We herein report an unprecedented strategy for the asymmetric α-chlorination of β-keto esters with hypervalent iodine-based Cl-transfer reagents using simple Cinchona alkaloid catalysts. Our investigations support an α-chlorination mechanism where the Cinchona species serves as a nucleophilic catalyst by reacting with the chlorinating agent to generate a chiral electrophilic Cl-transfer reagent in situ. Using at least 20 mol-% of the alkaloid catalyst allows for good yields and enantioselectivities for a variety of different β-keto esters under operationally simple conditions.
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http://dx.doi.org/10.1002/ejoc.202001217 | DOI Listing |
Nat Commun
January 2025
Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, 163 Xianlin Avenue, 210023, Nanjing, China.
Sulfur-containing units are fundamental components widely found in bioactive compounds, prompting notable efforts toward developing synthetic methodologies for incorporating sulfur functionality into organic precursors. The synthesis of sulfinate esters and sulfinamides has garnered significant interest owing to their immense potential for applications, especially in drug development. However, most existing synthetic protocols suffer from some limitations.
View Article and Find Full Text PDFJ Org Chem
January 2025
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, Guangxi 530004, China.
Among the known aromatic -heterocycles, pyrroles are significant and versatile privileged components in pharmacologically relevant molecules. Herein, we demonstrate a protocol for the selective construction of alkynylated pyrroles in a diversity-oriented fashion through divergent C2/C5 site-selective alkynylation of pyrrole derivatives by employing a palladium catalyst with two different solvent systems. In the presence of 1,4-dioxane, the C2-alkynylation process via chelation-assisted palladation is favored.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, University Town, Guangzhou 510006, China. Electronic address:
PM has a detrimental impact on human health and has become a focus of widespread concern. The tempo-spatial distribution of emerging pollutants has been extensively studied, while there is a scarcity of understanding their vertical distribution in atmospheric environment. Here we investigated the vertical profiles of phthalate esters (PAEs), organophosphate esters (OPEs), neonicotinoids (NEOs), and per-and polyfluorinated substances (PFASs) in PM at ground level (4.
View Article and Find Full Text PDFChem Biodivers
January 2025
Liverpool John Moores University, Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Byrom Street, Liverpool, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Diospyros discolor Willd., commonly known as Velvet apple or Mabolo, is an underutilized fruit. Traditionally, various parts of D.
View Article and Find Full Text PDFBiomacromolecules
January 2025
Polymer Research Centre and Centre for Advanced Functional Materials, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Nadia, Mohanpur 741246, West Bengal, India.
The present investigation aims to develop a reactive oxygen species (ROS) and esterase-responsive biodegradable mannosylated polyurethane to effectively deliver the encapsulated antileishmanial drug amphotericin B (AmB) selectively to infected macrophage cells. Owing to suitable amphiphilic balance, the as-synthesized glycosylated polyurethane () with aryl boronic ester-based diol () moiety as ROS-trigger, water-soluble mannose pendants, and fluorescent 4,4-difluoro-4-bora-3a,4a-diaza--indacene (BODIPY) chain ends for bioimaging formed nanoaggregates in an aqueous medium as confirmed by H NMR spectroscopy, dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and critical aggregation concentration (CAC) measurements. Aided by two endogenous stimuli present in phagolysosome, ROS and esterase, AmB-encapsulated polymeric nanoaggregates as drug delivery vehicles achieved an efficient reduction of both and intracellular amastigote burden compared to the free AmB.
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