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A variety of azetidine nitrones are prepared in moderate to good yields through copper(I) combined with 2-aminopyridine to catalyze skeletal rearrangement of O -propargylic oximes. Mechanistic studies reveal that the reaction undergoes a copper(I)-catalyzed tandem [2,3]-rearrangement, 4π-electrocyclization, ring opening, and recyclization over four steps in one pot. Substituents at the terminus of alkyne and oxime moieties have a significant impact on the formation of azetidine nitrones and exomethylene oxazolines, respectively. Furthermore, the obtained azetidine nitrone could easily participate in [3 + 2] cycloaddition with alkynoates, and a [2.2]-paracyclophane-derived azetidine nitrone is synthesized in 45% yield over five steps from bromo[2.2]-paracyclophane.

A variety of functionalized 2‐pyrrolidinones bearing N‐trifluoromethylphenyl moieties were prepared in moderate to good yields with high diastereoselectivity through copper(II)‐catalyst and base co‐catalyzed formal [4+1] cycloaddition of cinnamaldehyde nitrones with 1‐ethynylnaphthalen‐2‐ols in the presence of m‐CPBA as the oxidant. The triple bond of 1‐ethynylnaphthalen‐2‐ol served as one‐carbon synthon for the pyrrolidinone ring formation. Mechanistic studies revealed that m‐CPBA played an important role to interrupt the intramolecular O‐cyclization to afford the 2‐pyrrolidinones. Moreover, the reaction could be easily performed at gram scales and the obtained products were selectively converted into diverse pyrroline scaffolds. [ABSTRACT FROM AUTHOR]

In a two-phase heat transfer device, achieving a high capillarity of the wick while reducing flow resistance within a limited space becomes the key to improving the heat dissipation performance. As a commonly used wick structure, mesh is widely employed because of its high permeability. However, achieving the desired capillary performance often requires multiple layers to be superimposed to ensure an adequate capillary, resulting in an increased thickness of the wick. In this study, an ultra-thin biomimetic copper forest structural modification of copper mesh was performed using an electrochemical deposition to solve the contradiction between the permeability and the capillary. The experiments were conducted on a copper mesh to investigate the effects of various conditions on their morphology and capillary performance. The results indicate that the capillary performance of the modified copper mesh improves with a longer deposition time. The capillary pressure drops can reach up to 1400 Pa when using ethanol as the working fluid. Furthermore, the modified copper mesh demonstrates a capillary performance value (ΔPc·K) of 8.44 × 10−8 N, which is 1.7 times higher than that of the unmodified samples. Notably, this enhanced performance is achieved with a thickness of only 142 μm. The capillary limit can reach up to 45 W when the modified copper mesh is only 180 μm. Microscopic flow analysis reveals that the copper forest modified structure maintains the original high permeability of the copper mesh while providing a greater capillary force, thereby enhancing the overall flow characteristics. [ABSTRACT FROM AUTHOR]

We described a copper(II)‐catalyzed [3+2] cycloaddition of N‐aryl‐α,β‐unsaturated nitrones with disubstituted allenoates bifurcated to prepare various [1,3]oxazino[3,2‐a]indolines and dihydropyrido[1,2‐a]indolines in moderate to excellent yields. Mechanistic studies revealed that [1,3]oxazino[3,2‐a]indoline was a kinetically favored product and dihydropyrido[1,2‐a]indoline was thermodynamically favored product. Moreover, the reaction was easily performed at gram scales and chiral dihydropyrido[1,2‐a]indoline could be obtained by using chiral auxiliary. The present method highlights broad substrate scope, good functional group tolerance, and diversity of indoline scaffolds with high diastereoselectivity. [ABSTRACT FROM AUTHOR]

A variety of (E)-N-aryloxindole nitrones were prepared in good to excellent yields by using a copper-catalyzed coupling reaction of isatin oximes and arylboronic acids under mild conditions. Various arylboronic acids that contain sensitive functional groups were tolerated in the transformation, and detailed studies show that the carbonyl group of the isatin oximes serves as a ligand to control the formation of the (E)-oxindole nitrones. This method to prepare (E)-N-aryloxindole nitrones was easily performed on a gram scale and efficiently used to synthesize estrone-derived oxindole nitrone in high yield. [ABSTRACT FROM AUTHOR]

N-Vinyl nitrones derived from fluorenone have been prepared via a copper-mediated coupling between fluorenone oxime and vinyl boronic acids. These compounds undergo subsequent rearrangement and addition reactions that are distinct from the traditional [3 2] cycloaddition reactivity of nitrones. Thermal rearrangements of fluorenone N-vinyl nitrones give spiroisoxazolines, while treatment with alkynes provides fluorene-tethered isoxazoles. The scope and limitations of the preparation of fluorenone N-vinyl nitrones and their subsequent rearrangement and addition reactions are discussed. [ABSTRACT FROM AUTHOR]

