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A carrier-free nanomedicine self-assembled from palbociclib dimers and Ce6 for enhanced combined chemo-photodynamic therapy of breast cancer.

For the heteroleptic Ir(iii) complexes, unveiling the role of ancillary ligands is significant for designing excellent phosphorescent materials.

By means of density functional theory and time-dependent density functional theory, the radiative and non-radiative decay processes of iridium(iii) complexes are investigated to explore the role of N-heterocyclic moieties in chelating ligands.

Naphtho[2,3-b]furan-4,9-dione is an important privileged structural motif which is present in natural products, drugs, and drug candidates. Herein, visible-light-mediated [3+2] cycloaddition reaction for the synthesis of naphtho[2,3-b]furan-4,9-diones and dihydronaphtho[2,3-b]furan-4,9-diones has been developed. Under environmentally friendly conditions, a variety of title compounds were delivered in good yields. This new protocol shows excellent regioselectivity and remarkable functional group tolerance. This approach provides a powerful, green, efficient, and facile means to expand the structural diversity of naphtho[2,3-b]furan-4,9-diones and dihydronaph-tho[2,3-b]furan-4,9-diones as promising scaffolds for novel drug discovery.

Triplet potential energy surfaces, for phosphorescent materials, play a predominant role in determining the radiative and non-radiative decay processes.

Mitochondrial dysfunction is a feature of cancer cells and targeting cancer mitochondria has emerged as a promising anticancer therapy.

Background Enolase 2 (ENO2) is a crucial glycolytic enzyme in cancer metabolic process and acts as a “moonlighting” protein to play various functions in diverse cellular processes unrelated to glycolysis. ENO2 is highly expressed in head and neck squamous cell carcinoma (HNSCC) tissues relative to normal tissues; however, its impact and underlying regulatory mechanisms in HNSCC malignancy remain unclear. Methods Molecular alterations were examined by bioinformatics, qRT-PCR, western blotting, immunofluorescence, immunohistochemistry, immunoprecipitation, and ChIP-PCR assays. Metabolic changes were assessed by intracellular levels of ATP and glucose. Animal study was used to evaluate the therapeutic efficacy of the ENO inhibitor. Results ENO2 is required for HNSCC cell proliferation and glycolysis, which, surprisingly, is partially achieved by controlling PKM2 protein stability and its nuclear translocation. Mechanistically, loss of ENO2 expression promotes PKM2 protein degradation via the ubiquitin-proteasome pathway and prevents the switch of cytoplasmic PKM2 to the nucleus by inactivating AKT signaling, leading to a blockade in PKM2-mediated glycolytic flux and CCND1-associated cell cycle progression. In addition, treatment with the ENO inhibitor AP-III-a4 significantly induces HNSCC remission in a preclinical mouse model. Conclusion Our work elucidates the signaling basis underlying ENO2-dependent HNSCC development, providing evidence to establish a novel ENO2-targeted therapy for treating HNSCC.

Triplet potential energy surfaces are extremely important for phosphors because they are closely related to radiative and nonradiative decay processes. In this article, the correlations between the strctures and the triplet potential energy surfaces for Pt(II) complexes are investigated in detail with the help of density functional theory (DFT). The calculated results indicate that triplet hypersurface minima with different configurations, i.e., planar and bent, rely on the geometries of the platinum(II) complex. A bent configuration could cause an obvious decrease in the phosphorescence quantum yield, and an unusual low-lying triplet excited-state decay route is proposed. In addition, the extension of π-conjugation and addition of suitable substituents, for example

