Alkali-Amide-Catalyzed One-Pot Aminoallylation of Aldehydes with Allylbenzenes.

The deprotonation of allylbenzene was successfully demonstrated with a catalytic alkali amide base (NaN(SiMe3)2). The deprotonated allyl anion could be trapped by in situ generated N-(trimethylsilyl) aldimines to provide value-added homoallylic amines (39 examples, 68-98% yields) in a one-pot manner with excellent liner selectivity. Compared with the previously reported method for the synthesis of homoallylic amines, this method does not need to use the preinstalled protection groups on the imines, which need to be removed after the reaction to obtain the N-H free homoallylic amine derivatives.

One-Pot Rapid Access to Benzyl Silanes, Germanes, and Stannanes from Toluenes Mediated by a LiN(SiMe3)2/CsCl System.

Organo-silanes, germanes, and stannanes are considered to be conducive to the development of cross-coupling reactions because they are stable, nontoxic, and easy to handle. Using feedstock toluenes, one-pot direct benzylic C-H silylations, germylations, and stannylations are developed. Simply combining toluenes, LiN(SiMe3)2/CsCl, and R3MCl (M = Si, Ge, Sn) generates a diverse array of bench-stable benzyl silanes, germanes, and stannanes (38 examples, 53-90% yields). The syntheses developed here are easy to access on scale.

Nickel/Photoredox-Catalyzed Enantioselective Reductive Cross-Coupling between Vinyl Bromides and Benzyl Chlorides.

A visible-light-promoted nickel/photoredox-catalyzed reductive cross-coupling reaction between vinyl bromides and benzyl chlorides is reported. A diverse array of enantioenriched allylic centers containing products could be achieved in good yields (up to 90%) and high enantioselectivities (up to 95% ee). The mechanistic studies show that this reductive cross-coupling involves a radical pathway.

Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+ System.

Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp2)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe3)2 M = Li, Na]/Cs+ combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe3)2/CsF for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple methyl benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alcohol products. This finding greatly increases the practicality and impact of this chemistry. Some challenging substrates with respect to benzylic deprotonations, such as fluoro and methoxy substituted toluenes, are selectively transformed to 2-aryl acetophenones. The value of benzylic deprotonation of 3-fluorotoluene is demonstrated by the synthesis of a key intermediate in the preparation of Polmacoxib.

Nickel-Catalyzed Cross-Electrophile Coupling of 1,2,3-Benzotriazin-4(3H)-ones with Aryl Bromides.

The nickel-catalyzed cross-electrophile coupling of 1,2,3-benzotriazin-4(3H)-ones with aryl bromides to generate a diverse array of ortho-arylated benzamide derivatives has been developed. The reaction displayed good functional group tolerance with Zn as the reductant. The key to this transformation is the ring opening of benzotriazinones, which undergo a denitrogenative process to obtain various benzamide derivatives (29 examples, 42-93% yield). The scalability of this transformation was demonstrated.

Synthesis of pyrazole-4-carboxamides as potential fungicide candidates.

A series of novel pyrazole-4-carboxamides were rationally designed, synthesized, and their structures were characterized by 1H NMR, 13C NMR and HRMS. Preliminary bioassay showed that four compounds 8g, 8j, 8o and 8s exhibited more than 90% and even completed inhibition against Alternaria solani at 100 µg/mL; and 8d displayed 100% inhibition against Fusarium oxysporum at the same concentration. Moreover, 8j exhibited good in vitro fungicidal activity against A. solani with EC50 value of 3.06 µg/mL, and it also displayed completed in vivo protective antifungal activity against A. solani on tomato at 10 mg/L, as boscalid did. The molecular docking results indicated that 8j exhibited the high affinity with SDH protein by H-bond and π-π stacking interactions, which may explain the reasons for its good activities. These data support that compound 8j could be used as a fungicide candidate for further study. A practical method for the synthesis of pyrazole-4-carboxamides were provided and evaluation of their antifungal activities.

Design and Synthesis of N-phenyl Phthalimides as Potent Protoporphyrinogen Oxidase Inhibitors.

