Controllable Active Intermediate in CO Hydrogenation Enabling Highly Selective ,-Dimethylformamide Synthesis via -Formylation.

,-Dimethylformamide (DMF) is a widely used solvent, and its green and low-carbon synthesis methods are in high demand. Herein, we report a new approach for DMF synthesis using a continuous flow reaction system with a fixed-bed reactor and a ZnO-TiO solid solution catalyst. This catalyst effectively utilizes CO, H, and dimethylamine (DMA) as feedstocks, demonstrating performance with 99% DMF selectivity and single-pass DMA conversion approaching thermodynamic equilibrium.

Magneto-Photonic Effect of FeO@SiO Nanorods for Visualizing the Direction of Magnetic Fields with High Spatiotemporal Resolution.

In this work, we demonstrate the visualization of the complex magnetic fields by utilizing the magneto-photonic effect of FeO@SiO nanorod suspension with one-to-one correspondence between the visible colors and magnetic field directions. The selected anisotropic nanorods possess appropriate saturated magnetization and high electrostatic repulsion, which is magnetically direction-responsive but strength-insensitive, accurately detecting the field direction while eliminating the influence from intensity. The combined experiment-simulation study validates the accuracy of the simulation, allowing us to further determine the intensity distribution of the magnetic field.

A Highly Active Molybdenum Carbide Catalyst with Dynamic Carbon Flux for Reverse Water-Gas Shift Reaction.

Molybdenum carbide has been reported as an efficient and stable catalyst for reverse water-gas shift (RWGS) reaction. The conventional understanding of the mechanism suggests domination of the surface phenomena, with only surface or subsurface layers partaking in the catalytic cycle. In this study, we presented a highly active MoC catalyst from carburization process, which showed a mass-specific reaction rate over 260 μm with dynamic carbon flux in the bulk phase of the catalyst.

Boosted Efficiency of FeO for Photocatalytic CO Reduction via Engineering Fe-O-Ti Bonding.

Visible light-driven photocatalytic CO reduction (CORR) offers a sustainable and promising solution to environmental and energy challenges. However, the design of efficient photocatalysts is hindered by poor interface interactions in heterojunctions and a limited understanding of reaction kinetics. A modified FeO photocatalyst, M-FeO@MXene, is introduced featuring KH-550-modified M-FeO hollow nanocubes coated with MXene, constructed via an electrostatic and Fe-O-Ti bonding self-assembly method.

Borane-Catalyzed Intermolecular Aryl Transfer between Hydrosilanes: Shifting the Equilibrium by Removal of a Gaseous Hydrosilane.

The preparation of organosilanes is indeed far from trivial, despite their vast application. Herein, we report a straightforward and general hydrosilane iterative evolution system for the on-demand synthesis of heteroleptic-substituted hydrosilanes. A series of previously difficult-to-prepare hydrosilanes with two or three diverse substituents were readily obtained.

Synchronous recognition of amines in oxidative carbonylation toward unsymmetrical ureas.

Unsymmetrical ureas are commonly found in pharmaceuticals and bioactive compounds. However, devising strategies to introduce two distinct amines selectively in the construction of unsymmetrical ureas remains a challenge. In this work, we use a synchronous recognition strategy that takes advantage of radical and nucleophilic activation to discriminate between secondary and primary amines.

Novel antibacterial pullulan derivatives modified with quaternary phosphonium salts for infected wound treatments.

The development of novel antibacterial agents is urgently needed to tackle bacterial infection, the major global issue menacing human health. Among them, polymeric quaternary phosphonium salts are worth noticing owing to their strong antibacterial activities and other merits including low bacterial drug resistance. Herein, pullulan modified with quaternary phosphonium salts (PQP) was synthesized using esterification reactions of pullulan and (5-carboxypentyl)triphenylphosphonium bromide (CPTPPB) mediated by N,N'‑carbonyldiimidazole (CDI), and was evaluated as novel antibacterial agents for treating wound infection for the first time.

Synthesis of Chiral Endocyclic Allenes and Alkynes via Pd-Catalyzed Asymmetric Higher-Order Dipolar Cycloaddition.

A Pd-catalyzed asymmetric higher-order dipolar cycloaddition between allenyl carbonates and azadienes is achieved by exploiting novel alkylidene-π-allyl-Pd dipoles. This research provides a modular platform for the synthesis of challenging chiral endocyclic allenes bearing a medium-sized heterocyclic motif and a centrally chiral stereocenter in good yields with high enantio- and diastereoselectivities (29 examples, up to 97% yield, 97:3 er and >19:1 dr). Experimental and computational studies elucidate the possible reaction mechanism and the observed stereochemical results.