Water/alcohol soluble cathode interfacial materials (CIMs) are playing important roles in optoelectronic devices such as organic light emitting diodes, perovskite solar cells and organic solar cells (OSCs). Herein, n-doped solution-processable single-wall carbon nanotubes (SWCNTs)-containing CIMs for OSCs are developed by dispersing SWCNTs to the typical CIMs perylene diimide (PDI) derivatives PDIN and PDINO. The Raman and X-ray photoelectron spectroscopy (XPS) measurement results illustrate the n-doped behavior of SWCNTs by PDIN/PDINO in the blend CIMs. The blended and n-doped SWCNTs can tune the work function and enhance the conductivity of the PDI-derivative/SWCNT (PDI-CNT) composite CIMs, and the composite CIMs can regulate and down-shift the work function of cathode, reduce the charge recombination, improve the charge extraction rate and enhance photovoltaic performance of the OSCs. High power conversion efficiency (PCE) of 17.1% and 17.7% are obtained for the OSCs based on PM6:Y6 and ternary PM6:Y6:PC71BM respectively with the PDI-CNT composites CIMs. These results indicate that the n-doped SWCNT-containing composites, like other n-doped nanomaterials such as zero dimensional fullerenes and two dimensional graphenes, are excellent CIMs for OSCs and could find potential applications in other optoelectronic devices.

Current methods for tuning the plasmonic properties of metallic nanoparticles typically rely on alternating the morphology (i.e., size and/or shape) of nanoparticles. The variation of morphology of plasmonic nanoparticles oftentimes impairs their performance in certain applications. In this study, we report an effective approach based on the control of internal structure to engineer morphology-invariant nanoparticles with tunable plasmonic properties. Specifically, these nanoparticles were prepared through selective growth of Ag on the inner surfaces of preformed Ag-Au alloyed nanocages as the seeds to form Ag@(Ag-Au) shell@shell nanocages. Plasmonic properties of the Ag@(Ag-Au) nanocages can be conveniently and effectively tuned by varying the amount of Ag deposited on the inner surfaces, during which the overall morphology of the nanocages remains unchanged. To demonstrate the potential applications of the Ag@(Ag-Au) nanocages, they were applied to colorimetric sensing of human carcinoembryonic antigen (CEA) that achieved low detection limits. This work provides a meaningful concept to design and craft plasmonic nanoparticles.

A new and general strategy for the rapid construction of pyrrolotropones via a domino process involving 1,6-nucleophilic addition, isonitrile insertion, azacyclopropylidene-annulated cyclohexenone to tropone rearrangement, and subsequent aromatization, from the reaction of para-quinone methides (p-QMs) with p-toluenesulfonylmethyl isocyanide (TosMIC) has been proposed. The reaction does not require transition metals or stoichiometric oxidants and can be performed through one-step operation promoted by a base. This method uses easy-to-synthesize p-QMs and commercially abundant TosMIC and shows excellent scalability and broad substrate scope. Furthermore, the screening of these pyrrolotropone compounds in several human cancer cell lines shows excellent anticancer activity, which validates the feasibility of this protocol for generating bioactive compounds.

Background Breast cancer exhibits poor prognosis and high relapse rates following chemotherapy therapeutics. Thus, this study aims to develop effective novel agents regulating the core molecular pathway of breast cancer such as Wnt/β-catenin signaling. Methods The present study screened a novel inhibitor, called "C188", using MTT assay. The molecular formula of C188 is C21H15FN4O3 and the molecular weight is 390. Flow cytometry and Western blotting were employed to assess cell cycle arrest after treatment with C188. Wound-healing and transwell assays were applied to measure the cell migration and invasion viability. The regulatory effects of C188 on Wnt/β‑catenin signaling and localization of β‑catenin in the nucleus were investigated by Western blotting and immunofluorescence. Results We found that C188 significantly suppressed proliferation and growth in a dose- and time-dependent manner in breast cancer cells, but not in normal breast cells. The inhibitory effect was caused by cell cycle arrest at the G1-phase which is induced by C188 treatment. Additionally, C188 dramatically inhibited cell migration of breast cancer cells in a dose-dependent manner. The migration inhibition was attributed to the suppression of Wnt/β‑catenin signaling and localization of β‑catenin in the nucleus mediated by regulating phosphorylation of β‑catenin and its subsequent stability. Furthermore, the target genes, including Axin 2, c-JUN, and c-Myc, were downregulated due to the decrease of β‑catenin in the nucleus after exposure to C188. Conclusion C188 treatment resulted in the downregulation of cyclin D which led to cell cycle arrest at the G1 phase, and the inhibition of cell migration, indicating that C188 may be an effective novel therapeutic candidate as a potential treatment for human breast cancer.

