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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

Overcoming the low reactivity of thioethers, a C(sp3)–H bond functionalization of thioethers with styrenes using TBHP and DBU involving a radical relay process in metal-free conditions with theoretical questions elaborated is described.

The development and application of the de novo asymmetric synthesis of oligosaccharides from achiral starting materials using the Achmatowicz reaction is reviewed.

The synthesis of axially chiral compounds has attracted a great deal of attention in recent years. Herein, an efficient and economical synthetic route has been developed for 2-(3- carbamoylpyridin-2-yl) nicotinamide pyridine salts, axially chiral compounds. The starting material 1,10-phenanthroline is readily available. In this study, 2-(3-carbamoylpyridin-2-yl) nicotinamide pyridine salts are obtained in moderate to good yields. This protocol includes simple operations and has easy scalability. In addition, the axial chirality of the products is also preliminary studied.

Cobalt oxide (Co3O4) is currently suitable in energy storage applications because of its high capacity based on the conversion reaction mechanism. However, unmodified Co3O4 suffers from distinctly inferior rate capability and poor cycling stability. On the basis of the aforementioned considerations and density functional theory (DFT) simulations, the three-dimensional hierarchical porous structure (HPS) ultrasmall Co3O4 anchored into ionic liquid (IL) modified graphene oxide (GO) has been successfully prepared (ultrasmall/Co3O4-GA-IL). The ultrasmall/Co3O4-GA-IL consists of Co3O4 co-assembled with IL modified GO to generate the HPS which can facilitate ion transfer channels through reduction of the electron and ion transportation path and transmission impedance. In addition, N-doping graphene can enhance the inherent electrical conductivity of Co3O4, which is proved by the DFT calculations. By virtue of the novel superstructure, the ultrasmall/Co3O4-GA-IL electrode demonstrates a high reversible capacity of 1,304 mAh·g−1, an enhanced high-rate capability (715 mAh·g−1 at 5 C), and a capacity retention of 98.4% even after 500 cycles at 5 C rate, which corresponds to 0.0003% capacity loss per cycle. Pouch cells based on the cathode are further fabricated and demonstrate excellent mechanical and electrochemical properties under bent and folded state, highlighting the practical application of our deliberately designed electrode in wearable electronics.

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. Various graphene-based materials have been applied to address these issues. Graphene, with good conductivity and flexibility, exhibits synergistic effects with other active/catalytic/flexible materials to form multifunctional graphene-based materials, which play a pivotal role in FLSBs. This review summarizes the recent progress of graphene-based materials that have been used as various FLSB components, including cathodes, interlayers, and anodes. Particular attention is focused on the precise nanostructures, graphene efficacy, interfacial effects, and battery layout for realizing FLSBs with good flexibility, energy density, and cycling stability.

Porous metallic materials are widely used for lithium-ion battery (LIB) electrodes because of their low density, efficient ionic/electron pathways, and high specific surface area. In this study, we fabricate nanoporous Cu using chemical and electrochemical dealloying methods based on a Cu-Ga alloy. The effects of the dealloying conditions on the derived microstructure of the nanoporous metal and its evolution mechanisms are discussed. Analysis and control of the electrochemical dealloying process reveal that the sample morphology can be adjusted and the phase component can be controlled. Accordingly, a 3D CuGa2 electrode with a nanoporous structure is controllably synthesized, and it exhibits a higher specific capacity and cyclic stability than a 2D CuGa2 electrode when used as a LIB anode.

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. The CoP@CC anode exhibits good interfacial bonding between the CoP and CC, which can improve the conductivity of the integrated electrode. More importantly, the 3D network structure composed of CoP nanosheets and CC provides sufficient space to alleviate the volume expansion of CoP and shorten the electron/ion transport paths. Moreover, the support of CC effectively prevents the agglomeration of CoP. Based on these advantages, when CoP@CC is paired with the NCM523 cathode, the full cell delivers a high discharge capacity 919.6 mAh g