Protoporphyrinogen oxidase (PPO) has been identified as one of the most promising targets for herbicide discovery. A series of novel phthalimide derivatives were designed by molecular docking studies targeting the crystal structure of mitochondrial PPO from tobacco (mtPPO, PDB: 1SEZ) by using Flumioxazin as a lead, after which the derivatives were synthesized and characterized, and their herbicidal activities were subsequently evaluated. The herbicidal bioassay results showed that compounds such as 3a (2-(4-bromo-2,6-difluorophenyl) isoindoline-1,3-dione), 3d (methyl 2-(4-chloro-1,3-dioxoisoindolin-2-yl)-5-fluorobenzoate), 3g (4-chloro-2-(5-methylisoxazol-3-yl) isoindoline-1,3-dione), 3j (4-chloro-2-(thiophen-2-ylmethyl) isoindoline-1,3-dione) and 3r (2-(4-bromo-2,6-difluorophenyl)-4-fluoroisoindoline-1,3-dione) had good herbicidal activities; among them, 3a showed excellent herbicidal efficacy against A. retroflexus and B. campestris via the small cup method and via pre-emergence and post-emergence spray treatments. The efficacy was comparable to that of the commercial herbicides Flumioxazin, Atrazine, and Chlortoluron. Further, the enzyme activity assay results suggest that the mode of action of compound 3a involves the inhibition of the PPO enzyme, and 3a showed better inhibitory activity against PPO than did Flumioxazin. These results indicate that our molecular design strategy contributes to the development of novel promising PPO inhibitors.

Triazole-linked fluorescent bisboronic acid capable of selective recognition of the Lewis Y antigen.

Cell surface carbohydrates of the Lewis blood group antigens, Lewis X (Lex), Lewis Y (Ley), Lewis A (Lea), and their sialylated derivatives, such as sialy Lewis X (sLex) and sialy Lewis A (sLea), play important roles in various recognition processes. These cell surface carbohydrates have also been associated with the development and progression of many types of cancers. Recently, we synthesized four anthracene-based fluorescent bisboronic acid sensors (compounds 2a-d) linked by 'click' chemistry with tethers of different lengths to match the epitope of various Lewis group of sugars. Among the four compounds, 2a appears to have both high sensitivity and selectivity for Ley among other carbohydrate antigens.

Advancements in Soft Robotics: A Comprehensive Review on Actuation Methods, Materials, and Applications.

The flexibility and adaptability of soft robots enable them to perform various tasks in changing environments, such as flower picking, fruit harvesting, in vivo targeted treatment, and information feedback. However, these fulfilled functions are discrepant, based on the varied working environments, driving methods, and materials. To further understand the working principle and research emphasis of soft robots, this paper summarized the current research status of soft robots from the aspects of actuating methods (e.g., humidity, temperature, PH, electricity, pressure, magnetic field, light, biological, and hybrid drive), materials (like hydrogels, shape-memory materials, and other flexible materials) and application areas (camouflage, medical devices, electrical equipment, and grippers, etc.). Finally, we provided some opinions on the technical difficulties and challenges of soft robots to comprehensively comprehend soft robots, lucubrate their applications, and improve the quality of our lives.

A High-Stretching, Rapid-Self-Healing, and Printable Composite Hydrogel Based on Poly(Vinyl Alcohol), Nanocellulose, and Sodium Alginate.

Hydrogels with excellent flexibility, conductivity, and controllable mechanical properties are the current research hotspots in the field of biomaterial sensors. However, it is difficult for hydrogel sensors to regain their original function after being damaged, which limits their practical applications. Herein, a composite hydrogel (named SPBC) of poly(vinyl alcohol) (PVA)/sodium alginate (SA)/cellulose nanofibers (CNFs)/sodium borate tetrahydrate was synthesized, which has good self-healing, electrical conductivity, and excellent mechanical properties. The SPBC0.3 hydrogel demonstrates rapid self-healing (<30 s) and achieves mechanical properties of 33.92 kPa. Additionally, it exhibits high tensile strain performance (4000%). The abundant internal ions and functional groups of SPBC hydrogels provide support for the good electrical conductivity (0.62 S/cm) and electrical response properties. In addition, the SPBC hydrogel can be attached to surfaces such as fingers and wrists to monitor human movements in real time, and its good rheological property supports three-dimensional (3D) printing molding methods. In summary, this study successfully prepared a self-healing, conductive, printable, and mechanically superior SPBC hydrogel. Its suitability for 3D-printing personalized fabrication and outstanding sensor properties makes it a useful reference for hydrogels in wearable devices and human motion monitoring.

