Author, as appears in the article.: Zhang, Teng; Sole-Daura, Albert; Fouilloux, Hugo; Poblet, Josep M.; Proust, Anna; Carbo, Jorge J.; Guillemot, Geoffroy;

Department: Química Física i Inorgànica

e-ISSN: 1867-3899

URV's Author/s: Carbó Martin, Jorge Juan / Poblet Rius, Josep Maria

Keywords: Titanium compounds Titanium complexes Titanium Silicates Repulsive interactions Product distributions Polyoxotungstates Polyoxometalates Oxidative dehydrogenation reactions Oxidation reactions Oxidation Olefins Mechanistic study Epoxidation reactions Epoxidation Dft Dehydrogenation Coordination reactions Computational studies Catalytic oxidation Catalyst activity Alkene epoxidation Alkene

Abstract: Titanium complexes of silanol functionalized polyoxometalates (THA)(3)[SbW9O33(RSiO)(3)Ti((OPr)-Pr-i)] (Ti-SiloxPOMs) catalyze alkene oxidation with tert-butyl hydrogen peroxide (TBHP). However catalytic activity and product distribution in the oxidation of allylic alcohols are shown to depend on the steric surrounding generated by the SiloxPOM (R=Bu-t, Pr-i, Pr-n). Combined experimental and computational studies clarify how steric repulsions between the oxidant (Bu-t group) and the surrounding SiloxPOM govern the reaction pathways leading either to oxidation of the alcohol function (R=Bu-t) or to alkene epoxidation (R=Pr-n). Moreover, another consequence of this steric repulsive interactions is that outer-sphere mechanisms become competitive with the inner-sphere ones (coordination of allylic alcohol), whether for the oxidative dehydrogenation reaction or for the epoxidation reaction. In the case of unfunctionalized olefins (linear and cyclic), we show that reducing the bulkiness surrounding the active site leads to higher conversion to epoxide, emphasizing that these Ti-SiloxPOMs may behave as structural and functional models for metal single-site in Ti-Silicates.

Thematic Areas: Química Physical and theoretical chemistry Organic chemistry Medicina i Materiais Interdisciplinar Inorganic chemistry Farmacia Engenharias iv Engenharias iii Engenharias ii Engenharias i Ciências biológicas ii Ciências ambientais Ciências agrárias i Ciência de alimentos Chemistry, physical Catalysis Biotecnología Astronomia / física

licence for use: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 1867-3880

Author's mail: j.carbo@urv.cat josepmaria.poblet@urv.cat

Author identifier: 0000-0002-3945-6721 0000-0002-4533-0623

Record's date: 2023-03-06

Papper version: info:eu-repo/semantics/publishedVersion

Link to the original source: https://chemistry-europe.onlinelibrary.wiley.com/doi/full/10.1002/cctc.202001779

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Chemcatchem. 13 (4): 1220-1229

APA: Zhang, Teng; Sole-Daura, Albert; Fouilloux, Hugo; Poblet, Josep M.; Proust, Anna; Carbo, Jorge J.; Guillemot, Geoffroy; (2021). Reaction Pathway Discrimination in Alkene Oxidation Reactions by Designed Ti-Siloxy-Polyoxometalates. Chemcatchem, 13(4), 1220-1229. DOI: 10.1002/cctc.202001779

Article's DOI: 10.1002/cctc.202001779

Entity: Universitat Rovira i Virgili

Journal publication year: 2021

Publication Type: Journal Publications