169738-78-7Relevant articles and documents
Enantioselective synthesis of α,α-disubstituted-α-amino acids by a sequential nucleophilic addition to nitriles
Charette, Andre B.,Mellon, Christophe
, p. 10525 - 10535 (1998)
The sequential addition of two different nucleophiles to a tartaric acid-derived nitrile produced carbinamines. The adducts from chelation- controlled addition which are obtained in high diastereoselectivities and yields, were easily converted to α,α-disubstituted-α-amino acids.
Role of secondary structure in the asymmetric acylation reaction catalyzed by peptides based on chiral Cα-tetrasubstituted α-amino acids
Formaggio, Fernando,Barazza, Alessandra,Bertocco, Andrea,Toniolo, Claudio,Broxterman, Quirinus B.,Kaptein, Bernard,Brasola, Elena,Pengo, Paolo,Pasquato, Lucia,Scrimin, Paolo
, p. 3849 - 3856 (2007/10/03)
In a recent series of papers, Miller and co-workers were able to show that His(π-Me)-based, terminally protected peptides are potent catalysts of the asymmetric acyl transfer reaction, useful for the kinetic resolution of alcohols. In a structure-supporting solvent, one of the most active compounds, an Aib-containing tetrapeptide, is folded in a doubly intramolecularly H-bonded β-hairpin motif incorporating a type-II′ β-turn conformation. In this work, we have expanded the study of the Miller tetrapeptide by examining a set of analogues and shorter sequences (dipeptide amides), characterized by chiral Cα-tetrasubstituted α-amino acids of diverging bulkiness and optical configuration. Peptide synthesis in solution, conformational analysis by FT-IR absorption and 1H NMR techniques, and screening of catalytic activity as well have been performed. Our results confirm the close relationship between the β-hairpin 3D-structure and the catalytic activity of the peptides. A tetrapeptide analogue slightly more selective than the Miller compound has been found. However, the terminally protected, industrially more appealing, dipeptide amides are poorly effective.
