A novel visible-light photoredox catalysis protocol for the effective and efficient synthesis of 3-substituted chroman-4-ones and 2,3-dihydroquinolin-4(1)-ones via tandem radical addition/cyclization of alkenyl aldehydes has been described. This reaction features a broad substrate scope, mild reaction conditions, and good functional group tolerance character.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.joc.9b03253 | DOI Listing |
Chem Commun (Camb)
January 2025
Shanghai Key Laboratory of Functional Materials Chemistry, Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai 200237, China.
An efficient protocol was reported for the synthesis of 2-trifluoromethyl indoles through visible-light-promoted intermolecular cyclization of sulfoxonium ylides with azides, without the need for external photocatalysts, transition metals, or bases. The formation of 2-trifluoromethyl indoles involves an intriguing cascade process including azide rearrangement, intermolecular nucleophilic addition, and visible-light-promoted cyclization of a key intermediate. The protocol features high efficiency, mild conditions, excellent substrate compatibility and good regioselectivity.
View Article and Find Full Text PDFJ Org Chem
December 2024
State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.
Nat Commun
October 2024
Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
C-Glycosides are essential for the study of biological processes and the development of carbohydrate-based drugs. Despite the tremendous hurdles, glycochemists have often fantasized about the efficient, highly stereoselective synthesis of C-glycosides with the shortest steps under mild conditions. Herein, we report a desulfurative radical protocol to synthesize C-alkyl glycosides and coumarin C-glycosides under visible-light induced conditions without the need of an extra photocatalyst, in which stable and readily available glycosyl thiols that could be readily obtained from native sugars are activated in situ by pentafluoropyridine.
View Article and Find Full Text PDFOrg Biomol Chem
November 2024
School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China.
An efficient visible-light-promoted cascade difluoromethylation/cyclization reaction to access various CFH-substituted benzimidazo[2,1-]isoquinolin-6(5)-ones was developed using difluoromethyltriphenylphosphonium bromide salt as the precursor of the -CFH group under mild conditions. This protocol utilized an easily accessible and inexpensive organophotocatalyst, offering the benefits of a broad substrate scope, good functional group tolerance, and good to excellent yields, in addition to a simple operational procedure. Furthermore, the reaction mechanism was subjected to investigation, and it was demonstrated that a radical pathway constitutes a single electron transfer (SET) procedure.
View Article and Find Full Text PDFChem Commun (Camb)
September 2024
School of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225009, China.
Described herein is a novel visible-light-promoted three-component radical iodo-alkylative cyclization of alkynes using iodoform as a bifunctional iodine atom source. Visible-light irradiation of a polar-polar interaction complex of iodoform with malonate enables the cooperative hydrogen atom transfer process to generate alkyl radical and trigger a cascade reaction sequence.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!