Search

Herein, we present a highly efficient copper-catalyzed protocol for transforming propargyl gem-dichlorides into the corresponding chloro-substituted fluoroalkylated allenes. This protocol demonstrates a broad substrate scope and excellent tolerance towards various functional groups. Moreover, the strategy of utilizing the chloro-substituted pentafluoroethylation allenes for multiple transformations has shown significant value in synthetic chemistry. [ABSTRACT FROM AUTHOR]

A metal, ligand and solvent-free three component reaction of 1-aryl-1,3-butadienes, CS2 and amine has been developed. In this process, readily available CS2 and secondary amines were used for C-N and C-S bonds giving allyl dithiocarbamates with notable Markovnikov selectivity, mild reaction conditions, simple operation and compatibility with various functional groups (37 examples). This is first case of dithiocarbamic acid addition to an unsymmetrical 1,3-diene system. [ABSTRACT FROM AUTHOR]

Biofouling is a key process affecting the biocompatibility of biomaterial surfaces such as polyvinyl chloride (PVC). Investigating the physicochemical aspects of this process requires delving into the amino acid level to identify the interactions between proteins and biomaterials. In this computational study, we performed triplicate 50 ns molecular dynamics (MD) simulations along with potential of mean force (PMF) calculations to investigate the adsorption of the 20 standard amino acids on a PVC surface (171 chains, 35-mer each) at a constant concentration and neutral pH. Simulation results show that among the 20 amino acids, tryptophan exhibits the strongest affinity for PVC in terms of adsorption amount and interaction energy (−18.6 kJ mol−1). Moreover, hydrophobic interactions are the main driving force for the adsorption of amino acids onto the PVC surface, and there is a linear correlation between volume and adsorption energetics in each group of amino acids. Valine was the only exception to this trend; however, the increased energy value of valine within its class (−12.8 kJ mol−1) can be explained by its higher polarity. We further analyzed the correlation between intrinsic properties and the chemical nature of amino acids and their respective adsorption energetics. By performing structure–activity relationships, we identified the importance of hydrophobicity, aromaticity, size, and specific functional groups in their adsorption affinity towards PVC surfaces. We also identified the specific parameters contributing to the adsorption behavior of different classes of amino acids. The results of this study have direct implications for biofouling in medical devices, where PVC surfaces are commonly employed. Furthermore, these insights can potentially guide the medical device industry to develop materials with enhanced biocompatibility tailored for specific biomolecular interactions. [ABSTRACT FROM AUTHOR]

A general and practical K2CO3-promoted [3+2] annulation between trifluoroacetaldehyde N-triftosylhydrazone (TFHZ-Tfs) and 4-nitroisoxazoles has been developed to access structurally diverse trifluoromethylpyrazolo[3,4-d]isoxazoles. Mechanistically, CF3CHN2 is formed in situ by TFHZ-Tfs decomposition and involves a formal [3+2] dearomative cycloaddition with 4-nitroisoxazoles, followed by aromatization via the elimination of the nitro group. Furthermore, this protocol is metal-free, scalable, mild, and operationally safe, with a broad substrate scope and high functional group compatibility. [ABSTRACT FROM AUTHOR]

In this study, we present a ligand-free nickel(II)-catalyzed halogen exchange of aromatic halides with magnesium chloride. This method effectively facilitates the retro-Finkelstein reaction for a wide range of aryl bromides, iodides and triflates, demonstrating excellent functional group tolerance. Mechanistic studies reveal that magnesium plays a crucial role in the challenging reductive elimination from Ni(II) intermediates. [ABSTRACT FROM AUTHOR]

Going beyond the conventional approach of pairwise conjugation between two molecules, the integration of multiple components onto a central scaffold molecule is essential for the development of high-performance molecular materials with multifunctionality. This approach also facilitates the creation of functionalized molecular probes applicable in diverse fields ranging from pharmaceuticals to polymeric materials. Among the various click functional groups, the azido group stands out as a representative click functional group due to its steric compactness, high reactivity, handling stability, and easy accessibility in the context of multi-azide scaffolds. However, the azido groups in multi-azide scaffolds have not been well exploited for site-specific use in molecular conjugation. In fact, multi-azide compounds have been well used to conjugate to the same multiple fragments. To circumvent problems of promiscuous and random coupling of multiple different fragments to multiple azido positions, it is imperative to distinguish specific azido positions and use them orthogonally for molecular conjugation. This review outlines methods and strategies to exploit specific azide positions for molecular conjugation in the presence of multiple azido groups. Illustrative examples covering di-, tri- and tetraazide click scaffolds are included. [ABSTRACT FROM AUTHOR]

