An amide is formed by reacting an α-ketoacid or salt thereof in a decarboxylative condensation reaction with an amine or salt thereof comprising a nitrogen covalently bound to an atom selected from oxygen, nitrogen, and sulfur. The amide bond is formed between the α-carbon of the ketoacid and the nitrogen of the amine. The α-ketoacid can be formed using a novel sulfur reagent.
Nitrone protecting groups for enantiopure N-hydroxyamino acids: synthesis of N-terminal peptide hydroxylamines for chemoselective ligations
作者:S. Irene Medina、Jian Wu、Jeffrey W. Bode
DOI:10.1039/c004490c
日期:——
The synthesis of enantiopure N-benzylidene nitrones of N-hydroxy-α-amino acids and their incorporation using standard Fmoc-based peptide chemistry into solid-supported peptide chains is described. Deprotection and resin cleavage affords N-terminal peptide hydroxylamines, which are the key substrates for chemoselective ligations with C-terminal peptide α-ketoacids. This general route is applicable to
Synthesis of Small Glycopeptides by Decarboxylative Condensation and Insight into the Reaction Mechanism
作者:Aditya K. Sanki、Rommel S. Talan、Steven J. Sucheck
DOI:10.1021/jo802278w
日期:2009.3.6
believed to result from an intramolecular cyclization of the O-tert-butyl ester on a nitrilium ion intermediate followed by aromatization. A decarboxylativecondensation between O18-labeled phenyl pyruvic acid and N-hydroxyphenethylamine oxalate salt resulted in amide products lacking the O18-label, providing further support for the nitrilium ion in the reaction pathway.
A general strategy for the preparation of C-terminal peptide α-ketoacids by solid phase peptide synthesis
作者:Lei Ju、Jeffrey W. Bode
DOI:10.1039/b901198f
日期:——
A new cyanosulfur-ylide based linker makes possible the synthesis of C-terminal peptide α-ketoacids by solidphase synthesis. The preparation of the requisite linker and its application to a variety of C-terminal peptide α-ketoacids with unprotected side chains is reported.