Latest ArticlesAs a highly strained small molecule, [1.1.1]propellane has been widely used in various synthetic transformations owing to the exceptional reactivity of the central bond between the two bridgehead carbons. Utilizing strain-release approaches, the rapid development of strategies for the construction of bicyclo[1.1.1]pentane (BCP) and cyclobutane derivatives using [1.1.1]propellane as the starting material has been witnessed in the past few years. In this review, we highlight the most recent advances in this field. Accordingly, the reactivity of [1.1.1]propellane can be divided into three pathways, including radical, anionic and transition metal-catalyzed pathways under appropriate conditions.
The recent molecular iodine catalyzed [1, 2]-rearrangement of aryl amines and 3-amino-1H-indazolesfor the synthesis of 1, 2, 3-benzotriazines is highlighted.
Chemodynamic therapy (CDT) refers to generating hydroxyl radical (·OH) in tumor sites via hydrogen peroxide (H2O2) catalyzed by transition metal ions in cancer cells under acidic environment. However, H2O2 content is not enough for effective CDT, although H2O2 content in cancer cells is higher than that of normal cells. Herein, we synthesized DOX@BSA-Cu NPs (nanoparticles) for effective CDT by providing enhanced content of H2O2 in cancer cells. The results proved Cu2+ in NPs could be reduced to Cu+ by glutathione (GSH) and effectively converted H2O2 to ·OH. Moreover, the loaded low-dose doxorubicin (DOX) in the NPs could improve the content of H2O2 and resulted in more efficient generation of ·OH in cancer cells. Thus DOX@BSA-Cu NPs exhibited higher cytotoxicity to cancer cells. This research may provide new ideas for the further studies on more effective Cu(II)-based CDT nanoagents.
The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted. The sulfoxides and sulfones could be obtained by simply switching the reaction media, i.e., bis(2-butoxyethyl)ether (BBE) or poly(ethylene glycol)dimethyl ether (PEGDME). The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents. This strategy represents an economic and eco-friendly method that could find potential applications.
The effect of gold nanoparticle-decorated molybdenum sulfide (AuNP-MoS2) nanocomposites on amyloid-β-40 (Aβ40) aggregation was investigated. The interesting discovery was that the effect of AuNP-MoS2 nanocomposites on Aβ40 aggregation was contradictory. Low concentration of AuNP-MoS2 nanocomposites could enhance the nucleus formation of Aβ40 peptides and accelerate Aβ40 fibrils aggregation. However, although high concentration of AuNP-MoS2 nanocomposites could enhance the nucleus formation of Aβ40 peptides, it eventually inhibited Aβ40 aggregation process. It might be attributed to the interaction between AuNP-MoS2 nanocomposites and Aβ40 peptides. For low concentration of AuNP-MoS2 nanocomposites, it was acted as nuclei, resulting in the acceleration of the nucleation process. However, the structural flexibility of Aβ40 peptides was limited as the concentration of AuNP-MoS2 nanocomposites was increased, resulting in the inhibition of Aβ40 aggregation. These findings suggested that AuNP-MoS2 nanocomposites might have a great potential to design new multifunctional material for future treatment of amyloid-related diseases.
An energy-saving and eco-friendly method for the efficient construction of various tri- and tetra-substituted pyrrolecarbonitriles through ultrasound-assisted multicomponent tandem reaction of readily available alkenes, TMSCN and N, N-disubstituted formamides within 40 min under metal-, solvent-free and mild conditions was developed. The dual role of iodine (catalyst and oxidant) notably simplified the reaction conditions and reduced the chemical waste generated.
To explore the effects of microenvironmental adjustments on fluorescence, a pH-sensitive nano-composite system based on fluorescence resonance energy transfer (FRET) was constructed. The model system included a modified triblock copolymer (polyhistidine-b-polyethylene glycol-b-polycaprolactone) and gold nanoparticles. A near-infrared dye was used as the donor, and spectrally matched gold nanorods, attached after C-terminus modification with α-lipoic acid, were used as the receptor to realize control of the FRET effect over the fluorescence intensity for two polymer configurational changes (i.e., "folded" and "stretched" states) in response to pH. After synthesis and characterization, we investigated the self-assembly behavior of the system. Analysis by quartz crystal microbalance revealed the pH sensitivity of the polymer, which exhibited "folding" and "stretching" states with changes in pH, providing a structural basis for the FRET effect. Fluorescence spectrophotometry investigations also revealed the regulatory impact of the assembled system on fluorescence.
Cp*Co(Ⅲ)-catalyzed direct C-H amidation of azines has been developed. This conversion could proceed smoothly in the absence of external oxidants, acids or bases, with excellent regioselectivity and broad functional group tolerance. CO2 was released as the sole byproduct, thus providing an environmentally benign amidation process. The products obtained are important intermediates in organic synthesis.
Niobium carbide MXene quantum dots (Nb2C MQDs) derived from 2D Nb2CTx (MXene) are the rising-star material recently. Herein, a sulfur and nitrogen co-doped Nb2C MQDs (S, N-MQDs) were synthesized through a hydrothermal method. The obtained Nb2C MQDs have excellent green fluorescence with a quantum yield (QY) of 17.25%. In addition, they exhibited excitation-dependent photoluminescence, anti-photobleaching and dispersion stability. They emit light at 520 nm when excited at 390 nm. The Nb2C MQDs could be successfully applied to copper ion detection with detection limit of 2 μmol/L and Caco-2 cells imaging.
Considering that hydrogen peroxide (H2O2) plays significant roles in oxidative stress, the cellular signal transduction and essential biological process regulation, the detection and imaging of H2O2 in living systems undertakes critical responsibility. Herein, we have developed a novel two-photon fluorescence turn on probe, named as Pyp-B for mitochondria H2O2 detection in living systems. Selectivity studies show that probe Pyp-B exhibit highly sensitive response toward H2O2 than other reactive oxygen species (ROS) and reactive nitrogen species (RNS) as well as biologically relevant species. The fluorescence colocalization studies demonstrate that the probe can localize in the mitochondria solely. Furthermore, as a bio-compatibility molecule, the highly selective and sensitive of fluorescence probe Pyp-B have been confirmed by its cell imaging application of H2O2 in living A549 cells and zebrafishes under the physiological conditions.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
