Base-Free Transfer Hydrogenation of Menthone by Sub- and Supercritical Alcohols
Full article
| Common |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
The Journal of Supercritical Fluids
ISSN: 0896-8446
, E-ISSN: 1872-8162
|
| Output data |
Year: 2019,
Volume: 145,
Pages: 162-168
Pages count
: 7
DOI:
10.1016/j.supflu.2018.12.011
|
| Tags |
Base-free Enolization Menthone Raney® nickel Supercritical alcohols Transfer hydrogenation |
| Authors |
Philippov Alexey
1,2
,
Chibiryaev Andrey M.
1,2
,
Martyanov Oleg
1,2
|
| Affiliations |
| 1 |
Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Science
|
| 2 |
Novosibirsk State University
|
|
Funding (3)
|
1
|
Federal Agency for Scientific Organizations
|
V.44.1.15.
|
|
2
|
Federal Agency for Scientific Organizations
|
0303-2016-0001
|
|
3
|
Russian Foundation for Basic Research
|
18-29-06022
|
The base-free transfer hydrogenation (HTR) of menthone with six aliphatic alcohols as hydrogen source has been developed under sub- and supercritical conditions. Under sc conditions (at 350 °C and 78–210 atm) without any catalyst, all alcohols demonstrated the similar H-donor activity, which was high enough. The menthone conversion was about 64 ± 5 % for 5 hours of the reaction, whereas the selectivity on menthol reached 92–99 % for all alcohols except MeOH (73 %). The non-catalytic HTR at 250 °C was very slow and the conversion in the most active 2-PrOH was only 7.0–7.5 % for 9 hours of the reaction. Under subcritical conditions at 150 °C, the non-catalytic menthone reduction was negligible in all alcohols. But in secondary 2-PrOH and 2-BuOH, the base-free HTR catalyzed by Raney® nickel results in excellent conversion and selectivity of menthol at 150 °C, whereas no conversion of menthone was observed in primary alcohols under the same reaction conditions. A quasi-equilibrium of isomeric menthone/isomenthone mixture reached via enolization was evaluated under sub- and supercritical conditions and the Gibbs energies of the isomerization in each alcohol were calculated