One-Pot Synthesis of Indolin-3-ones Mediated by LiN(SiMe3)2/CsF.

Indolin-3-ones are essential heterocycles with wide-ranging biological activities and medicinal values, and therefore, efficient approaches to their synthesis remain in demand. Herein, a novel and operationally simple method to generate indolin-3-ones is reported by using a tandem reaction of N-methylbenzylamines and methyl 2-fluorobenzoates mediated by the LiN(SiMe3)2 and CsF system (34 examples, 30-85% yields). The synthesis of C2-quaternary indolin-3-one further demonstrated the potential practicability of these tandem reactions.

Design, Synthesis, and Herbicidal Activity of Pyrazole Amide Derivatives as Potential Transketolase Inhibitors.

The design and synthesis of new herbicidal active compounds based on a new target are of great significance for the development of new herbicides. Transketolase (TK) plays a key role in the Calvin cycle of plant photosynthesis and has been confirmed as a potential candidate target to develop and discover new herbicides. To obtain compounds with ultraefficient targeting of TK, a series of pyrazole amide derivatives were designed and synthesized through structural optimization for lead compound 4u based on TK as the new target. The bioassay results showed that compounds 6ba and 6bj displayed a highly inhibitory effect with the root inhibition of about 90% against Digitaria sanguinalis (DS) and 80% against Amaranthus retroflexus (AR) and Setaria viridis (SV) by the small cup method, which was better than the positive control mesotrione and nicosulfuron. Furthermore, compounds 6ba and 6bj exhibited an excellent inhibitory effect with the inhibition of about 80% (against DS) and over 80% (against SV) at the dosage of 150 g of active ingredient/ha by the foliar spray method. The TK enzyme activity inhibition test showed that the inhibition effect of target compounds against TK was consistent with the results of herbicidal activities. Also, molecular docking analysis showed that compounds 6ba and 6bj went deep into the active cavity of TK, bound to TK by a strong interaction, and might act on the enzyme TK. Above of all, compounds 6ba and 6bj are promising herbicide lead compounds targeting TK. Hence, they could be developed into more efficient herbicides by further structural optimization.

Polyacrylamide/sodium alginate/sodium chloride photochromic hydrogel with high conductivity, anti-freezing property and fast response for information storage and electronic skin.

Photochromic hydrogels have promising prospects in areas such as wearable device, information encryption technology, optoelectronic display technology, and electronic skin. However, there are strict requirements for the properties of photochromic hydrogels in practical engineering applications, especially in some extreme application environments. The preparation of photochromic hydrogels with high transparency, high toughness, fast response, colour reversibility, excellent electrical conductivity, and anti-freezing property remains a challenge. In this study, a novel photochromic hydrogel (PAAm/SA/NaCl-Mo7) was prepared by loading ammonium molybdate (Mo7) and sodium chloride (NaCl) into a dual-network hydrogel of polyacrylamide (PAAm) and sodium alginate (SA) using a simple one-pot method. PAAm/SA/NaCl-Mo7 hydrogel has excellent conductivity (175.9 S/cm), water retention capacity and anti-freezing properties, which can work normally at a low temperature of -28.4 °C. In addition, the prepared PAAm/SA/NaCl-Mo7 hydrogel exhibits fast response (<15 s), high transparency (>70 %), good toughness (maximum elongation up to 1500 %), good cyclic compression properties at high compressive strains (60 %), good biocompatibility (78.5 %), stable reversible discolouration and excellent sensing properties, which can be used for photoelectric display, information storage and motion monitoring. This work provides a new inspiration for the development of flexible electronic skin devices.

Discovery of Novel Pyrazole Acyl Thiourea Skeleton Analogue as Potential Herbicide Candidates.

