Conformational properties of peptides incorporating a fluorinated pseudoproline residue
Résumé
We have recently reported the synthesis of enantiomerically pure CF3-oxazolidine pseudoprolines (CF3-Psi Pro). Complete NMR studies, together with DFT calculations, have highlighted the marked stereoelectronic effects of the CF3 group on these new proline surrogates. In this paper, we describe for the first time the conformational features of dipeptides incorporating one CF3-Psi Pro residue. Extensive NMR analyses have been carried out in solution and revealed the presence of a stable type-VI beta-turn in a pseudotetrapeptide sequence.