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Herein is the first example of photocatalytic cross-coupling of alkenes with aldehydes by a single catalyst without an external photosensitizer and any additives. Irradiation of the aromatic aldehyde and cobaloxime catalyst results in the formation of an acyl radical, which undergoes radical addition with alkene or indole and subsequently β-H elimination to afford alkenyl ketone. The reaction features cheap and readily available raw materials, a broad substrate scope, and mild conditions, even for late-stage derivatization of bioactive compounds.

Represented herein is the first 1,3-difunctionalization of alkenes via photocatalysis. A single cobaloxime is used to carry out two catalytic cycles in which cobaloxime is used not only as a photocatalyst to initiate the reaction but also as a metal catalyst for the β-H elimination process. Electron-deficient alkenes, electron-rich alkenes, and unactivated alkenes could be directly converted to 1,3-bisphosphorylated products, even unsymmetric 1,3-bisphosphorylated products, with only H 2 as a byproduct under extremely mild reaction conditions.

A wide range of N -CF 3 imidoyl chlorides were synthesized for the first time via the N -trifluoromethylation of nitriles in DCM by using AlCl 3 -activated PhICF 3 Cl as the CF 3 source. The reactions of them with N - /O-/S-nucleophiles, as well as with 1,3-dipoles, were carried out to efficiently deliver N -CF 3 amidines/imidates/thioimidates and N -CF 3 azoles, demonstrating that they are a class of scalable NCF 3 -containing synthons in the synthesis of N -CF 3 compounds.

The anomalous Hall effect (AHE) is an important transport signature revealing topological properties of magnetic materials and their spin textures. Recently, MnBi 2 Te 4 has been demonstrated to be an intrinsic magnetic topological insulator. However, the origin of its intriguing AHE behaviors remains elusive. Here, we demonstrate the Berry curvature-dominated intrinsic AHE in wafer-scale MnBi 2 Te 4 films. By applying back-gate voltages, we observe an ambipolar conduction and n-p transition in ∼7-layer MnBi 2 Te 4 , where a quadratic relation between the AHE resistance and longitudinal resistance suggests its intrinsic AHE nature. In particular, for ∼3-layer MnBi 2 Te 4 , the AHE sign can be tuned from pristine negative to positive. First-principles calculations unveil that such an AHE reversal originated from the competing Berry curvature between oppositely polarized spin-minority-dominated surface states and spin-majority-dominated inner bands. Our results shed light on the underlying physical mechanism of the intrinsic AHE and provide new perspectives for the unconventional sign-tunable AHE.

Severe injuries to the peripheral nervous system (PNS) require Schwann cells to aid in neuronal regeneration. Low-frequency electrical stimulation is known to induce the cogrowth of neurons and Schwann cells in an injured PNS. However, the correlations between electrical stimulation and Schwann cell viability are complex and not well understood. In this work, we develop a machine learning (ML)-integrated workflow that uses conductive hydrogel biointerfaces to evaluate the impacts of fabrication parameters and electrical stimulation on the Schwann cell viability. First, a hydrogel array with varying MXene and peptide loadings is fabricated, which serves as conductive biointerfaces to incubate Schwann cells and introduce various electrical stimulation (at different voltages and frequencies). Upon specific fabrication parameters and stimulation, the cell viability is evaluated and input into an artificial neural network model to train the model. Additionally, a data augmentation method is applied to synthesize 1000-fold virtual data points, enabling the construction of a high-accuracy prediction model (with a testing mean absolute error ≤11%). By harnessing the model's predictive power, we can accurately predict Schwann cell viability based on a given set of fabrication/stimulation parameters. Finally, the SHapley Additive exPlanations model interpretation provides several data-scientific insights that are validated by microscopic cellular observations. Our hybrid approach, involving conductive biointerface fabrication, ML algorithms, and data analysis, offers an unconventional platform to construct a preclinical prediction model at the cellular level.

A simple and efficient method for the synthesis of unsymmetrical disulfides is reported. Using sodium sulfites and 2-mercaptobenzo heterocyclic compounds as starting materials, the unsymmetrical sulfur-sulfur bonds could be quickly constructed in the PPh 3 /I 2 reaction system under transition-metal-free conditions. This protocol has the advantages of mild reaction conditions, easily available starting materials, and wide substrate scope, showing potential synthetic value for the synthesis of a diversity of biologically or pharmaceutically active compounds.

