TY - JOUR
T1 - CeO2-catalyzed direct synthesis of dialkylureas from CO2 and amines
AU - Tamura, Masazumi
AU - Ito, Kazuki
AU - Nakagawa, Yoshinao
AU - Tomishige, Keiichi
N1 - Publisher Copyright:
© 2015 Elsevier Inc.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/11/1
Y1 - 2016/11/1
N2 - CeO2 showed higher activity for the direct synthesis of 1,3-dibutylurea (DBU) from CO2 and n-butylamine than the metal oxides tested. The solvent largely influenced the reaction over CeO2, and N-methylpyrrolidone (NMP) was preferable among various solvents tested from the viewpoints of activity and selectivity. The catalyst system composed of CeO2 catalyst and NMP solvent (CeO2 in NMP) was applicable to the reactions of various amines such as linear primary alkylamines or branched primary alkylamines, although tert-butylamine afforded low conversion. In contrast, secondary amines and aniline provided no yield of the ureas. The combination of 2-cyanopyridine with CeO2 in NMP (CeO2 in NMP with 2-cyanopyridine) promoted the transformation of the unreactive amines, showing that tert-butylamine and aniline were converted to the corresponding ureas in 82% and 80% yields, respectively. These yields are much higher than those reported in the previous literatures, indicating that CeO2 in NMP with 2-cyanopyridine drastically promoted transformation of amines with low reactivity.
AB - CeO2 showed higher activity for the direct synthesis of 1,3-dibutylurea (DBU) from CO2 and n-butylamine than the metal oxides tested. The solvent largely influenced the reaction over CeO2, and N-methylpyrrolidone (NMP) was preferable among various solvents tested from the viewpoints of activity and selectivity. The catalyst system composed of CeO2 catalyst and NMP solvent (CeO2 in NMP) was applicable to the reactions of various amines such as linear primary alkylamines or branched primary alkylamines, although tert-butylamine afforded low conversion. In contrast, secondary amines and aniline provided no yield of the ureas. The combination of 2-cyanopyridine with CeO2 in NMP (CeO2 in NMP with 2-cyanopyridine) promoted the transformation of the unreactive amines, showing that tert-butylamine and aniline were converted to the corresponding ureas in 82% and 80% yields, respectively. These yields are much higher than those reported in the previous literatures, indicating that CeO2 in NMP with 2-cyanopyridine drastically promoted transformation of amines with low reactivity.
KW - Carbon dioxide
KW - Cerium oxide
KW - Heterogeneous catalyst
KW - N-Methylpyrrolidone
KW - Urea
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U2 - 10.1016/j.jcat.2015.11.015
DO - 10.1016/j.jcat.2015.11.015
M3 - Article
AN - SCOPUS:84951975596
VL - 343
SP - 75
EP - 85
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
ER -