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Covalent–organic frameworks (COFs) are rarely used as heterogeneous catalysts for cycloaddition reactions, especially in [3+2] reactions. In this study, 4,4′,4″,4‴‐(pyrene‐1,3,6,8‐tetrayl) tetra‐aniline, 2,5‐dihydroxyterephthalaldehyde, and 2,5‐dimethylterephthalaldehyde are used to construct COFs with high porosity, crystallinity, and chemical stability. The phenolic and methyl groups on the pore channel of the COFs are precisely tuned to effectively serve as heterogeneous catalysts for the formal [3+2] reaction between 5‐alkoxyoxazoles and azodicarboxylate or nitrosobenzene compounds. The resultant COFs that are assembled from adjustable building unit ratios exhibit excellent catalytic performance for the targeted [3+2] reaction. [ABSTRACT FROM AUTHOR]

Exploring covalent organic frameworks with new linkages is regarded as an efficient method to modulate the corresponding properties, and a new linkage is essential to the progress of this field. Herein, condensation of 1,3,5-triformylphloroglucinol with 1,1′-(1,4-phenylene)bis(thiourea), 1,1′-(2,5-dimethyl-1,4-phenylene)bis(thiourea) or 1,1′-(3,3′-dimethyl-[1,1′-biphenyl]-4,4′-diyl)bis(thiourea) were applied to construct COFs with thiourea linkages for the first time. [ABSTRACT FROM AUTHOR]

As we know, the photoelectric properties of the covalent organic frameworks (COFs) can be properly adjusted by introducing an electron donor–acceptor (D–A) structure. In here, a two-dimensional D–A type Py-BPDAIP-COF with an excellent photoelectric characteristic was prepared in a post-modified method. Significantly, the introducing of very strong electron-withdrawing pyridinium structure dramatically improve inductive and conjugative effects of the electron acceptor unit of Py-BPDAIP-COF. And the electron-rich pyrene skeleton on the knot of the COF was as an electron donor. Then a strong electron push–pull effect between the donor and acceptor units can be transmitted to the COFs backbone, significantly improving the transfer and separation of light-generated electrons. The Py-BPDAIP-COF showed very excellent photocatalytic activity in visible light-induce aerobic hydroxylation, thiocyanation transformation and oxidative C-H functionalization. Therefore, we design and construct a highly efficient olefin-linked D–A type COF photocatalysts via tuning inductive and conjugative effects of pore wall surface. [Display omitted] • A new olefin-linked donor–acceptor pyridinium COFs has been prepared. • Ultra-efficient aerobic hydroxylation reaction could be catalyzed by Py-BPDAIP-COF. • The D-A units in Py-BPDAIP-COF dramatically increase its photocatalytic activity. • The other two organic reactions were also efficiently realized by Py-BPDAIP-COF. [ABSTRACT FROM AUTHOR]

Crystalline covalent organic frameworks (COFs) materials have good performance in photocatalytic conversions due to their excellent photoelectric properties in recent years. here, two new conjugated pyrene-based covalent organic frameworks (COFs), namely PyDF-COF and PyBMT-COF, were prepared through condensation polymerization of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and 2,5-difluoroterephthalaldehyde or 2,5-bis(methylthio)terephthalaldehyde, respectively. Highly selective aerobic hydroxylation of arylboronic acids can occur smoothly with high yields and a wide range of substrate universality. Compared with PyDF-COF, PyBMT-COF demonstrates a more efficient ability for this aerobic hydroxylation, indicating electron-donating thiomethyl groups of PyBMT-COF are more favorable to enhance distribution of electron cloud than electron-withdrawing fluorine groups of PyDF-COF, which make the PyBMT-COF more easily afford holes and electrons (h+-e-) separation, more effectively absorb visible light, and own narrower bandgap energy, higher photocurrent response, longer fluorescent lifetime and lower electrochemical impedance. [Display omitted] • Two new conjugated pyrene-based covalent organic frameworks have been prepared. • Highly selective aerobic hydroxylation of arylboronic acids proceeded in high yields and a wide substrate scope using PyBMT-COF as a photocatalyst.. • Electron-donating effect of thiomethyl groups in PyBMT-COF dramatically increases the photocatalytic activity compared with PyDF-COF. [ABSTRACT FROM AUTHOR]

A highly efficient catalytic asymmetric formal [3+2] cycloaddition reaction of 5-alkoxyoxazoles with azodicarboxylate compounds has been realized by a chiral N,N′-dioxide/Co(BF4)2·6H2O complex. A series of poly-substituted 1,2,4-triazolines compounds were obtained in moderate to excellent yields (70–99%) with excellent enantioselectivities (82–98% ee). [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are a novel class of crystalline porous polymers, which possess high porosity, excellent stability, and regular nanochannels. 2D COFs provide a 1D nanochannel to form the proton transport channels. The abovementioned features afford a powerful potential platform for designing materials as proton transportation carriers. Herein, the authors incorporate sulfonic acid groups on the pore walls as proton sources for enhancing proton transport conductivity in the 1D channel. Interestingly, the sulfonic acid COFs (S‐COFs) electrolytes being binder free exhibit excellent proton conductivity of ≈1.5 × 10−2 S cm−1 at 25 ℃ and 95% relative humidity (RH), which rank the excellent performance in standard proton‐conducting electrolytes. The S‐COFs electrolytes keep the high proton conduction over the 24 h. The activation energy is estimated to be as low as 0.17 eV, which is much lower than most reported COFs. This research opens a new window to evolve great potential of structural design for COFs as the high proton‐conducting electrolytes. [ABSTRACT FROM AUTHOR]

