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Complex nuclear magnetic resonance (NMR) signals of organic compounds containing multiple analogous substructures or mixtures pose a significant challenge to structural identification, thus resulting in frequent misassignment of structures. The GEMSTONE method, a single-scan technique that selectively excites a specific proton signal among the crowded NMR signals, was recently proposed as a solution. However, its extension to the polarization transfer method for heteronuclear spin systems was unsuccessful. Herein, we present an extension method that addresses the altered heteronuclear polarization transfer efficiency and enables the acquisition of ultraselective C and H- C correlation NMR subspectra with hertz-level signal selectivity in both dimensions. We demonstrate the effectiveness of this technique in the structural analysis of a chromopeptide pharmaceutical and a diastereomeric mixture of a fungicide.
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http://dx.doi.org/10.1002/anie.202304196 | DOI Listing |
J Am Chem Soc
September 2025
Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080-3021, United States.
The direct transformation of C-H bonds into C-C bonds via cross-dehydrogenative coupling (CDC) represents a powerful strategy in synthetic chemistry, enabling streamlined bond construction without the need for prefunctionalized substrates. While traditional CDC approaches rely on polar mechanisms and preactivation of one of the C-H partners, recent advances have introduced radical-based strategies that employ a hydrogen atom transfer (HAT) approach to access carbon-centered radicals from unactivated substrates. Herein, we report a nickel-catalyzed CDC reaction between aldehydes and alkenes for the synthesis of skipped enones, leveraging aryl radicals as intermolecular HAT agents.
View Article and Find Full Text PDFMol Immunol
September 2025
Department of Clinical Laboratory, The Affiliated Cancer Hospital of Xinjiang Medical University, Suzhou East Road No. 789, Urumqi, Xinjiang 830011, China. Electronic address:
Hypoxia plays a critical role in regulating the progression of non-small cell lung cancer (NSCLC) by modulating the tumor immune microenvironment (TIME). Tumor-associated macrophages (TAMs), important components of TIME, can be regulated by hypoxic conditions. Unfortunately, the molecular mechanisms by which hypoxia regulates TAMs in TIME to affect NSCLC progression has not been fully delineated.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
State Key Laboratory of Chemistry for NBC Hazards Protection, College of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China.
The activation of methane and other gaseous hydrocarbons at low temperature remains a substantial challenge for the chemistry community. Here, we report an anaerobic photosystem based on crystalline borocarbonitride (BCN) supported Fe-O nanoclusters, which can selectively functionalize C-H bonds of methane, ethane, and higher alkanes to value-added organic chemicals at 12 °C. Scanning transmission electron microscopy and X-ray absorption spectroscopy corroborated the ultrafine FeOOH and FeO species in Fe-O clusters, which enhanced the interfacial charge transfer/separation of BCN as well as the chemisorption of methane.
View Article and Find Full Text PDFLangmuir
September 2025
Federal University of São Paulo, Laboratory of Hybrid Materials, Diadema, São Paulo 09913-030, Brazil.
This study demonstrates the successful fabrication of nanostructured Langmuir-Blodgett (LB) films combining the conjugated copolymer poly(9,9-dioctylfluorene--3,4-ethylenedioxythiophene) (PDOF--PEDOT) with spherical and triangular silver nanoparticles (AgNP). The LB technique allowed precise control over the molecular arrangement and distribution of the nanoparticles at the air-water interface, resulting in compact, reproducible and structurally ordered nanocomposite films. The structural and morphological properties of the interfacial monolayers and LB films were investigated using surface pressure-area isotherms, Brewster angle microscopy, polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and quartz crystal microbalance.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2025
Computational Inorganic Chemistry Group, Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana 502284, India.
Over the past few years, alkali and alkaline earth metals have emerged as alternative catalysts to transition metal organometallics to catalyze the hydroboration of unsaturated compounds. A highly selective and cost-effective lithium-catalyzed method for the synthesis of an organoborane has been established based on the addition of a B-H bond to an unsaturated bond (polarized or unpolarized) using pinacolborane (HBPin). In the present work, the neosilyllithium-catalyzed hydroboration of nitriles, aldehydes, and esters has been investigated using high-level DLPNO-CCSD(T) calculations to unravel the mechanistic pathways and substrate-dependent reactivity.
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