Carbon-based materials incorporated with oxygen functional groups (OFGs-Gr) exhibit outstanding electrocatalytic performance for hydrogen peroxide (H2O2) production via the two-electron oxygen reduction reaction (2e− ORR). Currently, the nature of the active functional group and the underlying reaction mechanism are still under debate. Herein, we constructed the OFGs-Gr structures and systematically investigated the effect of the aqueous environment (including pH and electrode potential) on the catalyst performance in combination with ab initio molecular dynamics (AIMD). The carboxyl group (COOH-Gr structure) plays a key role in the neutral solution environment. The water molecules on COOH-Gr effectively modified the interaction of the C sites with OOH. The adsorption strength of OOH increases with increasing pH, resulting in an ether group (dopant-Gr in the C–O–C structure), maintaining excellent properties in alkaline media. Furthermore, our calculations demonstrate that the selectivity of H2O2 generation for dopant-Gr is increased by an elevated electrode potential, while the selectivity for COOH-Gr is decreased. These findings provide a dynamic perspective that elucidates that both pH and electrode potential synergistically influence the catalytic properties for H2O2 synthesis. [ABSTRACT FROM AUTHOR]

Wound healing potential is initially evaluated using a chorioallantoic membrane (CAM) assay. Alginate gel containing pristine and polymer-coated magnesium hydroxide nanoparticles (MHNPs) improves the healing response. PEGylated MHNPs have shown a rapid wound-healing process in Gallus gallus domesticus by promoting re-epithelialization as compared to pristine MHNPs. No toxicity or inflammation are observed in the blood, liver, and heart tissues during biochemistry and histopathological examination. Polymer (polyethylene glycol (PEG) and chitosan) functionalized MHNPs are synthesized using a one-step hydrothermal process. The average crystallite size determined from X-ray diffraction analysis of the pristine MHNPs is ∼31.3 nm and upon PEG and chitosan coating it reduces to 23.4 nm and 29.7 nm, respectively. FTIR confirms the presence of functional groups indicating the successful functionalization of the polymers. [ABSTRACT FROM AUTHOR]

Photoredox-catalyzed cross-coupling reaction is an efficient strategy for the construction of organic molecules. Herein, we developed a method to synthesize α-arylthioanisoles by constructing C–S bonds in the presence of a Ru-photoredox catalyst. Thus, a series of α-arylthioanisole compounds were efficiently obtained through decarboxylative cross-coupling under mild conditions. This protocol features high efficiency, broad substrate scope and good functional group tolerance. [ABSTRACT FROM AUTHOR]

Herein, we report a photoinduced 1,7-hydrosulfonylation of allylic ethers and amides via a sequential Pd-mediated 1,5-HAT process and Pd-catalyzed allylic nucleophilic attack of arylsulfonates. This rationally designed synthetic protocol allows for facile construction of a series of structurally novel allylic sulfonated scaffolds, and features mild conditions, cheap and readily available raw materials and functional group compatibility. [ABSTRACT FROM AUTHOR]

Copper(I)-catalyzed (4+3)-cycloaddition of 4-indolylcarbinols with aziridines has been accomplished to furnish azepinoindoles. The chirality transfer, substrate scope, functional group tolerance, natural product modification and tandem C–C/C–N bond formation are the important practical features. [ABSTRACT FROM AUTHOR]

A general protocol for regioselective electrochemical [2 + 2] cyclization of N-acyl indoles with alkynes was described. This novel method was carried out under mild, chemical oxidant-free, and transition-metal-free conditions, with a broad substrate scope and good functional group tolerance to provide cyclobutene-fused indolines with high regioisomeric ratios and was readily scalable to the gram scale. Mechanistic studies have suggested that the selective reduction of radical cations at the cathode to form a double radical intermediate is the key step in the reaction. [ABSTRACT FROM AUTHOR]

Catalytic multicomponent reactions offer an efficient synthetic approach for constructing multiple chemical bonds in a single step. However, the carboamination of unactivated alkenes, involving nitrogen radical species directly from N–H precursors, is infrequent due to the high bond energy and challenges in step matching. Herein we demonstrate a catalytic radical three-component reaction using simple primary sulfonamides, which provides a novel method for constructing a library of complex architectures through carbon–nitrogen and carbon–carbon bond formation. The newly developed method demonstrates a high degree of tolerance towards various functional groups, proving to be highly efficient in the late-stage modification of complex drug molecules and natural products under very mild conditions. [ABSTRACT FROM AUTHOR]

The green synthesis of medicines with an indazole skeleton has gained significant attention in recent years. Sustainable and environmentally friendly approaches for the synthesis of this important class of heterocyclic compounds from azobenzenes are attractive but rare. In this work, a series of neat, fast, and efficient reactions are well developed as a notable methodology for the photo-organic synthesis of indazoles. Metal and hydrogen source-free direct deoxygenative cyclization of o-carbonyl azobenzene under visible light is achieved through a new mechanism with huge potential in reduction cyclization reactions. Most examples are shown to give the corresponding 2H-indazole products in excellent yields, demonstrating that the present reaction has a wide substrate scope and good functional group tolerance. [ABSTRACT FROM AUTHOR]

