We report herein the three-step enantioselective synthesis of beta-trifluoromethyl alpha-amino acids including trifluorovaline (TFV) using stereoselective hydrogenation with [((R)-trichickenfootphos)Rh(cod)]BF(4) catalyst as the key step.

Preparative electrolysis of 1-methyl-5-nitroindole (1b, X = NCH3), 5-nitrobenzofurane (1c, X = O), and 5-nitrobenzothiophene (1d, X = S) at Hg, in acidic hydromethanolic media, leads to the formation of the corresponding 4-substituted amino derivatives 5, which result from the 100% regioselective addition to iminoquinone-type intermediate 4 of methanol or of any other good nucleophile present in the electrolytic solution. In acidic medium, the iminoquinonium intermediates 4b and 4c were trapped in a cycloaddition reaction with cyclopentadiene added to the electrolysis medium. The regiochemistry of the nucleophilic addition is discussed in light of AM1 calculations. Key words: 1-methyl-5-nitroindole, 5-nitrobenzofurane, 5-nitrobenzothiophene, iminoquinone, electrosynthesis.

Enantioselective Synthesis of β-Trifluoromethyl α-Amino Acids. -The structure of the chiral catalysts is essential for the enantioselective hydrogenation of either (Z)-alkyl or (Z)-aryl trifluoroamidoenoates. Enantiopure trifluorovalin is obtained from (IIa). Other selective deprotection reactions of (IIa) are demonstrated. -(BENHAIM*, C.; BOUCHARD, L.; PELLETIER, G.; SELLSTEDT, J.; KRISTOFOVA, L.; DAIGNEAULT, S.; Org. Lett. ; Wyeth Res., St-Laurent, Que. H4R 1J6, Can.; Eng.) -R. Steudel 39-193 s