling. This protocol showed good functional-group tolerance and moderate to good yields were achieved. The obtained HATNA products showed favorable photophysical properties, with molar absorption coefficients up to 1.69 × 10⁵ (M⁻¹ cm⁻¹) and high quantum yields up to 0.73.