title: Synthesis of coenzyme Q0through divanadium-catalyzed oxidation of 3,4,5-trimethoxytoluene with hydrogen peroxide.
abstract: The selective oxidation of methoxy/methyl-substituted arenes to the corresponding benzoquinones has been first realized using aqueous hydrogen peroxide as a green oxidant, acid tetrabutylammonium salts of the γ-Keggin divanadium-substituted phosphotungstate [γ-PW10O38V2(μ-O)2]5-(I) as a catalyst, and MeCN as a solvent. The presence of the dioxovanadium core in the catalyst is crucial for the catalytic performance. The reaction requires an acid co-catalyst or, alternatively, a highly protonated form of I can be prepared and employed. The industrially relevant oxidation of 3,4,5-trimethoxytoluene gives 2,3-dimethoxy-5-methyl-1,4-benzoquinone (ubiquinone 0 or coenzyme Q0, the key intermediate for coenzyme Q10and other essential biologically active compounds) with 73% selectivity at 76% arene conversion. The catalyst retains its structure under turnover conditions and can be easily recycled and reused without significant loss of activity and selectivity.
authors.affiliation: Boreskov Institute of Catalysis, Pr. Ac. Lavrentieva 5, Novosibirsk 630090, Russia. khold@catalysis.ru.
authors.forename: Olga V
authors.identifier: http://orcid.org/0000-0002-0152-8443
authors.initials: OV
authors.lastname: Zalomaeva
authors.affiliation: Boreskov Institute of Catalysis, Pr. Ac. Lavrentieva 5, Novosibirsk 630090, Russia. khold@catalysis.ru and Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia.
authors.forename: Vasilii Yu
authors.identifier: http://orcid.org/0000-0001-6555-095X
authors.initials: VY
authors.lastname: Evtushok
authors.affiliation: Boreskov Institute of Catalysis, Pr. Ac. Lavrentieva 5, Novosibirsk 630090, Russia. khold@catalysis.ru.
authors.forename: Gennadii M
authors.identifier: http://orcid.org/0000-0002-5134-4052
authors.initials: GM
authors.lastname: Maksimov
authors.affiliation: Boreskov Institute of Catalysis, Pr. Ac. Lavrentieva 5, Novosibirsk 630090, Russia. khold@catalysis.ru.
authors.forename: Raisa I
authors.identifier: http://orcid.org/0000-0001-9403-6255
authors.initials: RI
authors.lastname: Maksimovskaya
authors.affiliation: Boreskov Institute of Catalysis, Pr. Ac. Lavrentieva 5, Novosibirsk 630090, Russia. khold@catalysis.ru and Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia.
authors.forename: Oxana A
authors.identifier: http://orcid.org/0000-0002-5315-5124
authors.initials: OA
authors.lastname: Kholdeeva
mesh_terms: D016227:Benzoquinones / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D006861:Hydrogen Peroxide / Q000737:chemistry*; D016877:Oxidants / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014050:Toluene / Q000031:analogs & derivatives* / Q000737:chemistry; D014451:Ubiquinone / Q000031:analogs & derivatives; D014639:Vanadium / Q000737:chemistry*
chemical_list: D016227:Benzoquinones; D016877:Oxidants; D000644:Quaternary Ammonium Compounds; D014639:Vanadium; D014451:Ubiquinone; D014050:Toluene; C109863:ubiquinone-O; C017776:3,4,5-trimethoxytoluene; D006861:Hydrogen Peroxide; C009405:tetrabutylammonium; C024989:coenzyme Q10