ISSN:
1572-879X
Schlagwort(e):
enantioselective hydrogenation
;
chiral modifier
;
ethyl pyruvate
;
Pt/alumina
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract The enantioselective hydrogenation of ethyl pyruvate to (R)- or (S)-ethyl lactate has been studied over alumina- and carbon-supported Pt-metal catalysts modified by various heterocyclic N-compounds and substituted amides. The reactions were carried out under mild conditions in acetic acid; other solvents had a detrimental effect on enantioselectivity. An enantiomeric excess (ee) of 67% and a rate acceleration by a factor of 6, compared to the unmodified catalyst, was observed with alumina-supported Pt modified by (R)-1-(1-naphthyl)ethylamine. In contrast, carbon-supported Pd, Ru and Rh were non-selective and only little active. The studies indicated that besides naphthyl or quinolyl groups, two separate phenyl groups or one phenyl group together with two amino groups can provide a suitable anchoring of the chiral modifier on the Pt surface. The nature of interaction between the modifiers and ethyl pyruvate is briefly discussed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00808828
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