Latest ArticlesAn efficient Pd-catalyzed double annulation reaction of 1-(2, 6-dibromophenyl)-1 H-pyrroles with arynes is developed to synthesize π-extended dibenzo[d, k]ullazines in good to excellent yields. For the first time, the parent dibenzo[d, k]ullazine core is obtained and characterized.
Disclosed herein is an efficient Ag-catalyzed [4+1] heteroannulation reaction of enamides with α-carbonyl sulfoxonium ylides. The diastereoselective transformation provides a practical access to a diverse range of multi-functionalized oxazoline derivatives. The synthetic utility of the resultant tetra-substituted oxazolines is further demonstrated by a series of useful manipulations into valuable building blocks of pharmaceutical relevance.
The asymmetric transfer hydrogenation (ATH) of a wide range of ketones catalyzed by manganese complex as well as chiral PxNy-type ligand under mild conditions was investigated. Using 2-propanol as hydrogen source, various ketones could be enantioselectively hydrogenated by combining cheap, readily available [MnBr(CO)5] with chiral, 22-membered macrocyclic ligand (R, R, R', R')-CyP2N4 (L5) with 2 mol% of catalyst loading, affording highly valuable chiral alcohols with up to 95% ee.
Chemodivergent reactions of 2, 2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a CC bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2, 2-dimethoxyacetaldehyde reacted with aniline to form a new CN bond, in the presence of O2, via a CC bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new CO bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
We report a 2-iodoxybenzoic acid (IBX)-mediated intarmolecular oxidative spiro-fused tandem cyclization reaction of tryptophan analogs bearing an N-arylamides side-chain to rapidly afford polycyclic spiroindolines featuring multiple stereocenters including a quaternary stereocenters under mild reaction conditions. Among them, a novelty azaphosphol idine-containing spiroindoline compound is synthesized for the first time. It may open the door to azaphos pholidine-containing spiroindoline compound of potential interest in synthetic and medicinal chemistry. A plausible mechanism is proposed.
A facile tandem route has been developed for constructing quinazolinones from various aminobenzamides and in-situ generated aldehydes. Visible light was found to play a dual role: first oxidizes the alcohol to the aldehyde and then facilitates its cyclization with o-substituted aniline. Furthermore, alcohols are perfect alternatives to aldehydes because they are greener, more available, more economical, more stable, and less toxic than aldehydes. The first reaction step continuously provides material for the second step, which effectively reduces loss through volatilization, oxidation, and polymerization of the aldehyde, while avoiding its toxicity. A variety of quinazolinones can be prepared in the presence of visible light without any additional photocatalyst. The developed synthesis protocol proceeds with the merits of mild conditions, broad substrate scope, operational simplicity, and high atom efficiency, with an eco-energy source under metal-free, photocatalyst-free, and ambient conditions.
The σ-bond activation by main group element has received enormous attention from theoretical and experimental chemists. Here, the reaction of C–X (X=Cl, Br, Ⅰ) bonds in benzyl and allyl halides with a pincer-type phosphorus(Ⅲ) species was reported. A series of structurally robust phosphorus(Ⅴ) compounds were formed via the formal oxidative addition reactions of C–X bonds to the phosphorus(Ⅲ) center. Density functional theory calculations show that the nucleophilic addition process is more favorable than the direct oxidative addition mechanism. Isomerization of bent structures of phosphorus(Ⅲ) compound to poorly nucleophilic compounds to undergo further C–X bond activation can be rationalized by frontier molecule orbital analysis. This study not only provides a deep understanding of the reactivity of phosphorus(Ⅲ) species but also demonstrates a potential of main group elements for the small-molecule activation.
A Ru(Ⅱ)-catalyzed para-difluoroalkylation of aromatic aldehydes and ketones with a transient directing group has been developed. It utilizes less expensive ruthenium catalysts and allows facile access to challenging difluoroalkylated aldehydes. The mechanism studies suggest that the distinct coordination mode of ruthenium complex with imine moieties is responsible for para-selectivity.
The urgent need for fresh water resource is a public issue facing the world. Solar distillation for seawater desalination is a promising freshwater production method. Interfacial solar evaporation systems based on 2D photo-thermal membranes have been widely studied, but salt pollution is one of the main challenges for solar distillation. In order to solve this problem, a hydrophilic three-dimensional (3D) porous photo-thermal fiber felt (PFF) was obtained by one-step method, through a simple polydopamine (PDA) coating method with hydrophobic graphite felt as a substrate. The PFF had a good evaporation rate of 1.48 kg/m−2h-1 and its corresponding light-vapor conversion efficiency reached 87.4%. In addition, the PFF exhibited an excellent salt-resistant ability when applied to photo-thermal evaporation of high-salinity seawater with 10 wt% NaCl, owing to its intrinsic 3D macroporous structure for the migration circulation of salt ions. The development of the PFF offers a new route for the exploration of salt-resistant photo-thermal materials and is promising for the practical application of solar distillation.
The catalysts of three-dimensionally ordered macroporous (3DOM) Al2O3-supported core-shell structured Pt@MnOx nanoparticles (3DOM-Pt@MnOx/Al2O3) were successfully prepared by the gas bubbling-assisted membrane reduction-precipitation (GBMR/P) method. Pt@MnOx core-shell nanoparticles (NPs) are highly dispersed on the inner surface of 3DOM-Al2O3 support. Pt@MnOx/3DOM-Al2O3 catalysts, which combine both advantages of high-efficiency soot-catalyst contact by 3DOM-Al2O3 structure and the abundant active sites by the optimized Pt-MnOx interface, exhibit high catalytic activities for soot combustion, and the catalytic activities are strongly dependent on the thickness of MnOx shell. Among the catalysts, 3DOM-Pt@MnOx/Al2O3-1 catalyst with optimized Pt-MnOx interface shows the highest catalytic activity for soot combustion, i.e., its values of T50 and Sm are 351 ℃ and 98.6%, respectively. The highest density of Pt-MnOx active sites for adsorption-activation of gaseous O2 is responsible for enhancing catalytic activity for soot combustion. Pt@MnOx/3DOM-Al2O3 catalysts are promising to practical applications for the emission reduction of soot particles.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
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
