Syntheses of optically active trifluoromethylated amines via ring-opening reactions of optically active N-benzyl-2-trifluoromethylaziridine were achieved. Proton-catalyzed ring-opening reactions of the 2-trifluoromethylaziridine proceeded very smoothly, while the compound was found to be inert toward nucleophiles; thus, the trifluoromethylaziridine itself cannot be ring-opened by nitrogen or carbon nucleophiles. The N-alkylated aziridinium ion of trifiuoromethylaziridine was highly reactive to undergo smooth ring-opening by nitrogen and carbon nucleophiles.
Intramolecular SN2 reaction at α-carbon of trifluoromethyl group: preparation of optically active 2-trifluoromethylaziridine
We have succeeded in intramolecular nucleophilic substitution of the hydroxyl group in (S)-1-(alkylamino)-3,3,3-trifluoro-2-propanol. The reaction provides an optically pure (R)-1-benzyl-2-trifluoromethylaziridine in good yield from optically pure (S)-3-(benzylamino)-1,1,1-trifluoro-2-propanol, which was prepared from (S)-3,3,3-trifluoropropene oxide (75% ee). (C) 1997 Published by Elsevier Science Ltd.