Llinas, Antonio and Page, Michael I. (2004) Intramolecular general acid catalysis in the aminolysis of β-lactam antibiotics. Organic and Biomolecular Chemistry, 2. pp. 651-654. ISSN 1477-0539Metadata only available from this repository.
The rate of aminolysis of benzylpenicillin and cephaloridine by hydroxylamine, unlike other amines, shows only a first order dependence on amine concentration. The rate enhancement compared with that predicted from a Bronsted plot for other primary amines with benzylpenicillin is greater than 106. This is much more than an -effect and is compatible with rate-limiting formation of the tetrahedral intermediate due to a rapid intramolecular general acid catalysed breakdown of the intermediate. For cephaloridine, the rate enhancement is greater than 104 which demonstrates that -lactam C–N bond fission and expulsion of the leaving group at C3 are not concerted.
|Subjects:||Q Science > Q Science (General)|
Q Science > QD Chemistry
|Schools:||School of Applied Sciences|
School of Applied Sciences > Biomolecular Sciences Research Centre
1 M. I. Page, Adv. Phys. Org. Chem., 1987, 23, 165; M. I. Page, in
|Depositing User:||Sara Taylor|
|Date Deposited:||08 Feb 2008 14:37|
|Last Modified:||20 Oct 2008 10:06|
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