Catalizadores quirales PtGe. Su empleo en la hidrogenación enantioselectiva de 3,4-hexadiona

VIRGINIA VETERE, MARÍA BELÉN FARAONI, JULIO CÉSAR PODESTÁ, MÓNICA LAURA CASELLA

Gramado, Río Grande do Sul

Congreso; 17° Congresso Brasileiro de Catálise e VII Congresso de Catálise do Mercosul; 2013

Sociedade Brasileira de Catálise

ABSTRACT ? This work reports the synthesis of PtGe chiral catalysts using organogermanium compounds containing (-)-menthyl groups as substituents. Chiral inducers were carefully synthesized and characterized in order to obtain optically pure compounds. PtGe catalysts were prepared through a controlled surface reaction between the supported transition metal and the organometallic compound. This technique leads to reproducible and well defined phases. The catalysts were employed in the liquid phase enantioselective hydrogenation of 3,4-hexanedione. The systems obtained were active (95% conversion) and enantioselective (enantiomeric excess of 25% for 4-hydroxy-3-hexanone and 10% for 3,4-hexanediol). These results are very encouraging as they are comparable to those obtained previously by our group with similar PtSn catalysts and to those reported for classical Pt/cinchonidine systems. Organogermanium compounds presented here have advantages over their analogs tin, mainly due to their greater stability and non-toxicity.