New Synthetic Amino Acids for the Design and Synthesis of Peptide-Based Metal Ion Sensors
摘要:
The syntheses of two new nonstandard amino acids, Flu (6) and YBp (20), and a new synthesis of Dmd (12) are reported. These residues exhibit fluorescence, metal-coordination, and fluorescence-quenching properties, respectively. These building blocks have been incorporated into peptides via solid phase peptide synthesis to afford the prototype fur a photoinduced electron transfer-based metal ion chemosensor. The fluorescence of the peptides is modulated upon metal binding. This results from a metal. ion-induced conformational change that brings the side chains of the Flu and Dmd amino acids into proximity, thereby favoring photoinduced electron transfer (PET) fluorescence quenching.
Synthesis of 2-(2-Pyridyl)-2<i>H</i>-azirines via Metal-Free C–C Cross-Coupling of Bromoazirines with 2-Stannylpyridines
作者:Anastasiya V. Agafonova、Ilia A. Smetanin、Nikolai V. Rostovskii、Alexander F. Khlebnikov、Mikhail S. Novikov
DOI:10.1021/acs.orglett.1c03060
日期:2021.10.15
2-bromo-2H-azirine-2-carboxylic acid derivatives by the direct cross-coupling with 2-(trialkylstannyl)pyridines has been described. The reaction works well with 3-, 4-, or 5-substituted 2-stannylpyridines and can be also employed for the synthesis of 2-(thiazol-2-yl)-2H-azirines. According to DFT calculations, the reaction proceeds through the sequence of SN2′-substitution of bromine, 1,4-stannyl shift