Selectfluor-mediated tandem cyclization of enaminones with diselenides toward the synthesis of 3-selenylated chromones.

A practical and metal-free approach for the regioselective selenation of chromones employing Selectfluor reagent under mild conditions is described. The developed method is suitable for a wide substrate scope and affords 3-selenylated chromones in good to excellent yield with high selectivity. An ionic mechanism is proposed for this transformation. Furthermore, the application of potassium thiocyanate with enaminones for the synthesis of thiocyano chromones in this transformation is also successful.

Transition-metal-free radical difluorobenzylation/cyclization of unactivated alkenes: access to ArCF2-substituted ring-fused quinazolinones.

A mild and efficient transition-metal-free radical difluorobenzylation/cyclization of unactivated alkenes toward the synthesis of difluorobenzylated polycyclic quinazolinone derivatives with easily accessible α,α-difluoroarylacetic acids has been developed. This transformation has the advantages of wide functional group compatibility, a broad substrate scope, and operational simplicity. This methodology provided a highly attractive access to pharmaceutically valuable ArCF2-containing polycyclic quinazolinones.

Transition-metal catalyzed oxidative spirocyclization of N-aryl alkynamides with methylarenes under microwave irradiation.

A practical synthetic route to construct a variety of 3-benzyl spiro[4,5]trienones was developed via transition-metal Cu/Ag-catalyzed oxidative ipso-annulation of activated alkynes with unactivated toluenes using TBPB as an oxidant under microwave irradiation. This method allows the formation of two carbon-carbon bonds and one carbon-oxygen bond in a single reaction through a sequence of C-H oxidative coupling, ipso-carbocyclization and dearomatization. The advantages of this protocol are its operational simplicity and broad substrate scope, and the ability to afford the desired products in moderate to good yields.

Silver-catalyzed direct C-H oxidative carbamoylation of quinolines with oxamic acids.

A silver-catalyzed efficient and direct C-H carbamoylation of quinolines with oxamic acids to access carbamoylated quinolines has been developed through oxidative decarboxylation reaction. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance and excellent yields under mild conditions.

Transition-metal free C3-amidation of quinoxalin-2(1H)-ones using Selectfluor as a mild oxidant.

A practical and efficient synthetic route to construct a variety of 3-amidated quinoxalin-2(1H)-ones was developed via transition-metal free direct oxidative amidation of quinoxalin-2(1H)-ones with amidates using Selectfluor reagent as a mild oxidant. This protocol features mild reaction conditions, operational simplicity, broad substrate scope, and good to excellent yields.

Cucurbitacin B inhibits the migration and invasion of breast cancer cells by altering the biomechanical properties of cells.

Changes in cellular biomechanical properties affect cell migration and invasion. The natural compound Cucurbitacin B (CuB) has potent anticancer activity; however, the mechanism underlying its inhibitory effect on breast cancer metastasis needs further study. Here, we showed that low-dose CuB inhibited adhesion and altered the viscoelasticity of breast cancer cells, thereby, reducing cell deformability. In vitro and in vivo experiments proved that CuB effectively inhibited the migration and invasion of breast cancer cells. Further studies have found that CuB downregulated the expression of F-actin/vimentin/FAK/vinculin in breast cancer cells, altering the distribution and reorganization of cytoskeletal proteins in the cells. CuB inhibited signaling by the Rho family GTPases RAC1/CDC42/RhoA downstream of integrin. These findings indicate that CuB has been proven to mediate the reorganization and distribution of cytoskeletal proteins of breast cancer cells through RAC1/CDC42/RhoA signaling, which improves the mechanical properties of cell adhesion and deformation and consequently inhibits cell migration and invasion.

Higenamine enhances the antitumor effects of cucurbitacin B in breast cancer by inhibiting the interaction of AKT and CDK2.

