409320-12-3Relevant academic research and scientific papers
Nitroxyl peptides as catalysts of enantioselective oxidations
Formaggio, Fernando,Bonchio, Marcella,Crisma, Marco,Peggion, Cristina,Mezzato, Stefano,Polese, Alessandra,Barazza, Alessandra,Antonello, Sabrina,Maran, Flavio,Broxterman, Quirinus B.,Kaptein, Bernard,Kamphuis, Johan,Vitale, Rosa Maria,Saviano, Michele,Benedetti, Ettore,Toniolo, Claudio
, p. 84 - 93 (2002)
The achiral, nitroxyl-containing α-amino acid TOAC (TOAC = 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid), in combination with the chiral α-amino acid Cα-methyl valine [(αMe)Val], was used to prepare short peptides (from di- to hexa-) that induced the enantioselective oxidation of racemic 1-phenylethanol to acetophenone. The best catalyst was an Nα-acylated dipeptide alkylamide with the -TOAC-(αMe)Val- sequence folded in a stable, intramolecularly hydrogen-bonded β-turn conformation with large, lipophilic (hydrophobic) N- and C-terminal blocking groups. We rationalized our findings by proposing models for the diastereomeric intermediates between (R)-[and (S)]-1-phenylethanol and the catalyst Fmoc-TOAC-L(αMe)Val-NHiPr, based on the X-ray diffraction structure of the latter.
