| Autor: |
Ibrahim, Mohamed M., He, Guosen, Seebacher, Jan, Benkmil, Boumahdi, Vahrenkamp, Heinrich |
| Zdroj: |
European Journal of Inorganic Chemistry; October 2005, Vol. 2005 Issue: 20 p4070-4077, 8p |
| Abstrakt: |
The NS2ZnX coordination in thiolate-alkylating zinc enzymes is reproduced in (tripod)ZnX complexes with substituted pyrazolylbis(thioimidazolyl)borate tripod ligands. Intermediate (tripod)Zn nitrates and perchlorates are converted into (tripod)Zn thiolates, including the biologically relevant homocysteinate. Methylation with CH3I converts these to (tripod)ZnI and the corresponding thioethers CH3SR, including methionine. A kinetic investigation has shown the alkylations to be intramolecular SN2 processes that take place at the zinc-bound thiolates. They are considerably faster for the (NS2)Zn thiolates than for the (N2S)- and (N3)Zn-thiolates with similar pyrazolylborate-derived tripod ligands, in agreement with Nature’s choice of an NS2 donor set for zinc. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
Plný text