Identification of a potent palladium-aryldiphosphine catalytic system for high-performance carbonylation of alkenes.

The development of stable and efficient ligands is of vital significance to enhance the catalytic performance of carbonylation reactions of alkenes. Herein, an aryldiphosphine ligand (L11) bearing the [Ph2P(ortho-C6H4)]2CH2 skeleton is reported for palladium-catalyzed regioselective carbonylation of alkenes. Compared with the industrially successful Pd/1,2-bis(di-tert-butylphosphinomethyl)benzene catalyst, catalytic efficiency catalyzed by Pd/L11 on methoxycarbonylation of ethylene is obtained, exhibiting better catalytic performance (TON: >2,390,000; TOF: 100,000 h-1; selectivity: >99%) and stronger oxygen-resistance stability. Moreover, a substrate compatibility (122 examples) including chiral and bioactive alkenes or alcohols is achieved with up to 99% yield and 99% regioselectivity. Experimental and computational investigations show that the appropriate bite angle of aryldiphosphine ligand and the favorable interaction of 1,4-dioxane with Pd/L11 synergistically contribute to high activity and selectivity while the electron deficient phosphines originated from electron delocalization endow L11 with excellent oxygen-resistance stability.

Recent Advances in Hydrogenation of CO2 to CO with Heterogeneous Catalysts Through the RWGS Reaction.

With the continuous increase in CO2 emissions, primarily from the combustion of coal and oil, the ecosystem faces a significant threat. Therefore, as an effective method to minimize the issue, the Reverse Water Gas Shift (RWGS) reaction which converts CO2 towards CO attracts much attention, is an environmentally-friendly method to mitigate climate change and lessen dependence on fossil fuels. Nevertheless, the inherent thermodynamic stability and kinetic inertness of CO2 is a big challenge under mild conditions. In addition, it remains another fundamental challenge in RWGS reaction owing to CO selectivity issue caused by CO2 further hydrogenation towards CH4 . Up till now, a series of catalysis systems have been developed for CO2 reduction reaction to produce CO. Herein, the research progress of the well-performed heterogeneous catalysts for the RWGS reaction were summarized, including the catalyst design, catalytic performance and reaction mechanism. This review will provide insights into efficient utilization of CO2 and promote the development of RWGS reaction.

Water Activation Triggered by Cu-Co Double-Atom Catalyst for Silane Oxidation.

High-performance catalysts sufficient to significantly reduce the energy barrier of water activation are crucial in facilitating reactions that are restricted by water dissociation. Herein we present a Cu-Co double-atom catalyst (CuCo-DAC), which possesses a uniform and well-defined CuCoN6 (OH) structure, and works together to promote water activation in silane oxidation. The catalyst achieves superior catalytic performance far exceeding that of single-atom catalysts (SACs). Various functional silanes are converted into silanols with up to 98 % yield and 99 % selectivity. Kinetic studies show that the activation energy of silane oxidation by CuCo-DAC is significantly lower than that of Cu single-atom catalyst (Cu-SAC) and Co single-atom catalyst (Co-SAC). Theoretical calculations demonstrate two different reaction pathways where water splitting is the rate-determining step and it is accelerated by CuCo-DAC, whereas H2 formation is key for its single-atom counterpart.

Construction of Highly Active and Selective Molecular Imprinting Catalyst for Hydrogenation.

Surface molecular imprinting (MI) is one of the most efficient techniques to improve selectivity in a catalytic reaction. Heretofore, a prerequisite to fabricating selective catalysts by MI strategies is to sacrifice the number of surface-active sites, leading to a remarkable decrease of activity. Thus, it is highly desirable to design molecular imprinting catalysts (MICs) in which both the catalytic activity and selectivity are significantly enhanced. Herein, a series of MICs are prepared by sequentially adsorbing imprinting molecules (nitro compounds, N) and imprinting ligand (1,10-phenanthroline, L) over the copper surface of Cu/Al2O3. The resulting Cu/Al2O3-N-L MICs not only offer promoted catalytic selectivity but also enhance catalytic activity for nitro compounds hydrogenation by an creating imprinting cavity derived from the presorption of N and forming new active Cu-N sites at the interface of the copper sites and L. Characterizations by means of various experimental investigations and DFT calculations disclose that the molecular imprinting effect (promoted activity and selectivity) originates from the formation of new active Cu-N sites and precise imprinting cavities, endowing promoted catalytic selectivity and activity on the hydrogenation of nitro compounds.

Constructing multiple active sites in iron oxide catalysts for improving carbonylation reactions.

