Chinese Journal of Chemistry最新文献

Arylidenecyclopropanes (ACPs) are highly strained substrates that can be readily utilized for diverse transformations. This study showcases the outcomes of copper-catalyzed ring-opening hydrosilylation and hydroboration reactions of ACPs, showcasing precise cleavage of C—C bonds. The reaction presents an effective and convenient method for producing homoallylic silanes and boronates.

Single-atom catalysts (SACs) have attracted significant attention due to their high atomic utilization and tunable coordination environment. However, the catalytic mechanisms related to the active center and coordination environment remain unclear. In this study, we systematically investigated the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalytic activities of NiN₄, NiN₃, NiN₃H₂, NiN₄X, NiN₃X, and NiN₃H₂X (X denotes axial ligand) through density functional theory (DFT) calculations. This study unveils two distinct reaction pathways for ORR and OER, involving proton-electron pairs adsorbed from both the solution and the catalyst surface. The overpotential is the key parameter to evaluate the catalytic performance when proton-electron pairs are adsorbed from the solution. NiN₃ and NiN₃H₂ show promise as pH-universal bifunctional electrocatalysts for both ORR and OER. On the other hand, when proton-electron pairs are adsorbed from the catalyst surface, the reaction energy barrier becomes the crucial metric for assessing catalytic activity. Our investigation reveals that NiN₃H₂ consistently exhibits optimal ORR activity across a wide pH range, regardless of the source of proton-electron pair (solvent or catalyst surface).

A variety of 3-nitroindazoles and 3-aminoindazoles were prepared in good to excellent yields with high regioselectivity through TBN-mediated nitration at the C3-position of indazoles under the air conditions and sequential reduction. Mechanistic studies revealed that TBN played crucial roles to produce •NO₂ radical source in the presence of air conditions and C3-nitration of indazoles was initiated by N1-nitration and sequential migration of NO₂ group to C3-position. Moreover, this method could be easily applied in the gram scalable synthesis of ibuprofen and ciprofibrate-derived 3-aminoindazoles. The present method highlights air as mild oxidant, metal-free radical nitration of indazole, N—N bond formation and cleavage, and late-stage modification of drugs.

Alkenylsulfonates are commonly encountered in medicinal chemistry, polymer chemistry, and organic synthesis. In this research, an electrochemical reaction involving alkynes, NaHSO₃, and alcohols has been developed. This method yields functionalized alkenylsulfonates in good yields with broad functional group tolerance. Mechanism studies indicate that anodic oxidation of inorganic sulfite, radical insertion process, and HAT process are involved in this transformation.

Layer-by-layer (LbL) solution processing is an efficient method to realize high performance organic solar cells (OSCs). One of the drawbacks of the LbL-processed active layer is the large difference in the crystallinity of the donor and acceptor, which will lead to imbalance charge transfer and result in unfavorable charge recombination. Herein, we combined a novel volatile additive 3,5-dichloro-2,4,6- trifluorobenzotrifluoride (DTBF) with the LbL method to realize high-efficiency OSCs. DTBF interacts with the non-fullerene acceptor BTP-4F by non-covalent bonding, which enhances the crystallinity and compact stacking of BTP-4F. DTBF doped OSC has balanced and efficient electron transport properties, longer carrier lifetime, higher exciton dissociation and charge collection efficiencies, lower energetic disorder than the control OSC without any additives. Benefiting from the optimization of charge dynamics and micro-morphology by DTBF, the binary LbL-processed OSC achieved synergistic improvements in open-circuit voltage, short-circuit current density and fill factor. As a result, a champion power conversion efficiency (PCE) of 19% is realized for DTBF-optimized OSC, which is superior to the control OSC (17.55%). This work demonstrates a promising approach to modulate active layer morphology and fabricate high performance OSCs.

Near-infrared (NIR)-absorbing polymerized small molecule acceptors (PSMAs) based on a Y-series backbone (such as PY-IT) have been widely developed to fabricate efficient all-polymer solar cells (all-PSCs). However, medium-bandgap PSMAs are often overlooked, while they as the third component can be expected to boost power conversion efficiencies (PCEs) of all-PSCs, mainly due to their up-shifted lowest unoccupied molecular orbital (LUMO) energy level, complimentary absorption, and diverse intermolecular interaction compared to the NIR-absorbing host acceptor. Herein, an IDIC-series medium-bandgap PSMA (P-ITTC) is developed and introduced as the third component into D18/PY-IT host, which can not only form complementary absorption and cascade energy level, but also finely optimize active layer morphology. Therefore, compared to the D18/PY-IT based parental all-PSCs, the ternary all-PSCs based on D18/PY-IT:P-ITTC obtain an increased exciton dissociation, charge transport, carrier lifetime, as well as suppressed charge recombination and energy loss. As a result, the ternary all-PSCs achieve a high PCE of 17.64% with a photovoltage of 0.96 V, both of which are among the top values in layer-by-layer typed all-PSCs. This work provides a method for the design and selection of the medium-bandgap third component to fabricate efficient all-PSCs.

Twelve new limonoids (1—12), named trichilitins A—L, were isolated from the leaves and twigs of Trichilia connaroides, together with ten known compounds (13—22). The structures were elucidated by extensive spectroscopic investigations, X-ray diffraction analyses, and ECD calculations. Compound 1, which belongs to a unique class of ring B-seco limonoid, has been identified as 6/7/6/5 tetracyclic due to a key Baeyer-Villiger oxidation. Compounds 2—7 were identified as ring intact limonoids, while compounds 8—10 were established as ring D-seco ones, and 11 and 12 were determined to be rearranged ones. All of the compounds were tested for cytotoxicity against three human tumor cell lines (HCT-116, NCl-H1975, and SH-SY5Y). Compounds 6, 7, 13, 14, and 19 exhibited significant cytotoxic effects, especially 7 exhibited significant cytotoxic effects against HCT-116 with an IC₅₀ value of 0.035 μmol·L^–1 and was more active than the positive control, doxorubicin with an IC₅₀ value of 0.20 μmol·L^–1. Compound 7 effectively induced apoptosis of HCT-116, which was associated with S-phase cell cycle arrest. Furthermore, the Western blot analysis showed that compound 7 could induce cell cycle arrest by promoting the expression levels of p53 and p21.