A new protocol for the direct cobalt-catalyzed vinylation of aryl halides using β-halostyrene has been developed in order to form functionalized stilbenes. A variety of aromatic halides featuring different reactive group were employed. This method proceeded smoothly with a total retention of the double bond configuration in the presence of triphenylphosphine as ligand. Preliminary DFT calculations rationalize these results and proposed a reaction pathway in agreement with the experimental conditions. This procedure offers a new route to the stereoselective synthesis of stilbenes.
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http://dx.doi.org/10.1021/jo3005149 | DOI Listing |
ChemSusChem
January 2025
Key Laboratory of Material Chemistry for Energy Conversion and Storage (Ministry of Education), Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China.
A novel protocol to access vinyl sulfones and internal/terminal olefins via cobalt-catalyzed acceptorless dehydrogenation coupling (ADC) has been established. This system enables the divergent synthesis of three kinds of olefin compounds through the coupling of alcohols and sulfones under oxidant-free conditions. The broad applicability of this procedure is demonstrated by over forty olefin products, including pharmaceutical-related compounds and complex substrates, in a one-pot process.
View Article and Find Full Text PDFOrg Lett
June 2024
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
A ligand-controlled regiodivergent and stereoselective ring-opening isomerization of vinylcyclopropane was developed with cobalt catalysis. Employing the commercially available Xantphos ligand, the reactions afforded exclusively linear-type 1,3-dienes as the products. Interestingly, when switching the ligand to an amido-diphosphine ligand (PNP), branched-type 1,3-dienes were obtained with high regioselectivity and stereoselectivity.
View Article and Find Full Text PDFChem Commun (Camb)
April 2024
King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Thuwal 23955-6900, Saudi Arabia.
The development of an electrochemical cobalt catalyzed C-Cl bond activation at room temperature for the nucleophilic addition of aryl and vinyl chlorides to α-ketoamides is described. The overall method operates through an electrochemically induced low valent cobalt catalyst that oxidatively adds to aryl or vinyl chlorides affording medicinally important 3-hydroxy oxindole and 3-hydroxypyrrolidinone scaffolds. The development of an enantioselective version using a chiral pyrox ligand is also demonstrated.
View Article and Find Full Text PDFOrg Lett
January 2024
School of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550014, China.
Herein, we report a rare example of rhodium-catalyzed C-H activation/[4 + 2] annulation of alkenyl amides with bicyclic alkenes under mild and green conditions. The reactivity of the rhodium catalyst in this study differed from that observed in cobalt-catalyzed C-H activation/[3 + 2] annulation between vinylic amides and bicyclic alkenes. In addition, the reaction was performed in EtOH at room temperature, which also displayed excellent diastereoselectivity, good functional group tolerance, and air compatibility.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2024
Key Laboratory for Advanced Materials, Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China.
Chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi (NHK) reaction represents one of the most powerful approaches for the formation of chiral carbon-heteroatom bond. However, the construction of sterically encumbered tetrasubstituted stereocenter through NHK reaction still posts a significant challenge. Herein, we disclose a cobalt-catalyzed aza-NHK reaction of ketimine with alkenyl halide to provide a convenient synthetic approach for the manufacture of enantioenriched tetrasubstituted α-vinylic amino acid.
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