BRUNNER, H and HUBER, C (1992) ASYMMETRIC CATALYSIS .67. DIASTEREOSELECTIVE HYDROGENATION OF FOLIC-ACID WITH OPTICALLY-ACTIVE RHODIUM(I)-DIPHOSPHANE COMPLEXES. CHEMISCHE BERICHTE-RECUEIL, 125 (9). pp. 2085-2093. ISSN 0009-2940,
Full text not available from this repository.Abstract
With immobilized rhodium(I)-diphosphane catalysts supported on silica gel, the C = N bonds of the pyrazine ring of folic acid (1) are reduced with hydrogen in aqueous solution to give 5,6,7,8-tetrahydrofolic acid. A mixture of the two diastereomers 2a and 3a is obtained with (6S)- and (6R)-configuration, respectively, at the newly formed asymmetric center in the pterine system and (S)-configuration in the L-glutamic acid moiety. The unstable hydrogenation products are derivatized with (-)-menthyl chloroformate. An improved HPLC procedure for the analysis of the products has been developed. By using optically active chelate phosphanes as cocatalysts together with [Rh(cod)Cl]2, a diastereomeric excess of up to 24% of the natural isomer 2a with (6S,S)-configuration is attained in the heterogeneous hydrogenation of folic acid.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DIHYDROFOLATE-REDUCTASE; RHODIUM COMPLEXES; LEUCOVORIN; 5-FORMYLTETRAHYDROFOLATE; METHOTREXATE; ACCUMULATION; INHIBITORS; LIGANDS; CANCER; CELLS; DIASTEREOSELECTIVE HYDROGENATION; IMMOBILIZED ENANTIOSELECTIVE RHODIUM(I)-DIPHOSPHANE CATALYSTS; FOLIC ACID; (6S,S)-FOLINIC ACID; 5,6,7,8-TETRAHYDROFOLIC ACID, N-5-(MENTHYLOXYCARBONYL) |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:44 |
| URI: | https://pred.uni-regensburg.de/id/eprint/54401 |
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