Methoxycarbonylation of Aliphatic Diamines with Dimethyl Carbonate Promoted by in situ Generated Hydroxide Ion: A Mechanistic Consideration

Abstract

Abstract:The methoxycarbonylation reactions of aliphatic diamines with dimethyl carbonate are accelerated greatly in the presence of water. Theoretical investigations on the mechanistic aspects of the methoxycarbonylation of 1,6-hexanediamine strongly suggest that the hydroxide ion, generated in situ from the interaction of 1,6-hexanediamine with water, is an active catalytic species and plays a pivotal role in the rate-determining hydrogen abstraction step from the amino group.

Green synthesis of polyureas from CO2 and diamines with a functional ionic liquid as the catalyst

“…[3][4][5] Meanwhile, they can also be regarded as potential precursors of carbamates and isocyanates, which are useful raw materials of polyurethanes. 6 Although the 1,3-disubstituted ureas and cyclic ureas are obtained in moderate to excellent yields from monoamine [7][8][9][10][11][12] and ethylene diamine, 13 respectively, there have been limited reports of polyurea derivative synthesis directly from CO 2 and diamines. Polyurea is a new kind of polymer containing the urea functional group (-NH-CO-NH-), which shows good resistance to solvents, far superior thermal properties and much higher melting points than the commonly used polymers.…”

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A series of ionic liquids (P 4,4,4,6 BF 4 , P 4,4,4,6 Triz, as well as the newly prepared anion dual-functionalized amino-triz IL P 4,4,4,6 ATriz, etc.) were prepared, and their catalytic performance was tested in the synthesis of polyureas from CO 2 and diamines.

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Carbon dioxide uptake as ammonia and amine carbamates and their efficient conversion into urea and 1,3-disubstituted ureas

“…The 1,3-disubstituted ureas are valuable products with a wide range of application as intermediates in agrochemical, pharmaceutical, dye chemicals and recently as precursors of isocyanates and raw materials of polyurethanes [29][30][31][32][33][34]. Their traditional synthesis required unsafe chemicals such as phosgene or carbon oxide and Au or Pt catalysts [35][36][37][38].…”

Recent advances in dialkyl carbonates synthesis and applications

“…420 The continuousflow process was also carried out with the remarkable reactivity and selectivity. 421,422 The presence of water was suggested to greatly facilitate the methoxycarbonylation of aliphatic aniline, because the generated OHwas the active species and played a pivotal role in hydrogen abstraction from the amino group (rate-determining step). 19.…”