A metal-free inactive C(sp

Direct oxidative coupling of inert C(sp

Rational structure and morphology design of catalytic cathode materials is the key to realize excellent performances of lithium-oxygen batteries (LOBs). Herein, a three-dimensional (3D) open-structured Co₃O₄@MnO₂ heteromatrix has been designed through a facile two-step hydrothermal method. Unexpectedly, when it serves as oxygen reduction reaction/oxygen evolution reaction bifunctional catalytic cathodes for lithium-oxygen cells, the 3D open-structured Co₃O₄@MnO₂ heteromatrix-catalyzed LOBs exhibit outstanding electrochemical performances (a high specific capacity of 12,980 mA h g–¹ during the initial discharge and long cycle life of 331, 197, and 14 times with specific capacities fixed at 500, 1000, and even 3000 mA h g–¹, respectively), obviously superior to reported batteries based on low-dimensional and closed-ended catalysts. We find that the enhanced electrochemical performances are ascribed to the bifunctional catalyst and the 3D open structure of the Co₃O₄@MnO₂ heteromatrix, which can guide the homogeneous and fluffy deposition of discharge products Li₂O₂, demonstrating a promising application in both LOBs and flexible/wearable Li-air batteries.

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

In recent years, advancements in photocatalysis have allowed for a plethora of chemical transformations under milder conditions. Many of these photochemical reactions utilize hydrogen atom transfer processes to obtain desired products. Hydrogen atom transfer processes can follow one of two unique pathways: the first, a direct path and the second, an indirect path. In this paper, we highlight the ability of eosin Y to act as a direct hydrogen atom transfer catalyst from both synthetic and computational chemistry perspectives.

A highly diastereoselective spiro-cyclopropanation reaction of 2-arylidene-1,3-indanediones and dimethylsulfonium ylides has been developed via base-induced annulation. This efficient and simple protocol features simple operations, mild conditions and excellent functional group compatibility. A variety of structurally interesting spiro-cyclopropanes were prepared in excellent yields and diastereomeric ratios (up to 97% yield and 20 : 1 dr). Also, ring expansion of the cyclopropanation product to quickly deliver a complex indeno[1,2-c]pyridazine structure showcased an interesting application of this method.

In the past three decades, rare-earth metal triflates including scandium triflate, yttrium triflate, and the lanthanide (La−Lu) triflate, were widely employed in the organic chemistry, such as cycl...

Lithium-rich layered oxides with high energy density have been intensively investigated as advanced lithium-ion batteries cathode materials. However, capacity degradation and voltage decay caused by irreversible lattice oxygen loss and structural transformation during cycling restrict their application. Herein, we proposed a high valance cations Nb5+ doping strategy and synthesized a series of Li1.2Mn0.54-x/3Ni0.13-x/3Co0.13-x/3NbxO2 (x = 0, 0.01, 0.02 and 0.03) cathode materials. The effects of Nb5+ doping on crystallographic structure and electrochemical property were systematically studied. In virtue of the large ionic radii and strengthened Nb–O bonds, the doped samples present commendable structural stability and expanded interlayer spacing for Li-ions migration, which ensures the upgraded cyclic stability and rate performance. In particular, the electrode with x = 0.02 delivers a discharge specific capacity of 265.8 mAh g-1 at 0.2 C with decelerated voltage decay, while 86.9% capacity are remained after long-term cycles. Moreover, excellent discharge specific capacity of 153.4 mAh g−1 is still attained at 5 C accompanied with enhanced Li-ion diffusion kinetics.

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%). A plausible mechanism involving a Cu(I/II/III) catalytic cycle combined with radical rearrangement was proposed and confirmed with four key intermediates detected by high-resolution mass spectrometry.

The C(sp3)–H bond is found widely in organic molecules. Recently, the functionalization of C(sp3)–H bonds has developed into a powerful tool for augmenting highly functionalized frameworks in organic synthesis. Based on the results obtained in our group, the present account mainly summarizes recent progress on the functionalization of C(sp3)–H bonds of aliphatic alcohols, ketones, alkyl nitriles, and ethers with styrene or cinnamic acid using tert-butyl hydroperoxide (TBHP) as a radical initiator.1 Introduction2 Oxidative Coupling of Styrenes with C(sp3)–H Bonds3 Decarboxylative Cross-Couplings of α,β-Unsaturated Carboxylic Acids with C(sp3)–H Bonds4 Conclusions

A highly efficient benzylic hydroperoxidation has been realized through a visible-light-induced Csp3-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). Primary, secondary, and tertiary hydroperoxides as well as silyl, benzyl, and acyl peroxides were successfully prepared with good yields and excellent functional group compatibility.

