Header

UZH-Logo

Maintenance Infos

3-Amino-2H-azirines. Synthons for alpha,alpha-Disubstituted alpha-Amino Acids in Heterocycle and Peptide Synthesis


Heimgartner, Heinz (1991). 3-Amino-2H-azirines. Synthons for alpha,alpha-Disubstituted alpha-Amino Acids in Heterocycle and Peptide Synthesis. Angewandte Chemie Internationale Edition, 30:238-264.

Abstract

The recent upswing in peptide chemistry has been accompanied by an increasing interest in nonproteinogenic amino acids. These include the alpha,alpha-disubstituted glycines, the best known of which is Aib (2-aminoisobutyric acid, 2-methylalanine). These alpha-amino acids occur in natural oligopeptides such as the peptaibols, a class of membrane-active ionophores that has been isolated from fungal cultures. The twofold substitution at the alpha-C atom of the amino acids severely restricts the conformational freedom of the peptides and causes particular secondary structures to be favored; thus, alpha,alpha-disubstituted alpha-amino acids induce the formation of beta-turns or helices. 3-Amino-2H-azirines are ideal synthons for the construction of oligopeptides, cyclic peptides and depsipeptides (peptolides) containing such alpha,alpha-disubstituted alpha-amino acids. The presence of the ring strain in these molecules means that they can be used in peptide coupling without the need for additional activating reagents. Using 3-amino-2H-azirines a large array of heterocycles containing alpha,alpha-disubstituted alpha-amino acids as structural elements within their skeleton can be synthesized. The driving force in these reactions is the release of the strain on the three-membered ring, which usually takes place in a ring-expansion reaction. The mechanistic elucidation of these reactions, which can be quite complex, contains some surprises.

Abstract

The recent upswing in peptide chemistry has been accompanied by an increasing interest in nonproteinogenic amino acids. These include the alpha,alpha-disubstituted glycines, the best known of which is Aib (2-aminoisobutyric acid, 2-methylalanine). These alpha-amino acids occur in natural oligopeptides such as the peptaibols, a class of membrane-active ionophores that has been isolated from fungal cultures. The twofold substitution at the alpha-C atom of the amino acids severely restricts the conformational freedom of the peptides and causes particular secondary structures to be favored; thus, alpha,alpha-disubstituted alpha-amino acids induce the formation of beta-turns or helices. 3-Amino-2H-azirines are ideal synthons for the construction of oligopeptides, cyclic peptides and depsipeptides (peptolides) containing such alpha,alpha-disubstituted alpha-amino acids. The presence of the ring strain in these molecules means that they can be used in peptide coupling without the need for additional activating reagents. Using 3-amino-2H-azirines a large array of heterocycles containing alpha,alpha-disubstituted alpha-amino acids as structural elements within their skeleton can be synthesized. The driving force in these reactions is the release of the strain on the three-membered ring, which usually takes place in a ring-expansion reaction. The mechanistic elucidation of these reactions, which can be quite complex, contains some surprises.

Statistics

Citations

Downloads

2 downloads since deposited on 04 Dec 2013
0 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, further contribution
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:English
Date:1991
Deposited On:04 Dec 2013 15:18
Last Modified:16 Dec 2016 11:37
Publisher:Wiley-VCH Verlag
ISSN:1433-7851
Funders:Swiss National Science Foundation, F. Hoffmann-La Roche AG, Basel, Prof. Hans E. schmid-Stiftung, Anna-Feddersen-Wagner-Fonds, Stipendienfonds der Basler Chemischen Industrie

Download