Reported herein is a unified strategy to generate difluoroalkyl radicals from readily prepared α-difluorinated gem-diols by single electron oxidation. Under microwave irradiation, a catalytic amoun...

A Michael addition-driven four-component reaction (4-CR) was developed for derivatizing chromones by strategically suppressing competing 4-CR Ugi reaction without a catalyst. A series of structurally diverse 4-oxochroman-2-carboxamides was synthesized with this one-pot protocol. In addition, the new reaction was expanded for the synthesis of a series of tetrazole substituted chromones by replacing carboxylic acid with trimethylsilyl azide (TMSN3). The imine functional group and the corresponding aldehyde hydrolysed from the imine were utilized for further structural diversification.

A green 1,4-addition isocyanide-based three-component reaction was developed to synthesize chromanones via a facile, mild, and efficient one-pot protocol without a metal catalyst. The 1,4-addition of isocyanides occurred at the C-2 position of chromones instead of the Schiff base in neat water. We found that the hydrogen bond can dictate the stereo-outcome of olefins, providing an effective method for the diastereomer-selective synthesis of this type of chromanone. The novel green synthetic protocol allowed the quick synthesis of complex chromanones in an environmentally friendly manner.

An Ugi, ring expansion, pseudo-Dieckmann condensation and rearrangement cascade reaction was discovered for the synthesis of indoline-piperidinones in one pot. A series of targeted compounds was prepared by means of a mild reaction and a simple operation procedure, which could be applicable to a broad scope of Ugi starting materials. This cascade reaction generates opportunities for the tailored synthesis of a wide range of indoline-piperidinone scaffolds through tuneable Ugi inputs.

The degradative condensation of hexose, which originates from the C-C cleavage of hexose and condensation of degraded hexose fragment, is one of the possible reaction pathways for the formation of humins in hexose dehydration to 5-hydroxymethylfurfural (HMF). Herein, the impacts of several polar aprotic solvents on the degradative condensation of fructose to small-molecule carboxylic acids and oligomers (possible precursors of humins) are reported. In particular, a close relationship between the tautomeric distribution of fructose in solvents and the mechanism of degradative condensation is demonstrated. Typically, α-fructofuranose in 1,4-dioxane and acyclic open-chain fructose in THF favor the conversion of fructose to formic acid and oligomers; α-fructopyranose in γ-valerolactone or N-methylpyrrolidone favors levulinic acid and oligomers, whereas β-fructopyranose in 4-methyl-2-pentanone favors acetic acid and corresponding oligomers. This close correlation highlights a general understanding of the solvent-controlled formation of oligomers, which represents an important step toward the rational design of effective solvent systems for HMF production.

The short operation lifetime is a major factor which hinders the large-scale commercialization of phosphorescent organic light-emitting diodes (OLEDs). Unveiling the intrinsic degradation mechanism of phosphorescent material may be a feasible method for exploring the determined factors of operation lifetime. In this article, the ligand dissociation reactions and phosphorescent quantum yields of various bidentate Pt (II) complexes were investigated by means of the density functional theory (DFT) and time-dependent (TD)-DFT. The calculated results indicate for phosphorescent quantum yields, sulphur heterocycle can facilitate the radiative decay process and suppress the temperature-dependent nonradiative channel. In the aspect of ligand dissociation reactions, the corresponding dissociations of Pt (II) complexes can be effectively avoided via changing the coordinate forms of ligands. In addition, the relationship between geometric tailor and stability, emission color was also taken into account. An analysis of computed results can conclude that the electron-withdrawing and electron-dominating substituents can tune the emissive wavelengths from 477 to 624 nm and cause minor effect on the stability. This investigation could some meaningful information for designing stable Pt (II) complexes.

