Simultaneous construction of inherent and axial chirality by cobalt-catalyzed enantioselective C-H activation of calix[4]arenes.

The simultaneous construction of multiple stereogenic elements in a single step is highly appealing and desirable in the field of asymmetric synthesis. Furthermore, the catalytic enantioselective synthesis of inherently chiral calix[n]arenes with high enantiopurity has long been a challenging endeavor. Herein, we report an enantioselective cobalt-catalyzed C-H activation/annulation for the efficient construction of inherently chiral calix[4]arenes bearing multiple C-N axially chiral element.

Atroposelective N-N Axes Synthesis via Electrochemical Cobalt Catalysis.

Here, we disclosed an unprecedented cobalt electrocatalyzed atroposelective C-H activation and annulation for the efficient construction of diversely functionalized N-N axes in an undivided cell. A broad range of allene substrates and benzamides bearing different functionalities are compatible with generating axially chiral products with good yields and excellent enantioselectivities (up to 92% yield and 99% ee). A series of synthetic applications and control experiments were also performed, which further expanded the practicality of this strategy.

Curcumin alleviates zearalenone-induced liver injury in mice by scavenging reactive oxygen species and inhibiting mitochondrial apoptosis pathway.

Curcumin (CUR) is a compound extracted from turmeric that has a variety of functions including antioxidant and anti-inflammatory. As an estrogen-like mycotoxin, zearalenone (ZEN) not only attacks the reproductive system, but also has toxic effects on the liver. However, whether CUR can alleviate ZEN-induced liver injury remains unclear.

Cobalt-catalyzed atroposelective C-H activation/annulation to access N-N axially chiral frameworks.

The N-N atropisomer, as an important and intriguing chiral system, was widely present in natural products, pharmaceutical lead compounds, and advanced material skeletons. The anisotropic structural characteristics caused by its special axial rotation have always been one of the challenges that chemists strive to overcome. Herein, we report an efficient method for the enantioselective synthesis of N-N axially chiral frameworks via a cobalt-catalyzed atroposelective C-H activation/annulation process.

C-N Axially Chiral Heterobiaryl Isoquinolinone Skeletons Construction via Cobalt-Catalyzed Atroposelective C-H Activation/Annulation.

Herein, the atroposelective construction of isoquinolinones bearing a C-N chiral axis has been successfully developed via a Co-catalyzed C-H bond activation and annulation process. This conversion can be effectively carried out in an environmentally friendly oxygen atmosphere to generate the target C-N axially chiral frameworks with excellent reactivities and enantioselectivities (up to >99% ee) in the absence of any additives. Additionally, the current protocol has proved to be an alternative approach for the C-N axial architectures fabrication under electrochemical conditions for cobalt/Salox catalysis, and this strategy allowed the efficient and atom-economical synthesis of various axially chiral isoquinolinones under mild reaction conditions.

C-N Axially Chiral Heterobiaryl Skeletons Construction via Cobalt-Catalyzed Atroposelective Annulation.

Herein, the atroposelective construction of five-six heterobiaryl skeleton-based C-N chiral axis has been successfully accomplished via a Co-catalyzed C-H bond activation and annulation process, in which the isonitrile was employed as the C1 source and the 8-aminoquinoline moiety served as both directing group and integral part of C-N atropisomers, respectively. This conversion can be effectively carried out in an environmentally friendly oxygen atmosphere, generating the target axial heterobiaryls with excellent reactivities and enantioselectivities (up to >99% ee) in the absence of any additives, and the obtained 3-iminoisoindolinone products with a five membered N-heterocycle exhibit high atropostability. Additionally, the C-N axially chiral monophosphine backbones derived from this protocol possess the potential to become an alternative ligand platform.

Cobalt-catalyzed enantioselective C-H/N-H annulation of aryl sulfonamides with allenes or alkynes: facile access to C-N axially chiral sultams.

Herein we report a cobalt-catalyzed enantioselective C-H/N-H annulation of aryl sulfonamides with allenes and alkynes, using either chemical or electrochemical oxidation. By using O as the oxidant, the annulation with allenes proceeds efficiently with a low catalyst/ligand loading of 5 mol% and tolerates a wide range of allenes, including 2,3-butadienoate, allenylphosphonate, and phenylallene, resulting in C-N axially chiral sultams with high enantio-, regio-, and position selectivities. The annulation with alkynes also exhibits excellent enantiocontrol (up to >99% ee) with a variety of functional aryl sulfonamides, and internal and terminal alkynes.

Effects of Vitamin A on Immune Responses and Vitamin A Metabolism in Broiler Chickens Challenged with Necrotic Enteritis.

Necrotic enteritis (NE) is an important enteric inflammatory disease of poultry, and the effects of vitamin A (VitA) on NE birds are largely unknown. The present study was conducted to investigate the effects of VitA on the immune responses and VitA metabolism of NE broilers as well as the underlying mechanisms. Using a 2 × 2 factorial arrangement, 336 1-day-old Ross 308 broiler chicks were randomly assigned to 4 groups with 7 replicates.

