We present a novel and eco-friendly electrochemical strategy for the electrochemical activation of trifluoromethyl thianthrenium triflate to access trifluoromethylated imidazo-fused heteroaromatic compounds.

Comprehensive Summary

A novel and eco-friendly electrochemical activation of trifluoromethyl thianthrenium triflate (TT–CF₃ ⁺OTf⁻) for trifluoromethylation of imidazole-fused heteroaromatic compounds was established. This method involves the direct electrolysis of TT–CF₃ ⁺OTf⁻ without the requirement of external oxidants or catalysts, aligning with the principles of green chemistry. A wide range of imidazole-fused heteroaromatic compounds including imidazo[1,2-a]pyridines and benzo[d]imidazo[2,1-b]thiazoles have been successfully trifluoromethylated using this technique, exhibiting excellent compatibility with various functional groups and a broad substrate scope. Moreover, the method's applicability for one-pot sequential reactions enables the reduction of waste and resource consumption by eliminating the need for intermediate purification steps.

We reported Ru(II)-catalyzed C—H alkynylation of isoquinolones, quinazolones and phthalazinones with bromoalkynes. This protocol provides an approach towards access to various heterocyclic compounds in high yields (up to 95%).

Comprehensive Summary

A new, selective Ru(II)-catalyzed alkynylation reaction of isoquinolones, quinazolones and phthalazinones with readily available bromoalkynes has been developed. This reaction enables the selective construction of a new C(sp²)-C(sp) bond through C—H activation and C—Br functionalization, and offers an effective and selective route to synthesizing highly valuable alkynylated isoquinolone, quinazolone and phthalazinone derivatives with a wide substrate scope and high selectivity.

The terpolymer of CO₂, 1,3-butadiene and epoxides is synthesized by cationic ring-opening copolymerization of α-ethylidene-δ-vinyl-δ-valerolactone (EVL), an intermediate derived from CO₂ and 1,3-butadiene, with epoxides. The resulted poly(ester-ether) with moderate molecular weight bears all the C=C double bonds derived from 1,3-butadiene, enabling post-polymerization modification and functionalization. Photoinitiated crosslinking through these preserved C=C double bonds produces network with fluorescence and degradation properties.

Comprehensive Summary

The utilization of carbon dioxide (CO₂) as a C1 feedstock is consistently attractive, especially in the preparation of sustainable polymeric materials. In this contribution, a terpolymer of CO₂, 1,3-butadiene (BD) and epoxide is synthesized by scandium triflate catalyzed cationic ring-opening copolymerization of α-ethylidene-δ-vinyl-δ-valerolactone (EVL), an intermediate derived from CO₂ and BD, with epoxides. The obtained terpolymer with a CO₂ content of 22 mol% has a number-average molecular weight (M _n) up to 7.8 kg/mol and a dispersity (Đ) of 2.4. The reactivity ratios of EVL and cyclohexene oxide (CHO) are determined as 0.01 and 1.07, respectively, suggesting random characteristic of the terpolymer. The preserved C=C double bonds from BD allow for the further modification of the terpolymer by photoinitiated crosslinking. The yielded networks are fluorescent and degradable. This method offers enhanced versatility to the synthesis and additional functionalization of CO₂-based polymers.

Bifunctional rare earth complexes have been developed for the cycloaddition reactions of epoxides and CO₂, under atmospheric pressure, without co-catalyst to produce value-added cyclic carbonates. Comparative and kinetic experiments confirm the existence of intramolecular synergies between the central metal and the nucleophilic reagent within the catalytic molecule.

Comprehensive Summary

Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato) ligands bearing quaternary ammonium side-arms were synthesized and characterized. These complexes were used as single-component catalysts for the cycloaddition of CO₂ and epoxides, and their catalytic activities are obviously higher than those of their binary analogues. Further studies revealed that the halide anions (Cl^–, Br^–, I^–) and the metal complexes influenced the catalytic activity, and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction. A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields (55%—99%) with high selectivity (> 99%) at 30 °C and 1 bar CO₂, whereas internal epoxides required higher both reaction temperatures (60—120 °C) and catalyst loading (2 mol%) for high yields. The catalyst was recyclable for four times without noticeable loss of catalytic activity. Based on the results of kinetic studies and in situ IR reactions, a plausible reaction mechanism was proposed.

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time. Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities.

Comprehensive Summary

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time. Various selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities. As the substrates were 1-ethynyl naphthol derivatives, linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive; in contrast, cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

Herein, we report on the chemical synthesis of a tetrasaccharide precursor of the Treponema medium ATCC 700293. When the [2+2] glycosylation strategy could not be carried out due to the mismatch of donor-acceptor reactivities, we successfully completed the synthesis of the target tetrasaccharide precursor using a [3+1] glycosylation strategy.

