Discovery of Quinazolone Pyridiniums as Potential Broad-Spectrum Antibacterial Agents.

The overprescription of antibiotics in medicine and agriculture has accelerated the development and spread of antibiotic resistance in bacteria, which severely limits the arsenal available to clinicians for treating bacterial infections. This work discovered a new class of heteroarylcyanovinyl quinazolones and quinazolone pyridiniums to surmount the increasingly severe bacterial resistance. Bioactive assays manifested that the highly active compound exhibited strong inhibition against MRSA and with extremely low MICs of 0.

Synthesis and antibacterial medicinal evaluation of carbothioamido hydrazonyl thiazolylquinolone with multitargeting antimicrobial potential to combat increasingly global resistance.

The global microbial resistance is a serious threat to human health, and multitargeting compounds are considered to be promising to combat microbial resistance. In this work, a series of new thiazolylquinolones with multitargeting antimicrobial potential were developed through multi-step reactions using triethoxymethane and substituted anilines as start materials. Their structures were confirmed by H NMR, C NMR and HRMS spectra.

Unique aminothiazolyl coumarins as potential DNA and membrane disruptors towards Enterococcus faecalis.

Aminothiazolyl coumarins as potentially new antimicrobial agents were designed and synthesized in an effort to overcome drug resistance. Biological activity assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungi including drug-resistant pathogens. Especially, aminothiazolyl 7-propyl coumarin 8b and 4-dichlorobenzyl derivative 11b exhibited bactericidal potential (MBC/MIC = 2) toward clinically drug-resistant Enterococcus faecalis with low cytotoxicity to human lung adenocarcinoma A549 cells, rapidly bactericidal effects and no obvious bacterial resistance development against E.

Selective α-oxidation of amides visible-light-driven iron catalysis.

Hydroxyl radicals (˙OH) as one of the highly reactive species can react unselectively with a wide range of chemicals. The ˙OH radicals are typically generated under harsh conditions. Herein, we report hydroxyl radical-induced selective -α C(sp)-H bond oxidation of amides under greener and mild conditions an Fe(NO)·9HO catalyst inner sphere pathway upon irradiation with a 30 W blue LED light strip ( = 455 nm) using NaBrO as the oxidant.

Electrochemical trifluoroalkylation/annulation for the synthesis of CF-functionalized tetrahydroquinolines and dihydroquinolinones.

Tuning the electronic structure of protecting groups on the nitrogen atom of substrates has emerged as an effective strategy to achieve the tandem trifluoromethylation/C(sp)-H annulation using Langlois' reagent as the CF source for the electrochemical synthesis of functionalized tetrahydroquinolines and dihydroquinolinones.

Novel Thiazolylketenyl Quinazolinones as Potential Anti-MRSA Agents and Allosteric Modulator for PBP2a.

Bacterial infections caused by methicillin-resistant have seriously threatened public health. There is an urgent need to propose an existing regimen to overcome multidrug resistance of MRSA. A unique class of novel anti-MRSA thiazolylketenyl quinazolinones (TQs) and their analogs were developed.

CuCl -Catalyzed α-Chloroketonation of Aromatic Alkenes via Visible-Light-Induced LMCT.

Here we report a copper-catalyzed protocol for the synthesis of α-chloroketones from aromatic alkenes including electron-deficient olefins under visible-light irradiation. Preliminary mechanistic studies show that the peroxo Cu(II) species is the key intermediate and hydroperoxyl (HOO⋅) and chlorine (Cl⋅) radicals can be generated by ligand-to-metal charge transfer (LMCT).

A New Discovery of Unique 13-(Benzimidazolylmethyl)berberines as Promising Broad-Spectrum Antibacterial Agents.

A new hybridization of berberine and benzimidazoles was performed to produce 13-(benzimidazolylmethyl)berberines (BMB) as potentially broad-spectrum antibacterial agents with the hope of confronting multidrug-resistant bacterial infections in the livestock industry. Some of the newly prepared hybrids showed obvious antibacterial effects against tested strains. Particularly, 13-((1-octyl-benzimidazolyl)methyl)berberine (OBMB-) was found to be the most promising compound that not only exerted a strong activity (MIC = 0.

Aerobic Copper-Catalyzed Salicylaldehydic C -H Arylations with Arylboronic Acids.