Effects of Dietary Supplementation with Vitamin A on Antioxidant and Intestinal Barrier Function of Broilers Co-Infected with Coccidia and .

Necrotic enteritis (NE) impairs poultry production and causes great economic loss. The nutritional regulation of diets has the potential to alleviate NE. The present study was conducted to investigate the effects of dietary supplementation with vitamin A (VA) on the antioxidant and intestinal barrier function of broilers co-infected with coccidia and C.

Nickel-Catalyzed -Markovnikov Hydrodifluoroalkylation of Unactivated Alkenes.

An efficient Ni-catalyzed hydrodifluoroalkylation of unactivated alkenes with bromodifluoroacetate by using PhSiH as hydride source was developed. The transformation affords aliphatic difluorides with -Markovnikov regioselectivity. A wide range of highly remote alkenes, simple alkenes, drug molecules, commercially available CF precursors, and even nonfluorinated substrates are competent in this reaction under mild conditions, demonstrating the practicability of the strategy.

Reconstruction and optimization of the 3D geometric anatomy structure model for subject-specific human knee joint based on CT and MRI images.

Background: Nowadays, the total knee arthroplasty (TKA) technique plays an important role in surgical treatment for patients with severe knee osteoarthritis (OA). However, there are still several key issues such as promotion of osteotomy accuracy and prosthesis matching degree that need to be addressed.

Objective: It is significant to construct an accurate three-dimensional (3D) geometric anatomy structure model of subject-specific human knee joint with major bone and soft tissue structures, which greatly contributes to obtaining personalized osteotomy guide plate and suitable size of prosthesis.

Directed Cobalt-Catalyzed C-H Activation to Form C-C and C-O Bonds in One Pot via Three-Component Coupling.

Herein, we disclose an efficient cobalt-catalyzed three-component coupling of benzamides, diazo compounds, and -butyl hydroperoxide, which provides an efficient approach to construct C(sp)-C(sp) and C-O bonds in one-pot accompanied with C-H activation. This protocol features low catalyst loading (4 mol %), the avoidance of additives, and excellent functional group compatibility, providing three-component coupling adducts with high yields under mild conditions (up to 88%). Mechanism studies show that the reaction may involve a radical process.

Synthesis of 7-Amido Indolines by Cp*Co(III)-Catalyzed C-H Bond Amidation.

An efficient Cp*Co(III)-catalyzed C-H bond amidation of indolines at the C7-position using dioxazolone as amidating reagents was first reported. -Methyl--(pyrimidin-2-yl)aniline was also found to be a competent coupling partner. This protocol exhibits several unique characteristics, including excellent isolated yields, good functional group tolerance, and operational convenience.

Achieved RGBY Four Colors Changeable Electrochromic Pixel by Coelectrodeposition of Iron Hexacyanoferrate and Molybdate Hexacyanoferrate.

Although multicolor electrochromic materials and devices have been studied by many researchers, there is still none an inorganic single-layer film that has red, blue, and green three typical color states, while red, green, and blue (RGB) are indispensably for multicolor display. Iron hexacyanoferrate (FeHCF) is a kind of well-studied inorganic electrochromic material with relatively colorful properties and a great family of analogues. In this Research Article, the RGBY film with red, green, blue and yellow four typical color states are obtained successfully by coelectrodeposition of FeHCF and molybdate hexacyanoferrate (MoOHCF).

Directed Cobalt-Catalyzed -Markovnikov Hydroalkylation of Unactivated Alkenes Enabled by "Co-H" Catalysis.

The earth-abundant cobalt-catalyzed -Markovnikov hydroalkylation of unactivated alkenes with oxime esters was achieved by introducing an 8-aminoquinoline directing group on the alkenes. The catalytic system, consisting of commercially available Co(acac) and PhMeSiH, enables the construction of unfunctionalized C(sp)-C(sp) bonds and features exclusive -Markovnikov selectivity, good functional group tolerance, and the avoidance of an extra ligand, oxidant, or base. Mechanistic insight into this new catalytic system indicates the involvement of both alkyl radical and cobalt hydride intermediates.

Development of a Traceless Directing Group: Cp*-Free Cobalt-Catalyzed C-H Activation/Annulations to Access Isoquinolinones.

A new traceless directing group, 2-(hydroxymethyl)pyridine, has been reported for the Cp*-free cobalt-catalyzed C-H activation/annulation reaction to synthesize isoquinolinones. The reaction exhibits good functional group tolerance, affording products in good to excellent isolated yields under mild conditions. Notably, the directing group can be removed directly in situ along the catalytic process.

Manganese-catalyzed cascade annulations of alkyne-tethered N-alkoxyamides: synthesis of polycyclic isoquinolin-1(2H)-ones.

