查看更多>>摘要：The dibenzo[d,d'']benzo[1,2-b:4,3-b']difuran skeleton exhibits a V-shape, which is highly desirable in semi-conductor applications. In this study, we synthesized V-shaped highly fused phthalonitrile derivatives and investigated the use of peripheral substituents to tune the crystal packing of the compounds. The palladium-mediated double C-H activation of 3,6-bis(aryloxy) phthalonitriles afforded 6,7dicyano-dibenzo[d,d'']benzo[1,2-b:4,3-b']difurans. The peripheral substituents affected the packing structure of the single crystals, particularly in the compounds with nBu groups, in which two-dimensional (2D) layered structures were observed. The peripheral substituents also affected the optical properties in the solution, film, and powder states. The layered structure suggested an improvement in the mobilities of organic semiconductors.(C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Four manzamine-type alkaloids, including a novel compound, manzamine A 27 -N-oxide (1), as well as three previously reported analogues, manzamines A (2), E (3), and 8-hydroxy-manzamine A hydrochloride (4) were isolated from the organic extract of marine sponge Neopetrosia proxima. The structures of 1-4 were determined based on spectroscopic data and 1 was proved to be the first manzamine alkaloid possessing the 27 -N-oxide moiety. The structures, including absolute configurations of 1 and 4, were established using single X-ray diffraction analysis. Compounds 1-3 showed cytotoxicity towards Hep3B (IC50 = 10.1, 3.8, 5.8 mu M), SC-M1 (IC50 = 11.7, 3.7, 5.6 mu M) and MCF-7 (IC50 = 10.6, 4.1, 4.2 mu M) tumor cells.& nbsp;(C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A light-driven, catalyst-and additive-free photoenolization/nucleophilic addition reaction for the synthesis of 3-benzyl-3-hydroxyindolin-2-ones is presented. In this reaction, 2-methylbenzophenones undergo light-induced enolization process to afford hydroxy-o-quinodimethanes (hydroxy-o-QDMs), which are then immediately captured by the electrophilic isatins. The reaction utilizes green and clean light energy to realize the C-H activation of the inert benzyl position of 2-methylbenzophenones. This method tolerates a wide scope of substrates and provides concise access to a series of novel 3-benzyl3-hydroxyindolin-2-ones with 60-99% yields.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A novel method was developed for the synthesis of carbamoyl azides from hydroxamic acids via the Lossen rearrangement using diphenyl phosphorazidate, which acts as both the activator and azide source to produce the azides via an isocyanate intermediate. Using this method, various hydroxamic acids were converted into the corresponding carbamoyl azides, enabling their preparation without the use of highly explosive reagents.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A novel pterocarpan, named phaseollin A (1) was isolated from Lima bean (the seeds of Phaseolus lunatus L.). The structure of 1 was elucidated by the extensive spectroscopic analysis (1D and 2D NMR, HR-ESIMS) as well as the experimental and calculated ECD data analysis. Compound 1 showed moderate activity of inhibiting NO production on lipopolysaccharide (LPS)-induced RAW264.7 cells with IC50 value of 37.13 & nbsp;+/- 2.58 lM.(C 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Two new compounds, namely an uncommon eunicellin-based diterpenoid (clakrefielin A, 2) and a 9, 11secosteroid (cladiellasterol A, 4), along with a known carotenoid (all-trans-peridinin, 7), were isolated from the Ximao Island, Sanya Bay soft coral Cladiella krempfi. The structures of these compounds were established on the basis of extensive spectroscopic analysis, X-ray diffraction analysis, chemical transformations, as well as the comparison with the reported data in the literature. The biological activities of these compounds were investigated, and compound 7 was found to be a new protein tyrosine phosphatase 1B (PTP1B) inhibitor (IC50 = 7.2 lM). (C)& nbsp;2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report a cesium bicarbonate-mediated alkylation of 2,4-dihydroxybenzyaldehyde and 2,4-dihydroxyacetophenone to generate 4-alkylated products in acetonitrile at 80 degrees C with excellent regioselectivity, up to 95% isolated yields, and broad substrate scope.(c) 2022 Elsevier Ltd. All rights reserved.
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