Friedel-Crafts-type acylation of alkenes with acyl chlorides has been successfully conducted with a wide substrate scope by the combined use of AlCl and 2,6-dibromopyridine. Trisubstituted alkenes afford allylketones or vinylketones depending on the presence or absence of hydrogen atom(s) at the β-position to the acylation site, while monosubstituted alkenes exclusively afford vinylketones.
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http://dx.doi.org/10.1021/acs.orglett.9b02688 | DOI Listing |
Chemistry
December 2024
Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023, Dalian, Liaoning, China.
Herein we report a "carbonylative migration" strategy for the acylation-esterification type double functionalization of unactivated alkenes using alkyloxalkyl chlorides and CO as the reagents. The transformation is proceeded by the alkoxycarbonyl radical addition to unactivated alkenes, followed by the insertion of carbon monoxide to induce intramolecular migration of heteroaryl groups, which is different from the traditional reaction modes. The reaction conditions were mild and well tolerated with varieties of functional groups.
View Article and Find Full Text PDFJ Am Chem Soc
November 2024
Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
The direct use of readily available aldehydes as acyl radical precursors has facilitated diverse three-component acylative difunctionalization reactions of alkenes, offering a powerful route to synthesize β-branched ketones. However, asymmetric three-component acylative difunctionalization of alkenes with aldehydes still remains elusive. Here we report a copper-catalyzed asymmetric three-component radical acylarylation of vinylarenes with aldehydes and aryl boronic acids.
View Article and Find Full Text PDFOrg Lett
September 2024
Department of Chemistry, Jadavpur University, Kolkata-700032, West Bengal, India.
A one-step, two-component visible light-mediated CoCl·6HO-catalyzed oxidative acylation of alkenes by aldehydes to synthesize -epoxy ketone has been achieved in water at room temperature. The photocatalytic activity of Co(II) presented a remarkable achievement for synthesis of -epoxy ketones from aldehydes and olefins, with a wide substrate compatibility including aromatic, heteroaromatic and aliphatic aldehydes, styrenes with both electron-donating and withdrawing groups, α-substituted styrenes, stilbene, acrylates, and even the challenging unactivated aliphatic alkenes. Mechanistic studies including radical trapping experiments, intermediate detection by GCMS, Hammett analysis, and DFT studies unveil the nature of the photocatalytic pathway.
View Article and Find Full Text PDFChemistry
November 2024
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, 060-0810, Japan.
A photoinduced copper-catalyzed enantioselective conjugate addition of acylsilanes has been developed. The conjugate acylation of α,β-unsaturated ketones and aldehydes was promoted by a copper(I)/chiral NHC catalyst under visible-light irradiation for synthesizing various 2-substituted 1,4-dicarbonyl compounds in enantioenriched forms. Mechanistic studies combining experiments and quantum chemical calculations indicated a reaction mechanism involving copper-to-acyl charge transfer (i.
View Article and Find Full Text PDFNew Phytol
November 2024
College of Biology, Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, National Center of Technology Innovation for Saline-Alkali Tolerant Rice, Gerater by Area Institute For Innovation, Hunan University, Changsha, 410082, China.
Plants frequently encounter adverse conditions and stress during their lives. Abscisic acid (ABA) plays a crucial role in response to salt stress, and dynamic regulation of ABA levels is essential for plant growth and stress resistance. In this study, we identified a transcription factor, OsSGL (Oryza sativa Stress tolerance and Grain Length), which acts as a negative regulator in salt stress, controlling ABA synthesis.
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