Search

As novel and efficient difluoromethyl building blocks, difluoroacetohydrazonoyl bromides have been synthesized for the first time. The synthetic utility of this reagent for the construction of difluoromethyl organic compounds is demonstrated by their effective regioselective [3 + 2] cycloaddition reactions with ynones, alkynoates, and ynamides. The reactions provide a novel and efficient protocol to access difluoromethyl-substituted pyrazoles in good to excellent yields.

A highly efficient strategy for the construction of CF3-substituted 1,6-dihydropyridazines has been developed by cascade oxidation/cyclization of trifluoromethylated N-acylhydrazines. The produced ...

A highly efficient, metal-free, chemical oxidation of hydrazines has been implemented using environmentally friendly TCCA as oxidant. This benign protocol provides straightforward access to a wide range of azo compounds in THF in excellent yield. Altogether, 35 azo compounds were obtained in this way and scale-up preparations were performed. Additionally, a plausible mechanism was also proposed. Step-economical process, mild reaction conditions, operational simplicity, high reaction efficiency, and easy scale-up highlight the practicality of this methodology.

A visible-light-promoted decarboxylative acyl radical acylation/cyclization cascade reaction of N-methacryloylbenzamides for accessing acylated isoquinoline-1,3(2H,4H)-dione derivatives was described. In this report, α-keto acids were used for generating acyl radicals and inducing radical acylations. This protocol features mild reaction conditions, operational practicality and a broad substrate scope.

A novel and efficient method for synthesis of polysubstituted trifluoromethylpyridine derivatives by the Bohlmann-Rahtz heteroannulation reaction is described, which use trifluoromethyl-α,β-ynones as trifluoromethyl building blocks to react with β-enamino esters or β-enamino ketones in the presence of ZnBr

An efficient tin powder-promoted cascade condensation/allylation/lactamization of 2-formylbenzoic acids, hydrazides, and allyl bromides was developed for the synthesis of isoindolinones in good to excellent yields under mild conditions without any other additives or catalysts. Further manipulation of isoindolinones by iodocyclization process afforded the tricyclic tetrahydro-8 H-pyrazolo[5,1- a]isoindol-8-one derivatives, which could be converted into more complicated tetracyclic tetrahydro-4 H-azirino[1',2':2,3]pyrazolo[5,1- a]isoindol-4-ones.

An efficient and transition-metal-free method for the synthesis of the structurally diversified pyrroles is described. Various α,β-unsaturated ynones reacted with N-substituted ethyl glycine ethyl ester hydrochlorides in the presence of DBU to form the corresponding products in good yields. This protocol has the advantages of readily available starting materials, mild reaction conditions and a wide scope of substrates, which provides a practical route for the synthesis of polysubstituted pyrroles.

A metal- and additive-free strategy for the synthesis of oxindoles has been achieved through a chlorine radical-induced cascade chlorination/carbocyclization of N-aryl acrylamides. Trichloroiso­cyanuric acid (TCCA) is used as both radical initiator and chlorine source. A wide range of substrates can be applied in this process to directly afford chlorinated oxindoles via C–Cl and C–C bond formation.

A highly efficient strategy for the construction of CF

An efficient sulfide-catalyzed [2 + 1] annulation of para-quinone methides (p-QMs) with diverse bromides has been achieved. This catalytic strategy provides an efficient and straightforward protocol for accessing a variety of spiro-cyclopropanyl-cyclohexadienone compounds in good to excellent yields (64% to 96% yields) with outstanding diastereoselectivities (>20 : 1 dr), displaying good functional group tolerance as well as gram-scale capacity.

A novel and efficient N-arylation of trifluoromethylated N-acylhydrazones is described by using diaryliodonium salts as arylation reagents in the presence of copper salts. A wide variety of N-aryl acylhydrazones are obtained with good to excellent yields under mild reaction conditions.

α-Methylene-γ-lactams were synthesized from readily available N-acylhydrazones by a tin-mediated Barbier-type reaction. The method avoids the use of toxic allylstannanes and the reaction proceeds smoothly under mild conditions.

