A bioinspired heterogeneous catalyst based on the model of the manganese-dependent dioxygenase for selective oxidation using dioxygen

作者：Chaignon Jeremy; Gourgues Marie; Khrouz Lhoussain; Moliner Nicolas; Bonneviot Laurent; Fache Fabienne; Castro Isabel^*; Albela Belen^*

来源：RSC Advances, 2017, 7(28): 17336-17345.

DOI：10.1039/c7ra00514h

A hybrid bioinspired material with manganese(II) complexes grafted on the surface of a mesostructured porous silica is investigated. The Mn sites mimic the manganese-dependent dioxygenase (MndD), which is an enzyme that catalyses the oxidation of catechol derivatives. The metal complexes were introduced in the silica using a dinuclear complex [Mn2L2(Cl) p(2)(mu-Cl) p(2)] as a precursor with a clickable ligand N,N-1-bis [(pyridin-2-yl) methyl] prop-2-yn-1-amine (L). Azide moieties covalently grafted on MCM-41 type mesoporous silica were utilised to anchor the manganese complex through Huisgen cycloaddition using CuBr(PPh3)(3) as a catalyst. A second functional group - trimethylsilyl or pyridine-was grafted on the silica to bring, together with nanopore size confinement, a similar metal environment as in MndD. The mesostructure of the materials was maintained after incorporation of the Mn complex. Catalytic oxidation of 3,5-di-t-butyl-catechol (3,5-DTBC) into quinone occurred without the need of an additional base when the metal complex was confined in the porous solid. In comparision, the oxidation of 4-tbutyl-catechol (4-TBC) that always required a basic media led to a total oxidation into the ortho-quinone, contrary to the molecular analogue.

• 出版日期2017