STUDY OF THE PROCESS OF ANILINE ALKYLATION WITH ALCOHOLS IN THE PRESENCE OF A SUPPORTED COPPER CATALYST

Aniline alkylation with aliphatic alcohols in the presence of copper catalyst supported on aluminum oxide providing to obtain N-alkylanilines with high selectivity (up to 100 %).

Terminal and Internal Alkyne Complexes and Azide-Alkyne Cycloaddition Chemistry of Copper(I) Supported by a Fluorinated Bis(pyrazolyl)borate

Copper plays an important role in alkyne coordination chemistry and transformations. This report describes the isolation and full characterization of a thermally stable, copper(I) acetylene complex using a highly fluorinated bis(pyrazolyl)borate ligand support. Details of the related copper(I) complex of HCºCSiMe3 are also reported. They are three-coordinate copper complexes featuring η2-bound alkynes. Raman data show significant red-shifts in CºC stretch of [H2B(3,5-(CF3)2Pz)2]Cu(HCºCH) and [H2B(3,5-(CF3)2Pz)2]Cu(HCºCSiMe3) relative to those of the corresponding alkynes. Computational analysis using DFT indicates that the Cu(I) alkyne interaction in these molecules is primarily of the electrostatic character. The π-backbonding is the larger component of the orbital contribution to the interaction. The dinuclear complexes such as Cu2(μ-[3,5-(CF3)2Pz])2(HCºCH)2 display similar Cu-alkyne bonding features. The mononuclear [H2B(3,5-(CF3)2Pz)2]Cu(NCMe) complex catalyzes [3+2] cycloadditions between tolyl azide and a variety of alkynes including acetylene. It is comparatively less effective than the related trinuclear copper catalyst {μ-[3,5-(CF3)2Pz]Cu}3 involving bridging pyrazolates.

SYNTHESIS OF 2-NITRO-1,3-BIS(3,3’-DIHYDROXYMETHYL)-1,2,3-TRIAZOLYL-2-AZAPROPANE BY THE REACTION OF AZIDE-ALKYN CYCLOADDITION

2-Нитро-1,3-бис(3,3'-дигидроксиметил)-1,2,3-триазолил-2-азапропан (2-НДТАП) представляет интерес в качестве исходного вещества в синтезе высокоэнергетических соединений. В статье рассмотрен синтез 2-НДТАП реакцией азид-алкинового циклоприсоединения 1,3-диазидо-2-нитро-2-азапропана с пропаргиловым спиртом в среде трет-бутилового спирта в присутствии медного катализатора (проволока, порошок меди, оксид меди, нанооксид меди). Исследовано влияние катализатора и температуры процесса на его продолжительность, выход и качество продукта. Структура 2-НДТАП подтверждена методами ИК- и ЯМР-спектроскопии. В результате разработан метод получения 2-НДТАП с выходом 62 % и содержанием основного вещества выше 97 %. 2-Nitro-1,3-bis (3,3'-dihydroxymethyl)-1,2,3-triazolyl-2-azapropane (2-NDTAP) is of interest as a starting material in the synthesis of high-energy compounds. The article discusses the synthesis of 2-NDTAP the reaction of azide-alkyne cycloaddition 1,3-diazido-2-nitro-2-azapropane with propargyl alcohol in tert-butyl alcohol in the presence of a copper catalyst (wire, copper powder, copper oxide, nano copper oxide). The influence of the catalyst and the temperature of the process on its duration, yield and product quality has been investigated. The structure of 2-NDTAP was confirmed by IR and NMR spectroscopy. As a result, a method for obtaining 2-NDTAP with a yield of 62 % and a basic substance content of more than 97 % was developed.

Improved electrochemical conversion of CO2 to multicarbon products by using molecular doping

The conversion of CO2 into desirable multicarbon products via the electrochemical reduction reaction holds promise to achieve a circular carbon economy. Here, we report a strategy in which we modify the surface of bimetallic silver-copper catalyst with aromatic heterocycles such as thiadiazole and triazole derivatives to increase the conversion of CO2 into hydrocarbon molecules. By combining operando Raman and X-ray absorption spectroscopy with electrocatalytic measurements and analysis of the reaction products, we identified that the electron withdrawing nature of functional groups orients the reaction pathway towards the production of C2+ species (ethanol and ethylene) and enhances the reaction rate on the surface of the catalyst by adjusting the electronic state of surface copper atoms. As a result, we achieve a high Faradaic efficiency for the C2+ formation of ≈80% and full-cell energy efficiency of 20.3% with a specific current density of 261.4 mA cm−2 for C2+ products.

Investigation of the Zinc-Copper Catalyst NIAP-06-06 for Steam Conversion of Carbon Monoxide in the Synthesis of Methanol

The possibility to use the zinc-copper catalyst NIAP-06-06 for steam conversion of CO in the synthesis of methanol was explored. The catalyst was characterized by means of TPR H2, XRD and SEM methods and tested in the methanol synthesis in flow and circulation modes at a pressure of 5.0 MPa and gas hourly space velocity of 3000 h–1 over a temperature range of 220–260 °С. The catalyst was shown to be highly active and selective toward the methanol synthesis from a gas with the H2 /СО ratio 3.9, which is obtained by steam conversion of methane. The use of tubular catalytic reactors connected in series in the flow-circulation mode makes it possible to convert more than 70 % of CO and obtain crude methanol with the concentration of 95 %. In the circulation mode, a methanol output of 427.7 kg/(m3 cat·h) was achieved on the catalyst.