A new series of cationic ruthenium(II) complexes, [RuCl(PPh)(κ-NNN-L1)]Cl (1), [RuH(PPh)(κ-NNN-L2)]Cl (2), and [RuH(PPh)(κ-NNN-L3)]Cl (3), bearing a 2,6-bis (1-R-5-methyl-pyrazol-3-yl) pyridine ligand (L1: R = H, L2: R = CH--CF, L3: R = CH--OCH), were synthesized and characterized with NMR, HRMS, and single-crystal X-ray diffraction. Their catalytic application was investigated in the acceptorless dehydrogenation (AD) of primary alcohols. Complex 1 outperformed 2 and 3 in terms of the selectivity towards the aldehydes, and provided the aldehydes with a yield of up to 99%, with good functional group tolerance under mild conditions.
View Article and Find Full Text PDFHerein, a Pd/Cu bimetallic-catalyzed direct C-H heteroarylation of pyridines via the traceless protecting group strategy is described. A series of -methyl-activated pyridines and 1-methylindoles are coupled with high regioselectivity to produce the corresponding 3-(pyridin-2-yl)indoles in moderate to good yields, wherein related electron-rich heterocycles (e.g.
View Article and Find Full Text PDFThe entomopathogenic fungus Beauveria bassiana is a typical filamentous fungus and has been used for pest biocontrol. Conidia are the main active agents of fungal pesticides; however, we know little about conidial developmental mechanisms and less about maturation mechanisms. We found that a ZnCys transcription factor of bassiana (named BbCmr1) was mainly expressed in late-stage conidia and was involved in conidium maturation regulation.
View Article and Find Full Text PDFThe introduction of amines onto aromatics without metal catalysts and chemical oxidants is synthetically challenging. Herein, we report the first example of an electrochemical cross-dehydrogenative aromatization (ECDA) reaction of saturated cyclohexanones and amines to construct anilines without additional metal catalysts and chemical oxidants. This reaction exhibits a broad scope of cyclohexanones including heterocyclic ketones, affording a variety of aromatic amines with various functionalities, and shows great potential in the synthesis of biologically active compounds.
View Article and Find Full Text PDFEngineering high-performance electrocatalysts is of great importance for energy conversion and storage. As an efficient strategy, element doping has long been adopted to improve catalytic activity, however, it has not been clarified how the valence state of dopant affects the catalytic mechanism and properties. Herein, it is reported that the valence state of a doping element plays a crucial role in improving catalytic performance.
View Article and Find Full Text PDFThe NaIO-mediated sequential iodination/amidation reaction of -alkyl quinolinium iodide salts has been first developed. This cascade process provides an efficient way to rapidly synthesize 3-iodo--alkyl quinolinones with high regioselectivity and good functional group tolerance. This protocol was also amenable to the isoquinolinium salts, thus providing a complementary method for preparing the 4-iodo--alkyl isoquinolinones.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2020
Metallic catalysts with nanopores are advantageous on improving both activity and selectivity, while the reason behind that remains unclear all along. In this work, porous Zn nanoparticles (P-Zn) were adopted as a model catalyst to investigate the catalytic behavior of metallic nanopores. In situ X-ray absorption spectroscopy, in situ Fourier transform infrared spectroscopy, and density functional theory (DFT) analyses reveal that the concave surface of nanopores works like a pincer to capture and clamp CO and H O precursors simultaneously, thus lowering the energy barriers of CO electroreduction.
View Article and Find Full Text PDFMosquito-borne diseases have become an important public health issue of global concern because of their high incidence and transmission rate. As a vector for mosquito-borne diseases, studying the interaction mechanism between mosquitoes and mosquito-borne viruses will help control mosquito-borne diseases. The impaired innate immunity and immune barriers evasion caused by mosquito-borne viruses in mosquitoes pose a potential risk for the persistent infection of the virus in mosquitoes and the outbreak of mosquito-borne diseases.
View Article and Find Full Text PDFAn efficient Pd-catalyzed arylation of alkylpyridine based on the pyridinium activation strategy has been developed for synthesis of mixed aryl alkylpyridines. It was found that (1) the -methyl group in the pyridinium salts acted as a transient activator and could be automatically departed after the reaction, (2) CuBr was an indispensable additive for achieving the C-selective arylation, (3) the α-branched alkyl chain on the alkylpyridine greatly increased the yield of the product. Deuterium labelling experiment revealed that in the case of the α-branched alkylpyridine, the presence of CuBr completely inhibited the H/D exchange at the benzylic position and thus enabled the selective arylation at the C position.
View Article and Find Full Text PDFA selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl] and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand () has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a -ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.
View Article and Find Full Text PDFThe hydroformylation of long chain alkenes catalyzed by a water soluble Rh/TPPTS complex (TPPTS: sodium salt of sulfonated triphenylphosphine) in methanol was investigated. The mixture of rhodium precursor HRh(CO)(TPPTS), ligand TPPTS, methanol and a long chain alkene becomes a single phase under reaction conditions, which make the hydroformylation reaction proceed homogeneously. Both the conversion of long chain alkene and the selectivity to aldehydes (including the aldehydes forming methylacetals) could reach up to 97.
View Article and Find Full Text PDFOxygen evolution reaction (OER) is a pivotal reaction in many technologies for renewable energy, such as water splitting, metal-air batteries, and regenerative fuel cells. However, this reaction is known to be kinetically sluggish and proceeds at rather high overpotential due to the universal scaling relationship, namely, the adsorption energies of intermediates are linearly correlated and cannot be optimized simultaneously. Several approaches have been proposed to break the scaling relationship by introducing additional active sites; however, positive experimental results are still absent.
