Surface-modified spinel high entropy oxide with hybrid coating-layer for enhanced cycle stability and lithium-ion storage performance.

High-entropy oxide (HEO) has emerged as a promising anode material for high-energy lithium-ion batteries (LIBs) due to its high theoretical specific capacity. However, the further application of HEO is restricted by its complicated interface problems and inevitable expansion effect. In this work, a simple approach to coat spinel HEO (FeCoNiCrMn)O with a hybrid layer of lithium titanate (LTO) and carbon is presented.

Engineering of MnTe/MnO Heterostructures with Interfacial Electric Field Modulation for Efficient and Durable Li-O Batteries.

Design and synthesis of highly active and robust bifunctional cathode catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are of vital significance for practical applications of lithium-oxygen (Li-O) batteries. Herein, a built-in electric field (BIEF) strategy is reported to fabricate MnTe/MnO heterostructures with a large work function difference (ΔΦ) as a bifunctional cathode catalyst in Li-O batteries. The MnTe/MnO heterostructures with nanosheets and microporous structures result in an abundance of exposed active sites and facilitate mass transfer.

Self-Catalyzed Growth of CoN and N-Doped Carbon Nanotubes toward Bifunctional Cathode for Highly Safe and Flexible Li-Air Batteries.

The practical application of high-energy density lithium-oxygen (Li-O) batteries is severely impeded by the notorious cycling stability and safety, which mainly comes from slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at cathodes, causing inferior redox overpotentials and reactive lithium metal in flammable liquid electrolyte. Herein, a bifunctional electrode, a safe gel polymer electrolyte (GPE), and a robust lithium anode are proposed to alleviate above problems. The bifunctional electrode is composed of N-doped carbon nanotubes (N-CNTs) and CoN by chemical vapor deposition self-catalyzed growth on carbon cloth (N-CNTs@CoN@CC).

Recent Advances in Aerobic Oxidative of C-H Bond by Molecular Oxygen Focus on Heterocycles.

Aerobic oxidative cross-coupling represents one of the most straightforward and atom-economic methods for construction of C-C and C-X (X=N, O, S, or P) bonds using air as a sustainable external oxidant. The oxidative coupling of C-H bonds in heterocyclic compounds can effectively increase their molecular complexity by introducing new functional groups through C-H bond activation, or by formation of new heterocyclic structures through cascade construction of two or more sequential chemical bonds. This is very useful as it can increase the potential applications of these structures in natural products, pharmaceuticals, agricultural chemicals, and functional materials.

Synthetic Electrochemistry Enabled Esterification via Oxidative Mesolytic Cleavage of Alkoxyamines.

Stable benzylic carbocations were generated via mesolytic cleavage of TEMPO-derived alkoxyamines, which was realized by electrochemical oxidation. This strategy provided an efficient and unique approach to access stabilized carbocations under mild conditions. Esterification of benzylic carbocations using carboxylic acid produced a variety of benzylic esters with a broad substrate scope and excellent functional group compatibility.

Canonical and non-canonical functions of STAT in germline stem cell maintenance.

Background: Maintenance of the Drosophila male germline stem cells (GSCs) requires activation of the Janus kinase/signal transducer and activators of transcription (JAK/STAT) pathway by niche signals. The precise role of JAK/STAT signaling in GSC maintenance, however, remains incompletely understood.

Results: Here, we show that, GSC maintenance requires both canonical and non-canonical JAK/STAT signaling, in which unphosphorylated STAT (uSTAT) maintains heterochromatin stability by binding to heterochromatin protein 1 (HP1).

A Gradient Doping Strategy toward Superior Electrochemical Performance for Li-Rich Mn-Based Cathode Materials.

Lithium-rich layered oxides (LLOs) are concerned as promising cathode materials for next-generation lithium-ion batteries due to their high reversible capacities (larger than 250 mA h g ). However, LLOs suffer from critical drawbacks, such as irreversible oxygen release, structural degradation, and poor reaction kinetics, which hinder their commercialization. Herein, the local electronic structure is tuned to improve the capacity energy density retention and rate performance of LLOs via gradient Ta doping.

Efficient Aerobic Oxidative Coupling of Methyl Heteroarenes with Indoles.

