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1.
Org Lett ; 24(13): 2556-2561, 2022 04 08.
Article de Anglais | MEDLINE | ID: mdl-35348346

RÉSUMÉ

A visible-light-induced photocatalyst-free three-component radical cascade bicyclization has been achieved to obtain diverse difluoroamidosulfonylated dihydrobenzofurans in moderate to good yields. This protocol avoids potential toxicity and the tedious removal procedure for photocatalysts and also features mild reaction conditions and a good functional group tolerance. Moreover, mechanistic investigations reveal the formation of a charge-transfer complex and the involvement of an intramolecular 1,5-hydrogen atom transfer process in this transformation.


Sujet(s)
Hydrogène , Lumière , Catalyse , Radicaux libres
2.
Org Biomol Chem ; 20(5): 1112-1116, 2022 02 02.
Article de Anglais | MEDLINE | ID: mdl-35040469

RÉSUMÉ

The direct synthesis of isocoumarin skeletons has been realized through the Rh(III)-catalyzed [3 + 3] annulation of sulfoxonium ylides with iodonium carbenes. The synthetic protocol was constructed efficiently with broad functional group tolerance and mild reaction conditions. This reaction can be formally viewed as the result of C-H activation, carbene insertion and nucleophilic addition processes. Furthermore, the further conversions of the product and gram-scale reactions were also demonstrate to support the effectiveness of the synthesis protocol.

3.
Org Biomol Chem ; 19(35): 7701-7705, 2021 09 15.
Article de Anglais | MEDLINE | ID: mdl-34524333

RÉSUMÉ

A novel Rh(III)-catalyzed annulation of phthalazinones or pyridazinones with various allenes was developed, leading to the formation of indazole derivatives bearing a quaternary carbon in moderate to good yields. The targeted products were synthesized via sequential C-H activation and olefin insertion, followed by ß-hydride elimination and intramolecular cyclization. The synthetic protocol proceeded efficiently with broad functional group tolerance, high atom efficiency and high Z-selectivity. The practicability of this method was proved by synthetic transformation.

4.
J Org Chem ; 86(14): 9699-9710, 2021 07 16.
Article de Anglais | MEDLINE | ID: mdl-34184529

RÉSUMÉ

We investigated a novel Cu-catalyzed annulation of 2,3-allenoic acids with diphenylphosphine oxide, leading to the formation of 4-phosphate butenolides in up to 88% yield. The formation of the C-P bond provides new avenues for the functionalization of different furan-2(5H)-ones, with favorable features such as suitable functional group tolerance and mild synthesis conditions.


Sujet(s)
Cuivre , Oxydes , 4-Butyrolactone/analogues et dérivés , Catalyse , Phosphines , Phosphorylation
5.
BMC Complement Altern Med ; 19(1): 343, 2019 Dec 02.
Article de Anglais | MEDLINE | ID: mdl-31791318

RÉSUMÉ

BACKGROUND: Chloranthus serratus (Chloranthaceae) has been used to treat bruises, rheumatoid and bone pain. However, the anti-inflammatory mechanisms of C. serratus in vitro have not been fully elucidated. The present study aimed to explore the anti-inflammatory activity and potential mechanisms of C. serratus's separated part of water (CSSPW) in lipopolysaccharide (LPS)-induced RAW264.7 cells. METHODS: The concentrations of CSSPW were optimized by CCK-8 method. Nitric oxide (NO) content was detected by one-step method. The levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Gene expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was detected by real-time quantitative PCR (qPCR). Immunofluorescence and DCFH-DA fluorescent probes were used to detect p65 nuclear translocation and reactive oxygen species (ROS) content, respectively. Western blotting was used to assay the protein expression of mitogen-activated protein kinases (MAPK), nuclear factor-kappa B (NF-κB) and nuclear transcription factor E2 related factor 2/haem oxygenase-1 (Nrf2/HO-1) pathways. RESULTS: The final concentrations of 15 ng/mL, 1.5 µg/mL and 150 µg/mL were selected as low, medium and high doses of CSSPW, respectively. CSSPW treatment significantly reduced the generation of NO, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandinE2 (PGE2), iNOS mRNA and COX-2 mRNA in response to LPS stimulation. Furthermore, the protein expression of the MAPK and NF-κB pathways was suppressed by CSSPW treatment, as well as p65 nuclear translocation and ROS production. In contrast, the protein expression of the Nrf2/HO-1 pathway was markedly upregulated. CONCLUSIONS: CSSPW exerts its anti-inflammatory effect via downregulating the production of pro-inflammatory mediators, inhibiting the activation of NF-κB and MAPK pathways, as well as activating Nrf2/HO-1 pathway in LPS-induced RAW264.7 cells.


Sujet(s)
Heme oxygenase-1/métabolisme , Système de signalisation des MAP kinases/effets des médicaments et des substances chimiques , Magnoliopsida , Protéines membranaires/métabolisme , Facteur-2 apparenté à NF-E2/métabolisme , Extraits de plantes/pharmacologie , Animaux , Forme de la cellule/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Lipopolysaccharides/toxicité , Souris , Cellules RAW 264.7 , Espèces réactives de l'oxygène/métabolisme
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