Urea is a non-toxic, harmless, and abundant bulk organic chemical featuring high nitrogen content. Therefore, urea could be a prime green candidate for introducing nitrogen atoms into organic molecules. In this regard, urea in organic synthesis has been mainly employed as building block, component of solvent systems, catalyst, or for pH adjustment, while uses of urea as NH3-source towards the construction of small organic compounds are scarce. Here, nothing but high-temperature water (HTW) is employed to conduct the aquathermolysis of urea, generating NH3 to propel the Debus–Radzsisweski multicomponent reaction (MCR) towards imidazoles. The approach does neither require additional catalysts nor reaction auxiliaries or volatile organic compounds as solvent. Urea was used as N-source in combination with different 1,2-diketones and aldehydes featuring a variety of functional groups towards 23 lophine analogues (190 °C, 1–3 hours). Moreover, the presented synthesis performs equally or better than classical syntheses when acid-sensitive substrates are employed. The greenness of the synthesis using urea in HTW was assessed through green metrics and compared with syntheses reported in the literature in a large-scale fashion. Overall, the reported syntheses feature E-factor and process mass intensity values in ranges comparable to those of syntheses reported in literature. [ABSTRACT FROM AUTHOR]

Planar PV- or PIII-bridged bis(NHCs), which have only been employed in transition metal complex chemistry so far, were subjected to BCl3-containing solutions targeting the corresponding bis(NHC) BCl3 adducts. While the P(O)NEt2-bridged bis(NHC) showed the expected adduct formation, the PNEt2-bridged bis(NHC) reacted not only at the carbene moiety but also at the P-NEt2 functional group. The latter enabled access to the first 1,4-diphosphinine bis(NHC) main group adduct; its formation and properties were investigated by DFT calculations. Through the same route, a 1,4-diphosphinine bis(imidazolium) scaffold was generated and explored theoretically and experimentally. The new 1,4-diphosphinines are shown to possess high global aromaticity and a unique P-centred reactivity, allowing the formation of hitherto inaccessible [4 + 2]-cycloaddition products, thus suggesting potential new applications compared to previously known 1,4-diphosphinine derivatives. [ABSTRACT FROM AUTHOR]

Complex 1 [(C^C)Au(dppv)]PF6 (dppv = cis-1,2-diphenylphosphinoethylene) is reported to react efficiently and selectively with aliphatic and aromatic thiols in the presence of a base. This methodology enables the smooth introduction of various functional groups on the [(C^C)Au(P^P)]+ scaffold. [ABSTRACT FROM AUTHOR]

Protein-based adhesives have attracted substantial consideration due to their environmentally friendly advantages and the abundance of functional groups they possess. However, these adhesives suffered from poor properties, including poor bonding strength, low stability, and limited resistance to mildew, which hindered their widespread application in the wood processing sector. In this study, a straightforward and practical strategy for preparing keratin-based wood adhesives was presented. By incorporating hydrogen peroxide, the performance of the fabricated adhesives was significantly reinforced. The adhesion forces between wood substrates reached up to approximately 2.4 and 1.3 MPa under dry and wet conditions, respectively. All components used in the adhesive were derived from biomass and low cost. Furthermore, this keratin-based adhesive demonstrated excellent mildew resistance and bactericidal properties compared to other modified protein adhesives. Therefore, this study proposed an eco-friendly and effective approach to developing high-performance, multifunctional, and fully biobased protein adhesives. [ABSTRACT FROM AUTHOR]

Considerable interest in designing multi-responsive soft materials for diverse applications is leading to the development of systems that are embedded with functional groups with stimuli-responsive characters. Surface-active ionic liquids (SAILs) with an ability to form various structural aggregates represent an interesting candidate for designing soft materials with stimuli-responsive characters. Embedding photo-responsive moieties into SAILs with existing pH-responsive properties can unlock a broader range of potential uses. Herein, we prepared photo- and pH-responsive catanionic giant vesicles (GVs) through a synergetic interaction between the pH-responsive choline oleate ([Ch][Ol]) and photo-responsive (4-methyl-4-(2-(octyloxy)-2-oxoethyl)) morpholin-4-ium(E)-4-((4-(dimethylamino) phenyl) diazinyl) benzenesulfonate ([C8EMorph][MO]). The photo-responsiveness in the GVs was introduced through [C8EMorph][MO], which shows E–Z isomerisation under 460 nm light irradiation, whereas the pH-responsive character was obtained through [Ch][Ol]. We used absorbance measurements complimented with a computational study to characterize the photo-responsive behaviour. Irradiating the GVs with light of suitable wavelength and changing the pH of the system altered the behaviour of the aggregates. Small-angle neutron scattering (SANS) analysis showed that, before irradiation, the size of the bilayer thickness of the GVs was 28 Å and after irradiation it was increased to 31 Å, leading to an increment in the overall size of the GVs. This was due to the formation of Z-[C8EMorph][MO] after irradiation, which leads to a slight alteration in the interactions between both SAILs. Moreover, the change in pH of the vesicles caused alterations in the size and shape of the vesicles, as confirmed through the SANS analysis. The stability of the GVs in terms of temperature, dilution, and time was analysed to characterise the GVs for practical applications. The insights gained from this study could be valuable for developing materials for these applications such as probes, cargo carriers, and microreactors in future. [ABSTRACT FROM AUTHOR]