A novel and efficient protocol for the construction of trifluoroethyl pyrazolines has been developed by cascade cyclization/trifluoromethylation reaction of β,γ-unsaturated hydrazones. This strategy uses cheap and commercially available trichloroisocyanuric acid as promoter and TMSCF3 as the trifluoromethylating reagent, which make the trifluoromethylating process much cheaper. A wide range of substrates can be applied in this process to afford the trifluoroethyl pyrazolines in good yield.

An efficient [3+2] cycloaddition reaction of trifluoromethylated N-acylhydrazones with dimethyl maleate has been developed under basic conditions. This protocol provides an easy access to potentially bioactive trifluoromethylated pyrazolidines in moderate to excellent yields. It also illustrates that the trifluoromethylated N-acylhydrazones are useful trifluoromethyl building blocks for the synthesis of trifluoromethylated N-heterocycles.

A formal cross-dehydrogenative coupling reaction between α-hydroxy ketones and N-arylglycine derivatives for the synthesis of various β-hydroxy-α-amino acid derivatives is disclosed. The compatibility of substrate and oxidant in this reaction is achieved by controlling the dosing sequence, and the products are successfully obtained in 29–93% yields. This work provides a new method for the synthesis of β-hydroxy-α-amino acid derivatives which possesses high efficiency, convenience, and atom economy.

A simple and efficient synthetic approach is reported for the synthesis of 5-trifluoromethyl-5-aryl-3-methylidenepyrrolidin-2-ones in moderate to excellent yields via an acid-catalyzed one-pot multicomponent reaction of aromatic trifluoromethyl ketones, acylhydrazines, and ethyl 2-(bromomethyl)acrylate promoted by tin powder. The protocol is operationally simple. The overall process involves allylation and cyclization of the intermediate of acylhydrazones.

An efficient and practical cascade oxidation/halogenoaminocyclization of trifluoromethylated homoallylic N-acylhydrazines is developed. The protocol enables an efficient access to various biologically interesting CF3-containing pyrazoline compounds from readily accessible trifluoromethylated homoallylic N-acylhydrazines in good to excellent yields under mild conditions without any other additives or catalysts. The produced pyrazoline compounds can be further manipulated to other more complicated derivatives through transformation of residual halogen atom.

Sesamin, a lipid-soluble lignin originally isolated from sesame seeds, which induces cancer cell apoptosis and autophagy. In the present study, has been reported that sesamin induces apoptosis via several pathways in human lung cancer cells. However, whether mitophagy is involved in sesamin induced lung cancer cell apotosis remains unclear. This study, the anticancer activity of sesamin in lung cancer was studied by reactive oxygen species (ROS) and mitophagy. A549 cells were treated with sesamin, and cell viability, migration ability, and cell cycle were assessed using the CCK8 assay, scratch-wound test, and flow cytometry, respectively. ROS levels, mitochondrial membrane potential, and apoptosis were examined by flow cytometric detection of DCFH-DA fluorescence and by using JC-1 and TUNEL assays. The results indicated that sesamin treatment inhibited the cell viability and migration ability of A549 cells and induced G0/G1 phase arrest. Furthermore, sesamin induced an increase in ROS levels, a reduction in mitochondrial membrane potential, and apoptosis accompanied by an increase in cleaved caspase-3 and cleaved caspase-9. Additionally, sesamin triggered mitophagy and increased the expression of PINK1 and translocation of Parkin from the cytoplasm to the mitochondria. However, the antioxidant N-acetyl-L-cysteine clearly reduced the oxidative stress and mitophagy induced by sesamin. Furthermore, we found that cyclosporine A (an inhibitor of mitophagy) decreased the inhibitory effect of sesamin on A549 cell viability. Collectively, our data indicate that sesamin exerts lethal effects on lung cancer cells through the induction of ROS-mediated mitophagy and mitochondrial apoptosis.

A simple and efficient method for the visible light induced direct carbon alkylation of quinoxalin-2(1H)-ones at the C3 position is described. This protocol employs cheap and readily available phenyliodine(III) dicarboxylates as the alkylation reagents to conduct decarboxylative radical coupling reaction with quinoxalin-2(1H)-ones. The process exhibits excellent compatibility to functional groups and provides a convenient and selective access to various 3-alkylquinoxalin-2(1H)-ones in good yields.