In this study, polyaminophosphoric acid (PA)-functionalized ion-imprinted chitosan (CS) aerogel was fabricated for the first time, exhibiting good antibacterial property for selective La(III) recovery and oil/water separation. The as-prepared PA-CS-IIA-2 shows a remarkable adsorption capacity of 114.6 mg/g toward La(III) and high selectivity in the competitive adsorption systems, which is attributed to its abundant imprinting sites and surface functional groups. Benefiting from the amphiphilic property, the PA-CS-IIA-2 also exhibits an excellent adsorption performance for the extractant, oils, and organic solvents. Besides, the PA-CS-IIA-2 presents excellent regeneration and reusability characteristics. Moreover, compared with CS, the PA-CS-IIA-2 exhibits a significantly improved antibacterial activity originating from the PA component. Most importantly, the PA-CS-IIA-2 aerogel is capable of removing multiple pollutants all together and effectively inhibiting bacteria in the complex wastewater environments. Therefore, this study paves the way for developing high-performance rare-earth capture materials with multiple functions to meet diverse applications.

The hexagonal rare earth ferrites h -RFeO 3 (R = rare earth element) have been recognized as promising candidates for a room-temperature multiferroic system, and the primary issue for these materials is how to get a stable hexagonal structure since the centrosymmetric orthorhombic structure is generally stable for most RFeO 3 at room-temperature, while the hexagonal phase is only stable under some strict conditions. In the present work, h -Lu 1- x In x FeO 3 ( x = 0-1) thin films were prepared on a Nb-SrTiO 3 (111) single-crystal substrate by a pulsed laser deposition (PLD) process, and the multiferroic characterization was performed at room temperature. With the combined effects of chemical pressure and epitaxial strain, the stable hexagonal structure was achieved in a wide composition range ( x = 0.5-0.7), and the results of XRD (X-ray diffraction) and SAED (selected area electron diffraction) indicate the super-cell match relations between the h -Lu 0.3 In 0.7 FeO 3 thin film and substrate. The saturated P - E hysteresis loop was obtained at room temperature with a remanent polarization of about 4.3 μC/cm 2 , and polarization switching was also confirmed by PFM measurement. Furthermore, a strong magnetoelectric coupling with a linear magnetoelectric coefficient of 1.9 V/cm Oe was determined, which was about three orders of magnitude larger than that of h -RFeO 3 ceramics. The present results indicate that the h -Lu 1- x In x FeO 3 thin films are expected to have great application potential for magnetoelectric memory and detection devices.

Gaseous arsenic emitted from coal combustion flue gas (CCFG) causes not only severe contamination of the environment but also the failure of selective catalytic reduction (SCR) catalysts in power plants. Development of inexpensive and effective adsorbents or techniques for the removal of arsenic from high-temperature CCFG is crucial. In this study, halloysite nanotubes (HNTs) at low price were modified with CuCl 2 (CuCl 2 -HNTs) through ultrasound assistance and applied for capturing As 2 O 3 (g) in simulated flue gas (SFG). Experiments on arsenic adsorption performance, adsorption mechanism, and adsorption energy based on density functional theory were performed. Modification with CuCl 2 clearly enhanced the arsenic uptake capacity (approximately 12.3 mg/g) at 600 °C for SFG. The adsorbent exhibited favorable tolerance to high concentrations of NO x and SO x . The As 2 O 3 (III) was oxidized and transformed into As 2 O 5 (V) on the CuCl 2 -HNTs. The Al-O bridge had the highest adsorption energy for the O end of the As-O group (-2.986 eV), and the combination formed between arsenic-containing groups and aluminum was stable. In addition, the captured arsenic could be stabilized in the sorbent at high temperature, making it possible to use the sorbent before the SCR system. This demonstrates that CuCl 2 -HNTs is a promising sorbent for arsenic oxidation and removal from CCFG.

We investigate giant magnetoelectric coupling at a Mn 3+ spin crossover in [Mn III L]BPh 4 (L = (3,5-diBr-sal) 2 323) with a field-induced permanent switching of the structural, electric, and magnetic properties. An applied magnetic field induces a first-order phase transition from a high spin/low spin (HS-LS) ordered phase to a HS-only phase at 87.5 K that remains after the field is removed. We observe this unusual effect for DC magnetic fields as low as 8.7 T. The spin-state switching driven by the magnetic field in the bistable molecular material is accompanied by a change in electric polarization amplitude and direction due to a symmetry-breaking phase transition between polar space groups. The magnetoelectric coupling occurs due to a γη 2 coupling between the order parameter γ related to the spin-state bistability and the symmetry-breaking order parameter η responsible for the change of symmetry between polar structural phases. We also observe conductivity occurring during the spin crossover and evaluate the possibility that it results from conducting phase boundaries. We perform ab initio calculations to understand the origin of the electric polarization change as well as the conductivity during the spin crossover. Thus, we demonstrate a giant magnetoelectric effect with a field-induced electric polarization change that is 1/10 of the record for any material.