Since their inception in 2011, MXenes have evolved into avant-garde nanomaterials renowned for their high specific surface area and abundant functional groups. Their unique attributes make them well-fitted for use as adsorbents in remedying water contaminants. This study examined Ti3C2 MXene as an adsorbent, investigating its adsorption performance and the mechanisms involved in its interaction with sulfachloropyridazine (SCP) antibiotics. Characterization results from SEM, TEM, XRD confirmed the typical Ti3C2 MXene structure as an accordion-like multilayer morphology and well-defined crystalline structure. Adsorption kinetics, isotherms, and thermodynamic experiments were also conducted; the outcomes affirm the spontaneous and endothermic attributes of the adsorption, with a noted maximum adsorption capacity of 22.62 mg g−1 for SCP in an aqueous medium. Moreover, characterization (SEM, TEM, FTIR and XPS) and experiment results indicated that the adsorption mechanisms of SCP on Ti3C2 MXene can be primarily attributed to chemical adsorption based on functional groups and defects of adsorbents. It also effectively removes SCP from actual aquaculture wastewater. These results highlight the extensive potential of MXenes in addressing the remediation of sulfonamide antibiotics from water environments, signaling a broad and favorable application outlook. [ABSTRACT FROM AUTHOR]

Harnessing solar energy through photocatalysis has excellent potential for powering sustainable chemical production, supporting the United Nations' environmental goals. Single-atoms (SAs) dispersed on catalyst surfaces are gaining attention for their highly active and durable nature. Metal–organic frameworks (MOFs) can provide enough reactive sites to sustain selectivity and durability over time because of their tunable channels and functional groups. Owing to their organized structures, MOFs are ideal platforms for securing individual atoms and promoting solar-driven reactions. Few reviews have, however, reflected the possibility of combining MOFs and SAs to produce potent photocatalysts that may produce clean fuels and valuable chemicals. This review provides a general overview of methods for combining MOFs and SAs to generate photocatalysts. The challenges associated with these MOF-based single-atom systems are also critically examined. Their future development is discussed as continued refinement helps to more fully leverage their advantages for boosting photocatalytic performances – turning sunlight into chemicals in a manner that supports sustainable development. Insights gained here could illuminate pathways toward realizing the profound potential of MOF-based single-atom photocatalysts to empower production driven by renewable solar energy. [ABSTRACT FROM AUTHOR]

3-Acyl indoles play important roles in both organic synthesis and diverse types of functional molecules. Herein, a facile nitrogen heterocyclic carbene (NHC) and photocatalyst cooperatively-catalyzed 3-acylation of indoles was disclosed. The reaction proceeded via radical cross-coupling of indole-based aryl radical cations with NHC-bound ketyl radical species, which are less explored in radical NHC catalysis. The reaction exhibits mild reaction conditions, broad substrate scope, and good functional group tolerance. Mechanistic studies support our proposed reaction pathway. The synthesis of structurally diverse analogs of an aldose reductase inhibitor and antibacterial activity investigation further demonstrated the utility of the current acylation reaction. [ABSTRACT FROM AUTHOR]

We report herein the acid-catalyzed regioselective remote heteroarylation and reductive alkylation of alkenes. Various alkenes, including mono-, di-, and tri-substituted alkenes and cyclic alkenes, are applicable to this reaction. This method exhibits broad substrate scope, high functional group tolerance and high atomic economy. In addition, both gram-scale synthesis and product transformations demonstrate the potential utility of this reaction. It also provides an efficient and novel pathway to establish the valuable framework of 1,1-diaryl alkanes. Further mechanistic studies suggested that TfOH in situ generated by Cu(OTf)2 and trace H2O catalyzed the alkene migration. Then, heteroarylation was conducted by Friedel–Crafts type alkylation. [ABSTRACT FROM AUTHOR]

