With the rapid development of high speed and high frequency communication, organic low dielectric (low-k) materials with both ultra-low dielectric constant (D-k) and ultra-low dielectric loss (D-f) are urgently required to ensure signal transmission speed and reliability. 1,2-polybutadiene (1,2-PB) is renowned for its excellent dielectric properties, making it used in high-frequency printed circuit boards (PCBs). However, its poor thermal stability and mechanical properties hinder its application which requires persistent stability. To address this issue, a series of thermal-crosslinkable benzocyclobutene (BCB)-modified PBs were synthesized through a hydrosilylation reaction. These cured PBs exhibited significantly enhanced thermal stability with the glass transition temperature (T-g) exceeding 400 degrees C. In particular, they displayed ultra-low D-k (2.32-2.41) and ultralow D-f (lower than 0.001). It was found that the properties of cured PBs were related to BCB loadings. Among the cured polymers, PB-g-B30 demonstrated the optimal dielectric properties with a D-k of 2.34 and a D-f of 3.6 x 10(-4). Subsequently, a PB-g-B30/glass fiber laminate was fabricated, exhibiting superior dielectric and comprehensive properties when compared to commercial low-k laminates. This study provides a facile method to develop PBs with ultra-low D-k and D-f and enhanced thermal stability. The outstanding comprehensive properties indicate their potential as low-k materials in high-frequency communication applications.

An efficient Ir-catalyzed asymmetric allylic amination reaction of alkyl-substituted allylic carbonates is disclosed. With the Krische iridium complex as the catalyst, asymmetric allylic amination of alkyl-substituted allylic carbonates with pyridones proceeds effectively, affording pyridone derivatives containing a stereocenter alpha to the nitrogen atom in excellent yields and enantioselectivity (up to 99% yield, 95% ee). This catalytic system broadens the substrate scope of the reaction compared with that of the known catalytic systems. This reaction can also be conducted on a gram scale, further enhancing its potential for synthetic application.

Organofluorine compounds have attracted substantial interest in life and materials sciences due to the unique properties of fluorine atom(s) that often change the physicochemical and biological properties of organic molecules. Transition-metal-mediated cross-electrophile coupling between carbon electrophiles and fluoroalkyl electrophiles has emerged as a straightforward and efficient route for the synthesis of a wide range of fluoroalkylated compounds because of its synthetic convenience without the tedious synthesis of organometallic reagents. Moreover, alkenes or alkynes-involved three-component cross-electrophile couplings provide rapid and effective access to carbonfunctionalized fluoroalkylated alkanes and alkenes. Herein, we comprehensively summarize the transition-metal-mediated reductive fluoroalkylation of diverse carbon electrophiles through a historical perspective, including trifluoromethylation, difluoroalkylation, monofluoroalkylation, and so on. Different transition metals (Cu, Ni, etc.) and strategies are discussed, in which nickel-catalyzed reductive fluoroalkylation reactions represent an attractive and efficient synthetic route to site-selectively access organofluorine compounds.Key ScientistsAs early as 1965, McLoughlin and Thrower finished the first stoichiometric copper-mediated fluoroalkylation of aromatic iodides with fluoroalkyl iodides. However, excess aromatic iodides and elevated temperature were used for this method. In 1969, Kobayashi and Kumadaki reported studies on the copper-mediated trifluoromethylation of aromatic halides with excess trifluoromethyl iodide. After more than four decades, the Zhang group developed a nickel-catalyzed beta-fluorinated alkylation of (hetero)aryl iodides with fluoroalkylated secondary alkyl bromides in 2015, and a nickel-catalyzed difluoromethylation of (hetero)aryl chlorides with chlorodifluoromethane ClCF2H in 2017. The Zhang group also developed enantioselective nickel-catalyzed reductive alkyl-arylation of 3,3,3-trifluoropropene with (hetero)aryl and tertiary alkyl iodides. In 2018, the MacMillan group developed a novel copper/photoredox dual catalytic system for the trifluoromethylation of aryl bromides or alkyl bromides with (S)-(trifluoromethyl) dimesitylsulfonium triflate in the presence of tris-(trimethylsilyl) silanol. They also developed a nickel/photoredox catalyzed difluoromethylation of aryl bromides in the presence of silane. During this time, the Wang group reported a nickel-catalyzed monofluoroalkylation of aryl halides with monofluoroalkyl halides. From 2021 to 2023, the same group further developed a series of enantioselective nickel-catalyzed trifluoroalkylation of aryl, alkenyl, and acyl halides. Moreover, nonfluorinated alkenes or alkynes could also be used in three-component cross-electrophile couplings. In 2018, the Chu group reported a nickel-catalyzed fluoroalkyl-acylation of alkenes with acyl chlorides and fluoroalkyl iodides. Later, they developed a nickel-catalyzed enantioselective fluoroalkyl-arylation of unactivated alkenes tethering with a pendant chelating group. In 2019, the Cha & lstrok;adaj group reported a palladium-catalyzed reductive perfluoroalkyl-arylation of alkynes with perfluoroalkyl and aryl iodides. Transition-metal-mediated cross-electrophile coupling between carbon electrophiles and fluoroalkyl electrophiles has emerged as a straightforward and efficient route for the synthesis of a wide range of fluoroalkylated compounds. Moreover, alkenes or alkynes-involved three-component cross-electrophile couplings provide rapid and effective access to carbonfunctionalized fluoroalkylated alkanes and alkenes. image