Efficient hydrogen evolution reaction electrocatalysts based on inexpensive and earth-abundant elements could enable low-cost water splitting and H2 production, thus are compelling for the conversion of renewable electricity to fuels. In this work, we showcase the combinations of multiple surface engineering routes in a Ni2P electrocatalyst that achieves significantly enhanced catalytic performance. The surface roughness and structure disordering of the Ni2P arrays on carbon foil are precisely regulated by altering the annealing condition, resulting in a surface area-enlarged, defect-rich and superaerophobic catalytic surface. Density functional theory calculations are used to identify the effect of defective sites on the free energy for hydrogen adsorption in hydrogen evolution. Meanwhile, the superaerophobic surface is proved to accelerate removing gas bubbles on the electrode, thus facilitate the catalytic process. In addition, the enlarged surface area of material is considered to elevate the catalytic performance by providing more active sites in reaction. The designed catalyst obtained through a moderate treatment exhibits optimal electrocatalytic activity in acidic media: a low overpotential of 63 mV at 10 mA cm−2, small Tafel slope of 67 mV dec−1 and outstanding stability over 10 h. The synthetic strategy shows great promise to design efficient catalysts via subtle surface engineering.

For phosphorescent emitters, the rigidity of the geometry is a crucial indicator, which can directly determine the non-radiative decay rate. In this article, density functional theory (DFT) calculations were performed to investigate the influence of the small substituent groups on the rigidities of tridentate Pt(ii) complexes in detail. The calculated results indicate that the small substituent groups can serve as geometric controllers to suppress the structural distortion on going from the ground state (S0) to the lowest-lying triplet excited state (T1) (Jahn-Teller distortion). For instance, when electron-donating substituent groups, including -NH2, -N(CH3)2 and -OCH3, were employed, the rigidities of the corresponding Pt(ii) complexes can be effectively enhanced because the highest occupied molecular orbital (HOMO)-HOMO-1 energy gaps could be increased. Different from the electron-donating substituent groups, electron-withdrawing substituent groups, i.e., -NO2 and -COCH3, can cause a negligible change in HOMO and HOMO-1 energies during the S0 → T1 transition process, and therefore, for Pt-NO2 and Pt-COCH3, no Jahn-Teller distortion occurs. According to the calculated results, the rigidities of tridentate Pt(ii) complexes could be raised via tuning the energies of the frontier molecular orbital (FMO) with the help of small substituent groups.

Interface engineering is a critical factor in achieving high photovoltaic performances for large-area, printable, flexible and low cost organic solar cells (OSCs). Herein, we developed a solution-processable n-doped graphene cathode interfacial material (CIM) PDINO–G for OSCs by adding graphene to the classic material PDINO ((N,N-dimethyl-ammonium N-oxide)propyl perylene diimide). The dispersed graphene in PDINO–G was n-doped by the nitroxide radical of N-oxide in PDINO, which was certified by the ESR, Raman spectroscopy and XPS results. The n-doped PDINO–G CIM possessed increased conductivity, lower work function, reduced charge recombination and increased charge extraction rate. Previously, n-doped graphene was prepared only on the surface of chemical vapor-deposited (CVD) graphene films without solution processability. The effect of the CIM on the photovoltaic performance of OSCs was studied by selecting the photovoltaic model system of PTQ10 as the donor and IDIC-2F as the acceptor. The OSCs based on PTQ10:IDIC-2F with PDINO–G CIM demonstrated the best power conversion efficiency (PCE) of 13.01%, which was significantly enhanced in comparison with that of the devices without graphene modification on the PDINO CIM (12.23%). The universality of the high performance PDINO–G CIM was verified in two other photovoltaic systems based on PTQ10:IDIC and PM6:Y6. Especially, the single junction bulk heterojunction OSCs based on PM6:Y6 with PDINO–G CIM displayed a high PCE of 16.52% (average PCE of 16.3 ± 0.2%). The results indicate that the n-doped PDINO–G is an excellent CIM for OSCs. Furthermore, this PDINO-doped graphene can be applied in other optoelectronic devices such as tandem OSCs, organic light-emitting diodes, and high-performance perovskite solar cells as a cathode interfacial material considering its advantages of solution processability, low work function and high conductivity.

