Dynamic boron-doping switched chitin-based single-atom Pt catalyst for chemo-selective hydrogenation.

Biomass valorization is a way to promote the 'waste-to-wealth' concept, which is a pre-requisite condition for a future sustainable lifestyle. The direct utilization of natural polymer for value-added materials should be prioritized. With this object, we demonstrate a facile and economical method to prepare chitin-derived supramolecular nanowires-stabilized single-atom sites Pt catalysts (SS-Pt-CSNs).

Electrocatalytic Alkene Hydrogenation/Deuteration.

Traditional reductions of alkenes, such as using stoichiometric reductants with waste generation and catalytic hydrogenation with high-pressure H, are accompanied by environmental or safety issues. Herein, we demonstrated a universal method for the electrocatalytic hydrogenation and deuteration of alkenes with modified electrodes under ambient temperature. The key M-H/M-D species for alkene reduction were generated from the electrolysis of HO/DO on modified electrodes, which avoided the usage of H and D.

Elucidating the Discharge Behavior of Aqueous Zinc Sulfur Batteries in the Presence of Molybdenum(IV) Chalcogenide Catalyst: The Criticality of Interfacial Electrochemistry.

The aqueous zinc-sulfur battery holds promise for significant capacity and energy density with low cost and safe operation based on environmentally benign materials. However, it suffers from the sluggish kinetics of the conversion reaction. Here, we highlight the efficacy of molybdenum(IV) sulfide (MoS) to reduce the overpotential of S-ZnS conversion in aqueous electrolytes and study the discharge products formed at the solid-solid and solid-liquid interfaces using experimental and theoretical approaches.

Tandem MS Elucidation of the Late-Stage Degradation Mechanism of Nitroplasticizer.

Understanding the degradation behavior of nitroplasticizer (NP) and the subsequent production of nitro-organics is crucial for both environmental monitoring and material development. A nontargeted approach via LC-QTOF-MS was employed to thoroughly study the degradation mechanism of NP in its late aging stage. Both positive and negative modes of ESI were performed to increase the compound coverage.

Electrocatalytic reductive deuteration of arenes and heteroarenes.

The incorporation of deuterium in organic molecules has widespread applications in medicinal chemistry and materials science. For example, the deuterated drugs austedo, donafenib and sotyktu have been recently approved. There are various methods for the synthesis of deuterated compounds with high deuterium incorporation.

The developments of C-N bond formation electrochemical Ritter-type reactions.

With the development of organic electrochemical synthesis, a series of notable achievements have been made in electrochemical Ritter amination reactions, which have enriched the methods available for constructing C-N bonds. In this review, electrochemical Ritter amination reactions are introduced based on the classification of reaction substrates, including olefins, aromatics, alkylbenzenes, and the less reported carboxylic acids, ketones, sulfides, and alkanes. The application of electrochemical technology to Ritter reactions has improved the harsh conditions of the traditional reactions, and extended the substrate scope and the structural diversity of the products.

Multiscale Anion-Hybrid in Atomic Ni Sites for High-Rate Water Electrolysis: Insights into the Charge Accumulation Mechanism.

Single-atom catalysts, characterized by transition metal-(N/O) units on nanocarbon (M-(N/O)-C), have emerged as efficient performers in water electrolysis. However, there are few guiding principles for accurately controlling the ligand fields of single atoms to further stimulate the catalyst activities. Herein, using the Ni-(N/O)-C unit as a model, we develop a further modification of the P anion on the outer shells to modulate the morphology of the ligand.

Catalytic conversion of mixed polyolefins under mild atmospheric pressure.

The chemical recycling of polyolefin presents a considerable challenge, especially as upcycling methods struggle with the reality that plastic wastes typically consist of mixtures of polyethylene (PE), polystyrene (PS), and polypropylene (PP). We report a catalytic aerobic oxidative approach for polyolefins upcycling with the corresponding carboxylic acids as the product. This method encompasses three key innovations.

Valve turning towards on-cycle in cobalt-catalyzed Negishi-type cross-coupling.