Mythimna separata and Mythimna loreyi are global pests of gramineous cereals, heavily controlled with synthetic insecticides. Here, we generated two high‐quality chromosome‐level genome assemblies for M. separata (688 Mb) and M. loreyi (683 Mb). Our analysis identified Z and W chromosomes, with few genes and abundant transposable elements (TEs) found on the W chromosome. We also observed a recent explosion of long interspersed nuclear elements (LINEs), which contributed to the larger genomes of Mythimna. The two armyworms diverged ~10.5 MYA, with only three chromosomes have intrachromosomal rearrangements. Additionally, we observed a tandem repeat expansion of α‐amylase genes in Mythimna, which may promote the digestion of carbohydrates and exacerbate their damage to crops. Furthermore, we inferred the sex pheromone biosynthesis pathway for M. separata, M. loreyi and Spodoptera frugiperda. We discovered that M. loreyi and S. frugiperda synthesized the same major constituents of sex pheromones through different pathways. Specifically, the double bonds in the dominant sex pheromone components of S. frugiperda were generated by Δ9‐ and Δ11‐desaturase, while they were generated by Δ11‐desaturase and chain‐shortening reactions in M. loreyi. We also identified pheromone receptor (PR) genes and inferred their corresponding components. These findings provide a better understanding of sex pheromone communication and promote the development of a new pest control strategy involving pheromone traps, which are more effective and environmentally friendly than current strategies. [ABSTRACT FROM AUTHOR]

Radioactive iodine in nuclear waste has become an unignorable problem of environmental pollution. In this work, two covalent organic frameworks (T-COF-1 and T-COF-2) with triazine units were synthesized for exceptional iodine capture via weak molecular interactions. Besides, the iodine capture capacity can be tuned via the design of building units, where the nitrogen content can be modified at the molecular level. Interestingly, T-COF-2 with higher triazine unit content affords a higher iodine uptake value. [ABSTRACT FROM AUTHOR]

Front Cover: In article number 2100590 by Liwei Mi, Yuki Nagao, Zhongping Li, and co‐workers, covalent organic frameworks (COFs) with abundant built‐in sulfonic acid groups on the uniform 1D channel are prepared as proton‐conducting electrolytes. The excellent proton conductivity of 1.5 × 10−2 S cm−1 at 25 ℃ and 95% relative humidity (RH) with binder‐free properties is achieved for the sulfonated COFs, which rank in excellent performance as a proton‐conducting electrolyte. [ABSTRACT FROM AUTHOR]

Accumulation of Sulfonic Acid Groups Anchored in Covalent Organic Frameworks as an Intrinsic Proton-Conducting Electrolyte B Front Cover b : In article number 2100590 by Liwei Mi, Yuki Nagao, Zhongping Li, and co-workers, covalent organic frameworks (COFs) with abundant built-in sulfonic acid groups on the uniform 1D channel are prepared as proton-conducting electrolytes. The excellent proton conductivity of 1.5 × 10 SP -2 sp S cm SP -1 sp at 25 °C and 95% relative humidity (RH) with binder-free properties is achieved for the sulfonated COFs, which rank in excellent performance as a proton-conducting electrolyte. [Extracted from the article]

An asymmetric Meerwein–Ponndorf–Verley (MPV) reduction of glyoxylates was for the first time accomplished via an N,N′-dioxide/Y(OTf)3 complex with aluminium alkoxide and molecular sieves (MSs) as crucial additives. A variety of optically active α-hydroxyesters were obtained with excellent results. A possible reaction mechanism was proposed based on the experiments. [ABSTRACT FROM AUTHOR]

Thick electrode is a valid and practical strategy for achieving lithium-ion batteries with high energy density. However, before widespread practical application, the electron-ion transfer dynamics and structural stability of thick electrode must be optimized. Herein, the correlation between electrode structure design and electrochemical performances is discussed with consideration to electron-ion transfer processes and main attenuation mechanisms. The factors that affect electron-ion transfer and mechanical stability are analyzed systematically. The main design strategies for producing thick electrodes with excellent electrochemo-mechanical properties are summarized. Furthermore, state-of-the-art fabrication techniques for thick electrodes with special microstructures are reviewed, and their potential development directions are discussed. Finally, the challenges and feasible tendencies associated with developing thick electrodes are analyzed and proposed. This review aims to clarify the influence mechanism and key optimization strategies for the electrochemo-mechanical performances of thick electrodes and to illustrate the direction for the future development of fabrication technologies. This is critical for exploring robust thick electrodes with high energy/power densities and mechanical stability from a multi-scale and multi-field standpoint. [Display omitted] • Clarifying the importance of structural design of thick electrodes. • Analyzing the effect factors and strategies for thick electrode design. • Outlining state-of-the-art fabrication techniques for thick electrodes. • Pointing out critical issues and development directions for fabrication techniques. • Prospecting the future tendencies for the industrialization of thick electrodes. [ABSTRACT FROM AUTHOR]

A highly enantioselective dearomative cascade reaction between 2-isocyanoethylindoles and 3-alkenyl-oxindoles was realized using a chiral N,N′-dioxide–Mg(ii) complex catalyst. This reaction provides a straightforward access to polycyclic 3-spirooxindoles bearing cyclopenta[b]indole units with four contiguous stereocenters in excellent yields and moderate to good stereoselectivities via a Michael/Friedel–Crafts/Mannich cascade. [ABSTRACT FROM AUTHOR]

An abstract of the article "The Asymmetric Synthesis of Polycyclic 3-Spirooxindole Alkaloids via the Cascade Reaction of 2-Isocyanoethylindoles" by Xiaohu Zhao, Xiaohua Liu and colleagues is presented.