A metal-templated synthesis of precursors for (2S)- and (2R)-2-(3-[18F]fluoropropyl)tyrosines as potential radiotracers for positron emission tomography

New asymmetric metal-templated synthesis of enantiomers of (2S)- and (2R)-2-(3-[¹⁹F]fluoropropyl)tyrosine precursors were obtained based on a chiral Ni^II complex of the Schiff base derived from (S)-2-[N-(N’-benzylprolyl)amino]-benzaldehyde and racemic tyrosine in five steps. The free tyrosine derivatives which can be obtained upon decomplexation seem promising radiotracers for positron emission tomography imaging provided the introduction of ¹⁸F isotope.