5‐Bromofuran‐2‐carboxylates were conducted in a palladium‐catalyzed reductive homocoupling reactions in the presence of alcohols as the reductant to afford [2,2’]bifuran‐5,5’‐dicarboxylic acid esters, which are essential monomers of poly(ethylene bifuranoate), serving as an green and versatile alternative polymer for traditional poly(ethylene terephthalate). More details are discussed in the article by Yin and Jiang et al. on page 62—68.
A hollow polydopamine/Zn (HPDA/Zn) ultrasound contrast agent is exploited. In addition to having a good contrast-enhancement capability in ultrasound imaging, HPDA/Zn can also stabilize plaque by inhibiting CREB and reducing plaque-vulnerable markers and inflammatory factors, achieving the treatment of atherosclerosis. More details are discussed in the article by Wu et al. on page 199—206.
The back cover picture shows that a highly enantioselective gold‐catalyzed intermolecular [3+2] cycloaddition of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with nitrones was realized by the application of Ming‐Phos as chiral ligands, which provides both enantiomers of the cycloadducts with opposite configuration in high yields with high region‐ and enantioselectivity by the employment of either diastereomer of the chiral ligands. The design of the cover picture is inspired by the mixer tap. Just as the tap regulates hot and cold water, the enantioselective synthesis of a pair of products ( 3 and ent‐3 ) is realized by the rotation of ligand S‐ or R‐configuration. More details are discussed in the article by Zhang et al. on page 577—582.
The back cover picture shows a supramolecularly‐controlled topochemical reaction of conjugated dienes under irradiation in homogeneous system. Using this method, the cyclooctadiene‐cored derivatives are synthesized very efficiently. Moreover, the cyclooctadiene tetraimidazolium derivatives can be applied as fluorescent chemosensors for thymine in aqueous solution at physiological pH (7.4). More details are discussed in the article by Han et al. on page 1040—1044.
Two‐dimensional (2D) transition metal dichalcogenides (TMDs) usually have poly‐phases, such as 2H, 3R and 1T. Controlling the structure phase of 2D TMDs is the key for engineering the physical and chemical properties of the materials and hence is vital to the applications. Many approaches, including doping/intercalation, alloying, defects, strain, electric field and so on, have been developed to tune the thermodynamic stability of the different phases of TMDs and then phase selective synthesis or controlled phase conversion has been achieved. More details are discussed in the article by Xie et al. on page 753–760.
This picture describes Raman scattering process of molecules adsorbed on nanostructured particles. The SERS has been proven to be a versatile technique in application of energy systems. SERS allows nondestructive detection of reaction intermediate species, which is crucial for in situ characterization of reaction. In this review, the principles of SERS, fabrication methods of SERS-active substrates are discussed. The current advances in SERS applications, notably in Li-ion batteries, Li-S batteries, Li-O2 batteries, water splitting and fuel cells, are reviewed. More details are discussed in the article by Li et al. on page 355–369.
Efficient synthesis of polyester polyols with tunable molecular weight and microstructures from cyclic anhydride/epoxide mixtures by taking advantage of chain transfer reaction remains a great challenge. Dou et al. demonstrated that potassium acetate and 18-crown-6 combinations have great potential in synthesis of diverse polyester polyols with controllable molecular weight and high-end group fidelity. Polyester polyols could be efficiently prepared in laboratory by using commercially available cyclic anhydride without further purification with an extremely low catalyst loading. This binary catalyst can also promote the self-switchable copolymerization of cyclic anhydride/epoxide/cyclic ester mixtures. More details are discussed in the article by Wang et al. on page 83—92.
The development of azobenzene‐containing polymers (azopolymers) opens up an avenue for controlling their properties and functions with light. These polymers show shape changes and mechanical responses under the stimulation of light via photoisomerization of azobenzene groups. Herein, this report focuses on the growing research on moving polymers via photoisomerization, including their moving mechanisms and various applications. More details are discussed in the article by Wu et al. on page 1019—1022.
The development of chiral boron Lewis acids is highly essential for the chemistry of frustrated Lewis pairs. Three protocols including hydroboration, substitution and in situ hydroboration, have been successfully established to access the chiral boron Lewis acids. A rapid growth for the metal‐free asymmetric hydrogenation and hydrosilylation has therefore been achieved in the past decade. More details are discussed in the article by Du et al. on page 625—634.
Modulating charge transfer by constructing high-quality interfacial contacts and charge transfer channel is crucial for an efficient photocatalyst. In this work, a novel PCN/Cu3P nanosheet with intimate 2D/2D heterojunction was prepared via in-situ phosphorization. Boosted photocatalytic H2 evolution was achieved due to the smooth charge transfer in the 2D/2D heterojunction. More details are discussed in the article by Liu et al. on page 173—180.
The inside back cover picture shows the controllable skeleton rearrangement of 3‐substituted cyclobutanones under basic conditions. In this paper, a series of 3‐substituted cyclobutanones with different Z group underwent skeleton rearrangement with the treatment of K3PO4 and 18‐crown‐6 ether. Various lactones, lactams and acids were afforded in this concise reaction. More interestingly, an eight‐membered ring was produced with pentaflurophenyl group as a good leaving group. More details are discussed in the article by Lu et al. on page 1103—1106.
This cover picture describes that MOF-based artificial and semi-artificial photosynthesis systems have been sustainably catalyzing the CO2 reduction, H2 evolution, and other chemical processes upon sun-light irradiation. In such a way, our Earth was successfully protected from pollution and energy crisis due to the depletion of fossil fuels and excessive CO2 emission. More details are discussed in the article by Li et al. on page 335–354.
Development of efficient catalytic asymmetric synthesis of chiral seven‐membered nitrogen‐containing heterocycles has been great important because their occurrence in a great number of pharmaceuticals and natural compounds. This work developed a Pd‐catalyzed asymmetric aromative [4+3]‐cyclization reaction of amino‐trimethylenemethanes (TMM, 1,3‐dipoles) with fused 1‐azadienes, which enables access to synthetically important and biologically active benzofuran fused azepines and indeno‐azepines in excellent efficiency and stereoselectivity (up to 95% yield, 99% ee, >19 : 1 dr). More details are discussed in the article by Deng and Shao et al. on page 151 ‐ 157.
A copper‐catalyzed aerobic oxidative ring expansion reaction of isatins with 1,2,3,4‐tetrahydroisoquinoline for the synthesis of tetracyclic quinazolinones has been developed. The capacity of the resultant 5H‐isoquinolino[1,2‐b]quinazolin‐8(6H)‐one for a range of palladium‐catalyzed directing C—H activation has been further demonstrated, thus giving a broader access to diverse tetracyclic quinazolinones. More details are discussed in the article by Xiao and Deng et al. on page 87—92.
The inside back cover picture depicts the inverse-electron-demand Diels–Alder reactions of 2-pyrones with various readily available dihydropyrroles and dihydrofurans. By the catalysis of lanthanide salts, these reactions occur with high yields and enantioselectivities, thus providing a step-economical synthetic platform for densely functionalized cis-hydroindoles and cis-hydrobenzofurans. The synthetic utility of this approach is demonstrated by the concise synthesis of (–)-α-lycorane and (–)-lycorine alkaloids. More details are discussed in the article by Cai et al. on page 21—26.
