Molecular-Oxygen-Mediated Multicomponent Oxidative Cyclization: Synthesis of Tertiary-Alcohol-Unit-Bearing -Heterocycles via Transforming C-H to C-OH Bonds.

We developed a molecular-oxygen-mediated multicomponent oxidative cyclization strategy to synthesize -heterocycles containing tertiary alcohol units via the formation of key C-OH bonds and quaternary carbon centers. This formal [3 + 2 + 1] annulation offers a green and sustainable alternative for the C-OH bond formation, using O as both the oxidant and oxygen source under metal- and catalyst-free conditions. Notably, continuous [1,5]-hydrogen transfer together with excess alcohols promotes the formation of C-OH-bearing products.

A novel synthetic compound, deferiprone-resveratrol hybrid (DFP-RVT), promotes hepatoprotective effects and ameliorates iron-induced oxidative stress in iron-overloaded β-thalassemic mice.

A high amount of iron in β-thalassemia patients can lead to oxidative stress and organ dysfunction, especially liver, the main iron accumulated organ. Iron catabolism causes the generation of reactive oxygen species (ROS), triggering liver inflammation, fibrosis, and cirrhosis. Deferiprone-resveratrol hybrid (DFP-RVT) is chemically synthesized by combining deferiprone (DFP) and resveratrol (RVT) which shows an iron-chelating property along with antioxidant activity.

Eco-friendly α,β-C(sp)-H difunctionalization of tertiary amines sequential [1,5]-hydride transfer and hetero-Diels-Alder cyclization.

An unprecedented eco-friendly multi-component domino reaction for the synthesis of novel ,-acetals is reported. The protocol involves sequential coupling, [1,5]-hydride transfer and hetero-Diels-Alder cyclization. This new strategy enables direct α,β-difunctionalization of cyclic amines utilizing enamines generated .

Direct α,β-C-H Difunctionalization of Piperidines for the Construction of the ,-Acetal Skeleton via 1,5-Hydride Transfer.

Herein, we describe an unprecedented Lewis acid-catalyzed annulation of phenols with -aminobenzaldehydes via a cascade coupling/1,5-hydride transfer/cyclization sequence. The α- and β-positions of cyclic amines were functionalized utilizing enamines generated . A series of complex ,-acetal derivatives are synthesized in moderate to good yields in one step.

Organophotoelectrocatalytic C(sp)-H alkylation of heteroarenes with unactivated C(sp)-H compounds.

An organophotoelectrocatalytic method for the C(sp)-H alkylation of heteroarenes with unactivated C(sp)-H compounds through dehydrogenation cross-coupling has been developed. The C(sp)-H alkylation combines organic catalysis, photochemistry and electrochemistry, avoiding the need for external metal-reagents, HAT-reagents, and oxidants. This protocol exhibits good substrate tolerance and functional group compatibility, providing a straightforward and powerful pathway to access a variety of alkylated heteroarenes under green conditions.

Deferiprone-resveratrol hybrid attenuates iron accumulation, oxidative stress, and antioxidant defenses in iron-loaded human Huh7 hepatic cells.

Chronic liver diseases are complications of thalassemia with iron overload. Iron chelators are required to remove excessive iron, and antioxidants are supplemented to diminish harmful reactive oxygen species (ROS), purposing to ameliorate oxidative liver damage and dysfunctions. The deferiprone-resveratrol hybrid (DFP-RVT) is a synthetic iron chelator possessing anti-β-amyloid peptide aggregation, anti-malarial activity, and hepatoprotection in plasmodium-infected mice.

Photodriven Radical-Polar Crossover Cyclization Strategy: Synthesis of Pyrazolo[1,5-]pyridines from Diazo Compounds.

This work demonstrates the synthesis of a variety of perfluoroalkyl heterocycles via a visible-light-driven radical-polar crossover cyclization strategy. In this process, single-electron reduction/SV-type/cyclization sequences follow the radical addition reaction of a diazoester, which differs from the current role of diazoesters as radical precursors/acceptors. This transformation demonstrates excellent functional group compatibility and allows for the modification of many bioactive molecules with diazoesters.

Electron injection and defect passivation for high-efficiency mesoporous perovskite solar cells.

