N-Boc-trans-4-fluoro-l-proline (CAS number 203866-14-2) is a bulky Boc (tert-butoxycarbonyl) group protected l-proline with a fluoride substituent at 4-position. N-Boc-trans-4-fluoro-l-proline is a trans-configured diastereomer, meaning that the fluoride and carboxylic acid are on the opposite sides of the molecule. N-Boc-trans-4-fluoro-l-proline reacts with 2-fluoro-5-nitrobenzaldehyde (nucleophilic aromatic substitution) producing a 19F NMR chiral probe to determine the enantiomeric purity of chiral amino acids. N‑Arylsulfonyl‑l‑proline derivatives synthesized from N-Boc-trans-4-fluoro-l-proline is applied as a potent and selective αvβ1 integrin inhibitors. It shows inhibitive performance at half maximal inhibitory concentration (IC50) of 0.02 nM.
The carboxylic acid and the secondary amine of N-Boc-trans-4-fluoro-l-proline can coordinate to metal centers, forming a stable 5-membered ring. A Pd (II) complex with l-proline ligands has been explored yielding enantiomeric excess up to 24% in catalytic olefination reaction.