Fourteen novel tumor-targeting copper(II) and zinc(II) complexes, [Cu(ONQ)(QD1)(NO 3)]·CH 3 OH (NQ3), [Cu(ONQ)(QD2)(NO 3)] (NQ2), [Cu(NQ)(QD2)Cl] (NQ3), [Cu(ONQ)(QD1)Cl] (NQ4), [Cu(ONQ)(QD3)](NO 3) (NQ5), [Cu(ONQ)(QD3)Cl] (NQ6), [Zn(ONQ)(QD4)Cl] (NQ7), [Zn(ONQ)(QD1)Cl] (NQ8), [Zn(ONQ)(QD5)Cl] (NQ9), [Zn(ONQ)(QD2)Cl] (NQ10), [Zn(ONQ)(QD6)Cl] (NQ11), [Zn(ONQ)(QD7)Cl] (NQ12), and [Zn(ONQ)(QD3)Cl] (NQ13) supported on 8-hydroxyquinoline- N -oxide (H-ONQ), 2,2′-dipyridyl (QD1), 5,5′-dimethyl-2,2′-bipyridyl (QD2), 1,10-phenanthroline (QD3), 4,4′-dimethoxy-2,2′-bipyridyl (QD4), 4,4′-dimethyl-2,2′-bipyridyl (QD5), 5-chloro-1,10-phenanthroline (QD6), and bathophenanthroline (QD7), were first synthesized and characterized using various spectroscopic techniques. Furthermore, NQ1 – NQ13 exhibited higher antiproliferative activity and selectivity for cisplatin-resistant SK-OV-3/DDP tumor cells (CiSK3) compared to normal HL-7702 cells based on results obtained from the cell counting Kit-8 (CCK-8) assay. The complexation of copper(II) ion with QD2 and ONQ ligands resulted in an evident increase in the antiproliferation of NQ1–NQ6 , with NQ6 exhibiting the highest antitumor potency against CiSK3 cells compared to NQ1–NQ5 , H-ONQ, QD1 – QD7, and NQ7–NQ13 as well as the reference cisplatin drug with an IC 50 value of 0.17 ± 0.05 μM. Mechanistic studies revealed that NQ4 and NQ6 induced apoptosis of CiSK3 cells via mitophagy pathway regulation and adenosine triphosphate (ATP) depletion. Further, the differential induction of mitophagy decreased in the order of NQ6 > NQ4 , which can be attributed to the major impact of the QD3 ligand with a large planar geometry and the Cl leaving group within the NQ6 complex. In summary, these results confirmed that the newly synthesized H-ONQ copper(II) and zinc(II) coordination metal compounds NQ1–NQ13 exhibit potential as anticancer drugs for cisplatin-resistant ovarian CiSK3 cancer treatment. 8-hydroxyquinoline-N-oxide copper(II) and zinc(II) complexes could cause SK-OV-3/DDP cell apoptosis via mitophagy induction and ATP depletion. [Display omitted] • Tumor-targeting complexes NQ1 − NQ13 have been prepared. • These complexes are more selective for SK-OV-3/DDP tumor cells versus HL-7702 normal cells. • NQ4 and NQ6 could cause SK-OV-3/DDP cell apoptosis via mitophagy induction and ATP depletion. [ABSTRACT FROM AUTHOR]

[Display omitted] • A technique based on spatially selective electrodeposition of copper (Cu) to reveal latent fingerprints on metal substrates. • The latent fingerprints' primary, secondary and tertiary features could be clearly revealed. • The developing technology is not harsh to the conditions of fingerprint leaving. • The metal substrates could be copper, stainless steel, nickel sheet, and copper sheet with severe oxidation. • This method can show more precise line details compared with the traditional particle suspension method. Sebaceous fingerprints are prevalent daily and formed by natural secretions or contact with exogenous substances such as the face, hair, and cosmetics. This paper reports a technique based on spatially selective electrodeposition of copper (Cu) to develop latent sebaceous fingerprints on metal substrates. As the metal film was only selectively deposited on the valley line area (i.e., non-sebaceous area) but not the ridge line area (i.e., sebaceous area), a clear negative image of the fingerprint pattern could be formed. First, a simulation of the reaction process of electrodeposition was done. Then, the image contrast and the display accuracy were used as two key factors to evaluate the quality of the electrodeposited fingerprint. Parameters such as current density and deposition time were optimized, resulting in the victorious revelation of latent fingerprints' primary, secondary and tertiary features. Moreover, comparing the fingerprint patterns produced by the traditional particle suspension method and the electrodeposition method revealed that the latter can show more precise details of the lines. We further applied varying sebaceous densities (SD) and intensity of pressures (IP) to simulate different fingerprint legacy conditions, with conclusive results proving that the methodology we developed could be more rigorous on fingerprint legacy requirements. Finally, the experiments showed that this method could be utilized to develop latent fingerprints on other metal substrates, including copper sheets with severe oxidation, stainless steel, and nickel sheet. [ABSTRACT FROM AUTHOR]

Micro pin fin arrays have been widely used in electronic cooling, micro reactors, catalyst support, and wettability modification and so on, and a facile way to produce better micro pin fin arrays is demanded. Herein, a simple electrochemical method has been developed to fabricate copper vertical micro dendrite fin arrays (Cu-VMDFA) with controllable shapes, number density and height. High copper sulphate concentration is one key point to make the dendrite stand vertically. Besides, the applied current should rise at an appropriate rate to ensure the copper dendrite can grow vertically on its own. The Cu-VMDFA can significantly enhance the heat transfer coefficient by approximately twice compared to the plain copper surface. The Cu-VMDFA may be widely used in boiling heat transfer areas such as nuclear power plants, electronic cooling, heat exchangers, and so on. [ABSTRACT FROM AUTHOR]

Derivatives (III) are prepared by means of Chan-Lam reaction. [ABSTRACT FROM AUTHOR]