Density functional theory (DFT) calculations were performed to investigate the mechanism and the enantioselectivity of the aza-Henry reaction of isatin-derived ketimine catalyzed by chiral guanidine–amide catalysts at the M06-2X-D3/6-311+G(d,p)//M06-2X-D3/6-31G(d,p) (toluene, SMD) theoretical level. The catalytic reaction occurred via a three-step mechanism: (i) the deprotonation of nitromethane by a chiral guanidine–amide catalyst, (ii) formation of C–C bonds, (iii) H-transfer from guanidine to ketimine, accompanied with the regeneration of the catalyst. A dual activation model was proposed, in which the protonated guanidine activated the nitronate, and the amide moiety simultaneously interacted with the ketimine substrate by intermolecular hydrogen bonding. The repulsion of CPh3 group in guanidine as well as N-Boc group in ketimine raised the Pauli repulsion energy (∆EPauli) and the strain energy (∆Estrain) of reacting species in the unfavorable si-face pathway, contributing to a high level of stereoselectivity. A new catalyst with cyclopropenimine and 1,2-diphenylethylcarbamoyl as well as sulfonamide substituent was designed. The strong basicity of cyclopropenimine moiety accelerated the activation of CH3NO2 by decreasing the energy barrier in the deprotonation step. The repulsion between the N-Boc group in ketimine and cyclohexyl group as well as chiral backbone in the new catalyst raised the energy barrier in C–C bond formation along the si-face attack pathway, leading to the formation of R-configuration product. A possible synthetic route for the new catalyst is also suggested.

Background Demethylzeylasteral (T-96) is a pharmacologically active triterpenoid monomer extracted from Tripterygium wilfordii Hook F (TWHF) that has been reported to exhibit anti-neoplastic effects against several types of cancer cells. However, the potential anti-tumour effects of T-96 against human Prostate cancer (CaP) cells and the possible underlying mechanisms have not been well studied. Results In the current study, T-96 exerted significant cytotoxicity to CaP cells in vitro and induced cell cycle arrest at S-phase in a dose-dependent manner. Mechanistically, T-96 promoted the initiation of autophagy but inhibited autophagic flux by inducing ROS-mediated endoplasmic reticulum (ER) stress which subsequently activated the extrinsic apoptosis pathway in CaP cells. These findings implied that T-96-induced ER stress activated the caspase-dependent apoptosis pathway to inhibit proliferation of CaP cells. Moreover, we observed that T-96 enhances the sensitivity of CaP cells to the chemotherapeutic drug, cisplatin. Conclusions Taken together, our data demonstrated that T-96 is a novel modulator of ER stress and autophagy, and has potential therapeutic applications against CaP in the clinic.

The mechanism and charge effect of cycloisomerization of ω-alkynylfuran (Hashmi phenol synthesis) catalyzed by single-walled helical gold nanotubes (Au SWNTs) have been systematically investigated via density functional theory. Cycloisomerization of ω-alkynylfuran occurs by the 5-exo Friedel–Crafts-type (FCT) mechanism, namely 5-exo cyclization, furan ring opening, and ring closing of the dienone carbene–gold intermediate. The reactions with Au(6,0), Au(6,1), Au(6,2) and Au(6,3) SWNTs show low energy barriers along the 5-exo FCT path in acetonitrile solvent, but have different the rate-determining steps. From an energy perspective, the reaction rate-determining step catalyzed by Au(6,0) and Au(6,3) is the ring-closing of dienone carbine-gold intermediate, but that of Au(6,1) and Au(6,2) is the IM5 dissociation from the Au SWNTs, which can be attributed to the diversity of the d-band centers of the Au(6,m) SWNTs. The effect of the charge of the Au SWNTs on the catalytic activity was also investigated. Theoretical analysis shows a prominent charge effect, where the cationic Au(6,0), Au(6,3) SWNTs and anionic Au(6,1), Au(6,2) SWNTs are more favorable for the Hashmi phenol synthesis reaction. This results can be attributed to the Au(6,0) and Au(6,3) SWNTs with positive charge can reduce the adsorption energy of the substrate on the catalyst surface and decrease the energy barrier of the cyclization process and ring-closing step. Besides, the Au(6,1) and Au(6,2) with an anion could obviously decrease the dissociation energy of IM5 which is help for the Hashmi phenol reaction. Theoretical analysis shows that the structure and charge effects could influence the catalytic activity of Au(6,m) SWNTs toward Hashmi phenol synthesis. This work will provide insight into cycloisomerization of ω-alkynylfuran and valuable information for application of Au SWNTs in catalysis.

