Synthesis of β-amino-α-trifluoromethyl-α-amino acids exhibiting intramolecular interaction of CF3 with NHβ

We prepared β-amino-α-trifluoromethyl-α-amino acids through ring-opening reaction of N-tosyl-2-trifluoromethyl-2-ethoxycarbonylaziridine with aromatic and benzylic amines, and investigated the intramolecular interaction between the trifluoromethyl (CF3) group at the α-position and the NH group at the β-position (NHβ). NMR, UV/vis, and circular dichroism measurements indicated that the conformation of these compounds is fixed by intramolecular interaction of CF3 with NHβ to form a six-membered ring.