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Cs-azolides as highly active catalysts for carboxylation of amines for producing disubstituted ureas
( Truong Cong Chien ),( Dinesh Kumar Mishra ),김용진 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0
Disubtituted urea, a versatile class of organic compounds, has been widely used as intermediates in pharmaceuticals, agrochemicals, pigments and potential precursors of both carbamates and isocyanates. Conventionally, the preparation of urea involves either the toxic phosgenation or potentially explosive oxidative and reductive carbonylation of amines. In a continuous effort to develop eco-friendly alternative process to urea through the utilization of CO2, a set of novel and well-prepared Cesium azolides were investigated as highly efficient catalysts for the carboxylation of amines and CO2. Experimental variables for the optimization such as temperature, CO2 pressure, solvents and reaction time were also studied. The results indicated that these novel Cesium-azolide catalysts could facilitate the carboxylation of amine to provide various disubtituted urea with high selectivity in the absence of any dehydrating agents.
Novel ionic liquids for generating diureas
( Truong Cong Chien ),김용진,( Huynh Nguyen Thuy Tram ) 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1
Urea and its derivatives is one of the ubiquitous components found in dyes, fertilizers, pharmaceuticals and agrochemicals. Conventionally, urea derivatives have been industrially prepared via toxic precursors such as isocyanate or phosgene[1]. From the standpoint of eco-friendly and benign synthetic methodology, an alternative non-toxic route for the production of diureas from the direct coupling reaction of amine and CO<sub>2</sub> facilitated by ionic liquids (ILs) has been investigated [2-5]. We, herein, report novel basic ILs for the carboxylation of amine and CO<sub>2</sub>. Other experimental variables such as temperature, pressure, solvents and different types of ILs were also investigated. This synthetic approach was able to provide disubstituted ureas in high yield and selectivity without using any classical harmful precursors and/or dehydrating agents.
Guang Meang Son,Cong Chien Truong,Dinesh Kumar Mishra,Vivek Mishra,김용진 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.2
In this article, synthesis of 1,3-disubstituted urea (DSU) from three component reagent systems comprising amine, carbon dioxide, and propylene oxide is described. DSU is synthesized in the presence of a variety of ionic liquids (ILs) with/without promoters. Among used ILs, 1-butyl-3-methylimidazolium tetraiodoindateIII (represented as [Bmim][InI4]) is found to give the highest DSU product. A serious experiment clearly indicates that the tetraiodoindate anion plays an important role for the selective production of the DSU. Based on the in situ infrared spectroscopic studies, a plausible reaction mechanism for producing dicyclohexylurea from cyclohexylamine is proposed. The synthesis and characterization of [Bmim][InI4] are given in details. Moreover, the effect of reaction variables such as time, temperature, pressure, and the molar ratio of substrate to catalyst is also studied.
Catalytic conversion of CO<sub>2</sub> into value-added compounds
김용진,( Guang Meang Son ),( Cong Chien Truong ),( Duy Son Nguyen ),( Jin Ku Cho ),( Seung-han Shin ) 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1
Ionic liquids (ILs) have attracted much attention due to their tuneable properties according to their needs. However, the application of ILs just as solvent should pay much expense with respect to industrial viewpoint. Various usage of ILs as an active catalyst for the efficient organic transformation reactions have resulted in opening a new level of application fields [1-6]. Accordingly, there have been numerous reports on the dramatic enhancement in their catalytic activities just by incorporating metal salts into ILs [7-9]. Catalytic transformation of carbon dioxide into useful organic compounds has also attracted much attention during the last two decades due to economic and environmental benefits arising from the utilization of renewable source and the growing concern on the greenhouse effect. CO<sub>2</sub> is an abundant, cheap, and safe C1 building block in organic synthesis; however, due to the inert nature of CO<sub>2</sub>, efficient catalytic processes for chemical fixation remain a significant challenge. Herein, we present a couple of examples for ILs-based catalysts which provides enhanced activity towards various organic syntheses which meets the green chemistry.
