[2,3]-Sigmatropic Rearrangement of Allylic Selenimides: Strategy for the Synthesis of Peptides, Peptidomimetics, and <i>N</i>-Aryl Vinyl Glycines
作者:Alan Armstrong、Daniel P. G. Emmerson、Harry J. Milner、Robert J. Sheppard
DOI:10.1021/jo500341e
日期:2014.5.2
The scope of the NCS-mediated amination/[2,3]-sigmatropicrearrangement of enantioenriched allylic selenides has been expanded to provide access to three new product classes. The use of N-protected amino acid amides provides a novel strategy for accessing peptide chains containing unnatural vinyl glycine amino acid residues. Also reported is the use of amino acid esters, allowing the diastereoselective
A series of tri- and tetrapeptide derivatives, analogues of the gastrin C-terminal region with no phenylalanine residue, were synthesized. These peptides were tested for their ability to inhibit gastrin-stimulated acid secretion in vivo as well as binding of [125I]-(Nle11)-HG-13 to gastric mucosal cell receptors in vitro. Most of the peptides tested exhibited gastrin antagonist activity in vivo and in vitro. Most active derivatives were 20-30 times more potent than the well-known gastrin antagonist derivatives proglumide and benzotript and had 20-200 times more binding affinity. The smallest fragment exhibiting antagonist activity was the tripeptide Boc-L-tryptophyl-L-methionyl-L-aspartic acid amide.