View Article and Find Full Text PDFHerein, an efficient and green method for the selective synthesis of tertiary amines has been developed that involves iridium-catalyzed alkylation of various primary amines with aromatic or aliphatic alcohols. Notably, the catalytic protocol enables this transformation in the absence of additional base and solvent. Furthermore, the alkylation of nitrobenzene with primary alcohol to tertiary amine has also been achieved by the same catalytic system.
View Article and Find Full Text PDFPolysaccharides are some of the most important bioactive compounds in Lentinus edodes, but little attention has been devoted to the genetic basis of polysaccharide content. Here, the polysaccharide content of fruiting body, and 11 agronomic traits related to morphologic characteristics of fruiting body, yield and precocity of 50 L. edodes strains were screened and analyzed.
View Article and Find Full Text PDFThe first Pd-catalyzed multicomponent reaction of aryl iodides, alkenyl bromides, and strained alkenes has been developed, which allowed us to synthesize a variety of multisubsituted olefins in yields of 45-96% with excellent stereoselectivity. The configuration of the product was controlled by the configuration of the alkenyl bromides. Moreover, this practical methodology employing readily available substrates was found to be tolerant to a wide range of functional groups.
View Article and Find Full Text PDFIt is well-documented that CL316,243 (a β3 agonist) or rosiglitazone (a PPARγ agonist) can induce white adipocyte populations to brown-like adipocytes, thus increasing energy consumption and combating obesity. However, whether there is a combined effect remains unknown. In the present study, stromal vascular cells of inguinal white adipose tissue (iWAT-SVCs for short) from mice were cultured and induced into browning by CL316,243, rosiglitazone, or both.
View Article and Find Full Text PDFManganese-based oxides have exhibited high promise as noncoinage alternatives to Pt/C for catalyzing oxygen reduction reaction (ORR) in basic solution and a mix of Mn valence is believed to be vital in achieving optimum ORR performance. Here, it is proposed that, distinct from the most studied perovskites and spinels, Mn-based mullites with equivalent molar ratio of Mn and Mn provide a unique platform to maximize the role of Mn valence in facile ORR kinetics by introducing modest content of oxygen deficiency, which is also beneficial to enhanced catalytic activity. Accordingly, amorphous mullite SmMn O nanoparticles with finely tuned concentration of oxygen vacancies are synthesized via a versatile top-down approach and the modest oxygen-defective sample with an Mn /Mn ratio of 1.
View Article and Find Full Text PDFA simple and efficient strategy for the synthesis of 1-propenylnaphthols from readily accessible 3-arylallylnaphthyl ethers has been developed. By using KCO as base and 2-methoxyethanol as solvent, direct access to a wide range of 1-propenylnaphthols can be achieved in generally good yield (up to 99%) with high stereoselectivity toward the Z isomer. The control experiments indicate that the reaction proceeds through a sequential Claisen rearrangement/isomerization process.
View Article and Find Full Text PDFZhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
February 2017
DNA barcoding technique is a fast and accurate method for species identification. The DNA barcoding based on cytochrome c oxidase subunit Ⅰ (COⅠ) has recently been successfully applied for species identification of Culicidae. In this paper, we introduce the technique and principle of DNA barcoding, application and limitation of the technique based on CO I gene for species identification, as well as research development on applications of other molecular makers such as COⅡ,16S RNA, and the first and the second internal transcribed spacers (ITS1 and ITS2) in species identification and to assist the COⅠ gene in identifying Culicidae species.
View Article and Find Full Text PDFTiO2 has excellent electrochemical properties but limited solar photocatalytic performance in light of its large bandgap. One important class of visible-wavelength sensitizers of TiO2 is based on ZnFe2 O4 , which has shown fully a doubling in performance relative to pure TiO2 . Prior efforts on this important front have relied on presynthesized nanoparticles of ZnFe2 O4 adsorbed on a TiO2 support; however, these have not yet achieved the full potential of this system since they do not provide a consistently maximized area of the charge-separating heterointerface per volume of sensitizing absorber.
View Article and Find Full Text PDFStrongly coupled Nafion molecules and ordered porous CdS networks are fabricated for visible-light photoelectrochemical (PEC) hydrogen evolution. The Nafion layer coating shifts the band position of CdS upward and accelerates charge transfer in the photoelectrode/electrolyte interface. It is highly expected that the strong coupling effect between organic and inorganic materials will provide new routes to advance PEC water splitting.
View Article and Find Full Text PDFMicroRNAs are a family of small, non-coding RNAs that regulate gene expression in a sequence-specific manner. Estrogen-related receptor α (ERRα) is an orphan nuclear receptor which plays an important role in adipocyte differentiation. Our previous Solexa sequencing results indicated a high expression of miR-125a in adult pig backfat.
View Article and Find Full Text PDFThe process of preadipocytes differentiation plays a vital role in adipose tissue expansion and many factors are involved in this event. Cathepsin B (CTSB), secreted from lysosome, has been reported in regulating a variety of physiological processes. In this study, we demonstrated CTSB promotes lipid accumulation and adipogenic genes expression in porcine primary preadipocytes by degrading fibronectin (Fn), a key component of extracellular matrix.
View Article and Find Full Text PDF