CF3SO2Na-Mediated Five-Component Carbonylation of Triarylboroxines with TMSCF3 and THF/LiOH/NaI to Give Aroyloxyalkyl Iodides.

Herein, we developed an efficient and transition-metal-free multicomponent coupling reaction for the synthesis of aroyloxyl alkyl iodides. In the reaction among 2,4,6-triarylboroxines, THF, TMSCF3, LiOH, and NaI, five-component reactions could be precisely controlled by modulating CF3SO2Na, supplying one type of aroyloxyl alkyl iodides in moderate to high yields. The reaction exhibits good functional group tolerance and a wide substrate scope and can be easily transformed into other useful compounds. The mechanism is proposed on the basis of the control experiments.

One-Pot Three-Component Coupling Reaction of α-Amino Aryl Ketones, Indoles, and Perbromomethane Under Mild Conditions.

A simple and efficient one-pot three-component cascade reaction of α-amino aryl ketones, indoles, and CBr4 in moderate to good yields has been developed. This new strategy exhibits excellent mild reaction conditions and step-economy, easily accessible reactants, and simultaneous construction of three different new bonds (C=N, C-C, and N-Br) in a single step. It is worth noting that the protocol developed provides a simple and practical tool for the construction of diverse indole-containing heterocyclic frameworks, indicating its potential applications in medicinal and material chemistry.

Nickel-Catalyzed Arylcarbamoylation of Alkenes of N-(o-Iodoaryl)acrylamides with Nitroarenes via Reductive Aminocarbonylation: Facile Synthesis of Carbamoyl-Substituted Oxindoles.

Nickel-catalyzed arylcarbamoylation reactions of alkenes of N-(o-haloaryl)acrylamides with CO and nitroarenes via reductive aminocarbonylation to produce carbamoyl-substituted oxindoles with an all-carbon quaternary stereogenic center are presented. Starting with N-(o-haloaryl)acrylamides, simple CO, and inexpensive nitroarenes and using a Ni catalyst, a dinitrogen-based ligand, a Zn reductant, a TMSCl additive, and a base system, this protocol enables the synthesis of various carbamoyl-substituted oxindoles and allows the efficient late-stage derivatization of valuable molecules.

Merging Photoredox/Nickel Catalysis for Cross-Electrophile Coupling of Aziridines with Pyridin-1-ium Salts via Dearomatization.

Merging photoredox/nickel catalysis enabling the cross-electrophile coupling of aziridines with pyridin-1-ium salts involving dearomatization for the synthesis of ß-(1,4-dihydropyridin-4-yl)-ethylamines, especially including bioactive motif-based analogues, is described. This method allows incorporation of a 1,4-dihydropyridin-4-yl group and formation a N-H amino group to construct highly valuable ß-(1,4-dihydropyridin-4-yl)-ethylamine frameworks in a single step through the C2-N bond regioselective cleavage and dearomatization alkylation cascades with precise regioselectivity and excellent functional group tolerance, and represents an appealing cross-electrophile coupling strategy to accomplish transformations between two electrophiles, including aziridines and pyridin-1-ium salts, by avoiding prefunctionalization.

Oxidative alkylation/alkynylation of terminal alkenes via alkylaldehyde decarbonylation and 1,2-alkynyl migration.

A metal-free oxidative alkene alkylation/alkynylation of 1,4-enyn-3-ols with alkylaldehydes has been achieved, which offers a general access to the challenging quaternary carbon-containing but-3-yn-1-ones. The method features excellent functional group tolerance, broad substrate scope and exquisite selectivity, and provides a strategy for the difunctionalization of functional alkenes and utilization of alkylaldehydes as alkylating reagents through decarbonylation and 1,2-alkynyl migration.

Fe-mediated synthesis of N-aryl amides from nitroarenes and acyl chlorides.

Amides are prevalent in nature and valuable functional compounds in agrochemical, pharmaceutical, and materials industries. In this work, we developed a selective and mild method for the synthesis of N-aryl amides. Starting from commercially available nitroarenes and acyl halides, N-aryl amides with good yields can be obtained in water. Especially in the process of transformation, Fe dust is the only reductant and additive, and the reaction can be easily performed on a large scale.

Design, synthesis, and evaluation of new 2-oxoquinoline arylaminothiazole derivatives as potential anticancer agents.