Printable mesoscopic perovskite solar cells (p-MPSCs) do not require the added hole-transport layer needed in traditional p-n junctions but have also exhibited lower power conversion efficiencies of about 19%. We performed device simulation and carrier dynamics analysis to design a p-MPSC with mesoporous layers of semiconducting titanium dioxide, insulating zirconium dioxide, and conducting carbon infiltrated with perovskite that enabled three-dimensional injection of photoexcited electrons into titanium dioxide for collection at a transparent conductor layer. Holes underwent long-distance diffusion toward the carbon back electrode, and this carrier separation reduced recombination at the back contact.

Metal-free construction of dihydropyrazino[2,3-]indoles from 2-aminoacetophenones, isocyanates and 1,2-diamines.

A Brønsted acid/iodine co-mediated approach to construct dihydropyrazino[2,3-]indoles in 2-MeTHF as a green solvent at room temperature was established. A wide range of diversely substituted dihydropyrazino[2,3-]indoles (42 examples, 61-85% yields) were synthesized under mild conditions, even on a gram scale. This protocol features organocatalysts, an eco-friendly solvent, mild conditions, readily accessible substrates, broad substrate scope and simple work-up.

Regioselective CAlkylation of Indoles for the Synthesis of Bis(indolyl)methanes and 3-Styryl Indoles.

Herein, we describe an efficient transition-metal-free regioselective Calkylation of indoles for the synthesis of bis(indolyl)methanes and 3-styryl indoles. Nitrobenzene is employed as the oxidant to oxidize the alcohols in the presence of a strong base and the reaction avoids the use of transition metals such as Ru and Mn. The protocol provides a favorable route to access biologically active compounds such as arundine, vibrindole A, and turbomycin B.

Optical Imaging Opportunities to Inspect the Nature of Cytosolic Iron Pools.

The chemical nature of intracellular labile iron pools (LIPs) is described. By virtue of the kinetic lability of these pools, it is suggested that the isolation of such species by chromatography methods will not be possible, but rather mass spectrometric techniques should be adopted. Iron-sensitive fluorescent probes, which have been developed for the detection and quantification of LIP, are described, including those specifically designed to monitor cytosolic, mitochondrial, and lysosomal LIPs.

Visible Light-Driven α-Diazoketones as Denitrogenated Synthons: Synthesis of Fluorinated N-Heterocycles via Multicomponent Cyclization Reactions.

We disclose herein an efficient photochemical formal [3+2+1] annulation strategy for the transformation of diazocarbonyl compounds into various fluorinated nitrogen-containing heterocycles. This transformation is characterized by reacting fluoroalkyl radicals with α-diazoketones, which are used as infrequent denitrogenated synthons under visible light. Moreover, a wide range of N-heterocycles containing precious CF and perfluoroalkylated groups are constructed in moderate to good yields.

Cu(II)-catalyzed domino construction of spironaphthalenones by dearomatization of β-naphthols and using ,-dimethylaminoethanol as a C1 synthon.

Herein, a Cu(II)-catalyzed facile construction of synthetically valuable spiro compounds from β-naphthols in air is reported, in which ,-dimethylaminoethanol (DMEA) serves as an efficient and unique C1 synthon. This transformation proceeds through an -quinone methide (-QM) formation/Michael addition/dearomatization sequence, affording various spiro(naphthalenenaphtho)furan-2-ones in moderate to excellent yields.

Palladium-Catalyzed C-H Allylation/Annulation Reaction of Amides and Allylic Alcohols: Regioselective Construction of Vinyl-Substituted 3,4-Dihydroisoquinolones.

A palladium-catalyzed highly regioselective C-H allylation/annulation reaction of -sulfonyl amides with secondary or tertiary allylic alcohols has been developed to construct 3,4-dihydroisoquinolones bearing a synthetically valuable vinyl substituent. This cascade cyclization approach of allylic alcohols involving C-H allylation has not been reported previously. The commercially available allylic alcohol substrates, the only by-product of water, and the used terminal oxidant of O provide environmentally benign advantages.

Deferiprone-Resveratrol Hybrid, an Iron-Chelating Compound, Acts as an Antimalarial and Hepatoprotective Agent in -Infected Mice.

Free heme in plasma acts as a prooxidant; thus, it is bound to hemopexin and eliminated by the liver. High iron content in the liver can support growth and cause oxidative liver injury. Inversely, the withholding of excessive iron can inhibit this growth and protect the liver against malaria infection.