Cucurbitacin B (Cu B), a tetracyclic triterpenoid derived from Trichosanthes kirilowii Maxim, exhibits anticancer effects against various types of tumor. Higenamine, isolated from Radix Aconiti Lateralis Preparata, has been used as a dietary supplement for regulating metabolic function. The present study suggested that higenamine enhances Cu B-induced cytotoxicity in breast cancer cells and in vivo. Network pharmacology analysis was used to identify the possible mechanism of action. Cu B alone inhibited breast cancer cell growth, induced apoptosis, and arrested the cell cycle in the G2/M phase. Cu B combined with higenamine potentiated the cytotoxic effect of Cu B, resulting in the enhanced induction of apoptosis and G2/M arrest. The network pharmacology analysis also found that the major predicted targets of Cu B in breast cancer were AKT, endoplasmic reticulum, farnesyltransferase, CAAX box, α, platelet-derived growth factor receptor α, peroxisome proliferator-activated receptor, RET proto-oncogene, and vascular endothelial growth factor A. The possible targets of higenamine involved in the synergic action were cyclin A2, cyclin-dependent kinase 2 (CDK2), dihydrofolate reductase, and protein kinase CAMP­activated catalytic subunit α. The associated pathways were summarized by Kyoto Encyclopedia of Genes and Genomes pathway analysis, and it was hypothesized that higenamine may enhance the antitumor effects of Cu B in breast cancer through inhibition of the interaction of AKT and CDK2. The protein expression was assayed by western blot analysis. The combined treatment also resulted in significant inhibition of growth in vivo.

Metal-free oxidative coupling of quinoxalin-2(1H)-ones with arylaldehydes leading to 3-acylated quinoxalin-2(1H)-ones.

A facile TBHP-mediated direct oxidative coupling of quinoxalin-2(1H)-ones with arylaldehydes has been developed under metal-free conditions. This method provided a convenient and efficient approach to various 3-acylated quinoxalin-2(1H)-ones from readily available starting materials with excellent regioselectivity. This reaction proceeded efficiently under mild conditions over a broad range of substrates and with functional group tolerance.

Copper-catalysed difluoroalkylation of aromatic aldehydes via a decarboxylation/aldol reaction.

A copper-catalysed tandem decarboxylation/aldol reaction of simple aromatic aldehydes with 2,2-difluoro-3-oxo-3-arylpropanoic acid has been developed under mild conditions. This method provides a new route for the direct one-pot synthesis of difluorinated aldols in moderate to good yields from simple substrates.

Silver catalysed decarboxylative alkylation and acylation of pyrimidines in aqueous media.

Decarboxylative alkylation or acylation reactions of simple pyrimidines have been developed in aqueous media. Using aliphatic carboxylic acids or 2-oxocarboxylic acids and pyrimidines as substrates and silver as the catalyst, the 4-substituted alkyl or acyl pyrimidines were isolated in moderate to good yields.

Silver-catalyzed radical tandem cyclization: an approach to direct synthesis of 3-acyl-4-arylquinolin-2(1H)-ones.

A silver-catalyzed efficient and practical synthesis of 3-acyl-4-arylquinolin-2(1H)-ones or 3-acyl-4-aryldihydroquinolin-2(1H)-ones through intermolecular radical addition/cyclization in aqueous solution is reported. This method provides a novel, highly efficient, and straightforward route to substituted quinolin-2-ones or 3,4-dihydroquinolin-2-ones in one step. A possible mechanism for the formation of quinolin-2-ones is proposed.

Silver catalyzed decarboxylative direct C2-alkylation of benzothiazoles with carboxylic acids.

A novel and efficient silver catalyzed decarboxylative direct C2-alkylation of benzothiazoles with carboxylic acids for the synthesis of 2-alkyl benzothiazoles was developed.

Silver-catalyzed radical tandem cyclization for the synthesis of 3,4-disubstituted dihydroquinolin-2(1H)-ones.

A silver-catalyzed tandem decarboxylative radical addition/cyclization of N-arylcinnamamides with aliphatic carboxylic acids is reported. This method affords a novel and straightforward route to various 3,4-disubstituted dihydroquinolin-2(1H)-ones in aqueous solution.

nBu4NI-catalyzed direct synthesis of α-ketoamides from aryl methyl ketones with dialkylformamides in water using TBHP as oxidant.

A novel and easy practical direct synthesis of α-ketoamides has been developed without metals in water. This procedure was catalyzed by nBu(4)NI using TBHP as oxidant from simple substrates, aryl methyl ketones and dialkylformamides.

[Phosphorylated modification of genistein and their interaction with lysozyme].

A series of genistein's phosphates were synthesized through a simplified Atherton-Todd reaction and the structures of the phosphates were determined by electrospray ionization mass spectrometry (ESI-MS) and NMR. In case of monophosporyl derivatives, NMR spectra show that substitutions occur at the 7-position of genistein but not at its 4' and 5-position. Moreover, the non-covalent complexes of lysozyme with the four new genistein phosphates were detected by ESI-MS.