Investigations on electrochemical Delta a-methoxylation of selected dipeptides

Voltamperometric studies on the indirect electrochemical Delta *a-methoxylation of Boc-Pro-Gly-OMe and Boc-Val-Gly-OMe in MeOH in the presence of NaCl or NaBr as the mediator suggested that the first reaction step was a direct N-halogenation of the dipeptide by active chlorine or bromine adsorbed on...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied electrochemistry 2011-07, Vol.41 (7), p.809-815
Main Authors: Simka, Wojciech, Gorewoda, Tadeusz, Mazurkiewicz, Roman, Nawrat, Ginter
Format: Article
Language:English
Subjects:
Chlorine
Electrodes
Electrolysis
Optimization
Selectivity
Sodium bromides
Surface chemistry
Tetrahedrons
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Voltamperometric studies on the indirect electrochemical Delta *a-methoxylation of Boc-Pro-Gly-OMe and Boc-Val-Gly-OMe in MeOH in the presence of NaCl or NaBr as the mediator suggested that the first reaction step was a direct N-halogenation of the dipeptide by active chlorine or bromine adsorbed on the electrode surface. The kind of mediator (NaCl or NaBr), its concentration, the current density, and the applied electric charge had a significant influence on the reaction course. In the case of Boc-Pro-Gly-OMe, the use of sodium bromide was necessary to obtain a relatively high ratio of Delta *a-monomethoxylation to Delta *a, Delta *a-dimethoxylation. For Boc-Val-Gly-OMe, the selectivity for Delta *a-monomethoxylation was close to 100%, independently of the mediator. Optimisation of the selected electrolysis parameters allowed us to significantly improve the yield and selectivity of the Delta *a-methoxylation of Boc-Pro-Gly-OMe (Kardassis et al. Tetrahedron 54:3471, 1998) and to obtain good results in the Delta *a-methoxylation of Boc-Val-Gly-OMe.
ISSN:0021-891X
DOI:10.1007/s10800-011-0300-5