Rhodium(I)-catalyzed cyclization of allenynes with a tethered carbonyl group was investigated. An unusual insertion of a CO bond into the C(sp(2) )-rhodium bond of a rhodacycle intermediate occurs via a highly strained transition state. Direct reductive elimination from the obtained rhodacyle intermediate proceeds to give a tricyclic product containing an 8-oxabicyclo[3.2.1]octane skeleton, while β-hydride elimination from the same intermediate gives products that contain fused five- and seven-membered rings in high yields.
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http://dx.doi.org/10.1002/anie.201308824 | DOI Listing |
Nat Commun
January 2025
Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
1,4-Azaborine-based arenes are promising electroluminescent emitters with thermally activated delayed fluorescence (TADF), offering narrow emission spectra and high quantum yields due to a multi-resonance (MR) effect. However, their practical application is constrained by their limited operational stability. This study investigates the degradation mechanism of MR-TADF molecules.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFJ Org Chem
January 2025
Jiangxi Province Key Laboratory of Functional Organic Polymers, East China University of Technology, Nanchang 330013, China.
Org Biomol Chem
January 2025
Department of Natural Products & Medicinal Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500 007, India.
A new one-pot approach was developed for the construction of pyrano[3,2-]chromene-2,5-diones by reacting 4-hydroxycoumarins with ethyl 3-oxo-3-phenylpropanoates in the presence of ammonium salts or aminocrotonates under solvent-free conditions. The title compounds were formed by intramolecular cyclization through new C-C and C-O bonds. Structure assignment of compound 3e was confirmed by single crystal X-ray analysis.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
College of Chemistry, Xiangtan University, Xiangtan 411105, China.
Isoxazolidines are structurally important scaffolds in many natural products and bioactive compounds. Herein, we report a novel synthetic method for isoxazolidine derivatives through visible-light-induced photoredox cascade cyclization of nitroarenes with triethylamine under aerobic conditions. The resultant 5-hydroxyl isoxazolidine compounds were generally obtained in moderate yields with a broad range of compatible functionalities.
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