Copper-catalyzed defluorinative arylboration of vinylarenes with polyfluoroarenes

An unprecedented but challenging defluorinative arylboration has been achieved. Enabled by a copper catalyst, an interesting procedure on defluorinative arylboration of styrenes has been established. With polyfluoroarenes as the substrates, this methodology offers flexible and facile access to provide a diverse assortment of products under mild reaction conditions. In addition, by using a chiral phosphine ligand, an enantioselective defluorinative arylboration was also realized, affording a set of chiral products with unprecedented levels of enantioselectivity.

Matrine suppresses NLRP3 inflammasome activation via regulating PTPN2/JNK/SREBP2 pathway in sepsis

BACKGROUND

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Abnormal activation of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome plays a vital role in the pathogenesis of sepsis. Matrine is proved to show good anti-inflammatory properties, whereas its effect and the underlying molecular machinery on sepsis remains unclear.

PURPOSE

The aim of this study is to evaluate the effect and mechanism of Matrine on sepsis.

STUDY DESIGN

THP-1 cells and J774A.1 cells were stimulated by lipopolysaccharide (LPS) with nigericin or adenosine triphosphate (ATP) to establish an in vitro model. Cecal ligation and puncture (CLP)-induced sepsis mouse model was used. Matrine was given by gavage.

METHODS

To investigate the NLRP3 inflammasome activation, phorbol myristate acetate (PMA)-induced THP-1 cells were first primed with LPS and then stimulated by matrine, followed by treatment with nigericin or ATP. The concentration of interleukin 1β (IL-1β) and interleukin 18 (IL-18) in the cell culture supernatant was detected. The mechanism was explored by cell death assay, immunoblots and immunofluorescence in vitro. C57BL/6 mice were intragastrically administered with matrine for 5 days before CLP. The therapeutic effect of matrine was evaluated by symptoms, pathological analysis, ELISA and RT-qPCR.

RESULTS

Our results revealed that matrine inhibited IL-1β and IL-18 secretion, suppressed caspase-1 activation, reduced cell death, and blocked ASC speck formation upon NLRP3 inflammasome activation. Furthermore, matrine restrains NLRP3 inflammasome activation as well as pyroptosis through regulating the protein tyrosine phosphatase non-receptor type 2 (PTPN2)/JNK/SREBP2 signaling. Matrine also prominently improved the symptoms and pathological changes with reduced levels of TNF-α, IL-1β, and IL-6 in the lung tissues and serum in a dose-dependent manner.

CONCLUSION

Matrine effectively alleviates the symptoms of CLP-induced sepsis in mice, restrains NLRP3 inflammasome activation by regulating PTPN2/JNK/SREBP2 signaling pathway, and may become a promising therapeutic agent for sepsis treatment.

Catalyst-controlled selective borocarbonylation of benzylidenecyclopropanes: regiodivergent synthesis of γ-vinylboryl ketones and β-cyclopropylboryl ketones

Regioselective catalytic multi-functionalization reactions enable the rapid synthesis of complexed products from the same precursors. In this communication, we present a method for the regiodivergent borocarbonylation of benzylidenecyclopropanes with aryl iodides. Various γ-vinylboryl ketones and β-cyclopropylboryl ketones were produced in moderate to good yields with excellent regioselectivity from the same substrates. The choice of the catalyst is key for the regioselectivity control: γ-vinylboryl ketones were produced selectively with IPrCuCl and Pd(dppp)Cl₂ as the catalytic system, while the corresponding β-cyclopropylboryl ketones were obtained in high regioselectivity with Cu(dppp)Cl, [Pd(η³-cinnamyl)Cl]₂ and xantphos as the catalytic system. Moreover, γ-vinylboryl ketones and β-cyclopropylboryl ketones were successfully transformed into several other value-added products.

A novel procedure for regiodivergent borocarbonylation of benzylidenecyclopropanes has been developed. A variety of valuable γ-vinylboryl ketones and β-cyclopropylboryl ketones can be obtained selectively in excellent yields.

Copper-Catalyzed 1,2-Trifluoromethylation Carbonylation of Unactivated Alkenes: Efficient Access to β-Trifluoromethylated Aliphatic Carboxylic Acid Derivatives

A novel copper-catalyzed carbonylative trifluoromethylation of unactivated alkenes has been developed. A broad range of β-trifluoromethylated carboxylic acid derivatives were prepared in moderate to excellent yields from simple alkenes with excellent regioselectivity. It is noteworthy that ethylene gas, as the simplest olefin, can also be applied directly to obtain β-trifluoromethylated amides and ester. This transformation presents the first example on carbonylative trifluoromethylation of alkenes.

