Vicinal oxygen-containing tetra- and tri-substituted stereocenters exist widely in chromanone lactone and tetrahydroxanthone natural products. Their enantioselective construction in a single step remains elusive and poses a formidable challenge for chemical synthesis. Here, we report the first copper(I)-catalyzed asymmetric vinylogous additions of siloxyfurans to 2-ester-substituted chromones, which enable concise and enantioselective assembly of chromanone lactones. Both syn and anti adducts can be accessed with excellent diastereo- and enantioselectivity by judicious choice of the chiral ligands. Our approach allowed for the efficient synthesis of (-)-blennolide B with precise stereochemical control, which provides a formal synthesis of secalonic acid A.
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http://dx.doi.org/10.1002/anie.202203128 | DOI Listing |
Fitoterapia
December 2024
Institue for Inheritance-Based Innovation of Chinese Medicine, Guangdong Provincial Key Laboratory of Chinese Medicine Ingredients and Gut Microbiomics, School of Pharmacy, Shenzhen University Medical School, Shenzhen 518060, PR China. Electronic address:
Three new N-alkylated amino acid derivatives, penichrysoamides A-C (1-3), along with a new citric acid derivative, penichrysoacid A (4), a new chromanone lactone penichrysoacid B (5), and a new amide derivative, penichrysoamide D (6), as well as seven known benzamide derivatives (7-13), were isolated from the endophytic fungus Penicillium chrysogenum derived from the insect Periplaneta americana. The structures of these compounds, including their absolute configurations, were elucidated using spectroscopic and computational techniques. Biological evaluation revealed that compounds 8-13 exhibited significant COX-2 inhibitory activity, with IC values ranging from 275 nM to 1350 nM.
View Article and Find Full Text PDFJ Antibiot (Tokyo)
October 2024
Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan.
Herbidospora is one of the underexplored actinomycete genera from which only a limited number of secondary metabolites are reported. In our continuing investigation on less explored actinomycetes, a liquid culture of Herbidospora sp. RD 11066 was found to contain unknown metabolites that had no match in our in-house UV database.
View Article and Find Full Text PDFOrg Lett
November 2023
Institute of Microbial Chemistry (BIKAKEN), Tokyo, 3-14-23 Kamiosaki Shinagawa-ku, Tokyo 141-0021, Japan.
A copper-catalyzed asymmetric vinylogous conjugate addition of butenolide to 2-ester-substituted chromones is described, and it delivers - or -chromanone lactones with high stereoselectivities. The enantioselectivity-determining step varied with the use of B(OMe) as an additive, resulting in enhanced stereoselectivities, as revealed by density functional theory calculations, which also provided theoretical insight into the origin of the ligand-dependent diastereodivergence.
View Article and Find Full Text PDFChem Sci
August 2022
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
Chiral chromanone lactones are a class of natural products with important biological activity. We report a direct diastereo- and enantioselective vinylogous conjugate addition of butenolide to 2-ester substituted chromones. The transformation proceeded well in the presence of as low as 1 mol% of a chiral ,'-dioxide/Sc complex, 3 Å MS and a catalytic amount of hexafluoroisopropanol (HFIP).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2022
Institute of Microbial Chemistry (BIKAKEN), Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo, 141-0021, Japan.
Vicinal oxygen-containing tetra- and tri-substituted stereocenters exist widely in chromanone lactone and tetrahydroxanthone natural products. Their enantioselective construction in a single step remains elusive and poses a formidable challenge for chemical synthesis. Here, we report the first copper(I)-catalyzed asymmetric vinylogous additions of siloxyfurans to 2-ester-substituted chromones, which enable concise and enantioselective assembly of chromanone lactones.
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