TiO2 -Supported Re as a General and Chemoselective Heterogeneous Catalyst for Hydrogenation of Carboxylic Acids to Alcohols

Takashi Toyao; S M A Hakim Siddiki; Abeda S Touchy; Wataru Onodera; Kenichi Kon; Yoshitsugu Morita; Takashi Kamachi; Kazunari Yoshizawa; Ken-Ichi Shimizu

doi:10.1002/chem.201604762

TiO₂ -Supported Re as a General and Chemoselective Heterogeneous Catalyst for Hydrogenation of Carboxylic Acids to Alcohols

Chemistry. 2017 Jan 23;23(5):1001-1006. doi: 10.1002/chem.201604762. Epub 2016 Nov 22.

Authors

Takashi Toyao^{1

2}, S M A Hakim Siddiki¹, Abeda S Touchy¹, Wataru Onodera¹, Kenichi Kon¹, Yoshitsugu Morita³, Takashi Kamachi^{2

3}, Kazunari Yoshizawa^{2

3}, Ken-Ichi Shimizu^{1

2}

Affiliations

¹ Institute for Catalysis, Hokkaido University, N-21, W-10, Sapporo, 001-0021, Japan.
² Elements Strategy Initiative for Catalysis and Batteries, Kyoto University, Katsura, Kyoto, 615-8520, Japan.
³ Institute for Materials Chemistry and Engineering and International Research Center for Molecular Systems, Kyushu University, Fukuoka, 819-0395, Japan.

PMID: 27874230
DOI: 10.1002/chem.201604762

Abstract

TiO₂ -supported Re, Re/TiO₂ , was found to promote selective hydrogenation of carboxylic acids having aromatic and aliphatic moieties to the corresponding alcohols. Re/TiO₂ showed superior results compared to other transition-metal-loaded TiO₂ and supported Re catalysts for selective hydrogenation of 3-phenylpropionic acid. 3-phenylpropanol was produced in 97 % yield under mild conditions (5 MPa H₂ at 140 °C). Contrary to typical heterogeneous catalysts, Re/TiO₂ does not lead to the formation of dearomatized byproducts. The catalyst is recyclable and shows a wide substrate scope in the synthesis of alcohols (22 examples; up to 97 % isolated yield).

Keywords: alcohols; carboxylic acids; heterogeneous catalysis; hydrogenation; rhenium.