Copper-catalyzed borofunctionalization of styrenes with B2pin2 and CO

The construction of structurally complexed and high-value chemical molecules from simple and readily available feedstocks is a long-standing challenge to chemists. Here, we describe a copper-catalyzed borofunctionalization of styrenes with B₂pin₂ and carbon monoxide. A set of new sodium cyclic borates were obtained with NaO^tBu as the base. These unique sodium cyclic borates can be easily converted into a variety of multifunctional β-boryl vinyl esters, boryl carbonates, β-boryl aldehydes, and boryl vinyl ether. In addition, the procedure also features good functional group tolerance and utilizes CO as the C1 source.

A new copper-catalyzed borofunctionalization of styrenes with B₂pin₂ and carbon monoxide has been developed.

Pd/Cu-Catalyzed amide-enabled selectivity-reversed borocarbonylation of unactivated alkenes

The addition reaction between CuBpin and alkenes to give a terminal boron substituted intermediate is usually fast and facile. In this communication, a selectivity-reversed procedure has been designed and established. This selectivity-reversed borocarbonylation reaction is enabled by a cooperative action between palladium and copper catalysts and proceeds with complete regioselectivity. The key to the success of this transformation is the coordination of the amide group and slower CuBpin formation by using KHCO₃ as the base. A wide range of β-boryl ketones were produced from terminal unactivated aliphatic alkenes and aryl iodides. Further synthetic transformations of the obtained β-boryl ketones have been developed as well.

A selectivity-reversed borocarbonylation reaction has been developed with complete regioselectivity.

Copper-Catalyzed Borylative Methylation of Alkyl Iodides with CO as the C1 Source: Advantaged by Faster Reaction of CuH over CuBpin

CuH and CuBpin are versatile catalysts and intermediates in organic chemistry. However, studies that involve both CuH and CuBpin in the same reaction is still rarely reported due to their high reactivity. Now, a study on CuH- and CuBpin-catalyzed borylative methylation of alkyl iodides with CO as the C1 source is reported. Various one carbon prolongated alkyl boranes (RCH₂ Bpin and RCH(Bpin)₂ ) were produced in moderate to good yields from the corresponding alkyl iodides (RI). In this cooperative system, CuH reacts with alkyl iodide faster than CuBpin.

Pd/Cu-Catalyzed Defluorinative Carbonylative Coupling of Aryl Iodides and gem-Difluoroalkenes: Efficient Synthesis of α-Fluorochalcones

An unprecedented and challenging defluorinative carbonylation was achieved. Enabled by a Pd/Cu cooperative catalyst system, the first example of defluorinative carbonylative coupling has been established. With gem-difluoroalkenes and aryl iodides as the substrates, this methodology offers flexible and facile access to privileged α-fluorochalcones under mild reaction conditions in moderate-to-excellent yields. Mechanistic studies indicated transmetalation between palladium and copper intermediates as a crucial step of the catalytic cycle.

Ligand-Controlled Copper-Catalyzed Regiodivergent Carbonylative Synthesis of α-Amino Ketones and α-Boryl Amides from Imines and Alkyl Iodides

Regioselective transformation is among the long-standing challenges in organic synthesis. In this communication, a copper-catalyzed selectivity controlled regiodivergent borocarbonylation of imines with alkyl iodides has been developed. Various α-amino ketones and α-boryl amides were produced in moderate to good yields from the same substrates. The choice of the ligand is key for the regioselectivity control: α-amino ketones were produced selectively in good yields with (p-CF₃ C₆ H₄ )₃ P as the ligand, whereas the corresponding α-boryl amides were obtained with high regioselectivities when using ^Me IMes as the ligand.

Copper-Catalyzed Carbonylative Hydroamidation of Styrenes to Branched Amides

Amides are one of the most ubiquitous functional groups in synthetic and medicinal chemistry. Novel and rapid synthesis of amides remains in high demand. In this communication, a general and efficient procedure for branch-selective hydroamidation of vinylarenes with hydroxyamine derivatives enabled by copper catalysis has been developed for the first time. The reaction proceeds under mild conditions and tolerates a broad range of functional groups. Applying a chiral phosphine ligand, an enantioselective variant of this transformation was achieved, affording a variety of chiral α-amides with excellent enantioselectivities (up to 99 % ee) and high yields.