A series of novel 2-oxoquinoline derivatives containing arylaminothiazole were designed and synthesized as potential antitumor agents. The synthesized compounds were evaluated for their in vitro cytotoxicity activity against HeLa, NCI-H460, T24 and SKOV3 cancer cell lines using MTT assay. Among them, compound A7 exhibited the most potent activity against the test cancer cell lines, with the IC50 values ranged from 4.4 to 8.7 µM. The results of tubulin polymerization assay showed that compound A7 could inhibit tubulin polymerization in vitro. Meanwhile, molecular docking study revealed that A7 can bind to the colchicine site of tubulin and formed hydrogen bonds with key amino acid residues in the active site. Further mechanism study demonstrated that compound A7 blocked cell cycle arrest at G2/M phase, induced cell apoptosis and depolarized mitochondria of HeLa cells. Collectively, our findings suggest that A7 could serve as a promising lead for the development of more efficient microtubule polymerization inhibitors for cancer therapy.

One-Carbon Incorporation Using Cyclobutanone Oxime Ester Enabled [2 + 2 + 1] Carboannulation of 1,7-Enynes by C-C/N-O Bond Cleavage and C-H Functionalization.

A NiCl2-promoted [2 + 2 + 1] carboannulation of 1,7-enynes with internally oxidative cyclobutanone oximes to produce canyo-functionalized 4H-cyclopenta[c]quinolin-4-ones is disclosed. Through C-C/N-O bond cleavage and C-H functionalization, the process enables one-carbon incorporation using cyclobutanone oximes to achieve [2 + 2 + 1] carboannulation of 1,7-enynes, which is highlighted by allowing the formation of four new bonds with high selectivity and broad substrate scope.

Spiro-Functionalized Diphenylethenes: Suppression of a Reversible Photocyclization Contributes to the Aggregation-Induced Emission Effect.

Many aggregation-induced emission (AIE) materials are featured by the diphenylethene (DPE) moiety which exhibits rich photophysical and photochemical activities. The understanding of these activities behind AIE is essential to guide the design of fluorescent materials with improved performance. Herein by fusing a flexible DPE with a rigid spiro scaffold, we report a class of novel deep-blue material with solid-state fluorescent quantum yield (ΦF) up to 99.8%. Along with the AIE phenomenon, we identified a reversible photocyclization (PC) on DPE with visible chromism, which is, on the contrary, popularized in solutions but blocked by aggregation. We studied the steric and electronic effects of structural perturbation and concluded that the PC is a key process behind the RIMs (restriction of intramolecular motions) mechanism for these materials. Mitigation of the PC leads to enhanced fluorescence in solutions and loss of the AIE characteristics.

Metal-free oxidative [2+2+1] heteroannulation of 1,7-enynes with thiocyanates toward thieno[3,4-c]quinolin-4(5H)-ones.

A new metal-free oxidative [2+2+1] heteroannulation of 1,7-enynes with thiocyanates for producing thieno[3,4-c]quinolin-4(5H)-ones is presented. This reaction employs benzoylperoxide (BPO) as the oxidant and sodium thiocyanate as the sulfur source to enable the formation of three chemical bonds, two C-S bonds and one C-C bond, in a single reaction, and represents a new, practical access to S-heterocycles with the avoidance of the use of metal catalysts and excess bases.

Ultrafast and deep removal of arsenic in high-concentration wastewater: A superior bulk adsorbent of porous Fe2O3 nanocubes-impregnated graphene aerogel.

Bulk adsorbents for fast and deep removal of arsenic in water is highly demanded for practical treatment process, especially fixed-bed column process. In this study, a superior bulk adsorbent of porous Fe2O3 nanocubes-impregnated porous graphene aerogel (PGA/PFe2O3) is prepared using a simple template engineering. The maximum capacity for As(III) and As(V) reaches as high as 172.27 and 217.34 mg g-1 of Fe2O3, respectively. The adsorption equilibrium times of As(III) and As(V) on PGA/PFe2O3 are only 30 and 5 min, respectively (m/V = 0.5 g L-1, C0 = 5 mg L-1). Significantly, the high concentrations of As(III) and As(V) can be reduced below 10 µg L-1 within only 60 and 5 min, respectively. The aerogel is conducive to fast diffusion of arsenic and porous Fe2O3 nanocubes provide abundant adsorption sites. Moreover, the adsorbent exhibits an outstanding reusability. The adsorbent also shows a strong anti-interference to aquatic environment. A real realgar tailing wastewater (C0 = 3.076 mg L-1 for As(III) and 3.225 mg L-1 for As(V)) can be deep treated (below 10 µg L-1) within 4 h (m/V = 0.6 g L-1). The bulk adsorbent of PGA/PFe2O3 presents a high column treatment capacity of arsenic-containing groundwater (4750 BV for As(III), 5730 BV for As(V)), producing only 12 BV eluent. This work develops a superior bulk adsorbent for large-scale treatment of arsenic-containing wastewater.