I-Promoted In Situ Cyclization-Rethiolation Reaction: Synthesis of 2-Aliphatic- or Aromatic-Substituted Indolizines.

An efficient I-promoted one-pot one-step three-component reaction for the synthesis of sulfhydryl indolizines from methyl ketones, 2-pyridylacetate derivatives, and sulfonyl hydrazides via an in situ cyclization-rethiolation strategy has been developed. This protocol shows excellent substrate compatibility, including for chain and cyclic aliphatic methyl ketones, natural product pregnenolone acetate, and phosphorus-containing methyl ketones, affording a series of valuable aliphatic-substituted indolizines in good yields.

Photocatalytic C-H Activation and Amination of Arenes with Nonactivated -Hydroxyphthalimides Involving Phosphine-Mediated N-O Bond Scission.

Herein, we reported a metal-free photoredox/phosphine-catalyzed C-H amination of arenes. This allows for concise synthesis of highly functionalized -arylphthalimides from readily available -hydroxyphthalimides directly, without the preparation of activated -hydroxyphthalimide intermediates. Mechanistic studies reveal that the radical is produced via phosphine-mediated N-O bond scission.

Efficient synthesis of spiro diheterocycles multi-component dicyclization reaction.

A facile synthetic protocol for the preparation of spiro diheterocycles from easily available 2'-aminoacetophenones, isocyanates and 1,4-benzoquinones or quinone monoimines under mild conditions has been developed. This multi-component transformation is characterized by efficient construction of two heterocycles and one valuable quaternary carbon in one pot an cyclization-respiroannulation strategy. Moreover, this reaction showed a broad substrate scope, and generated diverse five-membered oxaspiros.

Application of ,-Dimethylethanolamine as a One-Carbon Synthon for the Synthesis of Pyrrolo[1,2-]quinoxalines, Quinazolin-4-ones, and Benzo[4,5]imidazoquinazolines [5 + 1] Annulation.

The synthesis of -heterocycles composes a significant part of synthetic chemistry. In this report, a Cu(II)-catalyzed green and efficient synthesis of pyrrolo[1,2-]quinoxaline, quinazolin-4-one, and benzo[4,5]imidazoquinazoline derivatives was developed, employing -dimethylethanolamine (DMEA) as a C1 synthon. Green oxidant O is critical in these transformations, facilitating the formation of a key intermediate─a reactive iminium ion.

Facile construction of ,-disulfonated 5-amino pyrazoles through an iodine-catalyzed cascade reaction.

A green and facile synthesis of previously unreported ,-disulfonated 5-amino pyrazoles was established through an iodine-catalyzed cascade reaction of easily accessible sulfonyl hydrazides, β-ketonitriles, and sodium sulfinates. Diverse ,-disulfonated 5-amino pyrazoles could be obtained in 38-88% yields. This methodology features green and mild conditions, broad substrate scope, and effortless work-up.

Employing Visible-Light Photoredox Catalysis in Multicomponent-Multicatalyst Reactions: One-Pot Synthesis of Spiroquinazolin-2-(thi)ones.

The multicomponent-multicatalyst reaction ((MC)R) and visible-light catalysis have emerged as green and powerful strategies for achieving ideal syntheses. Here, we report the first example of a visible-light-induced approach toward spiroquinazolin(thi)ones. This (MC)R features an eco-friendly energy source and solvent, metal-free catalysts, step- and atom-economy, a relay catalysis strategy, air as green oxidant, mild conditions, and easily accessible starting materials.

A novel stilbene derivative (GMQ3) suppressed proliferation and induced apoptosis in lung cancer via the p38-MAPK/SIRT1 pathway.

Lung cancer is the primary cause of cancer-related mortality worldwide. The anticancer effect of stilbene has been noted in various tumor types. GMQ3, which has a stilbene-mimicking skeleton, is a novel small-molecule compound with promising antitumor activity.

Anti-Malarial and Anti-Lipid Peroxidation Activities of Deferiprone-Resveratrol Hybrid in -Infected Mice.

Iron is essential for all organisms including fast-dividing malarial parasites. Inversely, iron chelators can inhibit parasite growth through the inhibition of DNA synthesis and can ameliorate oxidative cell damage. Deferiprone (DFP)-resveratrol (RVT) hybrid (DFP-RVT) is a lipophilic anti-oxidative, iron-chelating agent that has displayed potent neuroprotective and anti-plasmodium activities in vitro.