Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Continuous application of chemzymes in a membrane reactor: Asymmetric transfer hydrogenation of acetophenone
Autore:
Laue, S; Greiner, L; Woltinger, J; Liese, A;
Indirizzi:
KFA Julich GmbH, Res Ctr, Inst Biotechnol, D-52425 Julich, Germany KFA Julich GmbH Julich Germany D-52425 otechnol, D-52425 Julich, Germany Degussa, D-63403 Hanau, Germany Degussa Hanau Germany D-63403Degussa, D-63403 Hanau, Germany
Titolo Testata:
ADVANCED SYNTHESIS & CATALYSIS
fascicolo: 6-7, volume: 343, anno: 2001,
pagine: 711 - 720
SICI:
1615-4150(200108)343:6-7<711:CAOCIA>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
ENANTIOSELECTIVE HYDROGENATION; AROMATIC KETONES; REDUCTION; ALCOHOLS; CATALYST; OXAZABOROLIDINE; DENDRIMERS; COMPLEXES; LIGANDS; ACID;
Keywords:
asymmetric catalysis; catalyst immobilization; enzyme catalysis; hydrogen transfer; membranes;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: Liese, A KFA Julich GmbH, Res Ctr, Inst Biotechnol, D-52425 Julich, Germany KFA Julich GmbH Julich Germany D-52425 D-52425 Julich, Germany
Citazione:
S. Laue et al., "Continuous application of chemzymes in a membrane reactor: Asymmetric transfer hydrogenation of acetophenone", ADV SYNTH C, 343(6-7), 2001, pp. 711-720

Abstract

The application of homogeneously soluble catalysts is limited by the recovery in cases where the price of the catalyst is high. Biological catalysts,enzymes, can be efficiently recycled by means of an ultrafiltration membrane due to their high molecular weight, for example, in the continuously operated membrane reactor. In order to transfer this principle to chemical catalysis, we have attached a transfer hydrogenation catalyst, first invented by Gao and Noyori, to a polymer. The resulting homogeneously soluble, polymer-bound catalyst (chemzyme) can now be retained by ultrafiltration membranes like enzymes. On applying this catalyst in continuously operated membrane reactors, a continuous isopropoxide dosage is necessary in order to compensate deactivation caused by water residues in the reed stream. Thus, high space-time yields up to 578 g L-1 d(-1) and enantioselectivities up to 94% can be achieved. These results were compared to an enzyme catalyzed system consisting or a carbonyl reductase that also utilizes 2-propanol as a hydrogen source for the cofactor regeneration of NADH.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/04/20 alle ore 14:45:14