334023-36-8Relevant articles and documents
Facile and stereoselective synthesis of non-racemic 3,3,3-trifluoroalanine
Crucianelli, Marcello,Battista, Natalia,Bravo, Pierfrancesco,Volonterio, Alessandro,Zanda, Matteo
, p. 1251 - 1258 (2000)
A highly stereoselective enantiodivergent synthesis of non-racemic 3,3,3-trifluoroalanine 7 is reported. The methodology is based on the reduction, by 9-BBN or DIBAH, of the chiral sulfinimine 3 derived from ethyl trifluoropyruvate, followed by acidic hydrolysis of the resulting diastereomeric sulfinamides 4 and 5.
Sulfinimines of trifluoropyruvate: Novel intermediates for chiral non racemic α-trifluoromethyl α-amino acids
Bravo, Pierfrancesco,Crucianelli, Marcello,Vergani, Barbara,Zanda, Matteo
, p. 7771 - 7774 (2007/10/03)
A new and preparatively useful method for the synthesis of non racemic α-trifluoromethyl (Tfm)α-amino acids (AAs) is presented. Key-building blocks are the sulfinimines (S)-1a,b, prepared via Staudinger reaction from trifluoropyruvic esters and the chiral N-sulfinyl iminophosphorane (S)-5, which were reacted with benzyl and alkylmagnesium halides. The resulting N- sulfinyl α-Tfm α-amino esters 6a,b and 6c-g, respectively, were produced with opposite stereoselectivity. The stereocontrol with alkyl Grignard reagents was progressively higher with increasing steric bulk. Some of the adducts 6 were transformed into a-Tfm-phenylalanine (R)-8 (with regeneration and recycling the chiral auxiliary), αTfm-leucine (S)-11c, α-Tfm-butyrine (S)-11f and α-Tfm-alanine (8),11g in two steps in one-pot.