A strategy for the synthesis of isoxazolidine/1,2-oxazinane-fused isoquinolin-1(2H)-ones from alkyne-tethered N-alkoxyamides is described, in which cheap Mn(acac) is used as a catalyst to facilitate a radical cascade annulation. The method features mild conditions, additive-free reaction and broad substrate scope. It is the first example via manganese/air catalytic systems to construct isoquinolin-1(2H)-one heterocycles.

Cp*-Free Cobalt-Catalyzed C-H Activation/Annulations by Traceless N, O-Bidentate Directing Group: Access to Isoquinolines.

N, O-Bidentate directing-enabled, traceless heterocycle synthesis is described via Cp*-free cobalt-catalyzed C-H activation/annulation. The weakly coordinating nature of the carboxylic acid was employed for the preparation of isoquinolines. Meanwhile, the N-O bond of the α-imino-oxy acid can serve as an internal oxidant.

Mechanical Energy Expenditure-based Comfort Evaluation Model for Gesture Interaction.

As an advanced interaction mode, the gesture has been widely used for the human-computer interaction (HCI). The paper proposes a comfort evaluation model based on the mechanical energy expenditure (MEE) and the mechanical efficiency (ME) to predict the comfort of gestures. The proposed comfort evaluation model takes nineteen muscles and seven degrees of freedom into consideration based on the data of muscles and joints and is capable of simulating the MEE and the ME of both static and dynamic gestures.

Synthesis, characterization, DNA binding, topoisomerase I inhibition and antiproliferation activities of three new functionalized terpyridine platinum(II) complexes.

Three new platinum(II) complexes with pendent morpholine were synthesized, namely complex 1 ([Pt(L)Cl]CFSO), complex 2 ([Pt(L)(NH)](CFSO)) and complex 3 ([Pt(L)(PPh)](CFSO)), where L = 4'-[4-(4-morpholinobutyloxy)phenyl]-2,2':6',2″-terpyridine and PPh = triphenylphosphine. The detailed molecular structures of complex 3, L and its precursor L' (1,4'-[4-(4-bromobutyloxy)phenyl]-2,2':6',2″-terpyridine) were determined by single crystal X-ray diffraction. An evaluation of in vitro cytotoxicity for both ligand and complexes was performed by methyl thiazolyl tetrazolium (MTT) assay in three cancer cell lines and normal cells as the control, respectively.

Cobalt-catalyzed -selective alkoxylation of 1-naphthylamine derivatives.

A cobalt-catalyzed C(sp)-H alkoxylation of 1-naphthylamine derivatives has been disclosed, which represents an efficient approach to synthesize aryl ethers with broad functional group tolerance. It is noteworthy that secondary alcohols, such as hexafluoroisopropanol, isopropanol, isobutanol, and isopentanol, were well tolerated under the current catalytic system. Moreover, a series of biologically relevant fluorine-aryl ethers were easily obtained under mild reaction conditions after the removal of the directing group.

Cobalt(II)-Catalyzed Oxidative C-H Arylation of Indoles and Boronic Acids.

Co(II)-catalyzed C-H C2 selective arylation of indoles with boronic acids through monodentate chelation assistance has been achieved for the first time. The unique features of this methodology include mild reaction conditions, highly C2 regioselectivity, and employment of a Grignard reagent-free catalytic system. A wide range of substrates, including unreactive arenes, are well tolerated, which enables the construction of the coupling products efficiently.

[Research of Kinematics and Kinetics Models of Human Knee Joint].

Human knee joint as a research object, it has become an effective way to establish models of human knee joint. The types of human knee joint models are identified, and each type of model is simply introduced respectively. Focusing on the types of the kinematics and kinetics models of human knee joint on the basis of anatomy, the current research status is detailedly described and comprehensively analyzed at home and abroad correspondingly.

Mixed Directing-Group Strategy: Oxidative C-H/C-H Bond Arylation of Unactivated Arenes by Cobalt Catalysis.

A mixed directing-group strategy for inexpensive [Co(acac) ]-catalyzed oxidative C-H/C-H bond arylation of unactivated arenes has been disclosed. This strategy enables the arylation of a wide range of benzamide and arylpyridines effectively to afford novel bifunctionalized biaryls, which are difficult to achieve by common synthetic routes. Two different pathways, namely, a single-electron-transmetalation process (8-aminoquinoline-directed) and a concerted metalation-deprotonation process (pyridine-directed), were involved to activate two different inert aromatic C-H bonds.

Cobalt(II)-Catalyzed Decarboxylative C-H Activation/Annulation Cascades: Regioselective Access to Isoquinolones and Isoindolinones.

A new cobalt(II)-catalyzed decarboxylative C-H activation/annulation of benzamides and alkynyl carboxylic acids has been described. Alkynyl carboxylic acids were first employed as the coupling partners using inexpensive Co(OAc)2·4H2O as the catalyst. This method enables a switchable cyclization to isoquinolones and isoindolinones with excellent selectivity.