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 cover picture shows a critical review on the organic reactions catalyzed by dinucleating complexes via metal‐metal cooperation. The reaction modes for the catalysis involving late transition metals are including the bimetallic co‐activation of single molecules and dual‐activation of two molecules. More details including the pathways of the metal‐metal cooperation are discussed by Zeng et al. on page 185—201.
The cover picture shows a synergistically directed assembly route towards novel multi‐component coordination architectures driven by aromatic donor‐acceptor and coordination interactions. The huge structural discrepancies between coronene donor present and absent experiments clearly prove the significance of aromatic donor‐accepter pairs and their inherent cooperation mechanism in these assembly processes. More details are discussed by Bu et al. on page 871–877.
The inside cover picture shows an electrochemical oxidative Csp3‐H/S‐H activation with hydrogen evolution for the synthesis of tetrasubstituted olefins. This method features very high atom economy, besides hydrogen gas, under the base‐free, transition met‐al‐free, and oxidants‐free conditions, no other by‐products were generated. More details are discussed in the article by Lei et al. on page 547–551.
The cover picture shows a simple and efficient method to utilize ZrO2 as a catalytic assistant for the hydrolysis of cellulose to sugar in low acid aqueous system driven by synchronous cooling assisted microwave radiation. Results show the adsorption of ZrO2 has an obvious influence on the efficiency of the hydrolysis of cellulose to sugar, which is impacted by the surface roughness and particle size. By the use of the ZrO2 with suitable structure and size, the conversion of treated cellulose and the yield of total reducing sugar respectively reach 95.5% and 93.6%. More details are discussed in the article by Na et al. on page on page 399–405.
The cover picture shows a highly enantioselective organocatalytic protonation of monofluorinated silyl enol ethers to α‐secondary α‐fluoroketones using water as proton source. Notably, in the presence of D2O and MeOD, the facile access of chiral α‐deuterated α‐fluoroketones in excellent enantioselectivity is achieved. More details are discussed by Zhou et al. on page 799–806.
The inside cover picture shows the development of chiral pyridoxal and pyridoxamine catalysts by mimicking vitamin B6‐dependent enzymes. These chiral pyridoxals and pyridoxamines displayed extraordinary catalytic performances in asymmetric biomimetic transamination and Mannich reaction, to give various chiral α‐amino acids and α,β‐diamino acid esters in good yields with excellent diastero‐ and/or enantioselectivities. The research has provided some useful information for further applications of the catalytic power of vitamin B6 in the area of asymmetric cayalysis. More details are discussed in the article by Zhao et al. on page 103–112.
The inside cover picture shows the hydrogen transfer process of the production of acetic acid from ethanol and water mixture catalyzed by iridium catalyst owning bpyO ligand. A DFT mechanistic study indicates that the cooperation of the iridium center and bpyO ligand plays an important role in the catalytic activity, and that the hydrogen release process from the iridium center is the rate‐determining step. More details are discussed in the article by Lei et al. on page 883–886.
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.
Interfacial engineering is expected to be a feasible strategy to improve the charge transport properties of the hole transport layer, which is of crucial importance to boost the device performance of organic solar cells. In this study, the doping of F4‐TCNQ and N719 dye in the hole transport layer with and without integrating a graphene quantum‐dots layer has been explored in non‐fullerene acceptor‐based organic solar cells. More details are discussed in the article by Feng et al. on page 817–822.
The cover picture shows the copper‐catalyzed Ullmann‐Ma reaction of aryl halides with nucleophiles by the assistance of two‐generation ligands, amino acids and oxalic diamides or related amides. Ullmann‐Ma reaction is one of the most important transformations for the construction of aryl carbon‐carbon and carbon‐heteroatom bonds in organic chemistry. For the details about the history, development, scope and applications of Ullmann‐Ma reaction, please see the article by Cai et al. on page 879–893.
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.
The back cover picture shows the first LA‐catalyzed [3+2]IMCC of GDA‐epoxides with carbon‐carbon double bonds. This provides an efficient and general strategy for construction of bridged oxa‐[n.2.1] skeletons. A novel SN‐like mechanism through a carbon‐carbon bond cleavage of epoxide ring has been proposed. The colorful fireworks in the picture imply the generation of skeletal diversity from the epoxide‐diene, and express a dedication to the 100th Anniversary of Nankai University as well. More details are discussed in the article by Wang et al. on page 695–699.
This cover picture shows a heterogeneous photocatalytic decarboxylative coupling reaction of imidazo-fused heterocycles with N-arylglycines. In this reaction, eco-friendly carbon nitride nanosheet is found to be an efficient and recyclable photocatalyst, which could be recovered and reused at least 7 times. More details are given in the article by Yu et al. on page 97–103.
The inside cover picture shows a palladium‐catalyzed asymmetric dihydroxylation of 1,3‐dienes with catechols utilizing chiral pyridinebis(oxazoline) ligand. The reaction is proposed to proceed via a cascade Wacker‐type hydroxypalladation/asymmetric allylation process. This methodology provides a direct and straightforward synthesis to prepare chiral 2‐substituted 1,4‐benzodioxane motifs in moderate to good yield and enantioselectivity from readily available starting materials. More details are discussed in the article by Gong et al. on page 226–232.
The cover picture shows that the radical sam enzyme hpnh catalyzes the coupling of an extremely hydrophilic substrate s‐adenosylmethionine (sam) and an extremely hydrophobic substrate hopene, producing adenosylhopane as a key intermediate in bacteriohopanepolyol biosynthesis. Coupling of the two substrates with totally distinct properties is somewhat analogous to the “1 up, 1 down” buddy system in freediving, in which one diver dives down and the other stays above the surface. Meeting the buddy in the middle way in the late stage of diving is always the most gratifying moment for the divers. More details are discussed by zhang et al. on page 39—42.
The cover picture shows that a new class of axially chiral aryl‐alkene‐indole frameworks has been constructed by the strategy of designing 3‐alkynyl‐2‐indolylmethanols as versatile reactants for catalytic asymmetric cyclizations. This approach represents the first catalytic asymmetric construction of axially chiral alkene‐heteroaryl scaffolds, which will add a nascent member to the atropisomeric family. The authors devised the innovative strategy to construct the intriguing axially chiral frameworks, just like Nuwa used the 'five‐colored stone' to mend the sky in the mythology of ancient China. More details are discussed in the article by Shi and Jiao et al. on page 543—552.
Metal‐air batteries have achieved great proceedings in the past decade. This review summarizes progresses of cathode evolution and anode protection strategies in the area of Li/Na‐air batteries and prototypes of flexible batteries are presented. More details are discussed in the article by Zhang et al. on page 32—42.
The inside cover picture shows the journey of developing PIP amine directing group for C—H activation, from controlling the reactivity and diastereoselectivity to enantioselectivity. In the presence of Pd or base metal catalysts, PIP amine enabled the activation of inert C—H bonds to form diverse C—C and C—heteroatom bonds. Its tuneable structure has triggered the design of chiral auxiliaries for diastereoselective C—H activation. More recently, enantioselective activation of unbiased methylene C—H bonds has been achieved by cooperative effects between PIP amine and axial chiral ligands. More details are discussed in the article by Shi et al. on page 647–656.