We report a challenging copper-catalyzed C -H arylation of salicylaldehydes with arylboronic acids that involves unique salicylaldehydic copper species that differ from reported salicylaldehydic rhodacycles and palladacycles. This protocol has high chemoselectivity for the C -H bond compared to the phenolic O-H bond involving copper catalysis under high reaction temperatures. This approach is compatible with a wide range of salicylaldehyde and arylboronic acid substrates, including estrone and carbazole derivatives, which leads to the corresponding arylation products.

Iridium-Catalyzed Cycloisomerization of -Tethered 1,7-Enynes: Construction of an Azabicyclo[5.1.0]octene System.

An efficient method for the synthesis of azabicyclo[5.1.0]octenes through cycloisomerization of nitrogen-tethered 1,7-enynes catalyzed by [IrCp*Cl] was developed.

Pd-Catalyzed Remote Site-Selective and Stereoselective C(Alkenyl)-H Alkenylation of Unactivated Cycloalkenes.

A palladium-catalyzed alkenylation involving remote δ-position C(alkenyl)-H activation of cycloalkenes reacting with electron-deficient alkenes is described. This method features excellent site selectivity and stereoselectivity to efficiently afford only -selective highly substituted 1,3-diene derivatives with extra-ligand-free and good functional group tolerance including estrone and free N-H tryptamine under weakly alkaline conditions. Mechanistic studies suggest that picolinamide as a bidentate directing group enables the formation of unique alkenyl palladacycle intermediates.

Indole-nitroimidazole conjugates as efficient manipulators to decrease the genes expression of methicillin-resistant Staphylococcus aureus.

The biological resistance of methicillin-resistant staphylococcus aureus (MRSA) has pushed synthetic antibiotics to the forefront. To combat the resistance of MRSA, our new effort directed towards the development of novel structural candidates of enone-bridged indole nitroimidazole scaffolds, and wished to shed some light on the combination of some single pharmacophore with different biological activities. Bioassay revealed that the active compound 4b gave a satisfactory inhibition on MRSA (MIC = 1 μg/mL) and could effectively prevent the development of bacterial resistance.

Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylates via direct dehydrogenative C(sp)-O cross-coupling.

An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2 as the sole oxidant. This reaction exhibits high regio- and stereo-selectivity (E-isomers) with moderate to excellent isolated yields and a wide substrate scope (32 examples) including ethyl vinyl ketone and endofolliculina.

Palladium-catalyzed oxidative arylacetoxylation of alkenes: synthesis of indole and indoline derivatives.

A method for the oxidative arylacetoxylation of alkenes has been developed to synthesize indole and indoline derivatives from readily accessible substrates. The cinnamyl tethered anilines with picolinamide as a directing group provided 3-substituted indoles via intramolecular oxidative arylacetoxylation, and the 2-methyl substituted cinnamyl anilines furnished indoline derivatives with 3-position quaternary stereocenters in good to excellent yields via sequential intramolecular oxidative arylacetoxylation, hydrolysis and oxidation steps.

Synthesis of Spiro-dihydroquinoline and Octahydrophenanthrene Derivatives via Palladium-Catalyzed Intramolecular Oxidative Arylation.

A method for intramolecular sp C-H oxidative arylation of unactivated cyclic olefins has been developed to access spiro-dihydroquinoline and octahydrophenanthrene derivatives in a straightforward and efficient manner. Bearing picolinamide as a directing group, the alkenyl anilines cyclized to afford spiro-dihydroquinolines in moderate to excellent yields via direct oxidative arylation, while the alkenyl benzylamines furnished the octahydrophenanthrene derivatives in moderate yields via sequential oxidative arylation and double acetoxylation.

Catalytic Multisite-Selective Acetoxylation Reactions at sp vs sp C-H Bonds in Cyclic Olefins.

The first Pd-catalyzed multisite-selective acetoxylation reactions are disclosed at an unactivated alkene sp C-H bond versus secondary allylic sp C-H bond in cyclic olefins via the modulation of directing groups. The different directing groups overcome the key challenge in differentiating C-H bonds and provide a new controlling approach for site-specific C-H activation. A wide variety of substrates are readily acetoxylated under operationally simple conditions.

[Synthesis and antitumor activity of selenophosphocholine analogues containing tegafur].

Aim: To synthesize the selenophosphocholine analogues containing tegafur and test their antitumor activities.

Methods: The cyclic glyceroselenophospholopid conjugate of tegafur was synthesized by the reaction of hexaethylphosphorous triamide with N1-(2-furanidyl)-N3-(hydroxyalkyl)-5-fluyorouracil and 1-O-hexadecyl glycerol as well as selenium in one-pot. Cyclic glyceroselenophospholopid conjugate of tegafur reacted with triethylamine to give title compounds.