Chemical deracemization and (S) to (R) interconversion of some fluorine-containing α-amino acids
摘要:
Several omega-CF3-substituted alpha-amino acids have been prepared in optically pure form via two complementary approaches. Racemic fluorinated derivatives of 2-aminobutanoic acid, norvaline and norleucine were chemically deracemized by complexation with a Ni(II) salt and a chiral reagent derived from alpha-(phenyl)ethylamine. Additionally this procedure also allowed the conversion of readily available L-amino acids, CF3-analogs of cysteine and methionine, into the corresponding unnatural D-series. Optically pure amino acids are obtained upon disassembly of the Ni(II) complexes with recovery of the chiral ligand. (C) 2013 Elsevier B.V. All rights reserved.