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( Huynh Nguyen Thuy Tram ),( Thanh Tung Nguyen ),( Anh Vy Tran ),김용진 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0
Selenium compounds have been reported as a highly effective catalytic system in oxidative carbonylation of aromatic amines to corresponding carbamates and ureas. The present study reveals more about the selectively-promoting-effect of selenium oxide on Palladium- catalyzed reductive carbonylation of nitrobenzene to produce methyl N-phenyl carbamate with high yield of carbamate (~90%) and high selectivity (~90%) in the presence of pyridine as co-catalyst.
Palladium-catalyzed reductive carbonylation of nitrobenzene for producing isocyanate
( Nguyen Thanh Tung ),( Anh Vy Tran ),( Thuy Tram Huynh Nguyen ),김용진 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0
Organic isocyanates (R-NCO) have achieved great commercial importance as chemical intermediates in the manufacture of many useful chemicals. The conventional route has now been proven to have many serious problems, such as the use of extremely toxic phosgene in the carbonylation step and the byproduction of a large amount of corrosive hydrochloric acid. One attractive alternative method is direct carbonylation with carbon monoxide, because it can provide a one-step conversion of nitro aromatics to the isocyanate without the use of dangerous phosgene. In this research we present the direct reductive carbonylation of nitrobenzene to phenyl isocyanate using various types of palladium catalysts.
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.
Pd NHC complexes as catalyst for reductive carbonylation of nitrobenzene for generating urethanes
( Tran Anh Vy ),( Tram Thuy Huynh Nguyen ),( Tung Thanh Nguyen ),김용진 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0
Carbamates have been widely used due to their versatility such as intermediates in pharmaceuticals, pesticides, fertilizers or precursors of isocyanates. The conventional process for the production of carbamates involves the toxic usage of phosgene. The reductive of carbonylation of aromatic nitro compounds with carbon monoxide in the presence of alcohols has drawn much attention as a phosgene-free alternative to carbamates. There have been numerous attempts to afford carbamates from the reductive carbonylation of nitrobenzene facilitated by various complexes of transitional metals. In this research, N-heterocyclic carbene (NHC)-palladium(II) complexes have been investigated as active catalysts for the synthesis of carbamates. The results showed that the 97% yield of carbamates was obtained under the conditions at 1600C in 2 h in the presence of (NHC)-palladium(II) as main catalyst.