Photoinduced radical hydroperfluoroalkylation and the synthesis of fluorinated amino acids and peptides
摘要:
The photoinduced radical hydroperfluoroalkylation of unsaturated carboxylic acids using TTMSS as a H-donor was successfully developed. The stereoselective reaction using Oppolzer's camphorsultum was also achieved to give high stereoselectivity. The reaction was also effective for N-phthalimide-dehydroamino acid and the product was easily converted to the corresponding amino acid and a peptide derivative. (C) 2013 Elsevier B.V. All rights reserved.
afforded a number of fluorine containing α aminoacids such as β-fluorinated-alanines, 2-amino-n,n,n-trifluoroalkanoic acids, and fluorinated glutamic acids as well as other γ-heteroatom substituted glutamic acids. Here, an efficient enzymatic optical resolution using hog kidney acylase was conducted to obtain both optical isomers of 2-amino-n,n,n-trifluoroalkanoic acids. In addition, a novel sulfoxide
New Stereoconservative Syntheses of β,β,β- and γ,γ,γ-Trifluoro-α-amino, α-Hydroxy, and α-Mercapto Acids and Their Incorporation into a Peptide and Depsipeptide Fragment
作者:Hartmut Schedel、Wojciech Dmowski、Klaus Burger
DOI:10.1055/s-2000-8198
日期:——
Syntheses of β,β,β- and γ,γ,γ-trifluoro-α-amino, α-hydroxy and α-mercapto acids using hexafluoroacetone as protecting and activating reagent are described. The key step of the syntheses is the transformation of an Ï-carboxy group into a trifluoromethyl group on treatment with sulfur tetrafluoride. The carboxy activated species obtained are suitable for direct incorporation into peptide and depsipeptide fragments. RP-HPLC experiments and Mosher's TMPA method (1H and 19F) demonstrate that the reaction sequence occurs without racemization.
Chemical deracemization and (S) to (R) interconversion of some fluorine-containing α-amino acids
作者:Alexander E. Sorochinsky、Hisanori Ueki、José Luis Aceña、Trevor K. Ellis、Hiroki Moriwaki、Tatsunori Sato、Vadim A. Soloshonok
DOI:10.1016/j.jfluchem.2013.02.022
日期:2013.8
Several omega-CF3-substituted alpha-amino acids have been prepared in optically pure form via two complementary approaches. Racemic fluorinated derivatives of 2-aminobutanoic acid, norvaline and norleucine were chemically deracemized by complexation with a Ni(II) salt and a chiral reagent derived from alpha-(phenyl)ethylamine. Additionally this procedure also allowed the conversion of readily available L-amino acids, CF3-analogs of cysteine and methionine, into the corresponding unnatural D-series. Optically pure amino acids are obtained upon disassembly of the Ni(II) complexes with recovery of the chiral ligand. (C) 2013 Elsevier B.V. All rights reserved.