This review covers some unique diazo compounds, the coupling partners to access various versatile functionalized nitrogen heterocycles, such as indoles, indolines, isoquinolines, isoquinolones, and ...so on. Different transition metals (such as Rh, Pd, Ru, Ir, Cu, and Co) are involved in these transformations, which involve consecutive processes: transition metal‐catalyzed cascade C–H activation/carbene insertion/intramolecular annulation.
The cyano group is well known as a versatile intermediate for transformations into a multitude of useful functional groups such as carboxyl, carbamoyl, aminomethyl, carbonyl, and heterocycles. ...Moreover, benzonitriles and α-aminonitriles are practical synthetic and natural scaffolds. This paper reviews catalytic methodologies for direct cyanation reactions of C–H bonds. These are classified by the cyano-group sources and are sorted into three categories: (i) organic cyano-group sources, (ii) metallic cyano-group sources, and (iii) combined cyano-group sources. This review includes all the reported methods in the literature until the beginning of 2016.
The one‐step direct regioselective functionaliztion of inert C(sp2)–H bonds is an efficient and sustainable methodology for the synthesis of a variety of useful natural products and pharmaceutical ...intermediates. A range of functional groups have been widely used as directing group for various regioselective transformations. Among these, the weakly coordinating nitrile group has attracted much attention because it is a transformable, easily installed and readily removed directing group, which can be easily converted into a number of different functional groups, such as carboxyl, carbamoyl, aminomethyl, carbonyl, and heterocyclic functionalities. This review describes recent advances in nitrile‐directed C–H functionalizations catalyzed by palladium(II), ruthenium(II), rhodium(III) and iridium(I) catalysts. The review is divided into sections related to ortho‐, meta‐, and para‐C–H bond functionalizations, which are subdivided according to reaction type (olefination, arylation, halogenation, hydroxylation and acetoxylation).
Under microwave irradiation, eighteen new aroylhydrazone diorganotin complexes (
-
) were produced through the reaction of aroylhydrazine, 2-ketobutyric acid, and the corresponding diorganotin. ...Fourier transform infrared spectroscopy,
H,
C, and
Sn nuclear magnetic resonance spectroscopies, high-resolution mass spectroscopy, X-ray crystallography, and thermogravimetric analysis (TGA) were performed to characterize the complexes. The in vitro anticancer activity for complexes were assessed using a CCK-8 assay on human cancer cells of HepG2, NCI-H460, and MCF-7. Complex
revealed more intensive anticancer activity against MCF-7 cells than the other complexes and cisplatin. Flow cytometry analysis and transmission electron microscope observation demonstrated that complex
mediated cell apoptosis of MCF-7 cells and arrested cell cycle in S phase. Western blotting analysis showed that
induced DNA damage in MCF-7 cells and led to apoptosis by the ATM-CHK2-p53 pathway. The single cell gel electrophoreses assay results showed that
induced DNA damage. The DNA binding activity of
was studied by UV-Visible absorption spectrometry, fluorescence competitive, viscosity measurements, gel electrophoresis, and molecular docking, and the results show that
can be well embedded in the groove and cleave DNA.
Great progress has been made in the tandem annulation of enynes in the past few years. This review only presents the corresponding reactions of 1,3-enyne structural motifs to provide the ...functionalized pyridine and pyrrole derivatives. The functionalization reactions cover iodination, bromination, trifluoromethylation, azidation, carbonylation, arylation, alkylation, selenylation, sulfenylation, amidation, esterification, and hydroxylation. We also briefly introduce the applications of the products and the reaction mechanisms for the synthesis of corresponding N-heterocycles.
This review focuses on the most recent advances in the field of transition‐metal‐catalyzed direct intermolecular C−H amidation and amination of arenes. The manuscript is divided into two parts ...according to whether or not external oxidants are required. The first part includes the cases of simple neutral amines, amides, or sulfonamides in combination with external oxidants. The second section contains the examples of preactivated amino sources in the absence of any external oxidants. In each part, the content is classified in line with the different types of transition‐metal catalysts used, including Rh, Ru, Ir, Pd, Cu, Ni, Co, and Fe. In addition, the substrate scope and limitations as well as catalytic mechanism are discussed.
