98%
921
2 minutes
20
The substituent α-, β-, and γ-effects of the elements of the second and third periods on F NMR chemical shifts are evaluated including the establishment of stereochemical dependence of γ-effect, the latter particularly important in stereochemical studies of fluorine-containing compounds. Benchmark calculations performed for a series of 32 simple inorganic fluorine-containing molecules demonstrated a markedly good correlation between calculated and experimental fluorine chemical shifts characterized by a mean absolute error of 22.5 ppm in the range of about 900 ppm, which corresponds to a 2.5% error in the percentage terms.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/mrc.5275 | DOI Listing |
Beilstein J Org Chem
September 2025
Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997, Moscow, Russia.
Thioformylium methylide, which is readily generated from chloromethyl(trimethylsilyl)methyl sulfide by the action of fluoride, is used for the synthesis of spirocyclic derivatives from arylidene-azolones. Four types of the corresponding heterocycles have been studied. A series of 7-thia-3-azaspiro[4.
View Article and Find Full Text PDFMicrobiol Spectr
September 2025
Division of Pulmonary, Allergy and Critical Care, Department of Medicine, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
Bacterial surface glycan polymerases, such as Wzy, are integral membrane-bound glycosyltransferases that synthesize various surface-bound glycopolymers by linking repeat units via α-glycosidic or β-glycosidic bonds. Despite its central role in the widely employed "Wzy/Wzx-dependent pathway" for glycan synthesis, Wzy remains poorly understood, largely due to its high sequence variability. Using (pneumococcus) capsules as a model, we leveraged AlphaFold and Orientation of Proteins in Membranes computational tools to predict 3D molecular architectures of pneumococcal Wzys and elucidate their correlation with glycosidic linkage stereochemistry.
View Article and Find Full Text PDFJ Org Chem
September 2025
Department of Chemistry, Davidson College, Davidson, North Carolina 28036, United States.
Selective catalysis is a key objective in organic synthesis, and reactions with differing kinetic and thermodynamic products present the opportunity for divergent reaction outcomes with a single catalyst. We report a biocatalytic method in which a single transaminase can form either or cyclohexylamines in high diastereoselectivity. With the model substrate 4-methylcyclohexanone, cells expressing WT--ATA form either diastereomer of the amine product in >10:1 dr and >70% conversion, depending on reaction conditions, stereodivergence that also extends to a range of substrates.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
The asymmetric hydrogenation of substituted benzenes with oxazoline imino(pyridine) (OIP) molybdenum precatalysts is described. A comparison of the hydrogenation activities between alkylbenzenes and the corresponding styrenes revealed an alkene-activating effect, where the introduction of an alkene substituent resulted in the hydrogenation of both the alkene and the arene. Distinct reaction pathways for alkene and arene hydrogenation were observed with the outcomes dependent on the hydrogen pressure, the substitution pattern of the arene, and the placement of the alkene tethered to the arene.
View Article and Find Full Text PDFInorg Chem
August 2025
Central Hospital of Dalian University of Technology, School of Chemistry, Dalian University of Technology, Dalian 116024, China.
Rational design of chiral metallodrugs with precise stereochemical control and enhanced photodynamic performance is pivotal for advancing precision oncology. Herein, we report the stepwise assembly of homochiral dinuclear Ir(III) triple-stranded metallohelices (ΔΔ-/ΛΛ-) via dynamic imine ligation followed by reductive stabilization, yielding configurationally stable amine-bridged helical architectures with locked chirality. While both enantiomers exhibit comparable dark toxicities, the ΔΔ-enantiomer demonstrates enhanced photodynamic activity against multiple cancer cell lines under white light irradiation.
View Article and Find Full Text PDF