title: (2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline: two conformationally distinct proline amino acids for sensitive application in 19F NMR.
abstract: (2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline were synthesized (as Fmoc-, Boc-, and free amino acids) in 2-5 steps. The key step of each synthesis was a Mitsunobu reaction with perfluoro-tert-butanol, which incorporated a perfluoro-tert-butyl group, with nine chemically equivalent fluorines. Both amino acids were incorporated in model α-helical and polyproline helix peptides. Each amino acid exhibited distinct conformational preferences, with (2S,4R)-perfluoro-tert-butyl 4-hydroxyproline promoting polyproline helix. Peptides containing these amino acids were sensitively detected by (19)F NMR, suggesting their use in probes and medicinal chemistry.
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Caitlin M
authors.initials: CM
authors.lastname: Tressler
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Zondlo
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives* / Q000737:chemistry*; D011487:Protein Conformation; D013237:Stereoisomerism
chemical_list: C000593689:(2S,4S)-perfluoro-tert-butyl 4-hydroxyproline; D000596:Amino Acids; D010455:Peptides; D005461:Fluorine; D011392:Proline