Quinolines and their derivatives bearing fluorine-containing substituents are essential structural motifs found in numerous bioactive compounds and advanced functional materials. Therefore, there is an urgent need to develop new synthetic methods for fluoroalkylated quinoline derivatives. In this study, we present a facile and efficient approach to access fluoroalkylated quinoline derivatives by using Eaton's reagent as a cost-effective, and commercially available reagent. This Combes cyclization reaction demonstrated compatibility with various arylamines bearing diverse functional groups, resulting in the synthesis of 2,4-bis(trifluoromethyl)quinolines and 2,4-bis(difluoromethyl)quinolines in moderate to high yields. Furthermore, this reaction can be conveniently carried out in a solvent-free one-pot protocol.

Introducing polar functional groups into polyolefin chains through polar olefin monomer coordination (co)polymerization can directly and significantly improve the surface properties of polymer materials and expand their application range. Therefore, the related research has always received considerable attention from both academia and industry. Many experimental studies have been reported in this field, and molecular metal complexes have shown high catalytic activity and selectivity in polar olefin monomer polymerizations. Although considerable DFT calculations have also been conducted for better understanding of the (co)polymerization performance, the factors governing the activity, selectivity, and molecular weight of resulting polymers are still ambiguous. This review mainly focuses on the DFT studies of polar olefin monomer coordination (co)polymerization catalyzed by molecular metal complexes in recent years, discussing the chain initiation and propagation, the origin of polymerization activity and selectivity, and the specific role of additives in the (co)polymerization reactions.

The invention of a photocatalyst that can efficiently and stably manufacture H2O2 using only water, oxygen, and solar light as starting materials is a dream for the sustainable H2O2 industry and our human society. Although donor-acceptor (D-A) conjugated polymers have been well documented in the design of such photocatalysts, less attention has been paid to the optimization of the lengths of D and A moieties in the structure. Herein, a series of D-A conjugated microporous polymers named P(TPP-DBTSOx) by adopting tetraphenyl porphyrin (TPP) units as four-branched and donor moiety while oligomeric dibenzo[b,d]thiophene sulfone (DBTSO) segments with variable lengths (x = 1, 5, 50, and 200) as linear arms and acceptor moiety as well as the DBTSO homopolymer (PDBTSO) were synthesized and studied. It has been found that all these polymers can be used as photocatalysts for nonsacrificial light-driven H2O2 production from water and oxygen, but with the performance highly depending on their polymeric degrees of the (DBTSO)(x) segments. Among the families, P(TPP-DBTSO50) behaved the best and delivered the largest photocatalytic H2O2 production rate of 1064 mu mol g(-1) h(-1) under visible-light irradiation. However, when reusability and stability were concerned, P(TPP-DBTSO50) was found inferior to P(TPP-DBTSO1), the conventional D-A alternative copolymer. In the work, the great impact of the polymeric degree of the (DBTSO)(x) segments on the polymer photophysical properties, band alignments, charge carrier production and transport, and photocatalytic performance was studied and discussed in detail.