Direct oxidative coupling of inert C(sp )-H bond has been a great challenge. Herein, an environmentally friendly aerobic oxidative coupling of α-methyl substituted N-heteroarenes with indoles is reported. A variety of diheteroaryl ketones were prepared in good yields (up to 72 %).

TiO/MXene Hierarchical Bifunctional Catalyst Anchored on Graphene Aerogel toward Flexible and High-Energy Li-S Batteries.

The development of lithium-sulfur (Li-S) batteries with high-energy density, flexibility, and safety is very appealing for emerging implantable devices, biomonitoring, and roll-up displays. Nevertheless, the poor cycling stability and flexibility of the existing sulfur cathodes, flammable liquid electrolytes, and extremely reactive lithium anodes raise serious battery performance degradation and safety issues. Herein, a metallic 1T MoS and rich oxygen vacancies TiO/MXene hierarchical bifunctional catalyst (Mo-Ti/Mx) anchored on a reduced graphene oxide-cellulose nanofiber (GN) host (Mo-Ti/Mx-GN) was proposed to address the above challenges.

In Situ Growth of CoP Nanosheet Arrays on Carbon Cloth as Binder-Free Electrode for High-Performance Flexible Lithium-Ion Batteries.

Cobalt phosphide (CoP) is considered as one of the most promising candidates for anode in lithium-ion batteries (LIBs) owing to its low-cost, abundant availability, and high theoretical capacity. However, problems of low conductivity, heavy aggregation, and volume change of CoP, hinder its practical applicability. In this study, a binder-free electrode is successfully prepared by growing CoP nanosheets arrays directly on a carbon cloth (CC) via a facile one-step electrodeposition followed by an in situ phosphorization strategy.

asymmetric Achmatowicz approach to oligosaccharide natural products.

The development and application of the asymmetric synthesis of oligosaccharides from achiral starting materials is reviewed. This asymmetric approach centers around the use of asymmetric catalysis for the synthesis of optically pure furan alcohols in conjunction with Achmatowicz oxidative rearrangement for the synthesis of various pyranones. In addition, the use of a diastereoselective palladium-catalyzed glycosylation and subsequent diastereoselective post-glycosylation transformation was used for the synthesis of oligosaccharides.

The C(sp)-H bond functionalization of thioethers with styrenes with insight into the mechanism.

A metal-free inactive C(sp)-H bond functionalization of thioethers with styrenes using TBHP as an initiator and DBU as a base has been developed. This transformation has broken through the low activity of thioethers and realized moderate yields. Herein extended experiments were conducted to confirm the radical relay process, reaction energy and intermediate transformations.

Copper-Catalyzed Aldehyde Exchanged Amidation.

The synthesis of bioactive amides has been the pursuit of chemists. Herein secondary amides incorporated with an aldehyde group were first generated using aldehydes and secondary amines. Various (hetero)aryl aldehydes and even aliphatic aldehydes (>40 examples) were converted into the desired products in moderate to excellent yields (up to 89%).

Graphene-Based Materials for Flexible Lithium-Sulfur Batteries.

The increasing demand for wearable electronic devices necessitates flexible batteries with high stability and desirable energy density. Flexible lithium-sulfur batteries (FLSBs) have been increasingly studied due to their high theoretical energy density through the multielectron chemistry of low-cost sulfur. However, the implementation of FLSBs is challenged by several obstacles, including their low practical energy density, short life, and poor flexibility.

Recyclable Catalysts for Alkyne Functionalization.

In this review, we present an assessment of recent advances in alkyne functionalization reactions, classified according to different classes of recyclable catalysts. In this work, we have incorporated and reviewed the activity and selectivity of recyclable catalytic systems such as polysiloxane-encapsulated novel metal nanoparticle-based catalysts, silica-copper-supported nanocatalysts, graphitic carbon-supported nanocatalysts, metal organic framework (MOF) catalysts, porous organic framework (POP) catalysts, bio-material-supported catalysts, and metal/solvent free recyclable catalysts. In addition, several alkyne functionalization reactions have been elucidated to demonstrate the success and efficiency of recyclable catalysts.

A Flexible Li-Air Battery Workable under Harsh Conditions Based on an Integrated Structure: A Composite Lithium Anode Encased in a Gel Electrolyte.