Palladium-Catalyzed Tunable Carbonylative Synthesis of Enones and Benzofulvenes

A palladium-catalyzed four-component carbonylative coupling reaction involving aryl halides, internal alkynes, arylboronic acids, and CO has been developed for the first time. All-carbon substituted α-unsaturated ketones and benzofulvenes can be selectively obtained in a highly regio- and stereocontrolled manner. Using Cu(TFA)₂ as the additive, a series of tetrasubstituted α-unsaturated ketones were prepared in moderate to high yields. Using more acidic Lewis acid Cu(OTf)₂ as the additive, multisubstituted benzofluvenes were synthesized in moderate yields. This efficient methodology involved the formation of three new C-C bonds, and provided a divergent method for the quick construction of multisubstituted α-unsaturated ketones and benzofulvenes from easily available starting materials.

Deep-Blue and Hybrid-White Organic Light Emitting Diodes Based on a Twisting Carbazole-Benzofuro[2,3-b]Pyrazine Fluorescent Emitter

A novel deep-blue fluorescent emitter was designed and synthesized. The external quantum efficiency (η_EQE) of the blue-emitting, doped, organic light-emitting diode (OLED) was as high as 4.34%. The device also exhibited an excellent color purity with Commission Internationale de l’Eclairage (CIE) coordinates of x = 0.15 and y = 0.05. In addition, the triplet energy had a value of 2.7 eV, which is rare for an emitter with deep-blue emission, which makes it a preferred choice for high-performance white OLEDs. By optimizing the device architectures, the color of hybrid-white OLEDs could be tunable from warm white to cool white using the aforementioned material as a bifunctional material. That is, the η_EQE of the hybrid warm-white OLED is 20.1% with a CIE x and y of 0.46 and 0.48 and the η_EQE of the hybrid cool-white OLED is 9% with a CIE x and y of 0.34 and 0.33.

Near-Infrared Ternary Tandem Solar Cells

The paucity of near-infrared (NIR) organic materials with high absorption at long wavelengths, combined with large diffusion lengths and charge mobilities, is an impediment to progress in achieving high-efficiency organic tandem solar cells. Here a subcell is employed within a series tandem stack that comprises a solution-processed ternary blend of two NIR-absorbing nonfullerene acceptors and a polymer donor combined with a small-molecular-weight, short-wavelength fullerene-based subcell grown by vacuum thermal evaporation. The ternary cell achieves a power conversion efficiency of 12.6 ± 0.3% with a short-circuit current of 25.5 ± 0.3 mA cm^-2 , an open-circuit voltage of 0.69 ± 0.01 V, and a fill factor of 0.71 ± 0.01 under 1 sun, AM 1.5G spectral illumination. The success of this device is a result of the nearly identical offset energies between the lowest unoccupied molecular orbitals (LUMOs) of the donors with the highest occupied molecular orbital (HOMO) of the acceptor, resulting in a high open-circuit voltage. A tandem structure with an antireflection coating combining these subcells demonstrates a power conversion efficiency of 15.4 ± 0.3%.

Nickel-Catalyzed Carbonylative Synthesis of Functionalized Alkyl Iodides

Functionalized alkyl iodides are important compounds in organic chemistry and biology. In this communication, we developed an interesting nickel-catalyzed carbonylative synthesis of functionalized alkyl iodides from aryl iodides and ethers. With Mo(CO)₆ as the solid CO source, both cyclic and acyclic ethers were activated, which is also a challenging topic in organic synthesis. Functionalized alkyl iodides were prepared in moderate to excellent yields with outstanding functional group tolerance. Besides the high value of the obtained products, all the atoms from the starting materials were incorporated in the final products and the reaction had high atom efficiency as well.

