Two new visible-light-mediated strategies are described starting from aryldiazoacetates. The first approach describes their reaction with azides to afford the corresponding imines, and then reaction with aryldiazoketones produces alkyl 2-carboxylate-2,3,3-trisubstituted β-lactams. The second approach describes the reaction with sulfoxides to afford the corresponding sulfoxonium ylides, followed by reaction with aryldiazoketones to produce 5-alkoxy-2,2,4-trisubstituted furan-3(2H)-ones. These protocols take advantage of the photolysis of aryldiazoacetates and the photochemically promoted Wolff rearrangement of aryldiazoketones.
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http://dx.doi.org/10.1021/acs.orglett.1c03662 | DOI Listing |
Chemistry
January 2025
Southwest University, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, 400715, Chongqing, CHINA.
A visible-light-mediated strategy is reported for the direct synthesis of polychlorinated vicinal diaryl alkanes from aryl alkenes and chloroform. In this approach, two haloalkyl radicals generated from chloroform via halogen atom transfer (XAT) and direct single electron transfer (SET) within the same photoredox catalysis cycle enable the 1,4-dichloromethyldimerization of alkenes. Besides chloroform, this strategy is applicable to carbon tetrachloride, bromotrichloromethane, and α-bromo carboxylic esters, yielding corresponding 1,4-disubstituted vicinal diaryl alkanes.
View Article and Find Full Text PDFChem Commun (Camb)
December 2024
Universidade Estadual de Campinas, Instituto de Química, CEP 13083-862, Campinas, SP, Brazil.
A reaction sequence of visible light-mediated cyclopropanation/acid-promoted ring-opening is described for the formal alkylation of silyl enol ethers with aryldiazoacetates. Under the same conditions, the Danishefsky's diene can react with aryldiazoacetates to afford [4+1]-cycloaddition adducts. Key mechanistic aspects are proposed based on experimental evidence and DFT calculations.
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January 2025
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Key Laboratory of Research and Development for Natural Products, School of Pharmacy, Yunnan University Kunming 650500 P. R. China
Hydrogen atom transfer (HAT) processes provide an important strategy for selective C-H functionalization. Compared with the popularity of 1,5-HAT processes, however, net-1,2-HAT reactions have been reported less frequently. Herein, we report a unique visible-light-mediated net-1,2-HAT of amidyl radicals for the synthesis of β-amido ketone derivatives.
View Article and Find Full Text PDFOrg Lett
December 2024
College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou 311121, P. R. China.
Herein, a photocatalytic strategy for the synthesis of secondary alcohols by nucleophilic addition of an alkene with an aldehyde is described. This operationally simple methodology opens an approach for the synthesis of alcohols using commercially available reagents in moderate to excellent yields. Mechanistic studies indicate that the formation of the radical anion from alkene via single-electron transfer is the key step in this reaction.
View Article and Find Full Text PDFOrg Lett
December 2024
HitGen Inc., Building 6, No. 8 Huigu 1st East Road, Tianfu International Bio-Town, Shuangliu District, Chengdu 610200, Sichuan, P. R. China.
DNA-encoded library (DEL) technology has been developed to serve as a practical platform for the discovery of biologically active macrocyclic peptide compounds. However, the cyclization of linear peptides has been widely regarded as the challenging step in the production of macrocyclic peptide DELs. Herein, we describe a novel DNA-compatible macrocyclization strategy, which enables the construction of ring systems via visible-light-mediated desulfurative C-C bond formation.
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