A formidable challenge at the forefront of organic synthesis is the control of chemoselectivity to enable the selective formation of diverse structural motifs from a readily available substrate class. Presented herein is a detailed study of chemoselectivity with palladium-based phosphane catalysts and readily available 2-B(pin)-substituted allylic acetates, benzoates, and carbonates. Depending on the choice of reagents, catalysts, and reaction conditions, 2-B(pin)-substituted allylic acetates and derivatives can be steered into one of three reaction manifolds: allylic substitution, Suzuki-Miyaura cross-coupling, or elimination to form allenes, all with excellent chemoselectivity. Studies on the chemoselectivity of Pd catalysts in their reactivity with boron-bearing allylic acetate derivatives led to the development of diverse and practical reactions with potential utility in synthetic organic chemistry.
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http://dx.doi.org/10.1002/chem.201402353 | DOI Listing |
Food Chem
January 2025
State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, PR China. Electronic address:
Changes in chemical composition during food processing and handling are crucial for the alteration of food flavor and function, and accurate characterization of key chemical reaction pathways in complex food matrices is one of the core challenges in food chemistry research. Here, this study attempts to establish a strategy for sensitive characterization of chemical reactions during food processing based on on-line extraction electrospray ionization mass spectrometry (oEESI-MS). The process of making garlic into black garlic, a traditional global flavor food, was chosen as an exemplary research template.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Laboratory of Animal Biology, National Institute for Research and Development for Biology and Animal Nutrition, Calea Bucuresti No. 1, Balotesti, 077015 Ilfov, Romania.
The present study aimed to investigate the ability of an aqueous extract derived from mustard seed meal to counteract the effects of endotoxin lipopolysaccharide (LPS) on the intestinal epithelium. Caco-2 cells were cultured together with HT29-MTX and used as a cellular model to analyze critical intestinal parameters, such as renewal, integrity, innate immunity, and signaling pathway. Byproducts of mustard seed oil extraction are rich in soluble polysaccharides, proteins, allyl isothiocyanates, and phenolic acids, which are known as powerful antioxidants with antimicrobial and antifungal properties.
View Article and Find Full Text PDFMolecules
January 2025
School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
Ester collectors have rapidly developed into the main flotation collectors for copper sulfide minerals since they were developed. In this study, the collecting performance of four collectors, O-isopropyl-N-ethyl thionocarbamate ester (IPETC), 3-pentyl xanthate acrylate ester (PXA), O-isobutyl-N-allyl-thionocarbamate (IBALTC), and O-isobutyl-N-isobutoxycarbonyl-thionocarbamate (IBIBCTC), was investigated through microflotation tests, microcalorimetric measurements, and quantum chemical calculations. The results of the microflotation tests show that IBALTC and IPETC have stronger collecting abilities than IBIBCTC and PXA; the order of collecting ability is IBALTC > IPETC > IBIBCTC > PXA.
View Article and Find Full Text PDFMolecules
December 2024
Department of Physical Chemistry, Faculty of Chemistry, University of Łódź, Pomorska 163/165, 90-236 Łódź, Poland.
Extracts from natural waste like bark or leaves are great sources of phytochemicals, which contain functional groups (hydroxyl, carboxylic, vinyl, allyl) attractive in terms of polymer synthesis. In this study, the synthesis of epoxy with an extract of Scots pine bark as a natural co-hardener was evaluated. Ultraviolet-visible (UV-Vis) spectroscopy was used for the identification of phytochemicals with conjugated dienes and quantification of TPC.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Inst Org Chem, State Key Lab Organometallic Chem, 345 Lingling Lu, 200032, Shanghai, CHINA.
Rhodium-catalyzed regio- and enantioselective allylic arylation of racemic alkyl- and aryl- substituted allylic carbonates with arylboronic acids using commercially available BIBOP ligand is reported. This reaction proceeds at room temperature without base or other additive to deliver allylic arylation products in excellent yields, regio- and enantioselectivity (up to 95% yield, >20:1 b/l, >99% ee). Rh/BIBOP is disclosed as an efficient catalytic system for allylic substitution reaction.
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