Given the versatility and value of the structurally diverse organohalides and CF3-containing compounds in organic synthesis, we reported a green, oxidant-free electrochemical method using undivided electrochemical cells for radical bromination, chlorination and trifluoromethylation–formyloxylation of the various alkenes with readily available halogen radical (NaCl, NaBr), trifluoromethyl radical (CF3SO2Na) sources, and DMF as formyloxylation reagents. The protocol is operationally simple and robust and the Cl–, Br– or CF3– was directly oxidized at the anode, obviating the need for exogenous chemical oxidants.

A CuI promoted sulfenylation of organozinc reagents with arylsulfonyl chlorides/PPh3 has been explored. This reaction proceeded smoothly through an alkyl/aryl radical (generated from organometallics) under mild conditions and produced the desired sulfide products in excellent yields.

Sulfonyl chlorides were reduced to anhydrous sulfinate salts with magnesium under sonication. These sulfinates were alkylated to sulfones with alkyl chlorides in the presence of catalytic sodium iodide under sonication. A variety of aliphatic sulfones was efficiently prepared by this one-pot two-step procedure.

Trimethylchlorosilane was used as chlorine source for the α-chlorination of 1,3-dicarbonyl compounds with phenyliodonium diacetate as oxidant at room temperature. The reaction allows the selective synthesis of α-monochlorinated products from different kinds of 1,3-dicarbonyl compounds in good yield. The potential possibility of this conversion for bromination has also been investigated.

A highly efficient ZnBr2 promoted Michael addition/annulation cascade reaction of difluoromethyl-α,β-ynones with β-enamino derivatives has been developed. A series of CHF2-substituted pyridines has been synthesized by this method from readily accessible raw material in good yields under mild conditions. The 6-difluoromethyl-3-acylpyridines could be further converted into potentially biological active difluoromethylated 4-azafluorenes.

An efficient method of tin powder-promoted di- and mono-allylation of quinoxalin-2(1H)-ones has been developed, which provides a practical route for the synthesis of dihydroquinoxalin-2(1H)-one derivatives in good yields. This protocol uses the combination of allylbromides and tin powder to replace the traditional allylstannanes to make the organotin-participated process less toxic, and has the advantages of readily available starting materials, mild reaction conditions, and a wide scope of substrates.

Purpose A comprehensive systematic review of the literature was conducted on parameters from 18 F-FDG PET and a meta-analysis of the prognostic value of the maximal standard uptake value (SUVmax), metabolic tumor volume (MTV) and total lesional glycolysis (TLG) in patients with breast cancer (BC). Patients and methods Relevant English articles from PubMed, EMBASE, and the Cochrane Library were retrieved. Pooled hazard ratios (HRs) were used to assess the prognostic value of SUVmax, MTV, and TLG. Results A total of 20 primary studies with 3115 patients with BC were included. The combined HRs (95% confidence interval [CI] of higher SUVmax and higher TLG for event-free survival (EFS) were 1.53 (95% CI, 1.25-1.89, P = 0.0006) and 5.94 (95% CI, 2.57-13.71, P = 0.97), respectively. Regarding the overall survival (OS), the combined HRs were 1.22 (95%CI, 1.02-1.45, P = 0.0006) with higher SUVmax, and 2.91(95% CI, 1.75-4.85, P = 0.44) with higher MTV. Higher MTV showed no correlation with EFS [1.31(95% CI, 0.65-2.65, P = 0.18)] and similarly higher TLG showed no correlation with OS [1.20(95% CI, 0.65-2.23, P = 0.45)]. Subgroup analysis showed that SUVmax, with a median value of 5.55 was considered as a significant risk factor for both EFS and OS in BC patients. Conclusion Despite clinically heterogeneous BC patients and adoption of various methods between studies, the present meta-analysis results confirmed that patients with high SUVmax are at high risk of adverse events or death in BC patients, high MTV predicted a high risk of death and high TLG predicted a high risk of adverse events.