An efficient asymmetric synthesis of (2S,3S)-3-trifluoromethylpyroglutamic acid

Stereoselective Construction of an Asymmetric Carbon Center Possessing a Trifluoromethyl Group

“…An efficient asymmetric synthesis of (2S, 3S)-3-trifluoromethylpyroglutamic acid via conjugate addition of Ni(II) complex of the Shiff base of glycine with (S)-o-[N-(N-benzylpropyl)amino]benzophenone toward ethyl 4,4,4-trifluorocrotonate has been reported by Soloshonok et al (Scheme 59) [134] In this reaction, the diastereoselectivity depends on the reaction time; at the earlier state (30 sec) of the reaction, the diastereomeric ratio is trans:cis = 97:3 while after complete conversion of starting complex the ratio is trans:cis = 81:19. Thus, the addition reaction occurs reversibly with the stereochemical result subjected to kinetic and thermodynamic control.…”

Synthetic Approaches to α,β‐Diamino Acids

“…The enantiopure Ni(II) complex of benzophenone a-imino glycinate and the aluminum enolate of a chiral oxazinone derived from glycine have been used for the synthesis of fluorinated 2,3-diamino acids (98% d.e.) [7] and capreomycidine [8], respectively. Chiral imines can participate as inductors of asymmetry in the Mannich process.…”

Synthetic Applications of β‐Fluoroalkylated α,β‐Unsaturated Carbonyl Compounds

“…[15,19] Their incorporation into peptides gives rise to structural modifications (secondary structure), which also result in proteolytic stability (Schemes 5-6). [18] Zanda et al have developed an interesting synthesis of partially modified retro and retro-inverso y-[NHCH(CF 3 )]Gly peptides based on an aza-Michael reaction of a-amino esters with chiral b-trifluoromethylated a,bunsaturated amides.…”