A strategy for the formation of antimony-carbon bond was developed by nickel-catalyzed cross-coupling of halostibines. This method has been applied to the synthesis of various triaryl- and diarylalkylstibines from the corresponding cyclic and acyclic halostibines. This protocol showed a wide substrate scope (72 examples) and was compatible to a wide range of functional groups such as aldehyde, ketone, alkene, alkyne, haloarenes (F, Cl, Br, I), and heteroarenes. A successful synthesis of arylated stibine 3 a in a scale of 34.77 g demonstrates high synthetic potential of this transformation. The formed stibines (R Sb) were then used for the palladium-catalyzed carbon-carbon bond forming reaction with aryl boronic acids [R-B(OH) ], giving biaryls with high selectivity, even the structures of two organomoieties (R and R') are very similar. Plausible catalytic pathways were proposed based on control experiments.
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http://dx.doi.org/10.1002/anie.202011491 | DOI Listing |
Molecules
December 2024
Institute of Organic and Analytical Chemistry (ICOA UMR 7311), CNRS, University of Orleans, F-45067 Orléans, France.
The emergence of RNA viruses driven by global population growth and international trade highlights the urgent need for effective antiviral agents that can inhibit viral replication. Nucleoside analogs, which mimic natural nucleotides, have shown promise in targeting RNA-dependent RNA polymerases (RdRps). Starting from protected 5-iodouridine, we report the synthesis of -substituted-(1,3-diyne)-uridines nucleosides and their phosphoramidate prodrugs.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Nickel-catalyzed cross-electrophile coupling (XEC) reactions of (hetero)aryl electrophiles represent appealing alternatives to palladium-catalyzed methods for biaryl synthesis, but they often generate significant quantities of homocoupling and/or proto-dehalogenation side products. In this study, an informer library of heteroaryl chloride and aryl bromide coupling partners is used to identify Ni-catalyzed XEC conditions that access high selectivity for the cross-product when using equimolar quantities of the two substrates. Two different catalyst systems are identified that show complementary scope and broad functional-group tolerance, and time-course data suggest that the two methods follow different mechanisms.
View Article and Find Full Text PDFPolymers (Basel)
October 2023
Department of Mathematics and Natural Sciences, Gulf University for Science and Technology, Mubarak Al-Abdullah 32093, Kuwait.
The synthesis of three conjugated copolymers TPP1-3 was carried out using a palladium-catalyzed [3+2] cycloaddition polymerization of 1,6-dibromopyrene with various dialkynyl thiophene derivatives 3a-c. The target copolymers were obtained in excellent yields and high purity, as confirmed by instrumental analyses. TPP1-3 were found to divulge a conspicuous iodine adsorption capacity up to 3900 mg g, whereas the adsorption mechanism studies revealed a pseudo-second-order kinetic model.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2023
State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, 94 Weijin Road, Tianjin, 300071, P. R. China.
The total synthesis of the proposed structure of anti-glioblastoma natural product neaumycin B was achieved in 22 steps (longest linear sequence). The synthesis features HCl-mediated [6,6]-spiroketalization, a combination of Krische iridium-catalyzed crotylation, Marshall palladium-catalyzed propargylation, Fürstner nickel-catalyzed regio- and enantioselective vicinal monoprotected diol formation, Brown crotylation and asymmetric halide-aldehyde cycloaddition, so as to establish the challenging contiguous stereocenters.
View Article and Find Full Text PDFInorg Chem
September 2023
Anhui Laboratory of Molecule-Based Materials, Key Laboratory of Functional Molecular Solids, Ministry of Education, School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, China.
8-aryl or alkyl-naphthyl substituents are widely used as an effective axial shielding strategy for the suppression of chain transfer in late-transition metal-catalyzed ethylene (co)polymerization to yield high molecular weight polyethylene and copolymers. In this study, two 8-cycloalkylnaphthyl acenaphthene-based α-diimine ligands and the corresponding four nickel and palladium complexes were designed and synthesized to explore the effect of axial flexible shielding on ethylene (co)polymerization. In ethylene polymerization, the nickel complexes displayed high activities (up to 1.
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