Comprehensive Summary

Treponema is a Gram-negative anaerobic bacterium, among which the pathogenic Treponema can cause various diseases, such as venereal syphilis (Treponema pallidum), yaws (Treponema carateum), and oral diseases (Treponema denticola and Treponema medium). Although different from conventional lipopolysaccharides, the extracellular glycoconjugate of Treponema may still be a potential antigen and provide a candidate for vaccine development. Hence, we completed the first chemical synthesis of Treponema medium ATCC 700293 tetrasaccharide precursor containing L-ornithine (L-Orn) and D-aspartic acid (D-Asp) derivatives. The efficiency of non-reducing end disaccharide formation has been improved by optimizing the assembly of the protecting groups in the donors and acceptors. Our [3+1] glycosylation strategy attempted to reduce the length of the acceptor to increase the nucleophilicity of the hydroxyl group, thereby improving the efficiency of synthesizing the target tetrasaccharide. The L-Orn derivative was introduced at the final stage due to its influence on the glycosylation stereospecificity and efficiency. Therefore, the successful introduction of two amino acid derivatives and the synthesis of a tetrasaccharide precursor with complex functional-group modifications have provided valuable insights for synthesizing other complex bacterial glycans.

A nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids was reported, providing the corresponding arylated 2-fluoroallylic scaffolds with high regioselectivity and Z-stereoselectivity. Mechanistic studies proposed a Ni(II)-fluoroallyl pathway and clarified the origin of the high linear selectivity.

Comprehensive Summary

Herein, we report nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids, providing the corresponding arylated 2-fluoroallylic scaffolds. This approach used commercially available phosphine ligand Xantphos to obtain monofluorinated alkenes with high regioselectivity and Z-stereoselectivity. Mechanistic studies proposed a Ni(II)-fluoroallyl pathway and excluded the radical pathway. Meanwhile, DFT study of the reductive elimination clarified the origin of the high linear selectivity.

Inspired by the skin of Osteichthyes fishes, a Janus hydrogel coating consisting of slippery and sticky layers is successfully prepared by a two-step UV light irradiation at room temperature. The slippery layer replicates the structure of cycloid scales, while the nature of hydrogel mimics the mucus on fish skin. The Janus hydrogel coating possesses prominent mechanical, anti-fouling and drag reduction properties.

Comprehensive Summary

In nature, fishes have evolved functional skins with effective hydrodynamic performance and anti-fouling, facilitating predation and escaping from predators. Although a large number of fish scale-inspired structured surfaces have been explored, the incorporation of mucus on the structured surfaces has been largely ignored. Inspired by the skin of Osteichthyes fishes, a Janus hydrogel coating (JHC) is successfully prepared by a two-step UV light irradiation at room temperature. The bottom side of JHC (STH) achieves a shear adhesive strength of 103.3 ± 17.5 kPa and can strongly adhere to a large variety of surfaces, including metals, ceramic and polymers. The top surface of JHC (SLH) replicates the structure of cycloid scales, while the nature of hydrogel mimics the mucus on fish skin. SLH possesses prominent mechanical, anti-swelling, anti-fouling and drag reduction properties. The design strategy for JHC has potential applications in numerous fields, like, pipeline transportation, bioengineering, and shipping industry.

Metal NPs decorated block copolymer (BCP) hybrid nanomaterials were facilely fabricated via emulsion confined self-assembly and seed-mediated growth strategy. The obtained hybrid nanoparticles exhibited high catalytic efficiency for the reduction of 4-nitrophenol to 4-aminophenol.

Comprehensive Summary

Metal nanoparticles (NPs) decorated block copolymer (BCP) hybrid nanoparticles have attracted enormous attention for their actual value in catalysis, medical therapy, and bioengineering. The confined assembly of BCPs within evaporative emulsion droplet is verified as an effective method to provide polymeric scaffolds to load metal NPs. However, to date, it remains challenging to generate different types of metal NPs decorated BCP hybrid nanoparticles. Herein, we employed the emulsion confined self-assembly of poly(styrene-b- 2-vinylpyridine) (PS-b-P2VP) and the followed seed-mediated growth of Au and palladium (Pd) NPs onto well-defined BCP particles to design a series of Au/Pd decorated BCP hybrid nanoparticles, which exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with the reductant of NaBH₄. This work may inspire more researchers to investigate the selective decoration of different metal NPs onto the polymeric scaffolds, broadening the potential applications of the inorganic/organic hybrid nanoparticles.

Comprehensive Summary

Sensing the chirality of molecules is of great importance to fields such as enantioselective synthesis, pharmaceutical industry, and biomedicine. Plasmonic nanoparticles are ideal candidates for molecular sensing due to their inherent plasmonic properties that significantly enhance their sensitivity to surrounding molecules. Developing plasmonic nanoparticle-molecule complexes for chirality sensing has drawn enormous attention in recent years due to their intriguing properties and potential applications. Thus, in this review, we believe it is timely to circumnavigate the rational design of plasmonic nanoparticle-molecule complexes and widen the scope of their emerging applications in chirality sensing. First, we present different fundamental mechanisms for plasmon-based chirality that are built on the system of plasmonic nanoparticle-molecule complexes. Second, we review the typical applications of plasmonic nanoparticle-molecule complexes in chirality sensing. Third, we discuss the emerging biomedical applications that the plasmon-based chirality has attracted enormous interest. Finally, we provide an outlook on the challenges and opportunities in the field of plasmonic approaches for chirality sensing.