(338f) Selective C-C Bond Scission of Biomass-Derived Oxygenates Using Cerium Oxide-Supported Ruthenium Catalyst

Selective C-C Bond Scission of Biomass-Derived
Oxygenates Using Cerium Oxide-Supported Ruthenium Catalyst

Tomoo
Mizugaki,¹ Kohei Uesugi,¹ Kodai Nitta,1 Zen Maeno,¹
Takato Mitsudome,¹ Koichiro Jitsukawa,¹ and Kiyotomi
Kaneda*^1,2

1.
Graduate School of Engineering Science, Department of Materials Engineering
Science, Osaka University

2.
Research Center for Solar Energy Chemistry, Osaka University

kaneda@cheng.es.osaka-u.ac.jp

Current
requirements to reduce carbon dioxide emissions have led to the utilization of
renewable resources, such as plant biomass, as carbon-neutral feedstocks for
commodity chemicals. To date, much effort has been devoted to the direct C–O
bond cleavage of high-oxygen containing biogenic polyols, such as glycerols, to
produce valuable chemicals by hydrogenolysis and deoxydehydration. On the other
hand, C–C bond cleavage has not yet been widely researched despite its great
potential to extend the utility of biomass-derived chemicals. The existing C–C
bond cleavage methods often suffer from low selectivity toward the desired
chemicals and limited substrate scope. Therefore, the development of highly
selective and versatile C–C bond scission catalysts able to work under mild
conditions is highly desired to open new routes for industrially important
chemicals from a wide range of biomass derivatives.

In
this work, we chose levulinic acid as the model substrate, which is an
important platform biomass-derivative leading to a variety of useful C5
chemicals such as g-valerolactone (GVL),¹
1,4-pentanediol (1,4-PeD),¹ and 2-methyltetrahydrofuran (MTHF).²
However, there are fewer examples of the transformation of LA into C4 chemicals
through one-carbon scission reactions. We found that cerium oxide-supported
ruthenium nanoparticles (Ru/CeO₂) efficiently promoted the selective
one-carbon scission of levulinic acid to give 2-butanol in over 80% yield under
3 MPa of H₂ at 150 ^oC in water. The high generality of
this method is demonstrated by its broad substrate scope, where the cleavage of
C–C bonds chemospecifically occurs at positions adjacent to the carboxyl,
ester, and hydroxymethyl groups of oxygenated compounds (Scheme 1).

References

[1] T. Mizugaki, Y. Nagatsu, K. Togo, Z. Maeno, T.
Mitsudome, K. Jitsukawa, K. Kaneda, Green Chem. 2015, 17,
5136–5139.

[2] T. Mizugaki, K. Togo, Z. Maeno, T. Mitsudome, K.
Jitsukawa, K. Kaneda, ACS Sustainable Chem. Eng. 2016, 4,
682–685.