A highly general and selective Co-catalyzed biaryl coupling through C-F cleavage under phosphine or NHC-free conditions was described. A broad range of aryl fluorides including unactivated fluorides as well as those with sensitive functionalities could couple with various Ti(OEt)-mediated aryl Grignard reagents with high selectivity under the catalysis of CoCl/DMPU. Importantly, selective C-F bond activation couplings between two types of fluorines (difluorinated aromatics and on two different coupling partners) and in the presence of C-Cl or C-Br bonds could also be achieved.
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http://dx.doi.org/10.1021/acs.joc.6b02354 | DOI Listing |
Beilstein J Org Chem
January 2025
Sagami Chemical Research Institute, 2743-1 Hayakawa, Ayase, Kanagawa 252-1193, Japan.
2-Fluorobenzofurans underwent efficient nickel-catalyzed coupling with arylboronic acids through the activation of aromatic C-F bonds. This method allowed us to successfully synthesize a range of 2-arylbenzofurans with various substituents. The reaction, which proceeded under mild conditions, involved β-fluorine elimination from nickelacyclopropanes formed by the interaction of 2-fluorobenzofurans with zero-valent nickel species.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Defluorination reactions are increasingly vital due to the extensive use of organofluorine compounds with robust carbon-fluorine (C-F) bonds; particularly, the efficient defluorination of widespread and persistent per- and polyfluoroalkyl substances under mild conditions is crucial due to their accumulation in the environment and human body. Herein, we demonstrate that surface-modified silicate of pronounced proton affinity can confine active hydrogen (•H) onto nanoscale zerovalent iron (nZVI) by withdrawing electrons from nZVI to react with bound protons, generating confined active hydrogen (•H) for efficient defluorination under ambient conditions. The exposed silicon cation (Si) of silicate functions as a Lewis acid site to activate the C-F bond by forming Si.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Nanopharmaceutical Sciences, Nagoya Institute of Technology Gokiso, Showa-ku Nagoya 466-8555 Japan
In this study, we explore the potential of the difluoro(trifluoromethoxy)methyl group, CF-O-CF, an underexplored but promising structural analog of the trifluoromethoxy group (OCF). This moiety offers unique electronic properties and enhanced chemical stability due to its multiple C-F bonds, along with the added advantage of C-O bond cleavage, making it an attractive option in fluorine chemistry. We have succeeded in synthesizing difluoro(trifluoromethoxy)methyl compounds radical amino- and hydroxy-trifluoromethoxylations of β,β-difluorostyrenes.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Chemistry and Chemical Engineering, Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, Shandong University, Jinan 250100, P. R. China.
Herein, we describe a hexavalent tellurium-based chalcogen bonding catalysis platform capable of addressing reactivity and selectivity issues. This research demonstrates that hexavalent tellurium salts can serve as a class of highly active chalcogen bonding catalysts for the first time. The tellurium centers in these hexavalent catalysts have only one exposed interaction site, thus providing a favorable condition for the controlling of reaction selectivity.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESP), Beijing, China; Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), Beijing, China; Laboratory for Environmental Frontier Technologies (BLEFT), School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:
Widespread detection in soils and sediments underscores the potential threats posed by persistent, bioaccumulative and toxic perfluorooctane sulfonate (PFOS) to ecosystems and organisms. Nevertheless, the formidable energy of the C-F bond imparts stability and hampers degradation. This study investigates the potential of boron carbide (BC), a hard-ceramic material often utilized in armor and abrasion contexts, for degrading solid-phase PFOS through ball milling.
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