Synthesis of Trifluoromethyl‐Substituted Proline Analogues as ¹⁹F NMR Labels for Peptides in the Polyproline II Conformation

As good as a Pro: Another CF3-substituted amino acid, CF3MePro (see structure), has been added to the arsenal of 19F NMR labels; it is particularly suited for the study of proline-rich peptides. This amino acid was carefully designed and chosen from other synthesized isomers, according to strict selection criteria, as the most stable, nonracemizable, conformationally restricted, and compatible with solid-phase peptide-synthesis protocols. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z801022_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.