Adsorption studios of cyclic and acyclic α,-unsaturated ketones for selective reduction by hydrogen transfer on MgO

P. BELELLI; S, FUENTE; C. FERRETTI; CRISTIÁN A. FERRETTI, AGOSTINA SOLDANO, ROBERTO N. OLSECE, CARLOS R. APESTEGUÍA, JUANA I. DI COSIMO.

Montevideo

Congreso; QUITEL 2016, 42nd International Congress of Theoretical Chemists of Latin Expression; 2016

Químicos Teóricos de Expresión Latina

Primary and secondary unsaturated alcohols (UOL) are important organic compounds that are used for fragrance, cosmetic, pharmaceutical and food flavoring industries. The UOL production must be carried out through a selective hydrogenation process. Hydrogen transfer reduction (HTR) is an interesting route for the UOL catalytic synthesis, where the C=O group is saturated [1]. In this kind of reaction, the unsaturated ketone (UK) and the hydrogen source (usually a secondary alcohol like isopropyl alcohol, IPA) are in contact with a solid acid-base catalyst, without provision of H2. Using the density functional theory (DFT) approximation, we have investigated the separately adsorption of IPA, mesityl oxide (MO) and 2-cyclohexenone (CH) and their corresponding co-adsorptions of IPA with the UK species on terrace sites of MgO(100). The theoretical results indicated the non-dissociative adsorptions of isolated species. For the three species, the interactions are through the polar groups (OH or CO) with Mg5c-O5c pair of the oxide surface. IPA and MO species have similar adsorption energies when they are adsorbed independently and compite with the same active sites as it was observed experimentally. Moreover, CH has the strongest adsorption energy. For simultaneous co-adsorptions, IPA-MO and IPA-CH, IPA does not dissociate and this point is the basis for the HTR reaction because the H atom of IPA must be transferred to C atom of UK as a hydride species.