Lithium–sulfur (Li–S) batteries are promising candidates for next generation rechargeable batteries because of their high energy density of 2600 W h kg−1. However, the insulating nature of sulfur and Li2S, 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 TiO2@TiN hollow spheres (LTTHS) have been developed that combine the advantages of high adsorption TiO2 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. The cathode exhibits an initial specific capacity of 1254 mA h g−1 and a reversible capacity of 533 mA h g−1 after 500 cycles at 0.2C, which corresponds to an average coulombic efficiency up to 99%. The cell with the LTTHS@S cathode achieved an extended lifespan of over 1000 cycles. Such good performance can be assigned to the good adsorption and catalysis of the dual-function TiO2@TiN composite. This work proved that the TiO2@TiN composite can be an attractive matrix for sulfur cathodes.

MoS2 is currently under intensive research as a potential candidate for energy storage applications because of its high theoretical capacity. However, unmodified MoS2 suffers from inferior rate capability and poor long-term cycling stability. Inspired by a hornet making a nest and the favorable shape and structural strength of a honeycomb, a composite with a three-dimensional highly porous sandwiched honeycomb structure has been successfully prepared for the first time. Its novel structure originates from anchoring self-assembled flower-like porous MoS2 slices (MoS2-FPSs) on layer-by-layer reduced graphene oxide (rGO)–carbon nanotubes (CNTs) with the assistance of an ionic liquid (IL). The MoS2 ultrathin nanosheets are self-assembled to form MoS2-FPSs and then co-assembled with rGO and CNTs to generate a hierarchical porous structure. By virtue of this novel superstructure, the electrode demonstrates remarkable electrochemical properties with a high initial capacity (1456 mA h g−1) and an enhanced high rate capability (712 mA h g−1 at 5 A g−1), as well as one of the best long-term cycling stabilities with a capacity decay as low as 0.0075% per cycle (745 mA h g−1 at 5 A g−1 after 1000 cycles), confirming its potential application in high-performance lithium-ion batteries.

Confining the dissolution and diffusion of polysulfide is considered a key factor in the realization of high-performance lithium-sulfur battery. Here, we report a polydopamine (pDA) coated sulfur-carbon composite with a unique hierarchical tower-like structure (S-HTC@pDA) for lithium sulfur cathode. The internal layer by layer structure is capable of uniformly dispersing of sulfur, providing a continuous electronic conductive path and shortening the Li+ transport distance, while the external pDA coating can inhibit the diffusion of polysulfide. Benefited from the smart design, the S-HTC@pDA electrode achieved an excellent cycling stability, realizing a high discharge capacity of 916 mAh g−1 at the first cycle and a capacity retention of 79.4% after 500 cycles at 1 C. Therefore, this work provides a new concept in structure design for high performance lithium sulfur cathodes.

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)3 can catalyze the coupling reaction of ethers especially chain ethers and thioethers with azaarenes. This protocol features simple operations, a broad substrate scope (31 examples), moderate to good yields (up to 85%), and atom economy.

Rational morphology design and size control have been demonstrated an effective strategy to improve the electrochemical performance of cathode materials for lithium ion batteries. In this work, different morphologic Li-rich layered cathode materials Li1.2Mn0.54Ni0.13Co0.13O2 with hierarchical structures are conveniently synthesized through a facile solvothermal route followed by calcination treatment. The morphology and size of the as-prepared precursors are easily regulated by changing the addition of organic solvent with different viscosity and polarity. And their critical impacts on the microstructure and electrochemical property of Li-rich layered electrodes are further systematically investigated. In particular, the hierarchical structured Li1.2Mn0.54Ni0.13Co0.13O2 microspheres exhibit superior electrochemical performance and excellent cycling stability among all samples, delivering a discharge capacity of 281.9 mAh g−1 at 0.1 C with 84.8% retention after 100 cycles. A high discharge capacity of 143.0 mAh g−1 still can be achieved even at a high current density of 5 C. Besides, this work would also provide an effective and feasible strategy for the morphology controllable synthesis of high energy density oxide electrode materials for lithium ion batteries.

An efficient [3+2] cycloaddition of nitrones and carbodiimides has been developed. This 1,3-dipolar cycloaddition features high regioselectivity, mild and metal-free conditions, excellent functional group compatibility, and a broad substrate scope. The X-ray structures of two regio-isomers confirmed the regioselectivity of this transformation.