@article{oai:nagasaki-u.repo.nii.ac.jp:00000092,
 author = {Ueda, Atsushi and Ikeda, Misuzu and Kasae, Takuya and Doi, Mitsunobu and Demizu, Yosuke and Oba, Makoto and Tanaka, Masakazu},
 issue = {35},
 journal = {ChemistrySelect},
 month = {Sep},
 note = {Various racemic α-trifluoromethyl α,α-disubstituted α-amino acids were synthesized by the reaction of methyl 3,3,3-trifluoropyruvate imines with Grignard reagents. The optical resolution of racemates using (R)-1,1’-bi-2-naphthol {(R)-BINOL} esters gave optically active α-trifluoromethylated α,α-disubstituted α-amino acids, such as α-trifluoromethylalanine (αCF3Ala), α-trifluoromethylleucine (αCF3Leu), 
and α-trifluoromethylphenylalanine (αCF3Phe). The optically active (R)- or (S)-αCF3Ala was incorporated into the L-Leu-based pentapeptides, and their preferred conformation in solution and in the crystal state was studied by Fourier transform infrared (FT-IR) absorption, nuclear 
Overhauser effect spectroscopy (NOESY) NMR, and circular dichroism (CD) spectra, as well as X-ray crystallographic analysis. Both L?Leu-based peptides with (R)- or (S)-αCF3Ala formed right-handed 310-helical structures. Both peptide-backbones at the N-terminal residues 1-3 were very similar, but the φ and ψ torsion angles of residues 4 and 5 between peptides with (R)- or (S)- αCF3Ala were different., ChemistrySelect, 5(35), pp.10882-10886; 2020},
 pages = {10882--10886},
 title = {Synthesis of Chiral α-Trifluoromethyl α,α-Disubstituted α-Amino Acids and Conformational Analysis of L-Leu-Based Peptides with (R)- or (S)-α-Trifluoromethylalanine},
 volume = {5},
 year = {2020}
}