Surface engineering is a promising strategy to improve the catalytic activities of heterogeneous catalysts. Nevertheless, few studies have been devoted to investigate the catalytic behavior differences of the multiple metal active sites triggered by the surface imperfections on catalysis. Herein, oxygen vacancies induced Fe2O3 catalyst are demonstrated with different Fe sites around one oxygen vacancy and exhibited significant catalytic performance for the carbonylation of various aryl halides and amines/alcohols with CO. The developed catalytic system displays excellent activity, selectivity, and reusability for the synthesis of carbonylated chemicals, including drugs and chiral molecules, via aminocarbonylation and alkoxycarbonylation. Combined characterizations disclose the formation of oxygen vacancies. Control experiments and density functional theory calculations demonstrate the selective combination of the three Fe sites is vital to improve the catalytic performance by catalyzing the elemental steps of PhI activation, CO insertion and C-N/C-O coupling respectively, endowing combinatorial sites catalyst for multistep reactions.

Molecular targeted therapy and immunotherapy in advanced hepatocellular carcinoma: a systematic review and Bayesian network meta-analysis based on randomized controlled trials.

OBJECTIVE: The aim of this study was to compare and rank different targeted therapies or immunotherapies for advanced hepatocellular carcinoma based on efficacy. METHODS: A systematic search of the PubMed, EMBASE, and Cochrane Library databases was conducted. All systematic treatment regimens that reported comparisons with sorafenib were included in this analysis. The primary outcome measures were overall survival (OS) and progression-free survival (PFS), and other outcome measures included the objective response rate (ORR) and safety analysis according to reported treatment-related adverse events. RESULTS: A total of 29 RCTs involving 13376 patients were included in the analysis, including 10 single-agent therapies and 17 combination therapies. Compared with sorafenib, sintilimab plus IBI305 (HR: 0.57, 95% CI: 0.43-0.75), camrelizumab plus rivoceranib (HR: 0.62, 95% CI: 0.49-0.78), and atezolizumab plus bevacizumab (HR: 0.66, 95% CI: 0.52-0.83) ranked in the top three in terms of OS. CONCLUSIONS: PD-1/PD-L1 inhibitors combined with anti-vascular endothelial growth factor (anti-VEGF)-targeting drugs have shown better therapeutic effects in the systematic treatment of patients with advanced hepatocellular carcinoma, and the combination of targeted and immune therapy modes should be further developed.

Tailoring Active Cu2 O/Copper Interface Sites for N-Formylation of Aliphatic Primary Amines with CO2 /H2.

Heterogeneously catalyzed N-formylation of amines to formamide with CO2 /H2 is highly attractive for the valorization of CO2 . However, the relationship of the catalytic performance with the catalyst structure is still elusive. Herein, mixed valence catalysts containing Cu2 O/Cu interface sites were constructed for this transformation. Both aliphatic primary and secondary amines with diverse structures were efficiently converted into the desired formamides with good to excellent yields. Combined ex and in situ catalyst characterization revealed that the presence of Cu2 O/Cu interface sites was vital for the excellent catalytic activity. Density functional theory (DFT) calculations demonstrated that better catalytic activity of Cu2 O/Cu(111) than Cu(111) is attributed to the assistance of oxygen at the Cu2 O/Cu interface (Ointer ) in formation of Ointer -H moieties, which not only reduce the apparent barrier of HCOOH formation but also benefit the desorption of the desired N-formylated amine, leading to high activity and selectivity.

Active Pd Catalyst for the Selective Synthesis of Methylated Amines with Methanol.

Selective N-methylation of amines with methanol is an important reaction in the synthesis of high-value-added fine chemicals, including dyes, surfactants, pharmaceuticals, agrochemicals, and materials. However, N-methylated amines possess higher reactivities and are prone to further transform into N,N-dimethylated amines. Therefore, it is still a challenge to controllably regulate the selectivity of N-methylation using heterogeneous catalysts without the use of base. Herein, we developed a series of Pd/Zn(Al)O catalysts with abundant basic sites, and the selectivity of N-methylation was controlled by a heterogeneous Pd/Zn(Al)O catalyst with a Zn/Al ratio of 10 and a Pd loading of 0.4 wt % in the pressure of H2. The experimental results showed that the appropriate basic properties of the catalyst were beneficial to form the desired N-methylated amine. The low loading of Pd in the catalyst was highly dispersed on the support, providing sufficient active sites. These were attributed to the Zn vacancies formed by Al-doped Zn, which were beneficial to form the highly active and stable Pd sites. Furthermore, a series of amines and nitrobenzenes with different functional groups were well tolerated for the selective synthesis of N-methylated amines in the absence of base.

A biphosphine copolymer encapsulated single-site Rh catalyst for heterogeneous regioselective hydroaminomethylation of alkenes.

A novel porous organic polymer catalyst with in situ encapsulated single-site Rh (Rh@CPOL-DPMphos&p-3vPPh3) was developed and employed in heterogeneous hydroaminomethylation of alkenes, affording the corresponding amines in good to excellent regioselectivity and catalytic activity by a one-pot method. The combined actions of hierarchical pore confinement and the biphosphine ligand derived from the POP catalyst contributed to the improved regioselectivity.