Amidation and amination: Recent advances in the field of transition‐metal‐catalyzed direct intermolecular C−H amidation and amination of arenes are summarized. There are generally two types of reaction models. The first kind employs simple neutral amines, amides, or sulfonamides in combination of external oxidants. The second class utilizes preactivated amino sources in the absence of any external oxidants.
A Pd/norbornene-catalyzed direct meta-alkylation of nosyl-protected phenylalanine derivatives with alkyl iodides is reported in moderate to good yields. The use of diisopropyl ...bicyclo2.2.1hept-5-ene-2,3-dicarboxylate is identified as a more suitable transient mediator. A simple pyridine ligand is also essential for this reaction to proceed. No racemization was observed in this meta-methylation reaction.
A facile and novel silver tetrafluoroborate catalyzed electrophilic cascade cyclization reaction to generate halo-substituted benzoafluorenols under mild conditions is disclosed. Good chemical ...selectivity and mild reaction conditions were involved in the transformation. The halide-containing benzoafluorenols could be further elaborated via palladium-catalyzed cross-coupling reactions to introduce complexity.
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•Li2SiO3-coated LiNi0.6Co0.2Mn0.2O2 cathode is prepared by a direct and convenient method.•The Li2SiO3-coated improves the cycle stability of the material.•The 3.0mol.% Li2SiO3-coated ...LiNi0.6Co0.2Mn0.2O2 exhibits best electrochemistry properties.•The Li2SiO3-coated LiNi0.6Co0.2Mn0.2O2 presents excellent rate property.
Li2SiO3-coated LiNi0.6Co0.2Mn0.2O2 cathode material has been synthesized and exhibit much better electrochemical performance than pristine LiNi0.6Co0.2Mn0.2O2 at cut-off voltage 4.6V. The as-prepared samples are characterized by X-ray diffraction, field emission scanning electron microscopy, field emission transmission electron microscope, and X-ray photoelectron spectroscopic. The results show that the coating-layer Li2SiO3 is not incorporated into the LiNi0.6Co0.2Mn0.2O2 host structure and coated well on the surface of the active material. The sample coated with 3mol. % Li2SiO3 delivers a capacity of 168mAhg−1 at 0.2C after 100 cycles, and remains 85.5% of the first discharge capacity. The capacity retention at 1C is 73.6% after 100 cycles and the first discharge capacity reaches 158mAhg−1 at 10C. This superior performance is attributed to the coating layer which restrains the side reactions at electrode/electrolyte interface and enhances structure stability, meanwhile, it can decrease the electrode polarization because it is an excellent Li+-ion conductor.
In this paper, the inhibitory effect of various nanomaterials on the growth of Aspergillus niger was studied. Among them, copper nanorods had the most obvious inhibitory effect on the growth of ...Aspergillus niger. The phase of copper nanorods was modified by chitosan, and its inhibitory effect on the expansion of Aspergillus niger was measured. 1. Preparation of copper nanorods and chitosan@copper nanorods: Copper nanorods with a diameter of about 300–350 nm and a length of about 100–800 nm were prepared by the liquid-phase reduction method. The chitosan solution was prepared by using the characteristics of chitosan dissolved in dilute acid to prepare chitosan@copper nanorods and modify the phase of copper nanorods. 2. Determination of the inhibitory effect of various copper nanomaterials on the growth of Aspergillus niger, including Cuprous Oxide nanoparticles, copper nanorods, nano copper oxide, and copper hydroxide, which have certain inhibitory effects on the growth of Aspergillus niger. Among them, copper nanorods have a better effect. On this basis, chitosan@copper nanorods are obtained by modifying the phase of copper nanorods with chitosan. The measured antibacterial effect is that the EC50 value is 344 mg/L.
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