Heteropoly acid catalysts for the valorization of biorenewables: Isomerization of caryophyllene oxide in green solvents

Autor: Elena V. Gusevskaya, Kelly A. da Silva Rocha, Augusto Luís Pereira De Meireles, Ivan V. Kozhevnikov, Elena F. Kozhevnikova
Rok vydání: 2018
Předmět:
Zdroj: MOLECULAR CATALYSIS
ISSN: 2468-8231
Popis: The isomerization of caryophyllene oxide, one of the most widespread sesquiterpenes found in various essential oils, is catalyzed by the acidic Cs salt of tungstophosphoric heteropoly acid, Cs2.5H0.5PW12O40, to give rare polycyclic oxygenated sesquiterpenes with a clovane structure. Cloven-9-ol and clovan-2,9-diol can be obtained with up to 80% combined selectivity and 60% individual selectivity each (under different reaction conditions), which is the best result reported for these compounds so far. The process is environmentally benign and can be performed not only in conventional solvents such as 1,2-dichloroethane and acetone but also in eco-friendly “green” organic solvents such as dimethylcarbonate, diethylcarbonate and 2-methyltetrahydrofuran. The reactions occur under ambient conditions at low catalyst loadings without catalyst leaching. The solid catalyst can be simply centrifuged from the reaction mixture, and low boiling solvents can be separated from reaction products by distillation.
Databáze: OpenAIRE