New Data of Nonlinear Phenomenon in the Heterogeneous Enantioselective Hydrogenation of Activated Ketones

• Published in: Catalysis letters Vol. 124; no. 1-2; pp. 46 - 51
• Main Authors: BALAZSIK, Katalin, SZÖLLÖSI, György, BARTOK, Mihaly
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-08-2008; Springer; Springer Nature B.V
• Subjects: Alkaloids; Catalysis; Chemistry; Chemistry and Materials Science; Dimethyl acetals; Enantiomers; Exact sciences and technology; General and physical chemistry; Hydrogenation; Industrial Chemistry/Chemical Engineering; Ketones; Liquid phases; Nonlinear phenomena; Organometallic Chemistry; Physical Chemistry; Substrates; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Asymmetric hydrogenation; Cinchona alkaloids; Ketones; Platinum; Nonlinear phenomenon; Cinchona; Enantioselectivity; Transition metal; Ketone; Hydrogenation; Asymmetric hydrogenation, Platinum; Heterogeneous catalysis; Alkaloid; Cinchona alkaloids, Ketones; Dicotyledones; Angiospermae; Rubiaceae; Spermatophyta
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-008-9498-1

Results on nonlinear phenomenon (NLP) in the liquid phase hydrogenation of methyl benzoylformate (MBF) and pyruvaldehyde dimethyl acetal (PA) on chiral Pt-cinchona catalyst are reported for the first time (enantiomeric excess 90–95%). The new data support the conclusions of the NLP studies on ethyl pyruvate (EP) and ketopantolactone (KPL). Namely, the order of the adsorption strengths of the parent cinchona alkaloids are: CD > CN > QN ~ QD and the results of the NLP measurements indirectly verify the so-called 1:1 model of enantioselection. The new data, however, call attention to a new, substrate and modifier dependent phenomenon, which necessitates further experiments for a better understanding of the mechanism of the Orito reaction.