“Experimental and theoretical studies on chiral heterogeneous catalysts for hydrogenation reactions”

MÓNICA L. CASELLA; JOSÉ F. RUGGERA; ANDREA B. MERLO; VIRGINIA VETERE

Porto, Portugal

Otro; XXI ENCONTRO NACIONAL da Sociedade Portuguesa de Química: QUÍMICA & INOVAÇAO; 2008

The preparation of pure chemical compounds has been one of the most rapid growing areas in chemistry over the last decades with heterogeneous catalysis being recognised as providing new possibilities. In this contribution, two different strategies are studied to obtain enantioselectivity through heterogeneous catalysis: the use of a chiral species to modify a solid surface and the grafting of a chiral organotin compound on a metallic catalyst (via Surface Organometallic Chemistry on Metals techniques, SOMC/M). Both types of systems are applied to enantioselective hydrogenation  reactions.In the SOMC/M approximation, the modelization of organotin precursor compounds of general formula Men-Sn-R'3 (R' = achiral fragment) that could be employed for the obtention of enantioselective heterogeneous catalysts, was studied. To do so, molecular modelling, both at the level of Mechanics and Molecular Dynamics and Density Functional Theory (DFT), was used. It can be concluded that the Menthyl group, the only one that possesses a chiral center, could remain anchored to the superficial phase, is higher than the probability that only the fragments aquiral could remain on the surface, in agreement with experimental with experimental result.