An Optical Crack Growth Sensor Using the Digital Sampling Moiré Method.

High-accuracy crack growth measurement is crucial for the health assessment of concrete structures. In this work, an optical crack growth sensor using the digital sampling moiré (DSM) method is developed for two-dimensional (2D) crack growth monitoring. The DSM method generates moiré fringes from a single image through digital image processing, and it measures 2D displacements using the phase difference of moiré fringes between motion. Compared with the previous sensors using traditional photogrammetric algorithms such as the normalized cross-correlation (NCC) method, this new DSM-based sensor has several advantages: First, it is of a higher sensitivity and lower computational cost; second, it requires no prior calibration to get accurate 2D displacements which can greatly simplify the practical application for multiple crack monitoring. In addition, it is more robust to the change of imaging distance, which is determined by the height difference between two sides of a concrete crack. These advantages break the limitation of the NCC method and broaden the applicability of the crack growth sensor. These advantages have been verified with one numerical simulation and two laboratory tests.

Synthesis of N-arylsulfonamides via Fe-promoted reaction of sulfonyl halides with nitroarenes in an aqueous medium.

A fascinating Fe-promoted protocol for the synthesis of N-arylsulfonamides has been developed. Starting from commercially available nitroarenes and sulfonyl chlorides, moderate to excellent yields of the corresponding N-arylsulfonamides can be obtained. In particular, Fe dust serves as the sole reductant in the transformation and it can be easily performed on a large scale.

Metal-Free Oxidative Decarbonylative [3+2] Annulation of Terminal Alkynes with Tertiary Alkyl Aldehydes toward Cyclopentenes.

A new metal-free oxidative decarbonylative [3+2] annulation of terminal alkynes with tertiary alkyl aldehydes is presented, which features broad substrate scope and excellent selectivity. The selectivity of this reaction toward cyclopentenes and indenes relies on the nature of the aldehyde substrates. While treatment of tertiary γ,δ-unsaturated aldehydes with common terminal alkynes assembles cyclopentenes, 2-methyl-2-arylpropanals succeed in accessing indenes.

Copper-catalyzed oxidative cross-coupling of α-aminocarbonyl compounds with primary amines toward 2-oxo-acetamidines.

A general and mild method for the construction of a carbon-nitrogen bond via copper-catalyzed oxidative cross-coupling of amines with α-aminocarbonyl compounds was achieved. Amines, either aliphatic primary amines, aromatic primary amines or secondary amines can be used as the starting materials. When R2 was different from R3, two isomers would be observed. Therefore, this reaction system has a broad substrate scope and provides a facile pathway for the synthesis of 2-oxo-acetamidines.

PhI(OAc)2-mediated 1,2-aminohalogenation of alkynes: a general access to (E)-4-(halomethylene)oxazolidin-2-ones.

A new PhI(OAc)2-mediated 1,2-aminohalogenation of prop-2-yn-1-yl carbamates and various halogen sources is presented with excellent selectivity and high step-economy. The reaction is general and rapid for the construction of diverse (E)-4-(halomethylene)oxazolidin-2-ones through the generation of the three-membered ring or N-radical followed by intramolecular cyclization.

Hypervalent iodine-triggered transformation of homopropargyl sulfonamides into dihalo-2,3-dihydropyrroles.

A novel hypervalent iodine-triggered hydroamination of homopropargyl sulfonamides with copper halides to obtain dihalo-2,3-dihydropyrroles was efficiently developed. The reaction can provide access to chloro/bromo-cyclization extended from iodocyclization to prepare potentially useful halogenated building blocks for drug development with broad functional group tolerance and high yield yet in a short time.

Copper-Catalyzed C-H Oxidative Radical Functionalization and Annulation of Aniline-Linked 1,7-Enynes: Evidence for a 1,5-Hydride Shift Mechanism.

A new copper-catalyzed tandem C-H oxidative radical functionalization and annulation of aniline-linked 1,7-enynes with alkyl nitriles or acetone is described. This reaction allows the selective construction of 1H-cyclopenta[c]quinolines and benzo[j]phenanthridin-6(5H)-ones which rely on the substitution effect at the 2-position of the acrylamide moiety. The mechanism involving a 1,5-hydride shift process is proposed according to the control deuterium-labeled experiment.

Fast regioselective sulfonylation of pyridine/quinoline N-oxides induced by iodine.

Fast sulfonylation of pyridine/quinoline N-oxides induced by iodine is demonstrated herein. The regioselective protocol occurs under metal-free conditions in a short reaction time (10 min), exhibiting high efficiency (up to 92% yield) and good compatibility (up to 33 examples). A gram-scale reaction was conducted with only a slight loss of production.