We describe a tert -butyl nitrite-catalyzed oxidative dehydrogenation of hydrazobenzenes for producing azobenzenes. This method proceeds at ambient temperature and under an atmospheric environment by employing eco-friendly EtOH as the medium, representing a mild, general route to the synthesis of various symmetrical and nonsymmetrical azobenzenes in excellent yields with broad functional group tolerance., Competing Interests: The authors declare no competing financial interest., (© 2020 The Authors. Published by American Chemical Society.)

A NiCl 2 -promoted [2 + 2 + 1] carboannulation of 1,7-enynes with internally oxidative cyclobutanone oximes to produce canyo-functionalized 4 H -cyclopenta[ c ]quinolin-4-ones is disclosed. Through C-C/N-O bond cleavage and C-H functionalization, the process enables one-carbon incorporation using cyclobutanone oximes to achieve [2 + 2 + 1] carboannulation of 1,7-enynes, which is highlighted by allowing the formation of four new bonds with high selectivity and broad substrate scope.

We here describe a new Cu-catalyzed annulation cascade of alkyne-tethered α-bromocarbonyls with common alkynes for the synthesis of various heteropolycycle frameworks, including 1 H-benzo[ de]quinolin-2(3 H)-ones, 4 H-dibenzo[ de,g]quinolin-5(6 H)-one, and benzo[ de]chromen-2(3 H)-one, which were constructed with high selectivity. This was achieved by two-component annulation cascades, rather than atom-transfer radical cyclization (ATRC), with alkyne-tethered α-bromocarbonyls for one-step accessing heteropolycycles via C-Br bond split, intramolecular cyclization, intermolecular [4 + 2] annulation, and aryl C(sp 2 )-H functionalization cascades.

An alternative entry to transformations of N-sulfonyl-4-(2-(ethynyl)aryl)-1,2,3-triazoles with various generated in situ or external nucleophiles by means of silver catalysis for producing diverse functionalized isoquinolines is described. Mechanistically, the reaction is proposed to involve a key silver carbenoid intermediate, thus enabling the formation of multiple chemical bonds via ring opening, N 2 extrusion, silver carbenoid formation, nucleophilic addition, and complex annulations cascades.

Targeting the increased Fe(3+) content in tumors, we propose a novel molecular platform integrated cancer iron chelation therapy for (1)H-magnetic resonance imaging (MRI) detection of β-galactosidase (β-gal) activity. Following this idea, we have designed, synthesized, and characterized a series of β-d-galactosides conjugated with various chelators and demonstrated the feasibility of this concept for assessing β-gal activity in solution by (1)H-MRI T1 and T2 relaxation mapping.

pH plays an important role in tumor proliferation, angiogenesis, metabolic control, and the efficacy of cytotoxic therapy, and accurate noninvasive assessment of tumor pH promises to provide insight into developmental processes and prognostic information. In this paper, we report the design, synthesis, and characterization of two novel pH indicators 6-trifluoromethylpyridoxine 8 and α(4),α(5)-di-O-[3'-O-(β-d-glucopyranosyl)propyl]-6-trifluoromethylpyridoxine 17 and demonstrate 8 as an extracellular (19)F NMR pH probe to assess pH(e) of various tumors in vivo.

Increased emphasis on personalized medicine and novel therapies requires the development of noninvasive strategies for assessing biochemistry in vivo. The detection of enzyme activity and gene expression in vivo is potentially important for the characterization of diseases and gene therapy. Magnetic resonance imaging (MRI) is a particularly promising tool, since it is noninvasive and has no associated radioactivity, yet penetrates deep tissue. We now demonstrate a novel class of dual (1)H/(19)F nuclear magnetic resonance (NMR) lacZ gene reporter molecule to specifically reveal enzyme activity in human tumor xenografts growing in mice. We report the design, synthesis, and characterization of six novel molecules and evaluation of the most effective reporter in mice in vivo. Substrates show a single (19)F NMR signal and exposure to β-galactosidase induces a large (19)F NMR chemical shift response. In the presence of ferric ions, the liberated aglycone generates intense proton MRI T(2) contrast. The dual modality approach allows both the detection of substrate and the imaging of product enhancing the confidence in enzyme detection.

Comparison of the lectin-binding properties for highly dense beta-cyclodextrin-centered homo- and heteroglycoclusters with defined architecture provides evidence for the existence of strong synergic effects (heterocluster effect) on carbohydrate-protein recognition events.