Latest ArticlesRegioselevtive functionalization of perylene diimides (PDIs) at bay area often requires multistep synthesis and strenuous recrystallization. Direct bromination of perylene diimides only afford the 1, 6 and 1, 7-regioisomers. More importantly, the 1, 6-dibromo regioisomers could only be separated by preparative HPLC. Herein, we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives. This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs, which yields exclusively the 1, 6-regioisomers. Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer, which causes substantial changes on the optoelectronic properties. Moreover, the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm2 V−1 s−1, showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.
Benziodazole-triflate, as a novel heterocyclic hypervalent iodine(Ⅲ) reagent, was prepared from the reaction of hypervalent chloroiodine(Ⅲ) with silver triflate under mild conditions. The structure of this new reagent was elucidated by NMR spectroscopy and X-ray crystallography, and its reactions with diverse α-electron withdrawing group substituted carbonyl compounds were investigated. The results implied that benziodazole-triflate could be selectively used as both a 2-iodobenzamido-transfer reagent for the synthesis of oxazole compounds, and a triflate-transfer reagent for the triflation of β-keto-sulfones. Ionic mechanistic pathways, supported by density functional theory (DFT) calculations, were proposed to account for the divergent selectivities of the transformations.
The significance of axial chiral compounds in asymmetric organic catalysis, functional materials, and pharmaceutical useful molecules has encouraged advancements in the atroposelective synthesis of such compounds. Herein, we report the first atroposelective construction of axially chiral N-aryl benzimidazoles catalyzed by a polymer-supported chiral phosphoric acid. A varied library of atropisomers has been synthesized in 30%-96% yield with 58%-98% enantiomeric excess (ee) under a straightforward reaction setup (without the use of molecular sieves). Notably, even after 12 cycles, the immobilized catalyst maintained its reactivity and selectivity (TON > 540).
Fluorescence imaging-guided photodynamic therapy holds great promise for application in precise cancer diagnosis and treatment, which has motivated high requirements for phototheranostic agents. However, current photosensitizers (PSs) generally face limitations such as short emission wavelength and inadequate reactive oxygen species (ROS) production. Aggregation-caused quenching issue also hinders the phototheranostic efficiency of PSs. Herein, the π-bridge modulation strategy is proposed to construct ionic PSs with enhanced bioimaging and therapeutic outcomes. Two donor-π-acceptor (D-π-A) molecules TPCPY and TFCPY were obtained by incorporating phenyl and furan units as π-bridge, respectively. Both PSs feature aggregation-induced near-infrared emission. Under light irradiation, TPCPY and TFCPY can produce both type Ⅰ and Ⅱ ROS. Introducing furan ring in TFCPY enhances the ROS generation capacity by type Ⅰ photosensitization process, which is consistent with the reduced energy gap between singlet and triplet states from theoretical calculation. Furthermore, TFCPY can achieve quick cellular uptake, accumulate in mitochondria, and then efficiently kill cancer cells, which is superior to TPCPY. Consequently, TFCPY exhibited good antitumor outcomes and excellent in vivo fluorescence imaging ability. This work provides an efficient molecular engineering of introducing heterocycles into the D-π-A skeleton to develop high-performance PSs with both type Ⅰ and Ⅱ ROS generation.
Advanced oxidation processes (AOPs) governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation. Nevertheless, the low diffusion rates, inadequate interactions of the reactants, and limited active site exposure hinder treatment efficiency. Porous carbocatalysts with high specific surface area, tunable pore size, and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants. The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions. Additionally, the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites, which further enhances the catalytic activity. This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts. Moreover, engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances. Challenges and future research opportunities pertaining to the design, optimization, mechanistic investigation, and practical application of porous carbocatalysts in peroxide activation are also proposed.
Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is an attractive technology for the visualization of metabolite distributions in tissues. However, detection and identification of low-abundance or poorly ionized metabolites remains challenging. Although on-tissue chemical derivatization (OTCD) holds great promise for improving MALDI MS detection sensitivity and selectivity by modification of specific chemical groups, the available methods for subsequent metabolite annotation are limited. Herein, a laser-assisted chemical transfer (LACT)-based parallel OTCD strategy was established for visualizing and annotating carbonyl metabolites in murine brain tissues. Girard's T and Girard's P reagents were applied for parallel OTCD to generate the characteristic m/z pairs with a 19.969 Da mass shift (±0.020 Da tolerance) for rapid recognition of derivatized metabolites. The similarity of spatial distribution patterns of each m/z pair was further statistically evaluated to remove the ambiguous annotations due to the occurrence of interference compounds. As a result, 90 ion pairs were annotated as candidate carbonyl metabolites, 66 were previously known and 24 were potential unreported carbonyls. Furthermore, the spatial alterations of carbonyl metabolites in the ischemic rat brain were successfully visualized and characterized, including small molecule aldehydes and ketones, long-chain fatty aldehydes, and monosaccharides. This further emphasizes great potential of parallel OTCD strategy for efficient and confident molecular annotation of spatial submetabolomics data associated with brain diseases.
Lithium metal batteries, with their light mass anode and high theoretical specific capacity of 3860 mAh/g, have great potential for development in achieving high energy density. However, the generation of lithium dendrites and the loss of dead lithium pose a serious threat to the safety and long-cycle stability of batteries. Herein, we utilize the Lewis acid-base interaction principle for lithium-ion migration regulation. Through loading solid-acids onto molecular sieves to immobilize Lewis base (PF6−), we achieve accelerated dissociation of lithium salts and successfully increase the lithium ion transference number to 0.44. Lewis acid-base interaction helps lithium metal batteries achieve more uniform lithium deposition, with an average CE improved to 92.8%. The symmetrical cells can be plated/stripped stably for more than 800 h of cycling. Full cell with high surface-loaded LFP cathode (14 mg/cm2) exhibits impressively high capacity retention of 90.7% after 120 cycles at 0.5 C.
Conductive hydrogel membranes with nanofluids channels represent one of the most promising capacitive electrodes due to their rapid kinetics of ion transport. The construction of these unique structures always requires new self-assembly behaviors with different building blocks, intriguing phenomena of colloidal chemistry. In this work, by delicately balancing the electrostatic repulsions between 2D inorganic nanosheets and the electrostatic adsorption with cations, we develop a general strategy to fabricate stable free-standing 1T molybdenum disulphide (MoS2) hydrogel membranes with abundant fluidic channels. Given the interpenetrating ionic transport network, the MoS2 hydrogel membranes exhibit a high-level capacitive performance 1.34 F/cm2 at an ultrahigh mass loading of 11.2 mg/cm2. Furthermore, the interlayer spacing of MoS2 in the hydrogel membranes can be controlled with ångström-scale precision using different cations, which can promote further fundamental studies and potential applications of the transition-metal dichalcogenides hydrogel membranes.
The asymmetric conjugate additions of aryl Grignard reagents to trisubstituted enones by chiral P, N ligand L6 with low catalyst loading (0.25–1.0 mol%) are disclosed. Chiral 2-ester chromanone and its analogs bearing a quaternary stereogenic centers at C2 position were produced in high to excellent yields, enantioselectivities and high turnover number. The notable features of this reaction include its broad substrate scope, complete 1, 4-addition regioselectivities, applicability to both batch and flow for large scale synthesis. This report develops an efficient strategy to apply aryl Grignard reagents in asymmetric 1, 4-conjugation reactions and provides a direct method to incorporate quaternary chiral centers toward the synthesis of biologically relevant chromanone derivatives.
A novel organocatalytic asymmetric approach to oxazoline derivatives that proceeds through Mannich/annulation reaction of N-acylimines with 3-chlorooxindoles is presented. This strategy provides an efficient and convenient method to access enantioenriched oxazolines such as valuable chiral S, N-oxazoline ligand as well as Ferrox ligand in high yields with excellent enantio– and diastereroselectivity. Furthermore, the optically active oxazoline products can be converted to valuable 1, 2-amino alcohols. More importantly, the synthetic utility of this transformation is demonstrated in the expeditious assembly of chiral Phox-type ligand, which shows excellent catalytic activities.
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
