New phenomenon in competitive hydrogenation of binary mixtures of activated ketones over unmodified and cinchonidine-modified Pt/alumina catalyst

Autor:	Katalin Balázsik, Mihály Bartók, Kornél Szőri, György Szőllősi
Rok vydání:	2011
Předmět:	chemistry.chemical_classification Process Chemistry and Technology Enantioselective synthesis chemistry.chemical_element General Chemistry Aldehyde Catalysis Reaction rate chemistry.chemical_compound Adsorption chemistry Organic chemistry Reactivity (chemistry) Platinum Cinchonidine
Zdroj:	Catalysis Communications. 12:1410-1414
ISSN:	1566-7367
DOI:	10.1016/j.catcom.2011.05.028
Popis:	Competitive hydrogenations of eight binary mixtures of ethyl pyruvate (EP), methyl benzoylformate (MBF), ketopantolactone (KPL), pyruvic aldehyde dimethyl acetal (PA) and trifluoroacetophenone (TFAP) on platinum/alumina catalysts unmodified (racemic hydrogenation) and modified by cinchonidine (chiral hydrogenation) were studied under the experimental conditions of the Orito reaction. Reaction rates of chiral and racemic hydrogenations were determined and relative adsorption coefficients were calculated. In the competitive chiral hydrogenation of EP + MBF, EP + TFAP and KPL + MBF binary mixtures a new phenomenon was observed: namely the EP and KPL are hydrogenated faster than MBF and TFAP, whereas in racemic one the MBF and TFAP are hydrogenated faster than EP or KPL. Effects of the activated ketones structure on their reactivity and the stability of the surface complexes are discussed. It was found that differences in rate enhancement are caused by the differences both in the adsorptivity and in the reactivity of adsorbed substrates and adsorbed intermediate complexes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::12c68e9458263b76f69b22290d9f09de https://doi.org/10.1016/j.catcom.2011.05.028 Zobrazit plný text záznamu Full Text from ScienceDirect