Reaction of linear conjugated enynones, 1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile in the presence of lithium diisopropylamide LDA, as a base, in THF at room temperature for 3-7 h resulted in the formation of the product of dimerization, multisubstituted polyfunctional cyclohexanes, 4-aryl-2,6-bis(arylethynyl)-3-(aryloxomethyl)-4-hydroxycyclohexane-1,1-dicarbonitriles, in yields up to 60%. Varying the reaction conditions by decreasing time and temperature and changing the ratio of starting compounds (enynone and malononitrile) allowed isolating some intermediate compounds, which confirmed a plausible reaction mechanism. The relative stability of possible stereoisomers of such cyclohexanes was estimated by quantum chemical calculations (DFT method). The obtained cyclohexanes were found to possess photoluminescent properties.
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http://dx.doi.org/10.3390/molecules25245920 | DOI Listing |
Org Lett
July 2024
School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Xiasha West Higher Education District, Hangzhou 310018, China.
A copper-catalyzed intramolecular cascade reaction of conjugated enynones has been achieved via a pivotal 1,4-sulfinate migration step. This process leverages a cost-effective and ecofriendly copper salt as catalyst, enabling the efficient construction of five- and four-membered rings in a rapid, sequential manner, producing furan-tethered benzocyclobutenes in good to excellent yields under mild conditions. The reaction is characterized by 100% atom economy, outstanding efficiency, and excellent diastereoselectivity in the cases studied.
View Article and Find Full Text PDFOrg Lett
April 2024
Center for Metareceptome Research, Graduate School of Pharmaceutical Sciences, Chung-Ang University, 84 Heukseok-ro, Dongjak, Seoul, 06974, Republic of Korea.
An Eosin Y-catalyzed visible light-promoted 1,4-peroxidation-sulfonylation of enynones was achieved to give tetrasubstituted allenes. The photoredox catalysis of Eosin Y allowed the concomitant formation of peroxy and sulfonyl radicals, where the preferential peroxy radical addition to the alkene moiety of enynones resulted in the subsequent α-keto radical-sulfonyl radical cross couplings. The developed photoredox catalysis of Eosin Y demonstrates a regioselective 1,4-diradical addition strategy, opening up a new possibility of diradical functionalization of conjugate systems.
View Article and Find Full Text PDFAntimicrob Agents Chemother
February 2024
Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark.
The cell-to-cell communication system quorum sensing (QS), used by various pathogenic bacteria to synchronize gene expression and increase host invasion potentials, is studied as a potential target for persistent infection control. To search for novel molecules targeting the QS system in the Gram-negative opportunistic pathogen , a chemical library consisting of 3,280 small compounds from LifeArc was screened. A series of 10 conjugated phenones that have not previously been reported to target bacteria were identified as inhibitors of QS in .
View Article and Find Full Text PDFMolecules
May 2023
Key Laboratory of Applied Surface and Colloid Chemistry (MOE), Xi'an Key Laboratory of Organometallic Material Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
J Org Chem
July 2023
School of Pharmacy, Continuous Flow Engineering Laboratory of National Petroleum and Chemical Industry, Changzhou University, Changzhou, Jiangsu 213164, China.
A new Pd(II)-catalyzed annulation/iododifluoromethylation of enynones has been developed for the synthesis of versatile 1-indanones with moderate to good yields (26 examples). The present strategy enabled the concomitant incorporation of two important difluoroalkyl and iodo functionalities into 1-indenone skeletons with ()-stereoselectivity. The mechanistic pathway was proposed, consisting of the difluoroalkyl radical-triggered α,β-conjugated addition/5--dig cyclization/metal radical cross-coupling/reductive elimination cascade.
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