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Nickel-catalyzed carbonylative synthesis of functionalized alkyl iodides

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With Mo(CO)₆ as the solid CO source, carbonylative ether activation

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Good yields of functionalized alkyl iodides

An Imide-Based Pentacyclic Building Block for n-Type Organic Semiconductors

A new electron-deficient unit with a fused 5-membered heterocyclic ring was developed by replacing a cyclopenta-1,3-diene from electron-rich donor indacenodithiophene (IDT) with a cyclohepta-4,6-diene-1,3-diimde unit. The imide bridge endows dithienylbenzenebisimide (BBI) with a fixed planar configuration and low energy levels for both the highest occupied molecular orbital (HOMO; -6.24 eV) and the lowest unoccupied molecular orbit (LUMO; -2.57 eV). Organic field-effect transistors (OFETs) based on BBI polymers exhibit electron mobility up to 0.34 cm²  V^-1  s^-1 , which indicates that the BBI is a promising n-type building block for optoelectronics.

Direct Palladium-Catalyzed Carbonylative Transformation of Allylic Alcohols and Related Derivatives

A direct, palladium-catalyzed, carbonylative transformation of allylic alcohols for the synthesis of β,γ-unsaturated carboxylic acids has been developed. With formic acid as the CO source, various allylic alcohols were conveniently transformed into the corresponding β,γ-unsaturated carboxylic acids with excellent linear and (E)-selectivity. The reaction was performed under mild conditions; toxic CO gas manipulation and high-pressure equipment were avoided in this procedure.

Fabrication and application of a non-contact double-tapered optical fiber tweezers

A double-tapered optical fiber tweezers (DOFTs) was fabricated by a chemical etching called interfacial layer etching. In this method, the second taper angle (STA) of DOFTs can be controlled easily by the interfacial layer etching time. Application of the DOFTs to the optical trapping of the yeast cells was presented. Effects of the STA on the axile trapping efficiency and the trapping position were investigated experimentally and theoretically. The experimental results are good agreement with the theoretical ones. The results demonstrated that the non-contact capture can be realized for the large STA (e.g. 90 deg) and there was an optimal axile trapping efficiency as the STA increasing. In order to obtain a more accurate measurement result of the trapping force, a correction factor to Stokes drag coefficient was introduced. This work provided a way of designing and fabricating an optical fiber tweezers (OFTs) with a high trapping efficient or a non-contact capture.

Palladium-catalyzed carbonylative Sonogashira coupling of aryl diazonium salts with formic acid as the CO source: the effect of 1,3-butadiene

An efficient carbonylative cross-coupling of aryl diazonium salts with terminal alkynes using formic acid as the CO source has been developed. And 1,3-butadiene was found to play a crucial role in this transformation.

[The effect of phospholipid transfer protein on cigarette smoke extract induced epithelial-mesenchymal transition of rat alveolar type Ⅱ cells]

OBJECTIVE

To investigate the effect of phospholipid transfer protein(PLTP) on cigarette smoke extract(CSE) induced epithelial-mesenchymal transition(EMT) in rat alveolar Type Ⅱ cells (RLE-6TN).

METHODS

CSE of different concentrations (0%, 0.25%, 0.5% and 1%) was co-cultured for 2 or 3 days with RLE-6TN, either pre-treated or not pre-treated with siRNA-PLTP for 6 h. Expression levels of E-cadherin mRNA and Vimentin mRNA were examined by RT-PCR, while expression levels of PLTP, E-cadherin, N-cadherin and Vimentin were examined by Western blot.

RESULTS

Our results showed that the expression of E-cadherin mRNA decreased in CSE-treated groups: 1.01±0.05, 0.74±0.05, 0.65±0.03, 0.30±0.08 respectively at different concentrations of CSE (0 %, 0.25%, 0.5 %, and 1.0%); while the level of Vimentin mRNA increased significantly in 1% CSE treated cells(1.88±0.49), compared with control cells (1.01±0.20). Treatment with CSE at different concentrations (0%, 0.25%, 0.5% and 1%) showed that the protein levels of PLTP were 0.42±0.02, 0.89±0.25, 1.08±0.18, 1.61±0.06 respectively; those of E-cadherin were 1.61±0.04, 1.08±0.10, 0.62±0.08, 0.68±0.17, respectively; those of N-cadherin were 0.60±0.14, 0.57±0.26, 0.88±0.30, 1.94±0.54, respectively; and those of Vimentin were 0.61±0.05, 0.98±0.16, 1.07±0.14, 1.34±0.19, respectively; all P<0.05 when the 1% CSE group was compared with the control group. EMT induced by CSE was significantly inhibited by siRNA-PLTP.