Data-driven discovery of active phosphine ligand space for cross-coupling reactions.

The design of highly active catalysts is a main theme in organic chemistry, but it still relies heavily on expert experience. Herein, powered by machine-learning global structure exploration, we forge a Metal-Phosphine Catalyst Database (MPCD) with a meticulously designed ligand replacement energy metric, a key descriptor to describe the metal-ligand interactions. It pushes the rational design of organometallic catalysts to a quantitative era, where a ±10 kJ mol window of relative ligand binding strength, a so-called active ligand space (ALS), is identified for highly effective catalyst screening.

Access to N-α-quaternary chiral morpholines via Cu-catalyzed asymmetric propargylic amination/desymmetrization strategy.

Morpholines are widespread in many biologically and catalytically active agents, thus being an important aim of pharmaceutical and synthetic chemists. However, efficient strategies for the catalytic asymmetric synthesis of chiral morpholines bearing crowded stereogenic centers still remain elusive. Herein, we disclose a Cu-catalyzed asymmetric propargylic amination/desymmetrization strategy to help resolve this challenge.

Hyperconjugation-Driven Isodesmic Reaction of Indoles and Anilines: Reaction Discovery, Mechanism Study, and Antitumor Application.

Isodesmic reactions, in which chemical bonds are redistributed between substrates and products, provide a general and powerful strategy for both biological and chemical synthesis. However, most isodesmic reactions involve either metathesis or functional-group transfer. Here, we serendipitously discovered a novel isodesmic reaction of indoles and anilines that proceeds intramolecularly under weakly acidic conditions.

Skeletal Editing of Aromatic N-Heterocycles via Hydroborative Cleavage of C-N Bonds-Scope, Mechanism, and Property.

Skeletal editing of the core structure of heterocycles offers new opportunities for chemical construction and is a promising yet challenging research topic that has recently gained increasing interest. However, several limitations of the reported systems remain to be addressed. For example, the reagents employed are generally in high-energy, such as chlorocarbene precursors, nitrene species, and metal carbenes, which are also associated with low atomic efficiencies.

Selective Hydroboration of C-C Single Bonds without Transition-Metal Catalysis.

Selective hydroboration of C-C single bonds presents a fundamental challenge in the chemical industry. Previously, only catalytic systems utilizing precious metals Ir and Rh, in conjunction with N- and P- ligands, could achieve this, ensuring bond cleavage and selectivity. In sharp contrast, we discovered an unprecedented and general transition-metal-free system for the hydroboration of C-C single bonds.

Composite antibacterial hydrogels based on two natural products pullulan and ε-poly-l-lysine for burn wound healing.

Antibacterial hydrogels as burn wound dressings are capable of efficaciously defending against bacterial infection and accelerating burn wound healing. Thus far, a large plethora of antibacterial hydrogels have adopted numerous components and intricate preparation processes, yet restricting their practical industrialization applications. Simple and effective preparation methods of antibacterial hydrogels are hence urgently needed.

CeO-Supported Single-Atom Cu Catalysts Modified with Fe for RWGS Reaction: Deciphering the Role of Fe in the Reaction Mechanism by In Situ/Operando Spectroscopic Techniques.

Reverse water-gas shift (RWGS) reaction has attracted much attention as a potential approach for CO valorization via the production of synthesis gas, especially over Fe-modified supported Cu catalysts on CeO. However, most studies have focused solely on investigating the RWGS reaction over catalysts with high Cu and Fe loadings, thus leading to an increase in the complexity of the catalytic system and, hence, preventing the gain of any reliable information about the nature of the active sites and reaction mechanism. In this work, a CeO-supported single-atom Cu catalyst modified with iron was synthesized and evaluated for the RWGS reaction.

3-Methylpyridine: Synthesis and Applications.

3-Methylpyridine holds a pivotal role in organic chemistry as it constitutes a fundamental structure in numerous biologically active compounds. Its significance is underscored by its involvement in synthesizing vitamin B3 and developing pyridine insecticides, garnering considerable attention. Consequently, chemists have dedicated efforts to devising efficient and environmentally friendly methods for its preparation.

Red-light-mediated copper-catalyzed photoredox catalysis promotes regioselectivity switch in the difunctionalization of alkenes.