Catalytic Activity Enhancement on Alcohol Dehydrogenation via Directing Reaction Pathways from Single- to Double-Atom Catalysis.

To further improve the intrinsic reactivity of single-atom catalysts (SACs), the controllable modification of a single site by coordinating with a second neighboring metal atom, developing double-atom catalysts (DACs), affords new opportunities. Here we report a catalyst that features two bonded Fe-Co double atoms, which is well represented by an FeCoN6(OH) ensemble with 100% metal dispersion, that work together to switch the reaction mechanism in alcohol dehydrogenation under oxidant-free conditions. Compared with Fe-SAC and Co-SAC, FeCo-DAC displays higher activity performance, yielding the desired products in up to 98% yields. Moreover, a broad diversity of benzyl alcohols and aliphatic alcohols convert into the corresponding dehydrogenated products with excellent yields and high selectivity. The kinetic reaction results show that lower activation energy is obtained by FeCo-DAC than that by Fe-SAC and Co-SAC. Moreover, computational studies demonstrate that the reaction path by DACs is different from that by SACs, providing a rationale for the observed enhancements.

Lignin First: Confirming the Role of the Metal Catalyst in Reductive Fractionation.

Rhodium nanoparticles embedded on the interior of hollow porous carbon nanospheres, able to sieve monomers from polymers, were used to confirm the precise role of metal catalysts in the reductive catalytic fractionation of lignin. The study provides clear evidence that the primary function of the metal catalyst is to hydrogenate monomeric lignin fragments into more stable forms following a solvent-based fractionation and fragmentation of lignin.

Dual Vacancies Confined in Nickel Phosphosulfide Nanosheets Enabling Robust Overall Water Splitting.

Exploring highly efficient electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is of great significance for addressing energy and environmental crises. Vacancy engineering has been regarded as a promising way to optimize the catalytic activity of electrocatalysts. Herein, we put forward a conceptually new dual Ni,S vacancy engineering on 2D NiPS3 nanosheet (denoted as V-NiPS3 ) by a simple ball-milling treatment with ultrasonication. This material presents an ideal model for exploring the role of dual vacancies in improving the catalytic activity for overall water splitting. Structural analyses make clear that the formation of dual Ni,S vacancies regulates the electronic structure and catalytic active sites of NiPS3 nanosheet, leading to the superior HER/OER performance. Smaller overpotentials of 124 mV and 290 mV can be achieved at a current density of 10 mA cm-2 for HER and OER, respectively. The OER performance of V-NiPS3 is the best value among all state-of-the-art NiPS3 catalysts. In addition, the assembled two-electrode cell incorporating V-NiPS3 exhibits enhanced catalytic performance with a low cell voltage of 1.60 V at 10 mA cm-2 . This work offers a promising avenue to improve the electrocatalytic performance of the catalysts by engineering dual vacancies for large-scale water splitting.

Identification of earth-abundant materials for selective dehydrogenation of light alkanes to olefins.

Selective ethane dehydrogenation (EDH) is an attractive on-purpose strategy for industrial ethylene production. Design of an effective, stable, and earth-abundant catalyst to replace noble metal Pt is the main obstacle for its large-scale application. Herein, we report an experimentally validated theoretical framework to discover promising catalysts for EDH, which combines descriptor-based microkinetic modeling, high-throughput computations, machine-learning concepts, and experiments. Our approach efficiently evaluates 1,998 bimetallic alloys by using accurately calculated C and CH3 adsorption energies and identifies a small number of new promising noble-metal-free catalysts for selective EDH. A Ni3Mo alloy predicted to be promising is successfully synthesized, and experimentally proven to outperform Pt in selective ethylene production from EDH, representing an important contribution to the improvement of light alkane dehydrogenation to olefins. These results will provide essential additions in the discovery and application of earth-abundant materials in catalysis.

Recent Advances in Catalytic Hydrosilylations: Developments beyond Traditional Platinum Catalysts.

Hydrosilylation reactions, which allow the addition of Si-H to C=C/C≡C bonds, are typically catalyzed by homogeneous noble metal catalysts (Pt, Rh, Ir, and Ru). Although excellent activity and selectivity can be obtained, the price, purification, and metal residues of these precious catalysts are problems in the silicone industry. Thus, a strong interest in more sustainable catalysts and for more economic processes exists. In this respect, recently disclosed hydrosilylations using catalysts based on earth-abundant transition metals, for example, Fe, Co, Ni, and Mn, and heterogeneous catalysts (supported nanoparticles and single-atom sites) are noteworthy. This minireview describes the recent advances in this field.