Flexible lithium-air batteries (FLABs) with ultrahigh theoretical energy density are considered as the most promising energy storage devices for next-generation flexible and wearable electronics. However, their practical application is seriously hindered by various obstacles, including bulky and rigid electrodes, instability/low conductivity of electrolytes, and especially, the inherent semi-open structure. When operated in ambient air, moisture penetrated from an air cathode inevitably corrodes a Li metal anode, and most of the reported FLABs can only work under a pure oxygen or specific air (relative humidity: <40%) atmosphere, which cannot be regarded as a real "lithium-air battery".

ZnO quantum dot-modified rGO with enhanced electrochemical performance for lithium-sulfur batteries.

Lithium-sulfur batteries are considered the most promising next-generation energy storage devices. However, problems like sluggish reaction kinetics and severe shuttle effect need to be solved before the commercialization of Li-S batteries. Here, we successfully prepared ZnO quantum dot-modified reduced graphene oxide (rGO@ZnO QDs), and first introduced it into Li-S cathodes (rGO@ZnO QDs/S).

Benzylic Hydroperoxidation via Visible-Light-Induced Csp-H Activation.

A highly efficient benzylic hydroperoxidation has been realized through a visible-light-induced Csp-H activation. We believe that this reaction undergoes a direct HAT mechanism catalyzed by eosin Y. This approach features the use of a metal-free catalyst (eosin Y), an energy-economical light source (blue LED), and a sustainable oxidant (molecular oxygen).

Lychee-like TiO@TiN dual-function composite material for lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are promising candidates for next generation rechargeable batteries because of their high energy density of 2600 W h kg. However, the insulating nature of sulfur and LiS, the "shuttle effect" of lithium polysulfides (LiPSs), and the volumetric change of sulfur electrodes limit the practical application of Li-S batteries. Here, lychee-like TiO@TiN hollow spheres (LTTHS) have been developed that combine the advantages of high adsorption TiO and high conductivity TiN to achieve smooth adsorption/spread/conversion of LiPSs and use them as a sulfur host material in Li-S batteries for the first time.

Rare-Earth Y(OTf) Catalyzed Coupling Reaction of Ethers with Azaarenes.

Rare-earth catalysis has become a hot topic in the field of catalytic organic reaction. Chain ethers mostly have lower reactivity and lower boiling points which limited their reaction scope. Herein, we found a rare-earth Y(OTf) can catalyze the coupling reaction of ethers especially chain ethers and thioethers with azaarenes.

Self-assembled hierarchical porous NiMnO microspheres as high performance Li-ion battery anodes.

Hierarchical structured porous NiMnO microspheres assembled with nanorods are synthesized through a simple hydrothermal method followed by calcination in air. As anode materials for lithium ion batteries (LIBs), the NiMnO microspheres exhibit a high specific capacity. The initial discharge capacity is 1126 mA h g.

Self-standing LiMnNiO/graphene membrane as a binder-free cathode for Li-ion batteries.

Lithium-rich transition-metal layered oxides (LROs), such as LiMnNiO, are promising cathode materials for application in Li-ion batteries, but the low initial coulombic efficiency, severe voltage fade and poor rate performance of the LROs restrict their commercial application. Herein, a self-standing LiMnNiO/graphene membrane was synthesized as a binder-free cathode for Li-ion batteries. Integrating the graphene membrane with LiMnNiO forming a LiMnNiO/graphene structure significantly increases the surface areas and pore volumes of the cathode, as well as the reversibility of oxygen redox during the charge-discharge process.

Highly Efficient Recyclable Sol Gel Polymer Catalyzed One Pot Difunctionalization of Alkynes.

Amino-bridged gel polymer was discovered to catalyze alkyne halo-functionalization in excellent yields, regioselectivity, functional group compatibility, and recyclability. We have observed that both aromatic and aliphatic alkynes can be converted to α,α-dihalogenated ketones in the presence of polymer under metal-free conditions at room temperature within a short reaction time.

Advances in Decarboxylative Oxidative Coupling Reaction.

Since carboxylic acid derivatives are commercially available, nontoxic, cheap, and normally stable to air and moisture, carboxylic acid derivatives are ideal reactants for synthetic strategy. In recent years, decarboxylative oxidative coupling reactions, which normally involve direct C-H bond activation, have attracted more and more interest from the synthetic community. Compared with conventional methods, this strategy is more environmentally friendly and step-economic.