To discover novel transketolase (TKL, EC 2.2.1.1) inhibitors with potential herbicidal applications, a series of pyrazole acyl thiourea derivatives were designed based on a previously obtained pyrazolamide acyl lead compound, employing a scaffold hopping strategy. The compounds were synthesized, their structures were characterized, and they were evaluated for herbicidal activities. The results indicate that 7a exhibited exceptional herbicidal activity against Digitaria sanguinalis and Amaranthus retroflexus at a dosage of 90 g ai/ha, using the foliar spray method in a greenhouse. This performance is comparable to that of commercial products, such as nicosulfuron and mesotrione. Moreover, 7a showed moderate growth inhibitory activity against the young root and stem of A. retroflexus at 200 mg/L in the small cup method, similar to that of nicosulfuron and mesotrione. Subsequent mode-of-action verification experiments revealed that 7a and 7e inhibited Setaria viridis TKL (SvTKL) enzyme activity, with IC50 values of 0.740 and 0.474 mg/L, respectively. Furthermore, they exhibited inhibitory effects on the Brassica napus acetohydroxyacid synthase enzyme activity. Molecular docking predicted potential interactions between these (7a and 7e) and SvTKL. A greenhouse experiment demonstrated that 7a exhibited favorable crop safety at 150 g ai/ha. Therefore, 7a is a promising herbicidal candidate that is worthy of further development.

Maximizing performance and efficiency in 3D printing of polylactic acid biomaterials: Unveiling of microstructural morphology, and implications of process parameters and modeling of the mechanical strength, surface roughness, print time, and print energy for fused filament fabricated (FFF) bioparts.

Medical stents, artificial teeth, and grafts are just some of the many applications for additive manufacturing techniques like bio-degradable polylactic acid 3D printing. However, there are drawbacks associated with fused filament fabrication-fabricated objects, including poor surface quality, insufficient mechanical strength, and a lengthy construction time for even a relatively small object. Thus, this study aims to identify the finest polylactic acid 3D printing parameters to maximize print quality while minimizing energy use, print time, flexural and tensile strengths, average surface roughness, and print time, respectively. Specifically, the infill density, printing speed, and layer thickness are all variables that were selected. A full-central-composite design generated 20 samples to test the prediction models' experimental procedures. Validation trial tests were used to show that the experimental findings agreed with the predictions, and analysis of variance was used to verify the importance of the performance characteristics (ANOVA). At layer thickness = 0.26 mm, infill density = 84 %, and print speed = 68.87 mm/s, the following optimized values were measured for PLA: flexural strength = 70.1 MPa, tensile strength = 39.2 MPa, minimum surface roughness = 7.8 µm, print time = 47 min, and print energy = 0.18 kwh. Firms and clinicians may benefit from utilizing the developed, model to better predict the required surface characteristic for various aspects afore trials.

Synthesis of Homoallylamines Enabled by Cobalt or Palladium Catalyzed Allylic Substitution of Azaarylmethylamines.

Pd(OAc)2/Nixantphos or CoI2/Nixantphos catalyzed allylic substitutions with weakly acidic C(sp)3-H bonds of azaarylmethylamines are described. This method facilitates access to various kinds of heteroaryl rings containing homoallylamines (39 examples, 30-98% yields) with excellent functional group tolerance and diastereoselectivity. Compared with the Pd/Nixantphos complex, the Co/Nixantphos catalysis could obtain the cyclic products with good to excellent diastereoselectivities. Importantly, the CoI2/(R,R)-Me-Duphos catalyzed reactions exhibit moderate enantioselectivity. Additionally, the scalability of this transformation is successfully demonstrated.

Editorial on the Special Issue "Modification of Hydrogels and Their Applications in Biomedical Engineering".

Hydrogels and hydrophilic polymer networks play an important role in biomedical engineering due to their good biocompatibility, biodegradability, hydrophilicity, and mechanical properties, similarly to some soft tissues [...].

A Tandem Madelung Indole Synthesis Mediated by a LiN(SiMe3)2/CsF System.

A tandem Madelung indole synthesis by the reaction of methyl benzoate and N-methyl-o-toluidine has been discovered. The combination of LiN(SiMe3)2 with CsF is the key factor, which secures the high efficiency of such tandem transformations. Simply combining methyl benzoate, N-methyl-o-toluidine LiN(SiMe3)2, and CsF generated a diverse array of N-methyl-2-phenylindoles (31 examples, 50-90% yields). Furthermore, the scalability and the poststructural modifications of this indole synthesis were demonstrated.