Utility of Core-Shell Nanomaterials in the Catalytic Transformations of Renewable Substrates.

In recent years, core-shell nano-catalysts have received increasing attention due to their tunable properties and broad applications in catalysis. Control of the two components of these materials allows their catalytic properties to be tuned to various sustainable processes in synthetic and energy-related applications. This Concept article describes recent state-of-the-art core-shell materials and their application as heterogeneous catalysts for a range of sustainable catalytic transformations, focusing on two important classes of renewable substrates, CO2 and biomass. In the discussion, emphasis is directed to the role of the constituent parts of the core-shell structure and how they can be manipulated to enhance activity.

Acceptorless dehydrogenation and hydrogenation of N- and O-containing compounds on Pd3Au1(111) facets.

Catalytic dehydrogenation and hydrogenation of amines and alcohols are important in the synthesis of fine chemicals. Despite several efficient homogeneous catalysts having been identified, highly active heterogeneous catalysts remain elusive, although they would meet an unmet need. Here, we show that bimetallic Pd-Au nanoparticles with Pd-to-Au molar ratios of 3:1 immobilized on multiwall carbon nanotubes (Pd3Au1/CNT) display high catalytic activity in the oxidant-free and acceptorless dehydrogenation and hydrogenation of N- and O-containing heterocyclic compounds, amines/imines, and alcohols/ketones. Transmission electron microscopy analysis demonstrates the preferential exposure of Pd3Au1(111) facets on the Pd3Au1/CNT catalyst. Mechanistic insights combining experimental data with density functional theory calculations reveal that the Pd3Au1(111) surface enhances both dehydrogenation and hydrogenation reactions and provides a rationale for the observed enhancements.

Supported Ni nanoparticles with a phosphine ligand as an efficient heterogeneous non-noble metal catalytic system for regioselective hydrosilylation of alkynes.

A convenient and effective heterogeneous non-noble metal catalytic system for regioselective hydrosilylation of alkynes was successfully developed by the combination of Ni/Al2O3 with a xantphos ligand. The resulting catalytic system displayed excellent catalytic performance in the heterogeneous hydrosilylation of PhSiH3 with a wide range of aromatic and aliphatic terminal alkynes, affording the corresponding (E)-vinylsilanes in good to excellent yields with high regioselectivity.

CO2 Methanation via Amino Alcohol Relay Molecules Employing a Ruthenium Nanoparticle/Metal Organic Framework Catalyst.

Methanation of carbon dioxide (CO2 ) is attractive within the context of a renewable energy refinery. Herein, we report an indirect methanation method that harnesses amino alcohols as relay molecules in combination with a catalyst comprising ruthenium nanoparticles (NPs) immobilized on a Lewis acidic and robust metal-organic framework (MOF). The Ru NPs are well dispersed on the surface of the MOF crystals and have a narrow size distribution. The catalyst efficiently transforms amino alcohols to oxazolidinones (upon reaction with CO2 ) and then to methane (upon reaction with hydrogen), simultaneously regenerating the amino alcohol relay molecule. This protocol provides a sustainable, indirect way for CO2 methanation as the process can be repeated multiple times.

High expression of lncRNA-SNHG7 is associated with poor prognosis in hepatocellular carcinoma.

Expression of long non-coding RNA SNHG7 (lncRNA-SNHG7) and its clinical significance in hepatocellular carcinoma (HCC) were explored. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of lncRNA-SNHG7 in cancer tissues. Kaplan-Meier curves and multivariate Cox proportional models were used to study the impact on clinical outcome. Expression of lncRNA-SNHG7 was much higher in cancer tissues than that in para-cancer tissues. The lncRNA-SNHG7 expression was correlated with tumor number, lymph node metastasis and clinical stage (P<0.05). In addition, HCC patients with higher lncRNA-SNHG7 expression had significantly poorer progression-free survival time and overall survival time (P<0.001). Both univariate analysis and multivariate analysis indicated that high expression of lncRNA-SNHG7 was an independent predictor of poor prognosis in HCC. LncRNA-SNHG7 might contribute to the development of HCC and serve as a clinical biomarker and a therapeutic target for HCC patients.

Selective Acceptorless Dehydrogenation of Primary Amines to Imines by Core-Shell Cobalt Nanoparticles.

Core-shell nanocatalysts are attractive due to their versatility and stability. Here, we describe cobalt nanoparticles encapsulated within graphitic shells prepared via the pyrolysis of a cationic poly-ionic liquid (PIL) with a cobalt(II) chloride anion. The resulting material has a core-shell structure that displays excellent activity and selectivity in the self-dehydrogenation and hetero-dehydrogenation of primary amines to their corresponding imines. Furthermore, the catalyst exhibits excellent activity in the synthesis of secondary imines from substrates with various reducible functional groups (C=C, C≡C and C≡N) and amino acid derivatives.