title: Alkene Epoxidation Catalyzed by Ti-Containing Polyoxometalates: Unprecedented β-Oxygen Transfer Mechanism.
abstract: A DFT study revealed that the mechanism of alkene epoxidation with hydrogen peroxide catalyzed by Ti-containing polyoxometalates (POMs) depends on the Ti coordination environment: For rigid and hindered Ti centers, the unprecedented β-oxygen transfer from the titanium hydroperoxo species becomes favored over the α-oxygen one. Improving the model for catalyst description, the calculations were able to reproduce the Arrhenius activation energy values determined in kinetic studies. Unlike protonation, the possible ion-pairing between POMs and countercations has a minor effect on the electrophlicity of the catalyst and, consequently, on the activity of epoxidation.
authors.affiliation: Department de Química Física i Inorgànica, Universitat Rovira i Vigili , Marcel·lí Domingo s/n, 43007 Tarragona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Jiménez-Lozano
authors.affiliation: Boreskov Institute of Catalysis , Prospekt Akademika Lavrentiev 5, Novosibirsk 630090, Russia.|Novosibirsk State University , Pirogova Street 2, Novosibirsk 630090, Russia.
authors.forename: Igor Y
authors.initials: IY
authors.lastname: Skobelev
authors.affiliation: Boreskov Institute of Catalysis , Prospekt Akademika Lavrentiev 5, Novosibirsk 630090, Russia.|Novosibirsk State University , Pirogova Street 2, Novosibirsk 630090, Russia.
authors.forename: Oxana A
authors.initials: OA
authors.lastname: Kholdeeva
authors.affiliation: Department de Química Física i Inorgànica, Universitat Rovira i Vigili , Marcel·lí Domingo s/n, 43007 Tarragona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Poblet
authors.affiliation: Department de Química Física i Inorgànica, Universitat Rovira i Vigili , Marcel·lí Domingo s/n, 43007 Tarragona, Spain.
authors.forename: Jorge J
authors.initials: JJ
authors.lastname: Carbó