Pathogen-host cell interactions play an important role in many human infectious and inflammatory diseases. Several pathogens, including Escherichia coli (E. coli), Mycobacterium tuberculosis (M. tb), and even the recent 2019 novel coronavirus (2019-nCoV), can cause serious breathing and brain disorders, tissue injury and inflammation, leading to high rates of mortality and resulting in great loss to human physical and mental health as well as the global economy. These infectious diseases exploit the microbial and host factors to induce serious inflammatory and immunological symptoms. Thus the development of anti-inflammatory drugs targeting bacterial/viral infection is an urgent need. In previous studies, YojI-IFNAR2, YojI-IL10RA, YojI-NRP1,YojI-SIGLEC7, and YojI-MC4R membrane-protein interactions were found to mediate E. coli invasion of the blood-brain barrier (BBB), which activated the downstream anti-inflammatory proteins NACHT, LRR and PYD domains-containing protein 2(NLRP2), using a proteomic chip conjugated with cell immunofluorescence labeling. However, the studies of pathogen (bacteria/virus)-host cell interactions mediated by membrane protein interactions did not extend their principles to broad biomedical applications such as 2019-nCoV infectious disease therapy. The first part of this feature article presents in-depth analysis of the cross-talk of cellular anti-inflammatory transduction signaling among interferon membrane protein receptor II (IFNAR2), interleukin-10 receptor subunit alpha (IL-10RA), NLRP2 and [Ca2+]-dependent phospholipase A2 (PLA2G5), based on experimental results and important published studies, which lays a theoretical foundation for the high-throughput construction of the cytokine and virion solution chip. The paper then moves on to the construction of the novel GPCR recombinant herpes virion chip and virion nano-oscillators for profiling membrane protein functions, which drove the idea of constructing the new recombinant virion and cytokine liquid chips for HTS of leading drugs. Due to the different structural properties of GPCR, IFNAR2, ACE2 and Spike of 2019-nCoV, their ligands will either bind the extracellular domain of IFNAR2/ACE2/Spike or the specific loops of the GPCR on the envelope of the recombinant herpes virions to induce dynamic charge distribution changes that lead to the variable electron transition for detection. Taken together, the combined overview of two of the most innovative and exciting developments in the immunoinflammatory field provides new insight into high-throughput construction of ultrasensitive cytokine and virion liquid chips for HTS of anti-inflammatory drugs or clinical diagnosis and treatment of inflammatory diseases including infectious diseases, acute or chronic inflammation (acute gouty arthritis or rheumatoid arthritis), cardiovascular disease, atheromatosis, diabetes, obesity, tissue injury and tumors. It has significant value in the prevention and treatment of these serious and painful diseases. Graphical abstract.

Understanding the mechanism of the catalytic reaction is an effective way to design new high-performance catalysts. The mechanisms of alkyne/olefin hydrogenations catalyzed by a nonclassical Co–N2 ...

Understanding the mechanism of a catalytic reaction is of fundamental importance not only scientifically but also technologically to the design of high-performance catalysts. In this work, the mechanisms of 1-phenyl-1-propyne and cis-β-methylstyrene hydrogenations catalyzed by Cu55 and ligand-coated Cu55 are explored in detail by means of density functional theory (DFT). The calculated results indicate that the semihydrogenation selectivity of the catalyst can be effectively controlled by employing a suitable ligand. That is, the PCy3 and PPh3 ligands used to coat Cu55 can largely raise the energy barrier of the rate-determining step for cis-β-methylstyrene hydrogenation. By the study of energy decomposition analysis (EDA) and charge density difference, it can be found that the deformation energies of the substrate fragments play a crucial role in the energy barriers of the rate-determining steps. The large hindrance effect of the ligands is beneficial for improving the semihydrogenation selectivity of the catalysts. This study provides significant information for future catalyst design and on the physical origin of the phosphine ligand-coated nanoparticle catalysis for semihydrogenation.