The development of a reversal agent that can rapidly reverse clinically used nondepolarizing neuromuscular blocking agents (NMBAs) has long been a challenge. Here, we report the synthesis of a series of highly water-soluble acyclic cucurbit[n]urils (acCBs). Systematic structure-activity relationship studies reveal that introducing two propylidene units on the peripheral benzene rings not only remarkably improves the activity of the corresponding derivative acCB6 (FY 3451) in reversing the neuromuscular block of rocuronium, cisatracurium, vecuronium, and pancuronium, the four clinically used NMBAs, through stable inclusion, but also allows for high water-solubility as well as a maximum tolerated dose (2000 mg/kg on rats). In vivo experiments with rats show that, at the identical dose of 25 mg/kg, for rocuronium, vecuronium, and pancuronium, acCB6 can achieve a recovery time shorter than that of sugammadex for rocuronium and, at the dose of 100 mg/kg, realize comparably rapid reversal for cisatracurium.

The development of facile, efficient and versatile approaches for preparing pi-conjugated-polymer-based nanofibers (CPNFs) with controlled length, composition and surface chemistry is of paramount importance due to the promising applications of CPNFs in fields ranging from electronics to nanomedicine. In this article, we report the generation of uniform CPNFs consisting of a pi-conjugated oligo(p-phenylenevinylene) (OPV5) core and coronas of diverse properties with controllable length by the combination of activated-ester/amine chemistry and a self-seeding approach of living crystallization-driven self-assembly (CDSA). Poly(pentafluorophenyl methacrylate) (PPFMA) is used as a versatile precursor to efficiently prepare diverse corona-forming segments by click-type activated-ester/amine chemistry. Subsequently, amine-based 18-crown-ether-6 (18C6) and dimethylamino (DMA) groups used as model functional moieties were treated with the pentafluorophenyl esters of PPFMA, followed by coupling with OPV5 to afford OPV5-containing BCPs with varying corona-forming segments. By the self-seeding approach of living CDSA, uniform fiber-like micelles with either 18C6- or DMA-based coronas with controlled length can be obtained. The 18C6 and DMA units enable the installation of diverse functional units, such as metal ions, metal clusters, metal nanoparticles, chiral amines and porphyrins. This work presents a facile and versatile platform to generate uniform CPNFs with controlled length and varying functionalities. A versatile and facile platform is developed for the generation of uniform pi-conjugated nanofibers with controlled length and varying shells by the combination of pentafluorophenyl ester chemistry and a self-seeding strategy.

The amyloid fibrils of alpha-synuclein (alpha-syn) are crucial in the pathology of Parkinson's disease (PD), with the intrinsically disordered region (IDR) of its C-terminal playing a key role in interacting with receptors like LAG3 and RAGE, facilitating pathological neuronal spread and inflammation. In this study, we identified Givinostat (GS) as an effective inhibitor that disrupts the interaction of alpha-syn fibrils with receptors such as LAG3 and RAGE through high-throughput screening. By exploring the structure-activity relationship and optimizing GS, we developed several lead compounds, including GSD-16-24. Utilizing solution-state and solid-state NMR, along with cryo-EM techniques, we demonstrated that GSD-16-24 binds directly to the C-terminal IDR of alpha-syn monomer and fibril, preventing the fibril from binding to the receptors. Furthermore, GSD-16-24 significantly inhibits the association of alpha-syn fibrils with membrane receptors, thereby reducing neuronal propagation and pro-inflammatory effects of alpha-syn fibrils. Our findings introduce a novel approach to mitigate the pathological effects of alpha-syn fibrils by targeting their IDR with small molecules, offering potential leads for the development of clinical drugs to treat PD.