Highly complex fused systems are widely present in drug development. The direct electrosynthesis of fused systems through radical domino reactions features higher atom and step economy, using abundantly available starting materials and avoiding exogenous oxidants and reductants, and thus it has been in high demand and recognized as a green, powerful, and versatile synthetic tool but remains challenging because of the instability of the radical species under the electrolysis conditions and the inclusion of a quaternary ammonium salt. Herein, we developed a de novo electrosynthesis of 6-6-5 fused systems with two new rings constructed using a user-friendly undivided cell through decarboxylation and three-step radical addition under exogenous oxidant and quaternary ammonium salt free conditions. Excellent functional group, water and air compatibility was observed with good yields obtained. [ABSTRACT FROM AUTHOR]

The selective and controllable functionalization of unreactive C(sp3)–H bonds under mild conditions is a highly desirable yet challenging goal in both organic synthesis and pharmaceutical industry. Herein, we report an unprecedented visible-light mediated metal- and oxidant-free carbonylation of both benzylic and allylic C–H bonds with H2O. The synergistic combination of an organophotocatalyst 4CzIPN and a thiol enables the transformation of diverse arrays of benzylic and allylic C–H bonds into carbonyls in moderate to excellent yields with good functional group compatibility. Moreover, the oxidation of amines to aldehydes has also been realized by this protocol. Mechanistically, an oxidative radical-polar crossover (ORPC) process affords an alcohol intermediate, which then undergoes another ORPC process to furnish the carbonyl product. [ABSTRACT FROM AUTHOR]

Since the dawn of organometallic chemistry, transition metal complexes of unsaturated organic molecules, namely π-complexes, have remained a central focus: our thorough understanding of the electronic nature of such species, and their importance in countless reactive processes continues to drive research in their synthesis and utilisation. Since the late 1900s, research regarding the related chemistry for the heavier group 14 elements has become increasingly more fervent. Today, heavier congeners of a vast array of classical π-complexes have been realised, from alkene to arene systems, involving Si, Ge, Sn, and Pb. This has given deeper insights into the bonding observed for these heavier elements, which typically involves a lessened degree of π-bonding and an increased polarisation. This review aims to summarise this field, identifying these disparities, and highlighting areas which we believe may be exciting for future exploration. [ABSTRACT FROM AUTHOR]

Differentiating between two highly similar C–H bonds in a given molecule remains a fundamental challenge in synthetic organic chemistry. Directing group assisted strategies for the functionalisation of proximal C–H bonds has been known for the last few decades. However, distal C–H bond functionalisation is strenuous and requires distinctly specialised techniques. In this review, we summarise the advancement in Pd-catalysed distal C(sp2)–H and C(sp3)–H bond activation through various redox manifolds including Pd(0)/Pd(II), Pd(II)/Pd(IV) and Pd(II)/Pd(0). Distal C–H functionalisation, where a Pd-catalyst is directly involved in the C–H activation step, either through assistance of an external directing group or directed by an inherent functionality or functional group incorporated at the site of the Pd–C bond is covered. The purpose of this review is to portray the current state of art in Pd-catalysed distal C(sp2)–H and C(sp3)–H functionalisation reactions, their mechanism and application in the late-stage functionalisation of medicinal compounds along with highlighting its limitations, thus leaving the field open for further synthetic adjustment. [ABSTRACT FROM AUTHOR]

An asymmetric strategy is a constructive means to regulate the energy and properties of energetic materials. In this work, a series of asymmetric energetic compounds based on bi(1,2,4-triazole) were designed and synthesized, and the related structural features and performances were systematically investigated by NMR spectroscopy, FT-IR spectroscopy, MS, EA, and DSC for their impact on asymmetric functional groups. Among them, a single trinitromethyl group-modified energetic compound termed "TNBN" was confirmed by X-ray single-crystal diffraction analysis. Benefiting from the asymmetric trinitromethyl groups, the structure of TNBN showed a unique stacking pattern, and exhibited good detonation performance (8787 m s−1 and 31.1 GPa) and acceptable insensitivity to mechanical stimuli (IS = 30 J and FS = 288 N) compared with its similar symmetric counterparts. This work aids understanding of the structure–performance relationship of asymmetric energetic compounds and demonstrates that appropriate modulation of the asymmetric trinitromethyl group is an effective approach to achieve high-energy insensitive energetic materials. [ABSTRACT FROM AUTHOR]

A photocatalytic trifluoromethylation/cyclization reaction of N-allyl and N-homoallyl aldehyde hydrazones with trifluoromethyl thianthrenium triflate was developed for the synthesis of trifluoromethylated dihydropyrazoles and tetrahydropyridazines. Besides, PhI(O2CCHF2)2 was employed to realize the construction of difluoromethylated dihydropyrazoles and tetrahydropyridazines. These protocols exhibit a broad substrate scope and good functional group tolerance. [ABSTRACT FROM AUTHOR]

We describe the transition-metal-free coupling for polyfluoroalkoxy arenes using polyfluoroalkoxy borates, which serve as counterions to diaryliodonium salts and transferring mediators of polyfluoroalkoxy groups. This strategy demonstrates high functional group compatibility owing to the low nucleophilicity of the borate mediator, thus offering a practical approach for synthesizing diverse polyfluoroalkoxy arenes. [ABSTRACT FROM AUTHOR]