Dinesh Kumar Mishra,Aasif A. Dabbawala,Cong Chien Truong,Saeed M. Alhassan,Jonggeon Jegal,황진수 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-
Lactose is a reducing disaccharide consisting of two different monosaccharides such as galactose and glucose. The hydrogenation of lactose to lactitol is a formidable challenge because it is a complex process and several side products are formed. In this work, we synthesized Ru–Ni bimetallic nanohybrids as efficient catalysts for selective lactose hydrogenation to give selective lactitol. Ru–Ni bimetallic nanohybrids with Ru–NiOx (x = 1, 5, and 10 wt%) are prepared by impregnating Ru and Ni salts precursors with TiO2 used as support material. Ru–Ni bimetallic nanohybrids (represented as 5Ru–5NiO/TiO2) catalyst is found to exhibit the remarkably high selectivity of lactitol (99.4%) and turnover frequency i.e. (374 h−1). In contrast, monometallic Ru/TiO2 catalyst shows poor performance with (TOF = 251 h−1). The detailed characterizations confirmed a strong interaction between Ru and NiO species, demonstrating a synergistic effect on the improvement on lactitol selectivity. The impregnation-reduction method for the preparation of bimetallic Ru–NiO/TiO2 catalyst promoted Ru nanoparticles dispersed on NiO and intensified the interaction between Ru and NiO species. Ru–NiO/TiO2 efficiently catalyzed the hydrogenation of lactose to lactitol with high yield/selectivity at almost complete conversion of lactose at 120 °C and 55 bar of hydrogen (H2) pressure. Moreover, Ru–NiO/TiO2 catalyst could also be easily recovered and reused up to four runs without notable change in original activity.
Mishra, Dinesh Kumar,Dabbawala, Aasif A.,Truong, Cong Chien,Alhassan, Saeed M.,Jegal, Jonggeon,Hwang, Jin Soo Elsevier 2018 Journal of industrial and engineering chemistry Vol.68 No.-
<P><B>Abstract</B></P> <P>Lactose is a reducing disaccharide consisting of two different monosaccharides such as galactose and glucose. The hydrogenation of lactose to lactitol is a formidable challenge because it is a complex process and several side products are formed. In this work, we synthesized Ru–Ni bimetallic nanohybrids as efficient catalysts for selective lactose hydrogenation to give selective lactitol. Ru–Ni bimetallic nanohybrids with Ru–NiO<I> <SUB>x</SUB> </I> (<I>x</I> =1, 5, and 10wt%) are prepared by impregnating Ru and Ni salts precursors with TiO<SUB>2</SUB> used as support material. Ru–Ni bimetallic nanohybrids (represented as 5Ru–5NiO/TiO<SUB>2</SUB>) catalyst is found to exhibit the remarkably high selectivity of lactitol (99.4%) and turnover frequency i.e. (374h<SUP>−1</SUP>). In contrast, monometallic Ru/TiO<SUB>2</SUB> catalyst shows poor performance with (TOF=251h<SUP>−1</SUP>). The detailed characterizations confirmed a strong interaction between Ru and NiO species, demonstrating a synergistic effect on the improvement on lactitol selectivity. The impregnation-reduction method for the preparation of bimetallic Ru–NiO/TiO<SUB>2</SUB> catalyst promoted Ru nanoparticles dispersed on NiO and intensified the interaction between Ru and NiO species. Ru–NiO/TiO<SUB>2</SUB> efficiently catalyzed the hydrogenation of lactose to lactitol with high yield/selectivity at almost complete conversion of lactose at 120°C and 55bar of hydrogen (H<SUB>2</SUB>) pressure. Moreover, Ru–NiO/TiO<SUB>2</SUB> catalyst could also be easily recovered and reused up to four runs without notable change in original activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly active supported Ru–Ni bimetallic catalysts with NiO are prepared. </LI> <LI> Bimetallic Ru–5NiO/TiO<SUB>2</SUB> catalyst shows high selectivity to lactitol (99.4%). </LI> <LI> Optimization and kinetics studies of lactose hydrogenation. </LI> <LI> Bimetallic Ru–5NiO/TiO<SUB>2</SUB> catalyst is reused up to several consecutive times. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>