Controlling regioselectivity during difunctionalization of alkenes remains a significant challenge, particularly when the installation of both functional groups involves radical processes. In this aspect, methodologies to install trifluoromethane (-CF) via difunctionalization have been explored, due to the importance of this moiety in the pharmaceutical sectors; however, these existing reports are limited, most of which affording only the corresponding β-trifluoromethylated products. The main reason for this limitation arises from the fact that -CF group served as an initiator in those reactions and predominantly preferred to be installed at the terminal (β) position of an alkene.

Polyoxometalates Based Catalysts for Carbonylation Reactions: A Review.

As a type of diverse and structurally adjustable metal-oxo clusters, polyoxometalates (POMs) based materials have been extensively applied as a catalysis in various valuable reactions. This review summarized recent progress in the application of POMs-based catalysts for various carbonylation reactions including (1). Carbonylation of olefins, (2).

Tuning Adsorbate-Mediated Strong Metal-Support Interaction by Oxygen Vacancy: A Case Study in Ru/TiO.

The adsorbate-mediated strong metal-support interaction (A-SMSI) offers a reversible means of altering the selectivity of supported metal catalysts, thereby providing a powerful tool for facile modulation of catalytic performance. However, the fundamental understanding of A-SMSI remains inadequate and methods for tuning A-SMSI are still in their nascent stages, impeding its stabilization under reaction conditions. Here, we report that the initial concentration of oxygen vacancy in oxide supports plays a key role in tuning the A-SMSI between Ru nanoparticles and defected titania (TiO).

Selective Hydrogenation of Diethyl Malonate to 1,3-Propanediol Over Ga-Promoted Cu/SiO Catalysts With Enhanced Activity and Stability.

Cu catalysts with different compositions and different Cu and promoter contents were prepared by precipitation-gel method and studied for the selective hydrogenation of syngas or biomass-based diethyl malonate (DEM) to valuable 1,3-propanediol (1,3-PDO). The Ga-promoted 70Cu6Ga/SiO catalyst was found to exhibit the highest catalytic performance, achieving 100 % DEM conversion and 76.6 % 1,3-PDO selectivity under reaction conditions of 160 °C and 8 MPa H.

Cu-phen Coordination Enabled Selective Electrocatalytic Reduction of CO to Methane.

Manipulation of selectivity in the catalytic electrochemical carbon dioxide reduction reaction (eCORR) poses significant challenges due to inevitable structure reconstruction. One approach is to develop effective strategies for controlling reaction pathways to gain a deeper understanding of mechanisms in robust CORR systems. In this work, by precise introduction of 1,10-phenanthroline as a bidentate ligand modulator, the electronic property of the copper site was effectively regulated, thereby directing selectivity switch.

Stabilization of Pd by Cu Alloying: Theory-Guided Design of PdCu Electrocatalyst for Anodic Methanol Carbonylation.

Electrocatalytic carbonylation of CO and CHOH to dimethyl carbonate (DMC) on metallic palladium (Pd) electrode offers a promising strategy for C1 valorization at the anode. However, its broader application is limited by the high working potential and the low DMC selectivity accompanied with severe methanol self-oxidation. Herein, our theoretical analysis of the intermediate adsorption interactions on both Pd and Pd surfaces revealed that inevitable reconstruction of Pd surface under strongly oxidative potential diminishes its CO adsorption capacity, thus damaging the DMC formation.

Zirconium and hafnium catalyzed C-C single bond hydroboration.

Selective cleavage and subsequent functionalization of C-C single bonds present a fundamental challenge in synthetic organic chemistry. Traditionally, the activation of C-C single bonds has been achieved using stoichiometric transition-metal complexes. Recently, examples of catalytic processes were developed in which use is made of precious metals.

Synthesis of S(IV)-Stereogenic Chiral Thio-Oxazolidinones via Palladium-Catalyzed Asymmetric [3+2] Annulations.

Organic molecules bearing chiral sulfur stereocenters exert a great impact on asymmetric catalysis and synthesis, chiral drugs, and chiral materials. Compared with acyclic ones, the catalytic asymmetric synthesis of thio-heterocycles has largely lagged behind due to the lack of efficient synthetic strategies. Here we establish the first modular platform to access chiral thio-oxazolidinones via Pd-catalyzed asymmetric [3+2] annulations of vinylethylene carbonates with sulfinylanilines.