Ligands and additives are often utilized to stabilize low-valent catalytic metal species experimentally, while their role in suppressing metal deposition has been less studied. Herein, an on-cycle mechanism is reported for CoClbpy catalyzed Negishi-type cross-coupling. A full catalytic cycle of this kind of reaction was elucidated by multiple spectroscopic studies.

Roles of HNO and Carboxylic Acids in the Thermal Stability of Nitroplasticizer.

In the thermal aging of nitroplasticizer (NP), the produced nitrous acid (HONO) can decompose into reactive nitro-oxide species and nitric acid (HNO). These volatile species are prone to cause cascaded deterioration of NP and give rise to various acidic constituents. To gain insight on the early stage of NP degradation, an adequate method for measuring changes in the concentrations of HONO, HNO, and related acidic species is imperative.

Unraveling the Structure and Reactivity Patterns of the Indole Radical Cation in Regioselective Electrochemical Oxidative Annulations.

Oxidation-induced strategy for inert chemical bond activation through highly active radical cation intermediate has exhibited unique reactivity. Understanding the structure and reactivity patterns of radical cation intermediates is crucial in the mechanistic study and will be beneficial for developing new reactions. In this work, the structure and properties of indole radical cations have been revealed using time-resolved transient absorption spectroscopy, electrochemical UV-vis, and electrochemical electron paramagnetic resonance (EPR) technique.

Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry Analysis of Eutectic Bis(2,2-dinitropropyl) Acetal/Formal Degradation Profile: Nontargeted Identification of Antioxidant Derivatives.

In the eutectic mixture of bis(2,2-dinitropropyl) acetal (BDNPA) and bis(2,2-dinitropropyl) formal (BDNPF), also known as nitroplasticizer (NP), -phenyl-β-naphthylamine (PBNA), an antioxidant, is used to improve the long-term storage of NP. PBNA scavenges nitrogen oxides (e.g.

Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry: A Strategy for Optimization, Characterization, and Quantification of Antioxidant Nitro Derivatives.

As an antioxidant, -phenyl-β-naphthylamine (PBNA) inhibits the activity of oxidants, such as NO , to prevent the degradation of energetic materials. In the presence of NO , nitrated products can be generated in the process potentially. To characterize nitrated PBNA in a nontargeted analysis of complex samples as such, liquid chromatography tandem quadrupole time-of-flight (LC-QTOF), as an excellent analytic technique, is used due to its high resolution and sensitivity.

Electrophotochemical Ce-Catalyzed Ring-Opening Functionalization of Cycloalkanols under Redox-Neutral Conditions: Scope and Mechanism.

Selective cleavage and functionalization of C-C bonds in alcohols is gaining increasing interest in organic synthesis and biomass conversion. In particular, the development of redox-neutral catalytic methods with cheap catalysts and clean energy is of utmost interest. In this work, we report a versatile redox-neutral method for the ring-opening functionalization of cycloalkanols by electrophotochemical (EPC) cerium (Ce) catalysis.

Pfizer and Palbociclib in China: Analyzing an Oncology Pay-for-Performance Plan.

Objectives: China is poised to become the world's second-largest oncology drug market. Its ability to continue broadening health coverage is in question. Institutional innovations such as performance-based risk-sharing agreements (PBRSAs) have been developed to promote access to novel therapeutics beyond that provided by public health insurance and central procurement systems.

Scalable and selective deuteration of (hetero)arenes.

Isotope labelling, particularly deuteration, is an important tool for the development of new drugs, specifically for identification and quantification of metabolites. For this purpose, many efficient methodologies have been developed that allow for the small-scale synthesis of selectively deuterated compounds. Due to the development of deuterated compounds as active drug ingredients, there is a growing interest in scalable methods for deuteration.

In Situ Synthesis of CuN /Mesoporous N-Doped Carbon for Selective Oxidative Crosscoupling of Terminal Alkynes under Mild Conditions.