Oxidized carbon materials have abundant surface functional groups and customizable properties, making them an excellent platform for generating radicals. Unlike reactive oxygen species such as hydroxide or superoxide radicals that have been reported previously, oxidized carbon also produces stable carbon radicals under photo-irradiation. This has been confirmed through electron spin resonance. Among the various oxidized carbon materials synthesized, graphene oxide shows the largest number of carbon radicals when exposed to blue LED light. The light absorption capacity, high surface area, and unique structural characteristics of oxidized carbon materials offer a unique function for radical-mediated oxidative reactions. [ABSTRACT FROM AUTHOR]

The core skeleton syntheses of 3′H-spiro[cyclohexane-1,1′-isobenzofuran]-2,5-dien-4-one, and their derivatives (3a–3w) of spirobisnaphthalene urnucratins, plecmillins, and lignan kadsulignan, were explored using Suzuki–Miyaura coupling product biphenols as the precursors and intramolecular oxidative dearomatization with high-valence iodine reagent PIFA as the key step in 46–91% yields. A wide range of functional groups were tolerated. Then, using this strategy in combination with the Diels–Alder reaction, two skeleton molecules (5ah and 6d) of the natural products urnucratins and plecmillins were successfully constructed in 78% and 39% overall yields, which provides a potential methodology for the total synthesis of Type D spirobisnaphthalene urnucratins and other natural products with similar structures. [ABSTRACT FROM AUTHOR]

The π-conjugated rigid molecule Bph is a candidate for use as a channel system of single-molecule transistors. In this first-principles study, the practicality of the chemical modification of the channel molecule Bph for enhancing stability and improving performance is discussed. The insertion of methylene groups into the edges of a channel is suggested to enhance the stability of the cross-linking structures between electrodes because of the relaxation of S bonds. The calculation of electronic states and transmission indicates the sufficient on current of the methylene-inserted Bph derivative (Bph–CH2) in transistors through resonant tunneling. These results suggest the practicality of inserting methylene groups as a method of modifying channel molecules for achieving high stability and large on currents to realize single-molecule transistors. [ABSTRACT FROM AUTHOR]

Herein, we disclose the first reports on the utilization of vinylene carbonate as a C1 methylene source in ruthenium-catalyzed additive controlled regioselective C4-methylenation and weak chelation-assisted C8-formylmethylation of isoquinolinones. Adopting vinylene carbonate as both a C2 and C1 synthon is an important highlight of this work. Amide carbonyl acts as the traceless directing group in C8-formylmethylation. Remarkably, in this reaction, two C–C bonds form in one-pot producing dimeric isoquinolinones by employing vinylene carbonate as a methylene surrogate in the presence of copper acetate as an additive. Importantly, unsymmetrical dimers were achievable, albeit in low yield. Extensive control experiments are conducted to decipher the reaction mechanism. It is evident from the mechanistic studies, that the formation of a formylmethyl group in situ at the C4-carbon undergoes dimerization, oxidation and subsequent decarboxylation to produce methylene-bridged isoquinolinone dimers. This protocol is scalable and compatible with a repertoire of substrates and shows high functional group tolerance. Harnessing vinylene carbonate as both a C2 and C1 synthon is an important highlight of this work. [ABSTRACT FROM AUTHOR]

Functionalization of surface-grown coordination polymer layers by ion soft-landing of highly reactive molecular fragment ions is demonstrated. The ions form covalent bonds to terminal functional groups of the polymer at the vacuum interface, opening new perspectives for controlled bond formation using reactive ions. [ABSTRACT FROM AUTHOR]

The γ C-H amination of carboxylic acid presents a promising and sustainable strategy for synthesizing high-value pharmaceutical chemicals. Radical reaction pathways initiated by aroyloxy radical-involved hydrogen atom transfer (HAT) provide diverse but challenging opportunities for remote C-H functionalization. In this report, the first example of intramolecular γ C-H amination of carboxylic acids using a commercially available oxime auxiliary has been achieved. This innovative approach employs a radical relay chaperone, facilitating selective C-H functionalization via 1,5-HAT/radical cross-coupling and enabling the net incorporation of ammonia at the γ carbon of carboxylic acids. In addition, this protocol enables the recycling of the by-product benzophenone, and both product isolation and by-product recycling are silica gel-free. The reactions offer high chemo- and regio-selectivities, operate under mild reaction conditions, boast a broad substrate scope, exhibit good functional group compatibility, and are easily scalable. [ABSTRACT FROM AUTHOR]

