Abstract Despite of high conductivity and reducing ability, transition metal nanoparticles tend to aggregate and unavoidably impact the selectivity during the proton‐coupled reduction process of CO 2 RR. New strategy to regulate and utilize the electronic property of transition‐metal particles allows for effective tuning of eCO 2 RR activity. Through simple creation of N‐doped carbon shells surrounding Ni nanoparticles and controlling the amount and arrangement of the N atoms, successful and long‐lasting electrochemical reduction of CO 2 was accomplished. The inherent HER activity was almost completely suppressed. It exhibited FE CO above 90 % in a 500 mV potential window, with the optimal up to 96.5 % at −0.78 V vs RHE. In flow cell electrolysis, a current density of 289.4 mA/cm 2 was achieved with Faradic efficiency of 96.4 % towards CO. The results of control experiments using different catalysts imply that electron transfer between Ni core and shells was significantly influenced by the property of N atoms. High content of graphitic nitrogen is crucial for the catalytic performance.
Abstract In the presence of a ligand‐ and additive‐free Rh(I) catalyst various olefins and aliphatic amines are transformed into N‐alkyl amides in medium to high yields with excellent regioselectivities.
We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines or β-amino alcohols compounds using ruthenium catalysis. The reaction outcome is readily tuned by the simple addition of 4 Å molecular sieves (furfurylamines vs. β-amino alcohols) with high chemo-selectivity. The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols via a retro-aldol process. A series of arylamines was successfully transformed into the desired products with moderate to good yields.
【Objective】To study the effect of xenogeneic chemokine receptor CXCR4 gene transfection on tumorigenecity of malignant tumors by transduction of human CXCR4 gene into mouse melanoma B16 cells by use of gene transfer technology.【Methods】Liposome transfection assay was used to transduce human CXCR4 gene into mouse melanoma B16 cells.RT-PCR and FACS were selected to detect human CXCR4 expression in B16 cells.In vivo implantation experiments were used to study the tumorigenicity of B16 cells.【Results】G418-resistant clones were obtained after the transfection of B16 cells with human CXCR4 gene.And human CXCR4 transcript was detected by RT-PCR.The Results of FACS showed that B16 cells expressed human CXCR4 protein after the gene transfection.The tumor growth of B16 gene transfectants was inhibited compared to the controls in in vivo experiments.【Conclusion】Xenogeneic CXCR4 transfection down-regulates the tumorigenicity of melanoma.The mechanism may be related to the induction of immune cross-reaction by xenogeneic gene transfer.
Vielseitig und metallfrei: Benzothiophen-Boronsäuren katalysieren die Reduktion tertiärer, sekundärer und primärer Amide durch ein Hydrosilan. In der Reaktion wird eine Vielzahl von funktionellen Gruppen toleriert. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Fermi resonance is a common phenomenon, and a hidden caveat exists in the applications of infrared probes, causing spectral complication and shorter vibrational lifetime. In this work, using the cyanotryptophan (CNTrp) side chain model compound 5-cyanoindole (CN-5CNI), we performed Fourier transform infrared spectroscopy (FTIR) and two-dimensional infrared (2D-IR) spectroscopy on unlabeled 12C14N-5CNI and its isotopically labeled substituents (12C15N-5CNI, 13C14N-5CNI, 13C15N-5CNI) and demonstrated the existence of Fermi resonance in 5CNI. By constructing the Hamiltonian and simulating 2D-IR spectra, we show that the distinct Fermi resonance 2D-IR patterns in various isotope substituents are determined by the quantum mixing consequences at the v = 1 state, as well as the v = 2 state, where the Fermi coupling and anharmonicity play a crucial role. Our work provides important insights into the elusive type of Fermi resonance, where the coupling is much smaller than the anharmonicity, which is termed the weak coupling case.
Kohlendioxid kann zur selektiven reduktiven Methylierung sekundärer und primärer aromatischer und aliphatischer Amine verwendet werden. Vielfältige tertiäre Amine werden durch Einwirkung von CO2 und käuflichen Silanen in hohen Ausbeuten erhalten. Die Katalysereaktion toleriert Nitril-, Olefin-, Ether-, Ester- und Hydroxygruppen in den Substraten. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Abstract Formation of CC bonds from CO 2 is a much sought after reaction in organic synthesis. To date, other than CH carboxylations using stoichiometric amounts of metals, base, or organometallic reagents, little is known about CC bond formation. In fact, to the best of our knowledge no catalytic methylation of CH bonds using CO 2 and H 2 has been reported. Described herein is the combination of CO 2 and H 2 for efficient methylation of carbon nucleophiles such as indoles, pyrroles, and electron‐rich arenes. Comparison experiments which employ paraformaldehyde show similar reactivity for the CO 2 /H 2 system.
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