Chemical deracemization and (S) to (R) interconversion of some fluorine-containing α-amino acids
摘要:
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.
Selective Radical Trifluoromethylation of Native Residues in Proteins
作者:Mateusz Imiołek、Gogulan Karunanithy、Wai-Lung Ng、Andrew J. Baldwin、Véronique Gouverneur、Benjamin G. Davis
DOI:10.1021/jacs.7b10230
日期:2018.2.7
fluorine incorporation would constitute a fast and efficient alternative. Here, we reveal a mild method for direct protein radical trifluoromethylation at native residues as a strategy for symmetric-multifluorine incorporation on mg scales with high recoveries. High selectivity toward tryptophan residues enhanced the utility of this direct trifluoromethylation technique allowing ready study of fluorinated
We disclose the reductive trifluoromethylation of chemically stable homocystine and cystine to provide corresponding trifluoromethyl ethers by the CF3I/Na/Liq.NH3 system. Both non-protected and protected homocystines can be nicely converted into trifluoromethylated methionines under the same condition. The method described offers a robust synthesis of pharmaceutically important trifluoromethionine, suitable for multigram synthesis. Pentafluoroethylation of homocystine was also achieved by the CF3CF2I/Na/Liq.NH3 system. (C) 2011 Elsevier B.V. All rights reserved.
Simple preparation of trifluoromethionine and derivatives thereof
申请人:SHIBATA Norio
公开号:US20110015433A1
公开(公告)日:2011-01-20
Disclosed is a process for the simple preparation of trifluoromethionine, its analogs trifluoromethylcysteine, fluoroalkylhomocysteines, and fluoroalkylcysteines, and derivatives of them. These compounds are drug-candidate compounds or raw materials of drug-candidate compounds. Specifically, trifluoromethionine, trifluoromethylcysteine, a fluoroalkylhomocysteine, or a fluoroalkylcysteine is simply and conveniently prepared directly without passing through homocysteine or cysteine by adding metallic sodium to an optically active or racemic homocystine or cystine in liquid ammonia and further adding a fluoroalkyl iodide thereto under Birch reduction conditions.
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.