1,3-Difunctionalization of alkenes, as a novel route for the modern development of alkene transformations, has drawn significant research attention in recent years. Herein, we disclose a novel cobalt-catalyzed radical 1,3-diphosphination of alkenes, which enables straightforward access to 1,3-diphosphine skeleton compounds under mild conditions without additional oxidants and photosensitizers. This transformation features excellent functional group tolerance, operational simplicity, and high atom economy, and is amenable for late-stage functionalization of complex molecule skeletons. Preliminary bioactivity studies reveal that these valuable 1,3-diphosphine products show potential antitumor activity. [ABSTRACT FROM AUTHOR]

This study explores the impact of organic cations in bismuth iodide complexes on their memristive behavior in metal-insulator-metal (MIM) type thin-layer devices. The presence of electron-donating and electron withdrawing functional groups (-CN, -CH3, -NH2, and -N(CH3)2) on pyridinium cations induces morphological alterations in crystals, thus influencing the electronic or ionic conductivity of devices comprising sandwiched thin layers (thickness = 200 nm ± 50) between glass/ITO as bottom electrode (~110 nm) and copper (~80 nm) as the top electrode. It was found that the current-voltage (I-V) scans of the devices reveal characteristic pinched hysteresis loops, a distinct signature of memristors. The working voltage windows are significantly influenced by both the types of cation and the dimensionality of ionic fragments (0D or 1D) in the solid-state form. Additionally, the temperature alters the surface area of the I-V loops by affecting resistive switching mechanisms, corresponding log-log plots at three temperatures (-30 °C, room temperature and 150 °C) are fully studied. Given that a memristor can operate as a single synapse without the need for programming, aligning with the requirements of neuromorphic computing, the study investigates long-term depression, potentiation, and spike-time-dependent plasticity-a specific form of the Hebbian learning rule-to mimic biologically synaptic plasticity. Different polar pulses, such as triangle, sawtooth, and square waveforms were employed to generate Hebbian learning rules. The research demonstrates how the shape of the applied pulse series, achieved by overlapping pre- and postpulses at different time scales, in association with the composition and dimensionality of ionic fragments, lead to changes in the synaptic weight percentages of the devices. [ABSTRACT FROM AUTHOR]

The crystal structure and electrocatalytic performance of Ni-based MOFs were controlled by the symmetrical engineering of Br functional groups on the terephthalic acid ligand. The asymmetric coordination between metal active sites and the ligand makes Ni-DBC-1Br an excellent OER electrocatalyst with a significantly lower overpotential (247 mV) accompanied by a low Tafel slope of 58.1 mV dec−1 in 1 M KOH (pH = 13.88). [ABSTRACT FROM AUTHOR]

We have accomplished a unified strategy to achieve the structurally intriguing indolosesquiterpene alkaloids with diverse biological activity, xiamycin A (1a), xiamycin A methyl ester (1b) and oridamycins A (2a), and B (2b), which possesses a complex 6/6/6/5/6-fused pentacyclic skeleton bearing a carbazole moiety fused with a highly functionalized trans-decalin motif. Lewis acid-mediated epoxy-ene cyclization establishes the required pentacyclic scaffold with the installation of the four contiguous stereogenic centers. Further oxidative cleavage of the vinyl functionality, followed by successive functional group interconversions, completed the total synthesis of the indolosesquiterpene alkaloids. [ABSTRACT FROM AUTHOR]

The functionalization of α-C(sp3)–H bonds in amines has become a focal point of contemporary research. Here, we report a new approach utilizing photocatalysis α-C(sp3)–H bond functionalization in alicyclic and aliphatic secondary amines facilitated by intramolecular 1,5-hydrogen atom transfer (HAT). This finding unlocks a sustainable method for rapidly constructing complex heterocyclics via cross-dehydrogenative C–C coupling of protected amines and nitrogen-containing heterocycles. This protocol boasts broad applicability to various substrates, exhibits tolerance to numerous functional groups, and supports the late-stage modification of drug molecules. [ABSTRACT FROM AUTHOR]

The visible light-promoted O-alkenylation of phenols and naphthols with terminal alkynes is achieved using 2,4,6-tris(4-fluorophenyl)pyrylium tetrafluoroborate (T(p-F)PPT) as a photocatalyst at room temperature without the need of any external ligand or additive. Apart from its excellent functional group tolerance, the protocol described herein represents an appealing alternative strategy to classical transition-metal catalysed hydroarylation reactions. Mechanistic investigations revealed that the reaction involves a radical pathway. The utility of the hydroarylated products for the synthesis of fused benzofurans via a one-pot annulation was also demonstrated. Herein, we report the first intermolecular radical hydroarylation of alkynes. [ABSTRACT FROM AUTHOR]

