Nitrogen-Doped Carbon Nanotubes as an Effective Support of Heterogeneous Catalysts for Selective Alkene Oxidation

Kinetics and Catalysis - Nitrogen-doped carbon nanotubes (N-CNTs) with different degrees of nitrogen doping were synthesized. The effects of nitrogen in the N-CNTs on the...     

MODIFICATION AND VERIFICATION OF NUMERICAL ALGORITHMS FOR DAM-BREAK FLOW OVER A HORIZONTAL BED

Journal of Applied Mechanics and Technical Physics - Numerical simulation of dam-break water flow over a horizontal dry bed has been performed. We have modified and verified computational...     

Catalytic Performance of Zr-Based Metal–Organic Frameworks Zr-abtc and MIP-200 in Selective Oxidations with H2O2

The catalytic performance of Zr-abtc and MIP-200 metal–organic frameworks consisting of 8-connected Zr₆ clusters and tetratopic linkers was investigated in H₂O₂-based selective oxidations and compared with that of 12-coordinated UiO-66 and UiO-67. Zr-abtc demonstrated advantages in both substrate conversion and product selectivity for epoxidation of electron-deficient C=C bonds in α,β-unsaturated ketones. The significant predominance of 1,2-epoxide in carvone epoxidation, coupled with high sulfone selectivity in thioether oxidation, points to a nucleophilic oxidation mechanism over Zr-abtc. The superior catalytic performance in the epoxidation of unsaturated ketones correlates with a larger amount of weak basic sites in Zr-abtc. Electrophilic activation of H₂O₂ can also be realized, as evidenced by the high activity of Zr-abtc in epoxidation of the electron-rich C=C bond in caryophyllene. XRD and FTIR studies confirmed the retention of the Zr-abtc structure after the catalysis. The low activity of MIP-200 in H₂O₂-based oxidations is most likely related to its specific hydrophilicity, which disfavors adsorption of organic substrates and H₂O₂.     

Synthesis of pyrazolo- and [1,2,4]triazolo-[1,5-а]quinolin-9-ols by cycloaddition to 8-hydroxyquinoline N-imide

Chemistry of Heterocyclic Compounds - The reaction of 1-amino-8-hydroxyquinolinium mesitylenesulfonate with alkenes and alkynes containing electron-withdrawing substituents was performed in...