The 1,3-conjugated diynes are an important class of chemical intermediates, and the selective crosscoupling of terminal alkynes is an efficient chemical process for manufacturing asymmetrical 1,3-conjugated diynes. However, it often occurs in homogenous conditions and costs a lot for reaction treatment. Herein, a copper catalyzed strategy is used to synthesize highly ordered mesoporous nitrogen-doped carbon material (OMNC), and the copper species is in situ transformed into the copper single-atom site with four nitrogen coordination (CuN ).

Electrochemical Oxidation Enables Regioselective and Scalable α-C(sp)-H Acyloxylation of Sulfides.

A highly selective, environmentally friendly, and scalable electrochemical protocol for the construction of α-acyloxy sulfides, through the synergistic effect of self-assembly-induced C(sp)-H/O-H cross-coupling, is reported. It features exceptionally broad substrate scope, high regioselectivity, gram-scale synthesis, construction of complex molecules, and applicability to a variety of nucleophiles. Moreover, the soft X-ray absorption technique and a series of control experiments have been utilized to demonstrate the pivotal role of the self-assembly of the substrates, which indeed is responsible for the excellent compatibility and precise control of high regioselectivity in our electrochemical protocol.

Revealing the reduction process of Cu(ii) by sodium bis(trimethylsilyl)amide.

The mechanistic investigation of copper-catalysed transformations has been an important and fundamental task. Herein, we report via XAS and EPR spectroscopy that the sodium bis(trimethylsilyl)amide could reduce Cu(ii) to a Cu(i) species serving as an electron donor. XAS spectroscopy demonstrates that the newly formed Cu(i) species is the Cu[N(TMS)2]2Na ate complex, in which the nitrogen atoms coordinate with copper linearly.

Low-Pressure Flow Chemistry of CuAAC Click Reaction Catalyzed by Nanoporous AuCu Membrane.

Click chemistry has been widely used in bioconjugation, polymer synthesis, and the development of new anticancer drugs. Here, we report a nanoporous membrane made of AuCu alloy nanowires, which can effectively catalyze copper(I)-catalyzed 1,3-dipolar cycloaddition between azide and terminal alkyne (CuAAC) in flow condition with pressure less than one bar. Comparison studies of the nanowires before and after the reaction using X-ray photoelectron spectroscopy reveal Cu(0) and Cu(I) are main species that promote the reaction.

Binary Transition-Metal Oxide Hollow Nanoparticles for Oxygen Evolution Reaction.

Low-cost transition metal oxides are actively explored as alternative materials to precious metal-based electrocatalysts for the challenging multistep oxygen evolution reaction (OER). We utilized the Kirkendall effect allowing the formation of hollow polycrystalline, highly disordered nanoparticles (NPs) to synthesize highly active binary metal oxide OER electrocatalysts in alkali media. Two synthetic strategies were applied to achieve compositional control in binary transition metal oxide hollow NPs.

Copper-catalyzed selective radical-radical cross-coupling for C-S bond formation: an access to α-alkylthionitriles.

A new protocol for C-S bond formation was developed by selective cross-coupling between a thiyl radical and an isobutyronitrile radical. Using this strategy, a series of valuable α-alkylthionitrile derivatives were synthesized from basic starting materials. Preliminary mechanistic investigation was performed by EPR and XAFS, revealing that the transient thiyl radical could be stabilized by a copper catalyst to a persistent one.

Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica.

Well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV-vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe with Zn(II)-modified SiO support is thermodynamically favorable (Δ G = -12.

Nonresonant valence-to-core x-ray emission spectroscopy of niobium.

The valence-to-core (V2C) portion of x-ray emission spectroscopy (XES) measures the electron states close to the Fermi level. These states are involved in bonding, thus providing a measure of the chemistry of the material. In this article, we show the V2C XES spectra for several niobium compounds.

A stable rhodium single-site catalyst encapsulated within dendritic mesoporous nanochannels.

Catalysis plays an essential role in the modern chemical industry. However, it still remains a great challenge to improve the efficiency of many heterogeneous catalysts based on a per metal atom basis. Single-site catalysts (SsCs) with isolated metal atoms/ions anchored to the supports are thus highly desirable, providing an innovative solution towards highly efficient usage of precious metal atoms in heterogeneous catalysts.