An efficient iodide ion (I−)-enabled method for direct α-C(sp3)–H triazolization of ethers via a radical cross-coupling has been developed for regioselective construction of N2-substituted hemiaminal ethers. The developed C(sp3)–H triazolization reaction features the resulting products in good yields (up to 90%) and an excellent functional group tolerance to various ethers, including cyclic and linear ethers. Preliminary mechanistic study and DFT calculation investigation indicate that the reaction proceeds via a SN2-like desulfonylation radical coupling process and an (I−)-involved ternary complex is responsible for the high conversion ratio and the high regioselectivity. I− not only promotes the process but also prevents the in situ generated carbon-centered radicals (CCRs) from being oxidized into carbon cations in an oxidative environment. [ABSTRACT FROM AUTHOR]

A metal-free photoinduced alkynylation of carbamoyl radicals with hypervalent iodine(III) reagents for a facile synthesis of alkynyl amides is described. This protocol features good functional group tolerance and a broad substrate scope for direct synthesis of alkynyl amide derivatives in good to excellent yields under mild and redox-neutral reaction conditions. The synthetic application is demonstrated by the late-stage installation of alkynyl amides into natural products and active pharmaceutical relevant molecules. The mechanistic studies indicated the simultaneous existence of photoredox catalytic and direct photoexcited processes, and the quantum yields confirmed the occurrence of the radical chain propagation process. [ABSTRACT FROM AUTHOR]

An unprecedented Pd-catalyzed CO-free double carbonylation using Mo(CO)6 as a safe carbonyl source for the efficient synthesis of 1,4-ketoesters in an atom- and step-economic manner has been developed. The current method features operational safety, a wide substrate range, good functional group compatibility and easy scale-up. The application of carbonylation using a safe carbonyl source for the synthesis of biologically and synthetically useful carbonyl-containing molecules is underway in our lab. [ABSTRACT FROM AUTHOR]

Pyridazine is a significant skeleton that widely exists in drugs and bioactive molecules. We herein describe expeditious approaches to access polysubstituted pyridazines from readily accessible unactivated ketones and acylhydrazones via Cu-promoted C(sp3)–C(sp3) coupling/cyclization sequences in a single-step fashion. Notably, the disparate 3,4,6-trisubstituted pyridazines and 3,5-disubstituted pyridazines could be obtained by tailoring the ketone's structure and reaction conditions. These transformations feature good functional group compatibility, excellent step-economy, and chemoselectivity. The potential synthetic utility of these conversions is illustrated by scale-up reactions and late-stage derivatizations of the as-prepared pyridazine products. [ABSTRACT FROM AUTHOR]

The impact of substituents at the 4- and 7-positions of 1,10-phenanthroline-2,9-dicarboxamides on the photophysical properties of the ligands and their coordination compounds with the lanthanide triad--europium, gadolinium, and terbium--was analyzed. This study demonstrates how modification of the electronic nature of ligands through the incorporation of diverse functional groups affects the luminescence properties of their complexes. The introduction of various substituents leads to the appearance of intra-ligand or ligand-to-ligand charge transfer (CT) states. The highest luminescence efficiency was observed for LH·Eu(NO3)3 (Qin = 54.1% and QL = 9.6%), suggesting strong luminescence quenching of the CT state. It was found that a relatively low ΔE (-3000 cm-1) supports direct energy transfer from S1 to T1 bypassing the CT state, even though it is outside Reinhoudt's optimal range. The introduction of fluorines leads to the strongest luminescence quenching among all the substituents. [ABSTRACT FROM AUTHOR]

Herein, a palladium-catalyzed 1,1-aminoxylation of 3-butenoic acid and 2-alkynylanilines has been developed, achieving the installation of two distinct heteroatom motifs across an olefin skeleton. The strategy features a high step and atom economy and good functional group tolerance, which outlines an efficient approach for simultaneously building up γ-butylactone and indole skeletons. Notably, an external ligand, 2,9-dimethyl-1,10-phenanthroline, has been used to succeed in this protocol to effectively suppress the production of indole byproducts. [ABSTRACT FROM AUTHOR]

A synthetic strategy involving salicylaldehyde, 2-chloroprop-2-ene-1-sulfonyl fluoride (CESF), and pyrrole has been developed to construct novel pyrrole-4H-chromene-embedded vinyl sulfonyl fluoride derivatives with exclusive regioselectivity. This method exhibits moderate to excellent yields (45–93%) and showcases a wide substrate scope with excellent functional group compatibility. Additionally, the resulting sulfonyl fluorides were further diversified via sulfur fluoride exchange (SuFEx) reactions to produce sulfonates and sulfonamides, which are valuable structural motifs in medicinal chemistry. [ABSTRACT FROM AUTHOR]

We disclose herein a metal-free cascade reductive Friedel–Crafts alkylation/cyclization of keto acids/esters for the synthesis of tetralones and indanones. Owing to the simple reaction conditions and setup, this protocol features broad substrate generality, facile scalability, and remarkable functional group tolerance, including the synthesis of bioactive molecule sertraline. [ABSTRACT FROM AUTHOR]