CONCLUSION

PLTP may be involved in CSE induced EMT of rat alveolar cells.

Calculation of the radiation forces on a microsphere in the evanescent field of an optical nanofiber by ray tracing

We use ray optics to calculate the radiation forces on a dielectric microsphere in the evanescent field of an optical nanofiber. We theoretically demonstrate that the gradient force may attract the microsphere onto the fiber surface. The scattering force may transport the microsphere along the fiber and in the light propagating direction. The impact of the sphere-fiber distance, sphere radius, and fiber radius on the scattering and gradient forces are investigated. The radius of nanofiber can be optimized for particle transportation.

Chest wall recurrence location and the lower-bound target of preventive radiotherapy after transverse incision in modified radical mastectomy

We investigated the relationship between the lower-bound target of preventive radiation to the chest wall after modified radical mastectomy with a transverse incision and preoperative breast carcinoma characteristics to provide a basis for reducing radiation injury to neighboring tissues and individualizing preventive chest wall radiation targets. We analyzed the relationship between clinical stage, pathology, diseased region, condition of vessel tumor embolus, sex hormone levels, HER-2 expression levels, receipt of chemotherapy, and the distance of local chest wall recurrence under the edge of the transverse incision in 112 patients with local chest wall recurrence after radical mastectomy. There were 64 cases (57.1%) with local chest wall recurrence within 3 cm below the transverse incision fringe, 31 cases (27.7%) within 3-5 cm, 14 cases (12.5%) within 5-7 cm, and 3 cases (2.7%) exceeded 7 cm. There were statistically significant correlations between the distance from the focus of the chest wall recurrence to the inferior margin of the transverse incision and the T stage, HER-2 expression levels, and receipt of chemotherapy. For more than 97% of patients undergoing radical mastectomy with a transverse incision, the distance of local chest wall recurrence under the edge of the transverse incision was less than 7 cm. To accomplish individualized treatment in defining radiotherapy targets, we should pay attention to T stage, HER- 2 expression levels, and the receipt of chemotherapy when determining the lower-bound location of the target for preventive chest wall radiation after modified radical mastectomy with a transverse incision.

Synchronization of time-delayed chemically coupled burst-spiking neurons with correlated noises

Synchronization of two time-delayed chemically coupled neurons with burst-spiking states is studied. Different from the previous study by N. Buric et al. (Phys. Rev. E 78, 036211 (2008)), it is found that exactly synchronous burst-spiking dynamics can occur for small coupling strengths and time delays. The results are confirmed by common time delays and non-equal time delays. When common noise is added to the two neurons, synchronization is enhanced as noise strength is increased. But the results are different for larger time delay and smaller time delay. When noises are correlated, it is found that only strong noises with large correlation coefficient can induce exact synchronization. Even one percent of independent noises can influence synchronization much.

Quantification of deposition of neutrophilic granulocytes on vascular grafts in dogs with 111In-labeled granulocytes

A new radioisotopic technique has been developed for quantification of deposition of neutrophilic granulocytes on vascular grafts. Nine healthy mongrel dogs underwent bilateral femoral artery resection and reconstruction with grafts of femoral vein and Gore-Tex. Pure granulocytes that had been separated from whole blood by centrifugal elutriation were labeled with 111In-tropolone in plasma. The granulocyte harvesting efficiency was 25 +/- 12%, and the labeling efficiency was 87 +/- 7%. Three hours after injection of labeled granulocytes and 2 hours after reperfusion, the grafts were harvested and cut into several segments for study of areas of anastomoses and midsections. On the basis of the radioactivity in the blood and in anastomotic and graft sections, the area of graft sections, and the neutrophilic granulocyte and differential leukocyte counts, the number of neutrophilic granulocytes adherent to a unit area and the total number of neutrophilic granulocytes on graft sections were calculated. These quantifications of the deposition of neutrophilic granulocytes indicated that the midsections of Gore-Tex grafts retained more neutrophilic granulocytes than did the midsections of vein grafts. Although the anastomotic areas retained more neutrophilic granulocytes than did the midsections of vein grafts, the opposite finding prevailed for the Gore-Tex grafts. A major fraction of neutrophilic granulocytes on Gore-Tex grafts was incorporated into thrombus. Semiquantitative information obtained by scintigraphy of the deposition of neutrophilic granulocytes on vascular grafts also confirmed this observation.