The first catalyst-free post-Ugi cascade methodology was developed for expeditious access to structurally diverse and complex pyrazole-pyrazines in one-pot. This novel cascade reaction features an intramolecular N2-arylation of pyrazoles with allenes at the C-β position of triple bond. Screening in the colorectal cancer cell lines HCT116 and SW620 validated the feasibility of the methodology for generating bioactive compounds. The lead compound 7h which is active against HCT116 and SW620 with IC50 of 1.3 and 1.8 µM, respectively, can be synthesized and purified in a gram process synthetic scale in 7 hours. The mechanical studies indicated that compound 7h can induce cell cycle arrest in the G2/M phase and inhibit proliferation and viability in human colon cancer cells. Overall, compound 7h is represented as a promising starting point for the development of new anti-colorectal cancer drugs.

Unveiling the reaction mechanism is significant for developing high-performance catalysts. In this paper, a series of precisely controlled PdxM147-x (M = Cu, Pt, Au, Rh, Ru) dendrimer encapsulated nanoparticles (DENs) has been successfully synthesized. The mechanisms of PdxM147-x as catalysts for Suzuki cross-coupling reactions were investigated by combining experimental and theoretical methods. The experimental results indicate that Pd74Cu73 DEN shows similar activity to Pd147 DEN and excellent substrate adaptability under mild reaction conditions. Moreover, the Cu component can play an important role in tuning the catalytic activity of PdxCu147-x DEN. Density functional theory (DFT) calculations illustrate that the similar activities of the Pd147 and Pd74Cu73 DENs originate from the comparable energy barriers of the rate-determining steps. The partial density of states (PDOS) and electron density differences demonstrate that Cu decreases the intensities of the valence orbitals of the top and edge Pd atoms and weakens orbital interactions between the intermediates and Pd74Cu73 DEN, leading to low desorption energies of the products. This work can provide a promising strategy to reduce the cost of Pd catalysts in Suzuki cross-coupling reactions.

An Ugi, novel pseudo-Knoevenagel, ring expansion cascade reaction was discovered and utilized for the synthesis of aziridinyl succinimides in one-pot. Subsequently, densely functionalized aziridines and maleimides have been designed and synthesized through similar cascade reactions. The target compounds were prepared by means of a mild reaction and a simple operation procedure, which could be applicable to a broad scope of starting materials. This series of novel cascade reactions generates opportunities for the tailored synthesis of a wide range of biologically active scaffolds through tuneable Ugi inputs. Discovery of compound 8i with comparable potency to sorafenib in liver cancer cell lines could provide a new avenue for liver cancer drug discovery.

A facile microwave-assisted method for the synthesis of tetramic acid derivatives has been developed through an Ugi/Dieckmann cyclization strategy with DBU. This two-step one-pot procedure afforded the targeted tetramic acid analogues in good yields. With commercially available Ugi starting materials, microwave irradiation, a simple operation, excellent yields, and a broad scope, this reaction has the potential to produce a large number of tetramic acid analogues, which cannot be easily accessed by the classic synthetic methods.

The ability to produce a diverse spectrum of hollow nanostructures is central to the advances in many current and emerging areas of technology. Herein, we report a general method to craft hollow nanostructures with highly tunable physical and chemical parameters. The key strategy is to regenerate the nanoscale sacrificial templates in a galvanic replacement reaction through site-selective overgrowth. As examples, we demonstrate the syntheses of nanocages and nanotubes made of silver, gold, palladium, and/or platinum with well-controlled wall thicknesses and elemental distributions. Using the nanocages of silver and gold as models, we demonstrate they possess intriguing plasmonic properties and offer superior performance in biosensing applications. This study provides a powerful platform to customize hollow nanostructures with desired properties and therefore is expected to enable a variety of fundamental studies and technologically important applications.