A novel cascade reaction initiated by an enantioselective aminocatalysed 1,3-dipolar [6+4] cycloaddition between catalytically generated trienamines and 3-oxidopyridinium betaines is presented. The [6+4] cycloadduct spontaneously undergoes an intramolecular enamine-mediated aldol, hydrolysis, and E1cb sequence, which ultimately affords a chiral hexahydroazulene framework. In this process, three new C-C bonds and three new stereocenters are formed, enabled by a formal unfolding of the pyridine moiety from the dipolar reagent. The hexahydroazulenes are formed with excellent diastereo-, regio- and periselectivity (>20 : 1), up to 96 % ee, and yields up to 52 %. Synthetic elaborations of this scaffold were performed, providing access to a variety of functionalised hydroazulene compounds, of which some were found to display biological activity in U-2OS osteosarcoma cells in cell painting assays.
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http://dx.doi.org/10.1002/chem.202401156 | DOI Listing |
Org Lett
January 2025
Institute of Next Generation Matter Transformation, College of Material Sciences Engineering at Huaqiao University, 668 Jimei Boulevard, Xiamen, Fujian 361021, China.
Domino cascade reactions, which can construct multiple bonds in one pot, are efficient methods to synthesize N-heterocycles and other useful skeletons. Herein, we report an expedient synthesis of polysubstituted benzo[][1,5]naphthyridine via Mn(III)-mediated C-C bond cleavage of cyclopropanols. These reactions were initiated by addition of β-carbonyl radicals, generated from cyclopropyl alcohols in the presence of Mn(III), to 2-(2-isocyanophenyl)acetonitriles to give quinolin-3-amines, which went through intramolecular cyclizations and dehydrogenation to give the final products.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India.
Biaryl motifs are essential structural features in several drugs and functional molecules. Cyclic diaryliodonium has been scarcely explored as a bifunctional agent compared to ring opening and annulation reactions. Herein, a three-component cascade approach is developed to synthesize bifunctionalized biaryls employing cyclic diaryliodoniums as a biarylating agent.
View Article and Find Full Text PDFSmall
January 2025
Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
The ligands in metal-organic framework (MOF) play as light absorption center and transfer photogenerated electrons to metal node through ligand-to-metal charge transfer (LMCT) during photocatalysis, and energy utilization efficiency is strongly restricted by the light inertness of ligands. Herein, a ligand updating strategy is proposed by inserting energy centers to MOFs to activate the inherent ligands, realizing boosting hot electron generation and photocatalytic activities via the cascaded proceeding of energy transfer and charge transfer. By taking PCN-777 (a zeotype mesoporous Zr-containing MOF) as an example, this study shows that the embedded energy center of 1-pyrenecarboxylic acid (PCA) can activate the inherent ligand of PCN-777 through triplet-triplet energy transfer, where triplet excitons would dissociate into photocarriers migrating to the Zr metal cluster via LMCT process.
View Article and Find Full Text PDFBiomaterials
December 2024
Key Laboratory of Biomaterials of Guangdong Higher Education Institutes, Department of Biomedical Engineering, Jinan University, Guangzhou, 510632, China. Electronic address:
Owing to the excellent stability, anticancer activity and immunogenicity, peroxynitrite (ONOO) has been gained enormous interests in cancer therapy. Nevertheless, precise delivery and control release of ONOO in tumors remains a big challenge. Herein, B16F10 cancer cell membrane/liposome hybrid membrane (CM-Lip) based biomimetic nanodrug with high-efficient tumor-homing and NIR-II laser controlled ONOO boost properties was designed for melanoma treatment.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China. Electronic address:
This study aimed to investigate the molecular mechanisms of reactive oxygen species (ROS)-induced endoplasmic reticulum stress (ERS) in apoptosis and meat tenderization during postmortem aging. Yak longissimus dorsi muscle was incubated with N-acetylcysteine (NAC), 4-phenylbutyric acid (4-PBA) and NAC + 4-PBA, respectively, and stored at 4 °C for 0 h, 12 h, 24 h, 72 h, 120 h and 168 h. The results showed that NAC and 4-PBA treatments significantly reduced ROS content and endoplasmic reticulum stress levels.
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