Abstract
Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
| Original language | English |
|---|---|
| Pages (from-to) | 14848-14859 |
| Number of pages | 12 |
| Journal | Chemistry - A European Journal |
| Volume | 23 |
| Issue number | 59 |
| DOIs | |
| Publication status | Published - Oct 20 2017 |
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All Science Journal Classification (ASJC) codes
- Catalysis
- Chemistry(all)
- Organic Chemistry
Cite this
Rhenium-Loaded TiO2 : A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2. / Toyao, Takashi; Siddiki, S. M.A.H.; Morita, Yoshitsugu; Kamachi, Takashi; Touchy, Abeda S.; Onodera, Wataru; Kon, Kenichi; Furukawa, Shinya; Ariga, Hiroko; Asakura, Kiyotaka; Yoshizawa, Kazunari; Shimizu, Ken Ichi.
In: Chemistry - A European Journal, Vol. 23, No. 59, 20.10.2017, p. 14848-14859.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Rhenium-Loaded TiO2
T2 - A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2
AU - Toyao, Takashi
AU - Siddiki, S. M.A.H.
AU - Morita, Yoshitsugu
AU - Kamachi, Takashi
AU - Touchy, Abeda S.
AU - Onodera, Wataru
AU - Kon, Kenichi
AU - Furukawa, Shinya
AU - Ariga, Hiroko
AU - Asakura, Kiyotaka
AU - Yoshizawa, Kazunari
AU - Shimizu, Ken Ichi
PY - 2017/10/20
Y1 - 2017/10/20
N2 - Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
AB - Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
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U2 - 10.1002/chem.201702801
DO - 10.1002/chem.201702801
M3 - Article
VL - 23
SP - 14848
EP - 14859
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 59
ER -